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I supported Toymods
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June 2002
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3KR - How hard would it be to achieve?
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Wed, 25 June 2003 22:40
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Well we all know this :
How hard would this actually be to do? Specifically the twin cam head on a 3/4/5/7K motor?
Has anyone ever tried/had a look at different heads and whether they'd fit the good old K?
I might be talking shit, but, why not a 4AGE head onto a 2T or a 4AGE head onto a K motor? Aside from the ancilleries like driving cam gears, oil pumps, distributors, squish area ect?
Face it Mr Krogdahl did it...
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Location:
Brisbane
Registered:
December 2002
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Re: 3KR - How hard would it be to achieve?
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Wed, 25 June 2003 22:55
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wouldn't it be called a 3K-G why the R
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I supported Toymods
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melbourne.victoria.austra...
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June 2002
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Re: 3KR - How hard would it be to achieve?
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Wed, 25 June 2003 23:43
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i grabbed the R from bills original post...
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I supported Toymods
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I renounced punctuation
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I supported Toymods
Location:
melbourne.victoria.austra...
Registered:
June 2002
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 02:53
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i hear ya.
remember tho - k motor head is alloy. alloy can be heated and welded though so things like head bolt holes don't pose much in the way of a problem BUT making sure there is room for the bolt - that could be a problem.
yes to same bore spacing. you could deal with a mm here or there and weld up/reshape the combustion chamber, again, would make it pretty hard methinks.
custom head gasket well, no, not really. you make the surface of the head the same as the block as use the headgasket for that motor (if you get what i mean)
oil feeds and water jackets - now that bit would be a challenge - one that might actually kill off the idea to be honest. some massive work would be needed there.
indexing cam gears and getting the rotation right, well, for arguments sake if you used 4AG cam gears and then from a billet cam had a "dummy" made up to drive the distributor/oil pump and removed the lobes for the pushrods - you could actually put a keyway in it and use the gear from the crank of the 4AG. just a thought.
this all sounds pretty silly but VERY interesting at the same time.
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I supported Toymods
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 03:47
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Not at all. I don't think it's silly and it's certainly not impossible, and if you had machinist friends, it wouldn't even be expensive.
It would however be challenging. It sure beats engine swaps in terms of complexity.
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Location:
adelaide
Registered:
April 2003
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 04:53
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probably easier to cast your own head from scratch! the 3kR is an interesting motor that looks cool and is rare... if you have the money to think about adapting some other head it will probabaly be easier to spend the time and money just looking for an actual 3KR in japan!
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 05:42
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3K-R is for racing, but i think it was originally called a 152E or something along those lines. toysport have it on the history page iirc, google for "twin cam 3K"
the main difficulty i see when transferring heads are:
1-bore spacing.
2-head bolt position.
the bore spacing also affects valve position relative to the cylinder walls, so it's kinda important.
retapping the block in a K motor would be difficult, as they have sort of lumps for the bolts to go into, rather than a fully solid area of block  , so you'd have to modify head bolt position.
and all the things gianttomato said  chains or belts and water/oil can all be worked out. hmmmm roller rockers?
i have been thinking more and more about this of late (to avoid doing uni work:P ) and i'm thinking you'd have to start with either a new casting, or make a billet or plate/weld type of head.
for this you'd need some pretty accurate machining tools to get the angles right, and also for setting up cams etc...
good thing is that it would give you the opportunity to choose whatever 4 or 5 valve size/design you wanted, and optimise the port size/angles. downside is the obvious ridiculous cost of such a venture and that you are still limited by the piddly capacity of a K engine, so you have a limited torque in the end anyway
the K motors are really limited to about 8000rpm with stock valve gear... with DOHC, maybe that could go up to 10-11krpm? would it be worth it? would the bottom end hold up to the extra speed? (ie piston speed)
hmmmm, if anyone has access to nice machinery, i'd be very interested to start on something like this next year... would be fun
Cya, Stewart
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 05:56
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if anyone is really really interested in doing this, drop me a line, and we can discuss ideas. i'm thinking that i'dlike to get my hands on a 4AG 16V and 20V head, and then go from there, basically adapting dimensions as we go.
Cya, Stewart
stewie@unsw.edu.au
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Location:
New Zealand
Registered:
May 2002
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 06:31
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Probably look to the 2TG and 3T-GTE motors for ideas. These both run dummy shafts to run the oil pump etc. Using chain drive rather than belt may make it easier to get the chain the right length as you just shorten to suit and could adapt 2TG tensioners etc.
