7M cylinder head porting

[enjoi.this]

I totally agree dont go lurking, you deff know some excellent points on this subject. Like I said you wouldnt learn new things if you dont attempt them. That site you posted up is good shit, been reading a fair amount of it. When I dyno and tune going to be deffinatly be listening for knock, thats what thing I dont need :aigo:

What im really curious on is how the Turbo A's worked with theyr hemi c. chamber?

 

[IJ.]

Group A not Turbo A Chris there's a world of difference

 

[enjoi.this]

Group A not Turbo A Chris there's a world of difference

really wow! hahah opps my fingers wrote down different words...

 

[enjoi.this]

Did a few more things today. Cleaned up the c. chambers a bit more today. Found more areas to smooth and eliminate radius's from on the intake ports that I believe will help with the intake charge after unshrouding the valves. Polished the living crap out of the exhaust ports, getting much closer to being a mirror finish! :evil2:
took about 3.5 hours to do this so far today, still need to finish the other half of the intake side and cc the chambers.

Started making my pieces to do the cc'ing with such as the clear plexi piece that will sit on the deck. Need to find where to get a damn graduated cylinder of some type! Anyone know of somewhere to look besides local science distributors? (theres none around here..)
Also im curious on what kind of liquid I should use, will colored water be fine or could I just use antifreeze since its very distinctive color (green)

 

[jdub]

I would use a thin oil.

You could use a syringe...the large type used by vets for horses. Get 2 of them.

 

[IJ.]

Not understanding the need for any colour?

I used to grab a big 100Ml syringe from the local vet.
(CC should be around the 40cc mark stock)

 

[enjoi.this]

Not understanding the need for any colour?

I used to grab a big 100Ml syringe from the local vet.
(CC should be around the 40cc mark stock)

I remeber reading some material on doing ccing a long time ago. they use a green colored solution from what i remeber. Ill hit up a local vets office I guess and see if they will sell me a couple large syringes.

 

[IJ.]

I use plain water

You're filling the chamber till the air is gone from the fill hole so it's easy to see, remeber it's NOT getting an exact measurement just getting them all even volumes.

 

[enjoi.this]

I use plain water

You're filling the chamber till the air is gone from the fill hole so it's easy to see, remeber it's NOT getting an exact measurement just getting them all even volumes.

I drilled the holes off from center on the plate to cc, will probly help out with getting rid of air bubbles. also put the head on a slight angle just enough to help bubbles escape.

 

[BLACKCAT]

I would have the head perfectly level.

Came across this picture of a ported 7M exhaust port & wondered if anyone has thaught of using this shape.
Trying to copy the 2J design I suppose.

 

[enjoi.this]

I would have the head perfectly level.

Came across this picture of a ported 7M exhaust port & wondered if anyone has thaught of using this shape.
Trying to copy the 2J design I suppose.

On the 7M changing the shape of the port itself is a big no no as its been told. Not too sure what the advantages of having a port shaped like that could be. Looks as though there would be more turbulence involved?

 

[BLACKCAT]

Changing the shape of the exhaust port on the head is fine as long as its a bit smaller than the manifold port to allow for reversion.:icon_bigg
Looking at that picture a bit closer they would have to have a custom gasket made up as the original would not be suitable, not to mention reshaping the manifold itself.:nono:

 

[enjoi.this]

Spent a couple more hours the other day preparing to cc the heads. Cleaned and smoothed up the combustion chambers alot and tried to get them as close to the same as my eyes would allow.

This is what the C. Chamber looked like once I did clean up and slight polishing

The cc plate that was made worked very well after a trail run. The first time with only having one hole to put in the oil, there was no way to completly fill the chamber because of all the air trapped inside. So to fix the problem 4 smaller holes were drilled to allow the trapped air to escape. Worked like a hot damn once the proper venting was achieved!

These next 2 pics are of the deck with a line layer of grease applied around the edge of each chamber to seal it off. Also a small amount was applied to the valve seats to stop any oil from leaking into the ports. I was rather suprised at how well the the grease sealed off the chambers.

Found a 60 cc syringe at a local pharmacy. Was $3.75 for two of them. ATF was used since its a very thin oil but doesnt cost too make (has a cool red color too )

I forgot to take a pic when I still had the cc plate on.. Doh! whichever thats pretty much what it looked like with it anyways.

All the chambers measured out soo damn close it scared me slightly.. All the chambers measured out too 42cc. Except for 2 and 4 were 41cc (which I corrected to 42cc) I guess my eyes did not too bad trying to match them up!! :biglaugh:

 

[amichie]

All the chambers measured out soo damn close it scared me slightly.. All the chambers measured out too 42cc. Except for 2 and 4 were 41cc (which I corrected to 42cc) I guess my eyes did not too bad trying to match them up!! :biglaugh:

Can you please measure the head thickness. Original thickness I believe is 116mm. I cc'ed my chambers before starting my head porting project and measured 42 to 43 cc for all chambers. My head had never been shaved so you have achieved very close to the original chamber volume.

 

[jdub]

LOL...I see you found your colored fluid
Well done!

 

[IJ.]

Chris: It's called "Muscle memory" whenever I do hand work like this I tend to do a cut on one chamber/port then do the same cut on the next in line and so on then come back to the first one and do the seccond angle and repeat.

I've found I can get really accurate results and only need to lay out the entry outline and use 1 or 2 Go/No Go templates.

 

[Nick M]

looks OK, but I wouldnt have touched the combustion chambers if you dont know what you're doing. By unshrouding the valves that much, you removed the tumble/swirl that was engineered into the chambers by Toyota. Tumble and swirl is extremely important... it totally dictates flame front speed and direction. It also keeps the fuel from washing out the cylinders and collecting in the ring lands (bad).

I'm not an expert in this field, but I do know enough about cylinder head porting and c.chamber shaping to know that a dome shaped c.c. is not a good ideal. I hope you take my criticism positively as it certainly is not offered in a negative manner. I also know how much time you must've spent doing it.. so you're not going to be happy with my posting... If you use this head still, please at least CC the chambers so that each cylinder has close to the same static compression ratio.

That is all true, but needs qualifiers. Ever here of a hemi head? That is short for hemispherical combustion chambered head. Our pentroof is a descendant of that. The group A head is molded after it.

I think his reworked head looks kind of like a 2JZ head in the combustion chamber. Nice work.

 

[Nick M]

Eh, I just finished the thread, he did more mods. Now it looks like a group a head.

 

[amichie]

I am half way through a similar project.

Left images are of the modified chamber. Images on the right are of an untouched chamber.

Next step is to build a flow bench and see if the deshrouding of the intake valve has helped at all.

 

[blupastu408w]

I am half way through a similar project.

Left images are of the modified chamber. Images on the right are of an untouched chamber.

Next step is to build a flow bench and see if the deshrouding of the intake valve has helped at all.
[/IMG]

I've built my own flow bench... it (unshrouding the intake valve) helps tremendously. My combustion chambers look like yours. Looks good!