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Registered:
January 2004
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Is 5 valve better than 4 valve?
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Fri, 27 May 2005 12:54
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I have got my hands on an SAE technical paper titled 'Optimization of multi valve, four cycle engine design-the benefit of 5 valve technology' research done by Yamaha.Basically what Yamaha did was test head designs from 4 valve to 7 valve, throught their research they found 5 valve to be the best (I suppose their R1 motorbike is testiment to that!), some of the technical aspects gleaned from this paper include;(this is all compared to 4,6,7 valve heads, most test data was between a 4 valve and 5 valve motor with identical, comp ratio, bore/stroke etc, so basically they are comparing apples with apples, the only difference is the number of valves)
They found 5 valve to give the best intake valve opening area.
Intake valve opening area at maximum lift was greater by 25%.
5 valve allowed better placement of spark plug position.
Higher combustion efficiency.
Higher volumetric efficiency through all rev range (high speed AND low speed).
Higher engine flow rates at all valve lifts, up 25% at lower lifts.
Lighter valve train due to smaller valves resulting in higher rpm, therefore more power.
Higher intake and exhaust inertial tuning(scavenging)
Higher BMEP(brake mean effective pressure) through the whole rev range.
They found that if the 4 and 5 valve engines had the same valve opening area that the five valve had significantly higher volumetric efficiency which would give a broader power curve.
Being the owner of a 5 valve 4age and comparing my ride to 4 valvers I can see why mine performs so much better than any 4 valve I've been in, it will be interesting to see what the 'Arm chair experts(read 5 valve knockers)' think!!!! But I suppose all these arm chair experts spend more money on R&D than Yamaha 
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Location:
Sydney
Registered:
September 2004
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Re: Is 5 valve better than 4 valve?
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Fri, 27 May 2005 13:39
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I think it depends on the application, eg. a bigport 16v head is better in a turbo setup.
It does raise the question though... why are all the Formula Atlantic engines built with 16v heads?
Eddie.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Is 5 valve better than 4 valve?
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Fri, 27 May 2005 14:49
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| 170bhp wrote on Fri, 27 May 2005 22:54 |
But I suppose all these arm chair experts spend more money on R&D than Yamaha
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and i suppose all F1 and indy car teams run 5 valve too huh
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Location:
Adelaide
Registered:
May 2003
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Re: Is 5 valve better than 4 valve?
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Fri, 27 May 2005 15:09
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I would be interested on what engine platform they were testing on. The R1 being only 1000cc in size benefits from a smaller port sizing (as does the R6) due to the subsequent increased airstream velocity.
However, this benefit seems to significantly decrease as you get over a little plateau around 1200rpm.
From the simulations and tests ive seen it appears that Ve increases for 5 valves up to around 970cc and then plateaus off till about 1150-1200cc and drops again after that. Wheras for a 4 valve setup the Ve keeps rising (albeit at a slower rate) past the plateau. Of course this is Ve for head design only.
The lamina planes will need to be taken into account as well. Again, from what ive read and seen it appears that smaller engines benefit from a smaller port, as above, due to the turbulent (relatively) air achieving higher velocity into the engine due to a nice lamina around the port wall. However, for larger engines this advantage seems to dissapear and the use of larger ports (duh) is necessary to achieve the same velocity.
Anyway enough late night ramblings for me, ill try and dig up the tests that were done on Lotus, and Honda heads for one of the uni projects some guys were doing.
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Location:
Tasmania
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Fri, 27 May 2005 15:34
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I think the idear of Formula Atlantic, was to choose a engine that was based on a common production road car engine that was of compact, sporty and simple design. It would hardly matter what engine they chose as all teams would have to use the exact same one. I am guessing that when the 4A-G was first chosen for Formula Atlantic the 20 valve wasn't out yet, or it was very new with not alot of resurch and aftermarket bits avaliable yet. It would have been the decision of TRD-USA I guess, and they went with what they were familiar with. (20 valve not avaliable in USA). If they relaxed the rules, I'm sure some would try the 20 valve.
But I don't really know...
F1 rules are very tight. I'm not even sure if they would allow a 5 valve head.
