Toyota 5MGE chamber inquiry

[oldeskewltoy]

I understand the 7M is a 4 valve head, but can you physically bolt it on the 5M block?

The client WANTS to use the 5M head... I do what my client wants

Is the area that you want to weld angled in to the centre of the chamber, or parallel to the deck?

yes.... - (feigns understanding) my initial thoughts on this was to weld parallel to the deck, gain some compression*, while attempting to increase squish/quench. After having read the Toyota engineering paper I wonder if welding it and then adding a shallow tapered squish might be the best of all worlds????

[oldeskewltoy]

quick resurrection....

What is the collectives thoughts on indexing the spark plugs for this head????

not exactly scribed... but should do...

[wil8115]

Just run the recommended ngk for the app. With that style chamber I doubt you would even gain anything.

[RL]

I think someone has to ask " What's the application".

You are not going to find 100hp welding those areas, so what are you expecting from the engine.

[jacksoni]

look at this thread:
viewtopic.php?f=15&t=38721&hilit=squish%2Fquench

and:
http://physics.usc.edu/Undergraduate/te ... rfeeng.pdf

and especially this:
http://www.ae86drivingclub.com.au/downl ... squish.pdf

[oldeskewltoy]

look at this thread:
viewtopic.php?f=15&t=38721&hilit=squish%2Fquench

and:
http://physics.usc.edu/Undergraduate/te ... rfeeng.pdf

and especially this:
http://www.ae86drivingclub.com.au/downl ... squish.pdf

I had seen the bottom pdf before.... and that is what got me thinking...

the top link is very much what I'm thinking... (photo below from top link)





I've downloaded the 2ZR pdf... I can't capture all of that engine... it is completely different... direct injection, multi valve...


I am hoping that the 5MG chamber lends itself to a bit of modern development. I don't know what to expect(power wise), my client asked me for some headwork on his boosted 5MG, while doing research I saw chambers, and piston crowns that I believe can be improved. As has already been pointed out, my client MAY do better with other options(7M, 1J, or 2J)... but he is stubborn (ain't we all sometimes) and he wants to keep the 5MG. So... back to the purpose of this thread... if my client can get better combustion by reshaping the pistons and chambers, I was here asking if this is smoke and mirrors... or worthy of at least one mule... if my client is interested... and can be persuaded

[Cubic_Cleveland]

If your willing and able to do the work and your customer is willing to pay, I would go the angled squish route. Show him the toyota paper and he should understand that toyota wouldn't have spent millions in research, and put the things they learnt from that research into production for no benefit.

[RL]

The usual trick is to copy a modern design, but no one uses these old hemi style chambers in modern heads so it's hard to use any modern techniques. I would be looking at Harley, old 70's bike heads, or probably the newest the Aust Ford Falcon 6 cyl head. There is also some oldish Jap 2 valve heads that are sort of hemi.

Modern heads use flat chambers and non direct facing ports - stops flow going from the int straight out the exh -. You can see the Falcon goes toward a flatter valve angle and some squish.
https://www.google.com.au/search?q=falc ... d&tbm=isch

Other chambers
https://www.google.com.au/search?q=hemi ... 80&bih=965

https://www.facebook.com/cavanaughracingheads

[Calypso]

There's probably a reason why opposite quench pads are different depths from factory.

[oldeskewltoy]

I now have the head....




note the area in question is already angled!!!


The step @ the edge = 1.5mm, I've consulted a friend @ Loynings Engine Service, and we believe the machining limit is 1.8mm

[EthylCat]

Subscribing...

Getting ready to build one for a Model A Street rod.

Attempting to maximize performance and try to make it look like an old Offenhauser twin cam.

[lada ok]

Seems a shame to modify an engine, without before and after #'s
This would be a great project to do in stages

[Cubic_Cleveland]

I forget, was a custom piston an option? I would rather go that way with a small dome than mill the head that far. How far off the deck are the seats factory? As in will you be milling them with the 1.5mm cut?

[rklessdriver]

It is already angled but there is still the flat quench area with the step machined down to the angled area.

I personally would weld it up and angle the entire quench area to within a few thousands of the headgasket fire ring/sealing surface....

I would also soften and roll the machined "line" in the chamber between the intake and exhasut seats.

Will

[oldeskewltoy]

custom piston is still an option.

More revelations.....


exhaust



intake