[PONTIAC DUDE]

Awesome looking heads. Will be watching your results.

Hummmmmmmmmmmmmmmmmmm.

[Jim Robertson]

Decided intake and exhaust valve size on this set will be 2.150" and 1.720" respectively. With valves installed there is .177" between the valves. Valves are 5.750" long with a .250" tip length to obtain an installed height of 2.000"

The spring seat opening is 1.648" diameter. The thinnest place on the intake port is the machined spring seat. As best I can measure the thickness is a relatively consistent .090". Will have to be careful on the extensively ported models.

Did pour the intake mold tonight. Intake port volume is right at 350ccs as delivered with no pushrod tube and just enough seat to seal the 2.150" valve.

[Gach]

Wow! .090 that's pretty thin. So is a 2.250 intake valve out of the question

[slowbird]

Originally Posted by Gach

Wow! .090 that's pretty thin. So is a 2.250 intake valve out of the question

What does .090 thickness at the spring pocket have to do with valve head size?
Jim how deep are the pockets machined?

[johnta1]

I take it as the thickness from the port to the seat.
The port itself can't be enlarged more that .090"

The seat diameter won't affect the port?

[Gach]

The spring seat opening is 1.648" diameter. The thinnest place on the intake port is the machined spring seat. As best I can measure the thickness is a relatively consistent .090". Will have to be careful on the extensively ported models.

That's pretty thin. Good luck

[Jim Robertson]

Pics of the port mold attached. The lighter colored mold in the last photo is a ported iron Ram Air V.

Lots of good spring choices to fit within the 1.648" spring pocket. No worries. Pocket depths on these are vary between .119" to .150" as measured from the as cast surroundings.

Any enterprising machinist could install a 2.350" diameter intake valve. Lynn tells me the port wall thickness is generous so creating a port that supports the big valve is a possibility. 2.400" - 2.450" intake valve sizes are being discussed here.

[Gach]

Did pour the intake mold tonight. Intake port volume is right at 350ccs as delivered with no pushrod tube and just enough seat to seal the 2.150" valve.

My e-heads have 2.250 intake valve.

[Gach]

Going to be very interesting to see when that push rod go's though the center of that intake port. How it effects port flow. I'd like to know how they resolved that problem from the original iron castings. I remember Daran Morgan work on the old Ram V heads and his findings.

[SLICK1]

Originally Posted by Jim Robertson

Just unboxed a set V heads from McCarty Racing. Very interesting pieces. These will change the complexion of the Pontiac racing community...

These arrived very well packaged and came with seats and guides installed.

Observations as delivered:
Outward appearance - Casting quality is very good with very, very minimal flaws and no porosity noted on machined surfaces.

Machine work also appears to be of very good quality with nice finish work. Note at this point I have not actually bolted them on a block yet.

Intake ports measured just a tick over 2.15" diameter :-)

Intake flange is raised just a tick over .65" from the valley cover edge :-)

Intake throat dia is 1.935"; Exhaust throat dia is 1.489" :-)

Combustion chambers measured +4.270" across

Valve cover rail is angled 14 degrees compared to the stock Pontiac 20 degree angle as measured from the deck. It appears the outer portion of the valve cover rail is approximately .390" higher than an uncut E head...FYI just in case you want to run your power brake booster. :-)

Two oil drain back holes positioned adjacent to what would be #2 and #4 (or #3 and #5) exhaust valve spring pocket.

No pushrod holes drilled for either exhaust or intake.

Port work appears very nicely crafted with generous widths and short turn radiuses on both intake and exhaust. :-)

More to follow on flow volumes and miscellaneous

Jim

Thanks Jim for all the technical insight and pictures and We all can't thank Lynn enough for Giving Us even more room and options for advancement as well as Renewing the intrest and obtainability of the Legendary Ram Air V Head! (and in aluminum no less)

[tom s]

Lou,the push rod thru the port does not seem to hurt much on engines in the sub 8000 range.Over 7K im told the foils help.I think if you were going to build a prostock type 10K rpm engine that a port without it would be better.My pump gas engine seem to make equal HP as any other head with the same flo numbers and CR.Maybe Jim will comment.Tom

[Jim Robertson]

We will find out soon enough on the impacts of the intake pushrod tube. Lynn tells me an 8 - 10 cfm loss with tube (no air foil) compared to without any tube on the aluminum heads. Seems very logical numbers at this point but why test with out a tube?

I have heard the same rpm numbers as Tom described in the first two sentences of post #31 as it pertains to airfoil advantages versus just the round tubes. Our source is likely the same. :-)
Scarcity, rarity and value of the iron heads will likely keep the masses from ever confirming the hearsay. Maybe we can confirm this on the Alum heads...

Additional surface area in the intake runner would seem to be a fuel magnet possibly causing additional fuel separation...an operating RA V design has to have at least a tube so for max performance we will need to test/analyze results/adjust...and repeat as necessary...similar to all other new heads.

[Gach]

Good point Jim...look forward to your results.

[tom s]

Jim,when my alu heads get done,I will pull the iron heads off my alu block and send you one.They are bone stock with foils.You can flo without a tube,with a tube and with a foil and we might learn something.Dont know if you can figure out how they would act at RPMs.Maybe port speed?Tom

[BruceWilkie]

Originally Posted by Jim Robertson

The thinnest place on the intake port is the machined spring seat. As best I can measure the thickness is a relatively consistent .090". Will have to be careful on the extensively ported models.

Is that really enough support for a hefty roller spring? I know spring cups will help spread the load, but it just seems thin. Especially if the port beneath it gets massaged a tid.

On the subject of pushrod tubes and airfoils it seems possible to design an airfoil that could help lower rpm applications too.

Other than the spring support I question, this head looks to be a real nice piece. With the equally spread exhaust ports plus the port volume capacity it sure looks like a great piece for power adder cars.

BTW isnt that valve cover angle/height similar to the 55-64 heads? I know for sure a 55-60 valve cover rail is alot higher above the deck than 65 up.

When the time comes it is going to be a very tough decision for me between these or CV1's. I'll be following the development of these too.

20 years ago who could have dreamed we would have so many choices.

[bad69bird]

Tom and Jim good luck with your project!

[Jim Robertson]

Hope it is clear that the spring seat is not parallel to the roof of the intake port and thus the .090" spot is a very small fraction of the spring's load bearing surface. It would be nice if we had a cross section of this area.

Lynn, Do you have a design section through this area or a sacrificial head that could be cut to show the dimensions in this area?

[65nss4spdGTO]

Jim,

Good luck with your testing. I remember as a kid when I asked my dad why he didn't have a Ram Air V engine in his race car , he had two answers:

1. You have to know the right people to get those kind of parts.

2. We couldn't offered it anyway.

Calvin Hill
Hill Performance
708-250-7420

[TIN TIGR]

exciting times for pontiac folks...

[Slick]

Originally Posted by Jim Robertson

We will find out soon enough on the impacts of the intake pushrod tube. Lynn tells me an 8 - 10 cfm loss with tube (no air foil) compared to without any tube on the aluminum heads. Seems very logical numbers at this point but why test with out a tube?

Early on, Lynn mentioned the possibility of developing an overhead cam setup with these heads. Maybe that's the reason to determine air flow without the tubes?

Stuart