It makes sence to me that the 5 valve design would be a bit better. But only a small difference, and usually the difference in power due to the tuner and other parts selected is a bigger factor. I have heard the 20 valve 4AG have a more progressive torque curve, and the 16 valve (modifyed) is more peaky. This maybe why 20valves feel slow, maybe they have more power in midrange so never give that sudden power band. ??
How many people here actualy have a 210hp 4AG anyway?
I would like to get my engine up to around 200hp. I am thinking of using a fairly stock 4AG 20 valve, with 304 degree camshafts. Will that do it? I know valve timing would need to be looked at, but the basic package would be there right?
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Location:
Adelaide
Registered:
May 2003
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 00:26
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At those sort of cam durations you will need to disable the VVT-i, and also look into valve clearancing, since anything over 8.4mm lift on the 20v makes it an intereference engine.
The Formula Atlantic engines are actually built by Hasselgren rather than TRD. But from memory there were a couple of 20v engines a few years back, but they pretty much fell flat on their face.
From everything i have seen, the 20v head has worse squish areas than the 16v head. For the 4AGE that is, plus the valve angles arnt ideal by any stretch of the imagination.
With that Yamaha review remember that the 5valve heads they use were specifically designed for that purpose. Wheras the 20v 4AGEs seem to be a testing platform, basically a 20v head chucked on a 16v block with new pistons as Toyota seem fond of doing. Just look at the GZE for an example of that.
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I supported Toymods
Location:
Perth, Western Australia
Registered:
December 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 01:12
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I'd question the level of development in any side by side test. When comparing standard motors, I don't really have a preference for either over the other - look at their standard outputs, both are good and have very usable torque bands - what more do you want from a standard motor?!
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Location:
Tasmania
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 01:42
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I don't see why the VVT would need to be locked off for big (duration) cams. Some thought needs to be put into the exact timing of the cams (adjustable cam gears on both cams), but I can't yet see why you would want the VVT not to work.
From what I have read, and interpreted myself, you want the inlet cam to be timed at about 100 degrees for high rpm, and about 110 degrees at low rpm, which is what the VVT does.
Hasselgren is one of a few workshops that build the FA engines, but the important bits have to come from TRD. All FA engines have to use parts supplied exclusively by TRD, getting it put together by Hasselgren is a option. AFAIK
Yes the 20v head is just chucked on the 16v bottom end. But a bottom end is a bottom end, most motors are the same. How would they specificaly design the bottom end for the 20v head? Different bore/ stroke ratio? There are not many different designs that would make a difference.
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 05:16
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Takai, with regards to engine size they tested anumber of engines upto 90mm bore size, 5 valve substantially better. as to the 20v head just being chucked on a bottom end comeon guys get with it!!! we can only imagine the amount of R&D toyota and yamaha did before this motor went into production, Takai you make it sound like a decision they made over coffee, I very much doubt that!!and as for sayin well yamaha did the development work for the R1 Well bloody hell is it a suprise to find out that they also developed the 20v 4age for toyota!!!!!Takai alot of your thoughts on port size are definately 80's thinking! Takai I also don't know where you got your information for airflow, but the tech paper shows airflow versus valve lift and airflow versus rpm and again the 20v is far superior!!It doesn't significantly decrease, it significantly increases!! as rpm was increased VE for 4 valve dropped off as VE for 5 valve increased.Takai the valve angles on a 20v are far superior ESPECIALLY when you consider intake port angle!!! yeah no short turn there baby, if you think this is wrong look at ALL modern motors to see the difference in port angle, 20v does have one of the steepest but it follows the convention of many high speed motors in this regards, the old trend was very wide valve angle and flat intake port this is OLD SCHOOL, just about all motors now are very narrow valve angle and steep intake port, the valve angle allows for higher compression(higher combustion pressure therfore higher output) with out having to ruin the flame front with huge valve cut outs and huge wedge on the piston to get comp ratio back up again.you will see when they went from silver 20v to black 20v they actually reduced the squish area, cam timing is very very similar and they put out more BHP.in forced induction motor squish is actually detrimental, how do I know this? many SR20 turbo motors on the dyno!!
also any one that says small port bigger than 20v or big port better is such and such a case if you read my first post properly (if you can read and comprehend technical that is) you will see better VE, better flow, better CE, higher BMEP for 5 valve, if you compare two motors and one has all those things better and rpm etc are equal then output MUST be higher, no argument!!
