7M cylinder head porting

[IJ.]

Had to lay mine back when I went Ferrea OS valves

 

[enjoi.this]

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.

thought it was strange for what I measured out. Ill measure out the head then post up what it is.

 

[enjoi.this]

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.

Thats what I was trying to do when cutting. For each place material was being removed the cutter was being moved the same speed and direction. It would have been much better if I had done each cut inline. probly wouldnt have had to do as much final clean up on all the cut surfaces.

 

[BLACKCAT]

Opinions please for this intake mod on the 7M.

 

[IJ.]

Before and after flow figures?

 

[BLACKCAT]

Not mine, found on eBay.
http://cgi.ebay.com.au/500HP-TOYOTA...37;3A13|66:2|39:1|240:1318|301:0|293:1|294:50

 

[IJ.]

Ahh ok, just thinking back to the old days I saw quite a few Big port jobs that actually lost power as they changed the port shape so much it ruined the flow that sort of reminds me of them.

Forced induction makes it not quite as critical but I'd want to see flow figures before I'd drop the coin not to mention that has to be damn close to wated going by the head I sectioned a few years back.

 

[enjoi.this]

That is one massive intake port, could see it loosing power with something like that. There would be no air velocity with somthing so large.

 

[Nick M]

A hemipherical head really shines in race conditions as if flows very smoothly. The draw back is that it flows too smoothly and lower flow conditions suffer due to a lack of turbulance. I think you have a good compromise here chris should gain you quite a bit up top while still handle the low an mid range well.

This reminds me. Has anybodyseen pictures of the new Mercedes Hemi head used by Chrysler? The original hemi looks like the group A, the new one looks more like the 7M head. Quench.

 

[gofastgeorge]

That's why Chrysler went belly-up,
all BS........

A pent roof head is not a hemi head.

 

[Nick M]

Chrysler went belly up because their "Hemi" is really a pentroof? You people slay me.

 

[gofastgeorge]

You do not understand.........
Chrysler is all BS, on everything !

Like their Big Bad RAM Tough trucks.

A few years ago, I was turning onto a side street with my '71 Datsun PU,
when I was tail ended by a RAM at speed.
Nailed me so damn hard, it knocked me silly, and spun me around damn nearly a full 360 degrees.

When I could focus again, I climbed out of my little 35 year old import PU,
just knowing it was going to be crushed up to the axle.

But no !
At first I couldn't even see the damage, until I walked around to the back.
The bumper was pushed over to one side, and one corner of the back corner sheet matal was wrinkled.
I could even open the tail gate still.

But the RAM had a split bumper, split grill, and the nose of the hood was split.
And it was pissing green fluid all over the ground.

Yup, it was RAM Tough alright......

I drove away, the RAM was towed.

All of their stuff is built that way.
All smoke & mirrors,
All BS !

 

[gofastgeorge]

By the way, Honda had a hemi-head that had 4 valves.
I think it was one of their 500cc singles.
But the valves were all at different angles, each pointing toward the centerline of the cylinder.

Not sure what they were doing as far as valve train,
but the head looked like it would flow real well.

 

[mk3ukr]

That is one massive intake port, could see it loosing power with something like that. There would be no air velocity with somthing so large.

+1
This hogged out port can flow better on flowbench but for sure loose power in real life because of reduced air velocity.
Good reading from David Vizard
http://www.gofastnews.com/board/technical-articles/1247-porting-school-8-optimal-port-areas.html

 

[TurboStreetCar]

Could the OP please re host the pictures in the thread, they seem to be expired or lost.

Thanks,
Dan

 

[jonahs_supra]

Just got my head ported from Phillips racing
Here are my port pics on the intake and exhaust side(main focus was intake)

 

[MarkIII4Me]

Here's some pretty massive head porting that was done to my current build.