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Registered:
June 2004
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how much can i port a 5m-ge head?
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Tue, 13 July 2004 09:21
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has anybody got any idea how much porting i can do before i hit a water jacket? i hoped i could get the ports close to 40mm as possible(40mm sidedrafts). can you get aftermarket cams for this head? are the valves good in these heads, my 4m head has burnt out the exhaust valves before.
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I supported Toymods
Location:
Australia
Registered:
November 2003
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I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
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Re: how much can i port a 5m-ge head?
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Wed, 14 July 2004 04:27
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Probably the most common mistake with (back yard) porting is to just simply 'bore out the ports' to the biggest diameter and this is generally done without paying any attention to where the most gains will be made - the valve bowls. Doing what you sound like you're about to do may actually make your head worse. Whilst I'm not trying to dissuade you from doing your own porting, I suggest you read up a little before you start hacking away with the die grinder and destroy a perfectly good head.
Aftermarket cams are available, mostly from the US. Expect to pay big bucks. You could get yours welded and ground - there are a few mobs here in Melbourne that will do it with plenty of good profiles to choose from (not the standard 4-5 grinds offered by the aftermarket tuners).
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Registered:
June 2004
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Re: how much can i port a 5m-ge head?
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Wed, 14 July 2004 07:18
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despite what you might think, there are people out there who actually know as much as you think you know. the only engines i've ever worked on and studied thoroughly is a 4M. i know that the early pre-pollution heads had 38mm ports, part of the reason why they shit all over the pollution(post mid-'76) 4M's. that's why i asked "how much can i port a 5m-ge head?", because i don't know how much, and certainly didn't say i was gonna flog the ports out! 
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Registered:
June 2004
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Re: how much can i port a 5m-ge head?
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Wed, 14 July 2004 07:19
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despite what you might think, there are people out there who actually know as much as you think you know. the only engines i've ever worked on and studied thoroughly is a 4M. i know that the early pre-pollution heads had 38mm ports, part of the reason why they shit all over the pollution(post mid-'76) 4M's. that's why i asked "how much can i port a 5m-ge head?", because i don't know how much, and certainly didn't say i was gonna flog the ports out!
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I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
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Re: how much can i port a 5m-ge head?
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Wed, 14 July 2004 07:39
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Knock yourself out then. Take them out to 40mm. There's plenty of material there.
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...and certainly didn't say i was gonna flog the ports out!
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....i hoped i could get the ports close to 40mm as possible...
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The standard ports are 34mm. Sounds like flogging out to me but, hey, you're the one with the telepathic flow bench. 
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Location:
Brisbane
Registered:
May 2002
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Re: how much can i port a 5m-ge head?
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Wed, 14 July 2004 07:40
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hey, not to stir a shit fight, but when one of the know "m series GODS" post some advice (not to mention in a very polite manner) I'd think twice about ripping on them. (other ppl are not so keen to offer advice when they someone get abused for no reason...  )
In no way did he say you were stupid, all he said was that from stated plan of attack, you might be better off researching more into head porting in particular the valve bowl area, where as GT said most gains are made.
Anyway, best of luck with it
Cheers
Wilbo
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Location:
Newcastle
Registered:
April 2003
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Re: how much can i port a 5m-ge head?
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Wed, 14 July 2004 17:53
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| gianttomato wrote on Wed, 14 July 2004 17:39 |
The standard ports are 34mm. Sounds like flogging out to me but, hey, you're the one with the telepathic flow bench.
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I would have thought the inbuilt lip at the start of the port would be a good guide to go by as i think they open up a bit once near the valve area.
Unless you are going to make your own manifold you will probably see that the manifold closes down from the 40mm at the carbs to something a lot smaller so you will need to match this as well,then do the exhaust to let it all out again.
A 5M with triple carbs sounds like it would be nice but ports aren't the be all and end all.Choose the right cam grind and this will net the biggest results in my opinion.