Jonny2t love ya thinking  with regards to your valve timing locations you are spot on in your thinking vvt gives us the best of both worlds, and again you are right with regards to the Atlantic TRD parts!!!
CLG what do I want from a standard motor - MORE!!
as for the usual FUKED responses like why don't george bush use a 20v if they are so good, how about the rotary engine? why isn't it used in sports car racing or f1, because regulations state it can't be used, why can't 5 valve be used in F1, get the FIA regs, maximum 4 valves!!! Why can't the NR750 motor be used in motorbike racing? I remember that one clearly(most of you guys probably were sitting around making a mess for your mums in ya nappies!!) but Honda bought out this trick oval piston 4 cyl motor, 8 valves per cyl, it was like a mini V8, two rods per cylinder, it didn't even get one race in, NEW RULE, one conrod per piston, overnight it banned it, so because that motor is not running in motorbike racing following some of your thoughts it must be a useless motor!!!!!FUK I love listening to experts, how old are some of you guys? early 20's, yeah sure is a lot of technical in your favourite tech mag, fast fours or something weak like that!!!get on an engine dyno and learn the truths!!
I have had bigport, small port 20v and gze on engine dyno and the results consistantly come up the same, I used 20v for my turbo motor knowing the VE was higher, higher VE = more torque, more torque = more power, end of story!
FUK I LOVE EXPERTS!!!
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Location:
Rosanna, Melb
Registered:
June 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 05:41
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I can't remember where I heard it, so can't really back it up, but I thought Formula Atlantic went to 20V for a season, but they couldn't get them to perform as well so they returned to 16V after that.
Anyone confirm or deny this?
Hen
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 05:46
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To elaborate a little ...
20v's (in particular) have problems with flow interference between the valves at high speeds. You don't see that on the flow bench because they just can't flow the air fast enough.
So whilst they really will flow more air on the bench than a 16v, in the real world they won't.
They also have very poor squish areas and those are also needed to make good power. A 16v has very good squish, a blacktop has virtually none.
Anyway, to prove all this just hang on until around the end of the year or so until my 4AFE is done.
I am very sure that it will be far more powerful than any 20v ever built anywhere at any time. And I'll prove it.
A mate of mine in Amsterdam built an engine very similar to the one I'm putting together and he got 249hp at 9,000rpm.
I reckon mine will be better.
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 05:48
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| Henn wrote on Sat, 28 May 2005 15:41 |
I can't remember where I heard it, so can't really back it up, but I thought Formula Atlantic went to 20V for a season, but they couldn't get them to perform as well so they returned to 16V after that.
Anyone confirm or deny this?
Hen
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Don't know.
But I've never heard of a 20v making more than about 220-230hp odd. (doesn't mean they don't exist though)
I know for sure Jamie Aislabie in Rotorua in NZ built a 242hp 16v Formula Atlantic engine back in 1998 so if nothing else has changed he should be making more than that now.
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:05
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I very much doubt they have problems with flow interference!! yes I have flow benched one, and with the superflow bench we have we can suck harder than any motor!!! AND have a good look at a 20v head(ae101) then look at an R1 head, man are they similar, REAL similar, and what does an R1 rev to???? yeah REAL high speed!!! I'll take you up on what you said about your 4afe being more "powerful than ANY 20v everbuilt anywhere at anytime", you have to beat 302bhp!!!
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:07
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I very much doubt they have problems with flow interference!!
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Yes they do.
yes I have flow benched one, and with the superflow bench we have we can suck harder than any motor!!!
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No it can't.
I'll take you up on what you said about your 4afe being more "powerful than ANY 20v everbuilt anywhere at anytime", you have to beat 302bhp!!! ]
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There is no way on Earth that a 20v can make 302 hp.
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:10
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no way hey, I believe Bob Norwood made more, and the Schenk eddy curent dyno we have is very very accurate, read it and weep, 302bhp!!!(oh it is turbo charged but you said ANY 20v!!!)
