[steve25]

What I can’t see happening which did with the CNC head is that there where pretty big difference's in the levels of flow between exh ports, and at all lifted tested.

The difference’s I feel should have been smaller and at lifts under .400” there really should have been no difference seen in a CNC head between exh ports.

Now in terms of the intake side, it’s a yes to the difference’s if it’s due to there being left and right hand ports.

[Skip Fix]

These are numbers before valve job to just compare to my previous ones on a different bench. I'll post final after valve job, hopefully be done next week.

Gach probably go on a "throw down motor" extra parts for a street/strip type deal. Most of my headers are all round port so I have extras for any of my project cars. The ported 6Xs I have was my first thoughts but no d port exhaust, and they are so freaking heavy. And even out of the box round port E heads flow better! Who knows maybe a bathtub intake and 2 Holleys will end up on it.

[Gach]

Originally Posted by Skip Fix

These are numbers before valve job to just compare to my previous ones on a different bench. I'll post final after valve job, hopefully be done next week.

Gach probably go on a "throw down motor" extra parts for a street/strip type deal. Most of my headers are all round port so I have extras for any of my project cars. The ported 6Xs I have was my first thoughts but no d port exhaust, and they are so freaking heavy. And even out of the box round port E heads flow better! Who knows maybe a bathtub intake and 2 Holleys will end up on it.

That would be kool.

[slowbird]

Originally Posted by Skip Fix

These are numbers before valve job to just compare to my previous ones on a different bench. I'll post final after valve job, hopefully be done next week.

Gach probably go on a "throw down motor" extra parts for a street/strip type deal. Most of my headers are all round port so I have extras for any of my project cars. The ported 6Xs I have was my first thoughts but no d port exhaust, and they are so freaking heavy. And even out of the box round port E heads flow better! Who knows maybe a bathtub intake and 2 Holleys will end up on it.

You know if the same ports in the same head were flowed?

[Skip Fix]

Like this

[Gach]

Originally Posted by Skip Fix

Like this

Yeah I like ! Nice

[PAUL K]

Originally Posted by Skip Fix

Like this

Me too! The Holley's look great.

[Skip Fix]

Those actually are the two Holley 715s ran sideways on my old 409 in high school and IHRA raced in 1972 SMI recolored and put downleg boosters in place of the straights.
Hoping it will fit under the hood of the 65 GTO.

[PAUL K]

Originally Posted by Skip Fix

Those actually are the two Holley 715s ran sideways on my old 409 in high school and IHRA raced in 1972 SMI recolored and put downleg boosters in place of the straights.
Hoping it will fit under the hood of the 65 GTO.

Very cool!

[Skip Fix]

Yea I hang on to car parts for awhile My 409 project motor block is one from back then too.

[Skip Fix]

So i picked the heads up form the machine shop. head guy's comments a pretty good piece flows good(Superflow 1020 was the bench they used).

Bad things -looked like the CNC was done after valve job and on completely concentric with each other. Bowl is too big and left sharp edges and not enough room for a good bottom cut so he just did a mild blending and back cut the valves. He did not feel that would change numbers enough to warrant flowing again. Flow was good enough for 500-550 HP.

Retainers were good but the locks were bad maybe stamped, left a big gap between them on the valve and had a +0.060 offset-maybe why there were so many freaking shims! Switched to good locks zero offset so could drop some of the shims.Set IH at 1.750 to get the seat pressure at 150. Springs have a lot of room before coil bind . Was going to use a seat cup to locate springs better but the pocket OD of 1.6something and the OD of the spring none were available so went tithe an inner spring locator and fewer shims.

[tom s]

Mine have.900 coil bind as I remember

[Skip Fix]

Yea a lot of room Tom.

[Gach]

Originally Posted by Skip Fix

So i picked the heads up form the machine shop. head guy's comments a pretty good piece flows good(Superflow 1020 was the bench they used).

Bad things -looked like the CNC was done after valve job and on completely concentric with each other. Bowl is too big and left sharp edges and not enough room for a good bottom cut so he just did a mild blending and back cut the valves. He did not feel that would change numbers enough to warrant flowing again. Flow was good enough for 500-550 HP.

Retainers were good but the locks were bad maybe stamped, left a big gap between them on the valve and had a +0.060 offset-maybe why there were so many freaking shims! Switched to good locks zero offset so could drop some of the shims.Set IH at 1.750 to get the seat pressure at 150. Springs have a lot of room before coil bind . Was going to use a seat cup to locate springs better but the pocket OD of 1.6something and the OD of the spring none were available so went tithe an inner spring locator and fewer shims.

Good honest information thanks Skip

[Skip Fix]

Anyone CC a chamber yet? Trying to figure potential CR on a 4.151 4" potential build.

[Stan Weiss]

Since there a couple of new threads going about the speed master heads might as well bring this to the top with real user flow information.

Stan

[Steve C.]

Skip's statement: "Springs have a lot of room before coil bind"

This brings up the interesting and related topic.....

How Much Valvespring Coil-Bind Clearance Is Safe?

"About 0.060 inch used to be the textbook safety margin, with more OK and even desirable.
That's still an acceptable standard for everyday performance use, but for cutting-edge setups the "correct" safety margin can vary up or down."

https://www.motortrend.com/how-to/ho...rance-is-safe/



.

[Skip Fix]

To add in this thread cambers CC'd 76.6 for me.