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john marcella · 11-14-2018, 11:43 PM

Quote:

Originally Posted by Elarson

I'm asking this because I'm curious....not as one of the internet naysayers. Why did you choose this valve arrangement?

I'm obviously a fan of the RA5 layout but I wonder why nobody has gotten really bold and done a fully symmetric valve arrangement for the traditional Pontiac.

Thoughts?

Eric

The IEEIIEEI Is my Personal favorite configuration for a few reasons.

1 . The 4 most outer cylinders, 1. 7 .2 .8 s Runners will all be driving inwards towards the center of the motor eliminating any Architectural problems with bank stagger.

2. The fact that they drive inward will reduce the overall length of the runner as well as make it A more efficient design because it's straighter , But at the same time the center 4 Cylinders drive slightly outward increasing their length with minimal arc In the runner (that is If a single 4 cast Style manifold is used).
If a 2-4 style manifold is used all the runners drive straight directly underneath the carburetors and Are exactly the same length and will have the desired angle leading into the port in the head.

3. With the factory Pontiac lifter bore architecture, The exhaust lifter bores are Further from the cyl center line. This is what we need because of the valve Placement and side cant on the intake side. As the intake valve now uses What used to be the exhaust lift or bore.!

The only downfall is that you end up with 2 Siamese exhaust ports on each bank. However if you have enough chamber rotation it is a complete non issue !!!! and actually has more uniform heat across the head then Pontiac's inline design.
A completely symmetrical port head is a little better as far as heat uniformity. However in my personal opinion is ever so slightly behind in performance Capability and With Pontiacs existing lifter bore architecture it just wouldn't make sense.

slowbird · 11-14-2018, 11:50 PM

Quote:

Originally Posted by john marcella

The IEEIIEEI Is my Personal favorite configuration for a few reasons.

1 . The 4 most outer cylinders, 1. 7 .2 .8 s Runners will all be driving inwards towards the center of the motor eliminating any Architectural problems with bank stagger.

2. The fact that they drive inward will reduce the overall length of the runner as well as make it A more efficient design because it's straighter , But at the same time the center 4 Cylinders drive slightly outward increasing their length with minimal arc In the runner (that is If a single 4 cast Style manifold is used).
If a 2-4 style manifold is used all the runners drive straight directly underneath the carburetors and Are exactly the same length and will have the desired angle leading into the port in the head.

3. With the factory Pontiac lifter bore architecture, The exhaust lifter bores are Further from the cyl center line. This is what we need because of the valve Placement and side cant on the intake side. As the intake valve now uses What used to be the exhaust lift or bore.!

The only downfall is that you end up with 2 Siamese exhaust ports on each bank. However if you have enough chamber rotation it is a complete non issue !!!! and actually has more uniform heat across the head then Pontiac's inline design.
A completely symmetrical port head is a little better as far as heat uniformity. However in my personal opinion is ever so slightly behind in performance Capability and With Pontiacs existing lifter bore architecture it just wouldn't make sense.

That layout is like the Dodge hemi Pro Stock heads, correct?

john marcella · 11-14-2018, 11:57 PM

Quote:

Originally Posted by slowbird

That layout is like the Dodge hemi Pro Stock heads, correct?

Yes sr. A friend of mine named Rick Smith came up with it years ago. Hes the original founder of trick flow.

Elarson · 11-15-2018, 12:05 AM

Interesting stuff, thanks.
Let's hope this thread can stick to solid info like that instead of the usual pointless arguing.

Eric

slowbird · 11-15-2018, 12:22 AM

Quote:

Originally Posted by john marcella

Yes sr. A friend of mine named Rick Smith came up with it years ago. Hes the original founder of trick flow.

Those heads can make some huge power per inch!

JSPONT · 11-15-2018, 08:24 AM

subscribed

grandville455 · 11-15-2018, 09:16 AM

This Sounds Like it's gonna be a Awesome head! But Mainly max effort tho?

Dragncar · 11-15-2018, 02:19 PM

Custom intake, custom headers, sure sounds like max effort. If you are going to do a clean sheet head no reason to go with PMD intake and ex unless you want to tie one hand behind your back.
All the high end heads are big bucks anyway.

Stan Weiss · 11-15-2018, 02:31 PM

John,
With all of the work that will go into this head. Did you ever think about talking to the people who can CNC a Pontiac block about what it would cost to have them change the program and put the lifter bores where you want them?

Stan

wreckmastr · 11-15-2018, 02:50 PM

MHTTFMF

john marcella · 11-15-2018, 03:55 PM

Quote:

Originally Posted by Stan Weiss

John,
With all of the work that will go into this head. Did you ever think about talking to the people who can CNC a Pontiac block about what it would cost to have them change the program and put the lifter bores where you want them?

Stan

I make billet blocks.

john marcella · 11-15-2018, 04:28 PM

Stan, i Really do believe that I can get where we want to go with just offset lifter and existing lifter bore locations. Certainly a little coochie coo in the X direction as well as a slight bank angle change would be preferred but shouldn't be a big deal.
Won't really know for sure until I model everything up.

Stan Weiss · 11-15-2018, 05:09 PM

Quote:

Originally Posted by john marcella

I make billet blocks.

John,
I remember some years ago. I believe you were talking with "LOBES" about your CNC. But I did not know it was large enough to do blocks.

Stan

Gary Kubisch · 11-15-2018, 06:52 PM

Quote:

Originally Posted by john marcella

Yes sr. A friend of mine named Rick Smith came up with it years ago. Hes the original founder of trick flow.

It's been quite a few years, But I visited his shop here in Ohio and got to speak with him for a while.

Small world.

Scott Roberts · 11-15-2018, 08:36 PM

My opinion! John is gonna make this head just to prove a point... dont think he cares if he sells one set of heads... most likely he will sell a couple but that's it...
I say that from personal experiance... I built the funny car in 06 just because .... it cost me a small fortune and a lot of time to say it could be done...
John is way more advanced then I ever was or will be but similar philosophy....

7T2 · 11-15-2018, 09:46 PM

this head will be a casting... right?

Scott Roberts · 11-15-2018, 09:55 PM

Quote:

Originally Posted by 7T2

this head will be a casting... right?

Doubt it.billet only..why cast 2 sets...I get your point rhough...

LiL Jack · 11-15-2018, 10:19 PM

Quote:

Originally Posted by john marcella

Stan, i Really do believe that I can get where we want to go with just offset lifter and existing lifter bore locations. Certainly a little coochie coo in the X direction as well as a slight bank angle change would be preferred but shouldn't be a big deal.
Won't really know for sure until I model everything up.

Hurry up!

john marcella · 11-15-2018, 11:10 PM

Quote:

Originally Posted by 7T2

this head will be a casting... right?

Hell no.
The reality is I expect to make one set for myself and set them on the shelf and let them rot. I'm doing it because I always wanted to make a Pontiac head.

john marcella · 11-15-2018, 11:14 PM

Quote:

Originally Posted by Stan Weiss

John,
I remember some years ago. I believe you were talking with "LOBES" about your CNC. But I did not know it was large enough to do blocks.

Stan

8 months ago I teamed up with Magnetron.
We have 2 5axis 1 4axis Large horizontal pallet changer machine and another 3 axis machine. We do billet heads billet blocks ,we make tooling for castings and so on.....

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