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:14
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I was hoping the head arm chair expert would answer up 
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:15
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| 170bhp wrote on Sat, 28 May 2005 16:10 |
no way hey, I believe Bob Norwood made more, and the Schenk eddy curent dyno we have is very very accurate, read it and weep, 302bhp!!!(oh it is turbo charged but you said ANY 20v!!!)
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Yeah yeah, okay!
I meant N/A of course.
With the flow bench thing, I mean in terms of mach number and the extremely violent Hemholtz resonance that you only get in a running engine.
A flow bench can really pass a lot of air but can't reproduce what the air really does going down the inlet port.
Repco Brabham in the 1960's thought of this and so their flow bench was a very large supercharger that made very strong pulese in the inlet. It was driven by a Morris car engine to make it pass engine air!
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:17
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| 170bhp wrote on Sat, 28 May 2005 16:14 |
I was hoping the head arm chair expert would answer up
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Arm chair?
So my fifteen years of racing experience doesn't exist?
Results count, and my engines beat just about everyone in my class, Australia wide.
Get your facts straight thanks.
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:39
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To clarify how the VE was increased on the 20v with flow bench, the flow and intake tract were looked at, using isoentropic pressure data and reimann data we see that immediately before the intake valve is opened that a higher pressure than found on a 16v is found, this along with a higher intake pressure recovery with regards to location of piston in the cycle of events increased the mass air flow through the head, this increase in positive pressure in both these places is not as strong as on a 16v, this was at all lifts, mind you only lifts up to 9mm were used as there aren't too many cams with much more lift than this available for 20v, but the fact of the matter was that this inertial tuning was much stronger on 20v and I think it's not something that can be taken into consideration if you compare these motors back to back on paper, so many time I have laid waste to so called high HP 16v, I believe the 20v is more a sum of it's parts than just sitting down and saying compared to 16v the "insert different component here" is not as good as 16v!!!I have yet to see a 16v 4age with as wide a power band as a comparative 20v on the dyno, they usually end up much peakier, the 20v's always have a much wider flatter torque curve, give me that any day!! it's all about the area under the curve, if my curve has a lot more under it (all things like weight, gearing etc) the car will be faster.
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I supported Toymods
Location:
melbourne
Registered:
June 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:40
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id just like to thow in a few points here, coming form a supporter of 4 valve heads.
don't put too much faith in one technical document, experts have been known to get things wrong.
as far as i know the 20 valve 4age was the only 5 valve engine toyota ever made (correct me if i am wrong) why would this be if they are so wonderful?
ferrari tried a 5 valve engine at one stage, then went back to 4.
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:43
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Many years ago when we were developing peripheral port rotary engines we inserted pressure sensors between the intake and exhaust ports to measure what was happening, it was quite a find, the general concenus to what was actually happening was opposite, everyone out in the rotary engine building industry said certain things were happening inside th motor after all our pressure checks we found exactly the opposite and could change our port timing to suit, we had the test equipment to do this testing, we ended up maing lots of motors for overseas customers that were very powerful with very wide powerbands, I used to own a road car back in the late 80's powered by a peripheral port rotary that idled at 800rpm!!!! its called R&D and very very few places have the nounce or equipment to do it!!! but it sure does make a difference to the motors
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:43
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| 170bhp wrote on Sat, 28 May 2005 16:39 |
I have yet to see a 16v 4age with as wide a power band as a comparative 20v on the dyno, they usually end up much peakier, the 20v's always have a much wider flatter torque curve, give me that any day!! it's all about the area under the curve, if my curve has a lot more under it (all things like weight, gearing etc) the car will be faster.
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That's the VVT doing it's thing. Very little to do with the extra valve.
Take a look at a run from something like a 2ZZ, they're even better. Nice combustion chamber, interesting squish areas.
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:45
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ferrari used 5 valve for quite a while!! they dropped it because of cost, when they dropped it they picked up BHP by increasing the size of the motor, do your self a favour and drive a 348 back to back with a 355, I have and man the engines are from a completely different era!!!
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:48
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Bill, these are motors with no VVT, we did two motors with very similar cam specs, I did graph them myself and both had quad throttles and nearly line ball comp ratios, the 20v had much broader flatter torque curve, the 16v very peaky, on the track the 20v (I was going to say walked away) but it ran away, much to the dimay of the 16v owner
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 06:58
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Bill, what was the final outcome with the 3SGE/4 speed auto conversion??? driving, power, fuel consumption etc.