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Registered:
June 2004
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 00:01
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it's not a 5m, just a 5m-ge head on a 4M. i'm making my own manifold, i was gonna taper this slightly so i didn't have to flog the ports out. i would only like to have to take the ports to max 37mm.
GT, i'm sorry for goin' off, but i wasn't after a lecture, i wanted to know if there was enough material to do whatever i need to do.
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Location:
Gippsland Lakes. Vic.
Registered:
March 2004
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 01:01
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JOE KOOL
What I really don't understand is since you know so much as you infer , why did you have to ask here in the first place & then reply as you did when offered good, sound, helpfull advice that was definately not a lecture. With regards to you grinding into water jackets do you think people have x-ray vision that can be enabled by e-mail?
Cheers
EMMAC.
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Registered:
June 2004
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 01:22
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hey dipshit, i was aiming this at people that have knowledge of this specific head, that might have gone to a professional, that would know how much material there is in a port that you can remove safely. i never said i knew everything about 5m-ge heads, that's why i asked.
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Location:
Lost in the K hole
Registered:
May 2002
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 04:27
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if you want to port match the manifold, fine, but why on earth do you want to hog into the port intake tract AT ALL??
-short side radius
-valve bowl transition
-valve seat throat
if you know anything about porting, it is to NEVER touch the roof of the port, and unless abs necessary, never touch the floor.
and for hacking into GT 
...in the words of hansel from zoolander:
"listen to your friend billy zane, man, he's a cool dude"
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Location:
Brisbane
Registered:
May 2002
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 06:22
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| joecoolmk2 wrote on Thu, 15 July 2004 11:22 |
hey dipshit, i was aiming this at people that have knowledge of this specific head,
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And you got a reply from someone who knows a LOT about this specific head, then proceeded to behave like an impetuous child.
Attitudes like this really shit me. You're new around here and you've contributed next to nothing to this community, but despite this people are taking time out of their day to help you for FREE, expecting nothing in return, and this is the thanks they get. Nice work. 
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Location:
Gippsland Lakes. Vic.
Registered:
March 2004
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 07:07
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JOE KOOL
Oh dear,you've done it again. You really have shown everybody your attitude problem haven't you. Keep this up and you will find it much more appropriate to change the K in your user name to an F.
Cheers
EMMAC
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Registered:
June 2004
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 07:23
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i think there must be something wrong with your screen, or your eyes cuz there is no K in my user name. it was a simple question about the head, not about porting. thanks for your advice and all, but i know what i wanna do. just because i'm new here doesn't mean i'm new to everything. you's obviously do things differently to me, and that's why you don't understand what i'm doing, and why. i correct myself, there is a K in my user name, not where you're looking though, so you might have gone cross-eyed for a second. 
[Updated on: Thu, 15 July 2004 07:25]
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Location:
Lost in the K hole
Registered:
May 2002
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Registered:
June 2004
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 08:11
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i give up. where did you pull 8.3:1 comp ratio from? how and wny would i run triple carbs on a turbo motor???? no, i'm not turboing it, just to make it easy.
here it is:
-4M
-5M-GE head
-no turbo's, no superchargers
-raised compression (9-9.5:1)
-minor porting/polishing
-triple solex 40mm carbs
-custom manifold
-custom stainless steel headers
-twin 2 inch exhaust system
-reprofiled cams (like GT mentioned)
-W50 gearbox, it it doesn't hold again, back to W40.
-two distributors, two ignition coils.
that's about it for this engine, then i'll see if i can get a 1UZ-FE.
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Location:
Lost in the K hole
Registered:
May 2002
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Registered:
June 2004
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 08:19
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i still don't understand where you get your figures from. show me them then i might believe you.
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 08:24
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Featuring the 4M carbureted motor, this sedan was reasonably competitive at its time. The 2.6l single-cam straight 6 cylinder motor put out 108 horsepower at 5000 RPM and 134 lb-ft of torque at 2800 rpm. The motor's respective bore and stroke are, in mm, 80x85. The motor also sported an 8.5:1 compression ratio- A reactionary one set for the bad gas offered in the gas-crunch late Seventies.