If you were going to do it you would want to start with the 7K so at least you have decent capacity to get greatest benefit and you are dealing with a fairly fresh engine block. I would be looking to engines such as the 4E-FTE for an appropriate cylinder head, may be closer to the correct bore spacing.
Having said all that, will it be worthwhile? Is the twin cam going to provide that much of a benefit? Remember, many of the fastest 4 cylinder drag cars in the world (7 sec bracket) actually use the pushrod 3TC motors.
Callum
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 07:46
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Thanks Puprple, i fogot about the 4EFTE...
as far as 5K/7K go. i think the 5K might be best option. it has same stroke as 4K, but bigger capacity. the 7K has longer stroke...
my idea of having OHC is to be able to pull 10K+rpm. as well as having extra breathing capacity for turbo and/or SC... so revs will be really important.. if i was going to go the 7K, i may as well start with the 7A.... i guess same with the 5k -> 4A..
hmmm why would i do this at all?? maybe just because ... and the look on ppls faces at dyno/track days when they ask what you have in there....
"oh, just a 4K....twin-cam, twin-charged :D"
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I supported Toymods
Location:
melbourne.victoria.austra...
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June 2002
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 08:51
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4efte....good point. 1.3 litre motor.
what other 4 cylinder OHC motors are there, i can think of :
(namely thinking of heads here)
4age
4age 20v
4afe
4efe
3sge
18rg
2tg
Anything else i've missed? what about diesels, not up with those motors? or any 6 cylinders that could have two cylinders lopped off to make a 4 cylinder head?
the only thing that would make this idea prohibitive would be cost.
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I supported Toymods
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 08:54
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It may be worthwhile thinking beyond the Toyota square
SR16/20DE
Mitsu stuff ?4G series motors
Fiat
Alfa
Lancia etc
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 09:16
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Have a look at a 2NZ-FE head, I think the bore spacing might be pretty close. No idea of how the head bolt spacing would be though ...
FWIW I have one at home, and the porting looks almost identical to the 3K-R's.
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Location:
melb
Registered:
May 2002
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 09:21
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its a cool idea - but hate to be the one to say its a little impractical - Its a "little" impractical.
why not just put a 4ag where the 3k originally sat? you get 300cc extra straight out of the box.
the only advantage the 3k has over the 4a is weight - even then i dont think its that much.
bubble bursting time over.
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I supported Toymods
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 09:22
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Bill, do scissor gears drive the 'second' cam on the NZ-FE head(like on the 4AFE, 1UZFE...)?
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Location:
Tasmania
Registered:
May 2002
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 09:38
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I think the 2NZ-FE (Echo motor) has a single row chain driving both cams. VVT is on the inlet cam. Same design as 1ZZ-FE I think.
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 11:09
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Yes, they have a single-row chain to drive both cams. The inlet cam has full VVT-i as well.
I'll be back in Aus next week, I'll measure it up and post the results here - I think I've got an old TRD 3K head gasket hanging on the wall so that'll help!
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Location:
Carlingford, Sydney
Registered:
May 2002
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 11:32
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awesome guys
(i just wanted to get these sent to my email address )
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 13:26
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| chrisss wrote on Thu, 26 June 2003 19:21 |
its a cool idea - but hate to be the one to say its a little impractical - Its a "little" impractical.
why not just put a 4ag where the 3k originally sat? you get 300cc extra straight out of the box.
the only advantage the 3k has over the 4a is weight - even then i dont think its that much.
bubble bursting time over.
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well, impratical it is, foolish? probably that too. there is no rational reason why we would want to put a twin cam head on a small motor like a 4K when there are other better, already made versions out there....
i think it just comes down to.. because...
because i want to build a head (and eventually a whole engine.. something like a 2L V8 would be nice), because setting up a motor to do ridiculous revs would be fun, because it is not the doen thing, and for the heck of it....
most of all because it is a challenge...
it really isn't eben a good idea  and starting with a newer block would be much more sensible... but..... but....
? 
Cya, STewart
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I supported Toymods
Location:
melbourne.victoria.austra...
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June 2002
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Re: 3KR - How hard would it be to achieve?
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Thu, 26 June 2003 23:59
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stewart
you forgot the only because that makes anything worthwhile.
its because you CAN!!!!!!!!
bill if you could get those measurements up that would be sensational! thanks for that! in the meantime i'll look down the 4A head to 3K path - see how we go.
thanks guys
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Location:
adelaide
Registered:
April 2003
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Re: 3KR - How hard would it be to achieve?