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Location:
Adelaide, South Australia
Registered:
March 2005
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 07:28
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| shinybluesteel wrote on Sat, 28 May 2005 16:10 |
as far as i know the 20 valve 4age was the only 5 valve engine toyota ever made (correct me if i am wrong) why would this be if they are so wonderful?
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a 40Valve 4.5L V8 was made back in 1991, to power the GT4500 concept car. To my knowlege the 20V 4AGE is the only "Production" 5valve motor from the toyota stable, but not "The only one" ever.
As for which 4AGE is better, I've got no idea. Though some interesting arguments have been made on both sides.
Cjeers
Jordan
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Location:
Tasmania
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 07:52
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I have a far more down to earth question. Where can I buy camshafts (long duration ones, maybe 304 degrees, or whatever is best) for the 4AGE 20 valve?
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Location:
Adelaide
Registered:
May 2003
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 08:24
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Since you seem to be basing all your information on this tech document, you might want to share it around....
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 10:08
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Just to make things clear, we're talking about two different things here.
The unlimited F1 scene, and the 5 valve engines simply didn't perform. No way to rationalise it, they just weren't as good as the four valve. A few companies tried them and it's a waste of time.
Re: 4AGE's, yes the 20v's make more power but considering they have a vastly better inlet manifold and inlet ports they really should be a lot better than what they do.
As for the final answer as to which engine has a better spread of torque by comparing one run of each type, that's poor science.
Again, let me finish my 4AFE (Yes I know it's not a G but it's a four valve) and show you what a really good one will do.
Bring on any 20v N/A you like.
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Location:
Sydney
Registered:
July 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 10:45
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What an interesting thread -- although there seems to be just a little to much pride and emotion for what should ultimately be a technical discussion.
A few thoughts...
There are other tradeoffs in the 4-valve vs. 5-valve argument which haven't been considered in this thread so far.
One of them would be valvetrain packaging and complexity. This is going to influence the design of most production engines considerably. Pointing to whether or not 5 valves are used by various manufacturers is only evidence of an overall cost/benefit decision by a manufacturer, and doesn't really tell you that much about the technical superiority of one design or another.
Think of all the pushrod engines still being manufactured for example. The manufacturer's choice to use one system over another is obviously not simply dictated by outright performance.
Another issue would be valvetrain mass. 5-valve engines might have an advantage when using regular cams due to lower valve mass. F1 engines have a different set of tradeoffs due to the use of exotic materials and pneumatic valve springs. If you change the valve material in your own car, you'll likely change this tradeoff as well.
Actually, there are even more problems with saying that because something is used in F1 it is the best. It just means that it's the best design to use when you are building a car with a massive budget to whichever rules the FIA gave you this year.
The discussions about flowbenching are also interesting, but probably more suitable for a different thread. I don't know too much about flowbenching, but from thinking about it it seems to have some inherent limitations.
A flowbench seems to generate a continuous vacuum, while a real engine is generating a pulsating vacuum. Clearly this will have different characteristics, as there will be resonance effects due to the mass of the intake charge. So simply comparing flow bench numbers for two different head designs is probably not enough to declare a clear winner. In fact, the tradeoff will be influenced by a lot of factors other than the number of valves... the valve timing, pulse frequency, port diameter, rod/stroke ratio... probably lots more. Engines are dynamic devices, which is what makes them so interesting.
Anyway, the point of this message is that the whole 5-valve vs. 4-valve war is a bit silly. Engineering is about tradeoffs, and what works in one situation might not work as well in another.
PS. Since when did age have anything to do with having a clue?