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Location:
Lost in the K hole
Registered:
May 2002
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 08:26
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its called maths
less swept volume: 2563cc VS 2759
4m piston dome VS a 5mge piston dome
combustion chamber volume between the 4m and 5mge
have you considered the potential of fouling the piston flycuts?
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Registered:
June 2004
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 08:47
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i did the math just then, and yours were wrong. the compression would be 8.12:1. maybe i should turbo it instead, although i know exactly what all of you think about that idea. could you explain the last part you said ed?
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Location:
1st street on the right
Registered:
November 2002
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 08:55
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Why won't you just listen. Your question has been answered. I grew up with a father and an uncle who did nothing but prep race cars. I was re-building f/ford engines and gearboxes at 12 and I still ask these guys questions because they know what I can admit I don't.
You WILL foul the pistons as I just compared them. Meaning the piston tops are higher and not cut to clear the valves.
You were asking about this specific head, yes and your first question was "how much porting can I do?"
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it was a simple question about the head, not about porting.
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Hmmm
And I wouldn't question Ed's maths and the only thing of GT's I'd question is the furry animal attached to his chin.
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Location:
Lost in the K hole
Registered:
May 2002
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 08:56
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| joecoolmk2 wrote on Thu, 15 July 2004 18:47 |
and yours were wrong. the compression would be 8.12:1.
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meh, i just did it roughly in my head. being 0.18 out doesnt make much difference, the point i was trying to make still stands.
as for the fly cuts - whats the valve approach angle and dia of the 5mge valves? the 4m piston design is interference type and i suspect youd be on thin ice wrt clearances. definitly worth checking, thats all...
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Location:
Lost in the K hole
Registered:
May 2002
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 08:58
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| clubagreenie wrote on Thu, 15 July 2004 18:55 |
and the only thing of GT's I'd question is the furry animal attached to his chin.
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im not sure di would like being referred to as a furry animal
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Registered:
June 2004
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 09:09
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i promise never to defend myself and never have my say or opinion never again. 
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I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 09:17
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You are making the claims of 9-9.5:1 CR.
Please explain how one might achieve that when you are:
- decreasing the swept volume,
- increasing the head combustion chamber capacity, and
- decreasing the dome of the piston.
Being such a student of the 4M, you will no doubt be aware of the 3 different types of pistons available:, flat top for post emissions motors, light dome for the 41030 head and nipple dome for the 41032 head. The capacity of the largest dome is approximately 4 cc.
Being meticulous in your preparation, you no doubt will have measured the head chamber capacity of your 5MGE head and worked it out to be approximately 62cc (a startling 21cc larger than the 41030 or 41032 heads). However, you lack the significantly larger dome of the 5MGE piston which brings the CR up to 8.8:1. You also are reducing the swept volume by a full 33 cc.
I'm sure you are fluent with the formula for calculating static compression ratio.
I suggest you do the calculations and see how 8.3:1 is derived.
I am now interested to see where you are getting 9 - 9.5:1.
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Registered:
June 2004
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 10:06
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clubagreenie said:
"You WILL foul the pistons as I just compared them. Meaning the piston tops are higher and not cut to clear the valves."
gianttomato said:
"However, you lack the significantly larger dome of the 5MGE piston which brings the CR up to 8.8:1."
which one of you has lost there mind and gone blind too?
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I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
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Re: how much can i port a 5m-ge head?
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Thu, 15 July 2004 21:40
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Whilst I couldn't be as confident as clubagreenie that the 5MGE valves would foul any of the 4M pistons (you haven't clarified which one you're going to use to achieve your 9.5:1 CR), the 5MGE pistons have decent reliefs (not really a flycut) for the intake valves that none of the 4M pistons have. Have a look at the ACL online piston catalogue to see what I mean, but given that you have studied them so closely, no doubt you have a very clear image of exactly what I mean. I am sure someone with a great knowledge of these engines like yourself will be doing a dummy build and checking valve to piston clearance (taking into account your reprofiled cams).
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