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Fri, 27 June 2003 14:23
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hey stew if you are into big revs perhaps you could think of fitting a large capacity water cooled motorcycle motor to something??? we thought about putting a moto engine into a suzuki van a few years ago, the gearbox ould have been too much 'fun' though
ab
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I supported Toymods
Location:
melbourne.victoria.austra...
Registered:
June 2002
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Re: 3KR - How hard would it be to achieve?
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Sat, 28 June 2003 04:53
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i compared a 4AGE head this morning onto a K motor block. actually i borrowed a 4AGE headgasket and tried it on the K motor block - there is NOT MUCH IN IT.
the combustion chambers, well, practically sit in the same spots. a couple of holes with the water jackets line up, and most of the bolt holes for the head actually line up too. i think there are three which would need the 4A head bolt holes filling and then re-drilling about 2mm inwards and you'd be done.
the only thing you would need to do is cover up where the pushrods sit.
the only thing about the combustion chambers is there is a difference in piston size between the two, which would make the chamber hang over the metal between the cylinders (between the bores is what i'm trying to say)
next will be to get myself a shitter K motor...
the quest continues.
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Location:
sydney
Registered:
March 2003
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Re: 3KR - How hard would it be to achieve?
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Sat, 28 June 2003 11:58
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just remember changin positions where the water flows could cause hot spots in the engine
its not just a matter of blockin here and openin there
and also a new timing belt would have to be made from scratch
and positions of tensioners and such calculated
drain holes have to be good enough so oil doesnt stay in head and then pressurise top end
oil galleries to head have to be just right too
all for the sake of 100 to 120 kw
i know its fun to do this type of stuff
but sit down and calculate the costs first
i hear of alot of projects not even makin it past 25% done due to lack of money
if u know someone with millim machine might be bit cheaper but still a bloody big job
toyota doesnt design and engine in a week u know
and for under 10000 dollars
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Location:
Mentone
Registered:
May 2002
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Re: 3KR - How hard would it be to achieve?
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Sat, 28 June 2003 12:49
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A little bit of topic but there is a guy who has used a bmw motorbike head on his mini a series engine. The block face only had a few extra holes and most things lined up.
Anything is possibel in the 60's and early 70's the race mini guys were running bda's, lotus twin cams, coventry climax, and cut down 2 cyclinder bda engines on mini gearboxes which if you dont know share oil. Maked you think how lasy we can be and still get away with easy conversions now.
Brad
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Location:
Blue Mountains, NSW
Registered:
May 2003
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Re: 3KR - How hard would it be to achieve?
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Sat, 28 June 2003 14:28
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Theres a guy up in QLD who, using 2TGs and 18RGs as an example, manufactures twincam 12 valve heads for Holden 186s and 202s.
He charges $5000 for the kit, so that gives you some idea of the money involved.
A friend of mine wants to put one of these in an EH and turbo it, after he gets his Crappadore going (four years in his back yard with a 5 litre gathering cobwebs - To think he sold a really nice T-18 to buy it!).
Has anyone thought of Suzuki G13B engines? From a Swift GTI - you could use 1.3L Sierra engine mounts and bellhousing to get it RWD and bung it in a Corolla. They are great engines. Or the head may be worth investigating at least.
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Location:
New Zealand
Registered:
May 2002
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Re: 3KR - How hard would it be to achieve?
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Sun, 29 June 2003 10:00
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| TE35 wrote on Sun, 29 June 2003 02:28 |
Has anyone thought of Suzuki G13B engines? From a Swift GTI - you could use 1.3L Sierra engine mounts and bellhousing to get it RWD and bung it in a Corolla. They are great engines. Or the head may be worth investigating at least.
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This setup has been used in a few RWD Toyota Starlet rally cars over here in NZ. There was one that was extremely competitive.
Callum
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: 3KR - How hard would it be to achieve?
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Wed, 02 July 2003 08:24
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Okay, I found an old TRD 3K head gasket and held it up against the 2NZ head, and it's not REMOTELY close!
Each individual cylinder is not too bad, but the bore spacing is a good 10mm or so different between each engine, so the end cylinders have a fair bit of overlap from the head gasket to nearly halfway over the inlet valves ...
Sorry.
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I supported Toymods
Location:
melbourne.victoria.austra...
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June 2002
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) and redrilled/tapped. Lining up oil feeds/drainbacks and water galleries might make the whole thing a bit nightmarish. Hello custom head gasket.