[Updated on: Sat, 28 May 2005 10:57]
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:12
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Oh Bill god you give me a laugh, I quote "as to the final answer as to which engine has a better spread of torque by comparing one run of each type, that's poor science" first off we have dyno'ed many of them and it always the same and at the end of the day this thread has come down to comparing 4 to 5 valve and all the stuff I have ever seen you write about this on the net you give the good ol 20v a bit of a bashing, it's a direct comparison between the two, how much dynoing have YOU done????(I don't mean hanging around a dyno room either )
Bored you bring out some really good points, I have in years past grown sick of the old V8 mentallity to turbo charging you know the one "if turbo's were so good how come the drag boys don't use them" doesn't mean turbos are no good now....does it? or maybe it does Bill 
Takai not just a tech article, haven't you been reading??? lots of dynoing as well
hey Bill they don't use traction control and ABS in F1.......must be crap then
I love to give you a run NA but FUK why bother when turboed they just KIK ASS!!!!
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:14
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Oh Bill they don't use turbocharging in F1 either....must be crap
gotta love your argument!!!!
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Location:
Adelaide
Registered:
May 2003
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:19
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| 170bhp wrote on Fri, 27 May 2005 22:54 |
I have got my hands on an SAE technical paper titled 'Optimization of multi valve, four cycle engine design-the benefit of 5 valve technology' research done by Yamaha.
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Funny, your original post didnt mention anything about dyno time. Just an SAE Tech Paper...
Again... care to share.
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:24
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| 170bhp wrote on Sat, 28 May 2005 21:14 |
Oh Bill they don't use turbocharging in F1 either....must be crap
gotta love your argument!!!!
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Well, if you're going to be a f**king idiot, you can have the thread all to yourself.
You're too stupid to debate.
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:32
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Takai the first post didn't the rest do. at first I thought I'd just share the paper until the experts came out, then ya gotta pull out the dyno facts.
yay I don't have to hear Bill's two bob's worth thank fuk
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Location:
Sydney
Registered:
July 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:40
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You do realise that carrying on like this is irrelevant, and just makes you look bad.
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Location:
Adelaide
Registered:
May 2003
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:43
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So care to share the article.
None of the current SAE journal listings show any article or paper by that title....
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:48
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bored, I sure do, but over the years I have seen a certain someone always reply to tech articles and if it isn't what he says, it must be wrong, it's very frustrating! I put up legitimate technical information to be told by people that haven't done any testing that it's wrong. If anything these people are wasting their own time here, they should be working for large automotive firms in engine design etc as they are wasting their talents on tech fourums hmmm very narcisstic
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:49
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takai - 860032
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Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:50
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| Quote: |
read it and weep, 302bhp!!!(oh it is turbo charged but you said ANY 20v!!!)
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We live in a big country with a lot of workshops, a number of 16V Turbocharged 4A's are making around this power and more So it's nothing to get too excited about.
The boys with the 16V 4A's running in the 10's down the strip must be making some good hp too
Pity this thread turned into a petty dispute, could have been a good read
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Location:
Adelaide
Registered:
May 2003
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:53
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| 170bhp wrote on Sat, 28 May 2005 21:49 |
takai - 860032
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Ah it would help if my archive extended back past 1989. Ill go get it when im next near the library.
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 11:59
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ke382tg i'm not running much boost at all, so I think 302bhp is pretty good, also considering that for what I want to do with the car, much more than this will be too much. if I was drag racing yeah maybe more but for what I want to do on the tyres I have to do it, 302 is plenty(and I don't have to rev too hard). I was hoping maybe it would be interesting read but then everyone came out with the well worn out "if they were so good.........", "how come the pope don't have a 20v......" "if it's not in F1 it must be......" etc etc.
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Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 12:37
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| Quote: |
ke382tg i'm not running much boost at all, so I think 302bhp is pretty good, also considering that for what I want to do with the car, much more than this will be too much. if I was drag racing yeah maybe more but for what I want to do on the tyres I have to do it, 302 is plenty(and I don't have to rev too hard).
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302bhp is damn good power from a 1.6L
The big number crunchers have tended to be the drag guys and dyno fans. A few though have made some good numbers on "sensible" boost.
A few interesting points have been raised in this thread re: 5v vs 4v. Some not so interesting.
Cheers.
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 13:58
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FWIW I checked up and as far as I can tell five valve engines have been permitted since at least the early 80's up until at least 2003.
I have a copy of the 2003 regs (I suspect 2004 is the same) and rule 5.1.5 states that "Engines may not have more than five valves per cylinder."
So for perhaps twenty years any manufacturer has has had every opportunity to make a five engine work.
Can someone please tell me the last time a five valve engine won a GP?
The phrase "The bullshit stops when the flag drops" springs to mind.
Also, do not lie about what I have written. Please find evidence anywhere at all where I say the 20v is a poor engine.
They're not and I've never said they are.
It's just that they'd be a lot better if they had four valves and a pentroof combustion chamber - That's the only two things letting them down.
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Location:
Brisbane
Registered:
June 2003
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Re: Is 5 valve better than 4 valve?
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Sat, 28 May 2005 15:22
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Great read, we need more of this.
170bhp: Bill Sherwood a good bloke, give hime a break FFS..
Heated debates = ok / Insults = Fast Fours Forums
Got the point...?
Everyones talking pure performance, what about the consumer demands side of things??
Costs, reliability etc etc... Everyday Joe doesnt appreciate 5-valves - its not really a deciding factor on purchase, is it?
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 01:29
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One anecdote I rarely tell because I have trouble believing it is a phone call I made to a guy in Melbourne.
I forget the original reason I rang him for but we got talking about 16v 4AGE and how I wanted to attack one with a milling machine to rehsape the inlet port so it'd angle down into the head like a 20v one does.
That guy had apparently already done it, and said that at around 10,000rpm (I think, not sure but it was very high revs) was getting a bit over 290hp from it.
I mean it's possible - The inlet port is the big restriction in the 16v heads - but I'd really like to see it to check it out.
That's the sort of port figure you'd expect from a very good 16v with everything exactly right.
Nearly 300hp and no turbo in sight.
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Toymods Vice President
Location:
Sydney
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 02:26
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I don't really want to buy into this debate but I'll add some info about the F1 stuff.
Ferrari sourced some engineers from Honda during the years when people actually tried to use 5V angines in F1 to do analysis on the 4V vs 5V. The conclusion they came to was that the 5V made more power than the 4V however the amount of fuel used by the 5V compared to the 4V was too much higher to make it worthwhile. The efficiency in terms of power produced per mass of fuel was lower in the 5V engine. The additional fuel required to be carried by a car with 5V made it slower in a full race simulation than a 4V car.
Is this relevant at all to a performance street car? That's up to you. I'll stick with engines with a little more swept volume than 4A's so I'm not overly concerned about this discussion.
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 08:14
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| Joshstix wrote on Sun, 29 May 2005 12:26 |
I don't really want to buy into this debate but I'll add some info about the F1 stuff.
Ferrari sourced some engineers from Honda during the years when people actually tried to use 5V angines in F1 to do analysis on the 4V vs 5V. The conclusion they came to was that the 5V made more power than the 4V however the amount of fuel used by the 5V compared to the 4V was too much higher to make it worthwhile. The efficiency in terms of power produced per mass of fuel was lower in the 5V engine. The additional fuel required to be carried by a car with 5V made it slower in a full race simulation than a 4V car.
Is this relevant at all to a performance street car? That's up to you. I'll stick with engines with a little more swept volume than 4A's so I'm not overly concerned about this discussion.
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Were did you read that?
All the info I have ever heard and read says that they just didn't make the power as the four valve ones did. Yamaha sent their best five valve to Cosworth in the UK in the late 80's early 90's (I think) and the Cossie engineers were very underwealmed as to the power it made.
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Location:
ghetto area 2745
Registered:
November 2003
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 09:41
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Were did you read that?
All the info I have ever heard and read says that they just didn't make the power as the four valve ones did. Yamaha sent their best five valve to Cosworth in the UK in the late 80's early 90's (I think) and the Cossie engineers were very underwealmed as to the power it made.[/quote]
hmmm cosworth 
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Location:
Land of Oz
Registered:
June 2004
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 11:53
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Hi,
Well, it appears that 4 is better than 5, so logic determines that 2 is better than four! Lighter also, without those extra valves thumping up and down.
seeyuzz
river
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 12:00
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"Well, it appears that 4 is better than 5, so logic determines that 2 is better than four! Lighter also, without those extra valves thumping up and down"
River, I think your onto something, that's it next week I'm putting in a 4AC
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 12:08
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Two stroke anyone?
No valves ..... 
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Registered:
January 2004
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 12:11
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Fuk two strokes, they smell and I gotta keep putting oil in, no for me it's 'back to the future' style.....flux capacitor all the way
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Location:
nelson, new zealand
Registered:
October 2004
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 12:34
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coupla things....
maybe the reason for the 20v not doing as well in the atlantic series is development time, the 16v has been used since the mid 80s... thats a lot of tim eot get it right....
and about the intake ports of a smallport, mate of mine has one thats made to pull 10k, they actually filled in the ports.... now its a peaky engine and i cant remeber the power is makes (well over 200 though) but something i thought you may find interesting
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Location:
Sydney
Registered:
September 2003
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 13:45
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What the fastest 20V turbo and whats the fastest 16V turbo ?
Have any 20Vs beaten the time set by Bens MR2 ?
Anyway 16V Rocks No i havent tested it nore do i give a rats ass, the fact is, in turbocharging money can be better spent else where than screwing around with 20V heads
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Location:
Tasmania
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 14:15
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Well it seams everyone has heard something from someone about 4v versus 5v a long time ago. But very few can state their sources so we can look it up for ourselves.
I follow most of what has been said, but all I come away with is that they are very similar up to 200hp. As standard, the 20valve 4AG is better of course with quad throttles. Over 200hp no one can agree, because we don't really know. I do like the idear of the 20valve and late 4A-FE/7A-FE intake ports.
But the 5 valve design? I have no idear.
Bill, can you tell us more about your 4A-FE? Sounds very exciting. Cam specs? Custom pistons? Rev limit? I still think you should have saved your best 4A motor for the AE86.
The Formula Toyota series use a silver 20 valve 4AG, with Webber sidedraft carbies, some very nice extractors, and no VVT.
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Is 5 valve better than 4 valve?
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Sun, 29 May 2005 14:58
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| Jonny2TG wrote on Mon, 30 May 2005 00:15 |
Bill, can you tell us more about your 4A-FE? Sounds very exciting. Cam specs? Custom pistons? Rev limit? I still think you should have saved your best 4A motor for the AE86.
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The cams will have around 290deg duration but a lot of lift.
The pistons will have to be specially made as there's nothing available that comes remotely close to what I need. (Funny shaped squish areas and dished as well)
It'll run to 9600rpm.
It's for the KP-61 Starlet, so in a ~800kg car should be a lot of fun.
Gone for a week, catch ya when I get back.
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Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
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Re: Is 5 valve better than 4 valve?
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Mon, 30 May 2005 02:34
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I'm with river on this one
Give me 8 valves, 45degree *wide* valve angles, massive dome combustion chambers and Hugh Jass valve sizes
Damn cheap to service, being that there is only half the number of valves to play with
Bill,
I very much like the fact that you have made mention to the 2zz-ge. I find it funny that people forget this motor exists. 4 valves, 1800cc, 8200rpm and 140kW straight from the factory with 21st century emission and noise level compliance. If i had money i would sooooo play with a few.
In all truth, i haven't a lot to add to this discussion as i am not that well experienced with the full variety of 4A engines, nor do i claim to posses a full knowledge of flow technonics and head/engine design principles and experience.
I will say that in my experience of the two engines (smallport 16V 4age vs silvertop 20V) in STOCK form, side by side in the SAME car (AE92)..... i thought the 20V's performance was rather lacklustre. Yes it revved higher, and was a little smoother, but one would have expected more from so many "improvements" in the WHOLE engine package beyond the addition of the extra valve.
I would go so far as to ask someome with the ability to take a stock 20V and a stock smallport 16V and do some engine dyno testing...
# in stock forms (i mean complete stock, down to exhausts and intakes)
# after addition of quad TBs to the 16V (on par with 20V)
# after addition of VVT on par with 20V
I would be VERY interested to see the results.
Me, i love the smallport 16V. Simply because i picked one out of a scrap metal bin for $100, chucked it in my AE71 and thrashed the crap out of it for a year including a 15.8 sec pass and 69rwKW, then added 11psi and some less-than-ideal tuning for a quiet 14.1 pass and 116rwkW.
To this day it still gets thrashed and STILL hasnt missed a beat - and i havent even cracked open more than the sump and manifolds....
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