[Aaron Quinton]

Thanks. I finished mine by hand as well. The CNC path left .005-.006" deep grooves in the rough chambers which I also removed. I would have that a 2x difference in surface area of the chamber would matter at running temps.

Originally Posted by john marcella

The finish on my whole head is a cutter finish done by hand not cnc. IMO polishing is just a waste of time.

[Aaron Quinton]

Now that's a fair point. The grooves will give little flow eddies which would help keep the air attached to the chamber as it flows into the cylinder. That would show up on a flow bench if it helps.

Originally Posted by David Holmberg

Damn that's impressive.

The grooves have to influence the outer boundary of air, giving at least a small amount of direction. It may be nothing, or it may be an unintended consequence that proves positive.

[David Holmberg]

I did forget to mention they moved the spark plug slightly too, overall should be a nice improvement for the old E-head.

[john marcella]

Originally Posted by Aaron Quinton

Thanks. I finished mine by hand as well. The CNC path left .005-.006" deep grooves in the rough chambers which I also removed. I would have that a 2x difference in surface area of the chamber would matter at running temps.

Mine were finished by hand cuz I made many changes to everything after I made the motor a 521. So basically they are a hand ported set of heads at this point.

It had nothing to do with removing tool path step over. Waste of time. But if it gives you a warn fuzzy feeling, go at it.

[Half-Inch Stud]

Originally Posted by David Holmberg

Aaron, my guess is the grooves help with the swirl.

Chamber grooves helping with wet flow too?

By looking; I like how the Heart Chamber keeps the plug free from wet fuel.

[john marcella]

Where the hell do you guys get this stuff ?

[Tim Corcoran]

I have a set of 72cc eheads that were cnc ported by SD a few years back. During a freshen up I had the ports polished just to remove the tool marks nothing more. Heads were flowed before and after, picked up 3 cfm intake and 4 exhaust. Car picked up a few .01's and a little MPH also. I know everyone says to leave the tool marks but sometimes I don't listen. In this case I am glad I didn't.

[ponjohn]

Originally Posted by Tim Corcoran

I have a set of 72cc eheads that were cnc ported by SD a few years back. During a freshen up I had the ports polished just to remove the tool marks nothing more. Heads were flowed before and after, picked up 3 cfm intake and 4 exhaust. Car picked up a few .01's and a little MPH also. I know everyone says to leave the tool marks but sometimes I don't listen. In this case I am glad I didn't.

Plus Dave has his own new comb chamber tool path.

[Tom Vaught]

Dave B is kicking out some very good parts.

Tom V.

[Chad Speier]

I back to backed a fully ported manifold with smooth finish vs totally burr finished at the race track. Done the work in the guys trailer. Put it back on and made more hits.

All my stuff is finished in burr. Including fabricated stuff. Finished many heads in burr only.

The biggest issue I've had is people calling me lazy because I didn't spend another 2 hours making it pretty.

[Ken Criss]

Originally Posted by Chad Speier

I back to backed a fully ported manifold with smooth finish vs totally burr finished at the race track. Done the work in the guys trailer. Put it back on and made more hits.

All my stuff is finished in burr. Including fabricated stuff. Finished many heads in burr only.

The biggest issue I've had is people calling me lazy because I didn't spend another 2 hours making it pretty.

Chad that's because you tested both ways but you can't tell armatures anything they know it all and smooth is pretty and got to be faster. Good job

[mike leech]

Marcella has cutter finished my junk for years.....LOL

[77 TRASHCAN]

Originally Posted by 900HP

A lot smaller too so no big domes needed. 52cc as I recall?

Keep hi-jacking, we'll all live!!! LOL
I think Kaase's chambers were 37cc's in 2005???
I want to know about the headers you fabricated, your self...
Those are tri-Y's ??? I can't easily see a collector???
Tell us more, if you wish,
Thanks again for your contributions!!!
Jeff

[900HP]

Originally Posted by 77 TRASHCAN

Keep hi-jacking, we'll all live!!! LOL
I think Kaase's chambers were 37cc's in 2005???
I want to know about the headers you fabricated, your self...
Those are tri-Y's ??? I can't easily see a collector???
Tell us more, if you wish,
Thanks again for your contributions!!!
Jeff

You can read a lot about it here: http://forums.maxperformanceinc.com/...d.php?t=740238

and Popular Hot Rodding did a very nice article on it in the August 2014 issue (currently on newsstands but hard to find)

[77 TRASHCAN]

I've got the PHR magazine, the last one...I guess ever...and have read the thread.

The end of the collector looks like about 2-2.5" dia...LOL

I've seen Tri-Y headers on a successful pontiac stock elim. car recently, close to what you guys made, but they appeared to go more for the equal length effect...
Thanks for the attitude adjustment on what size primaries, HAVE to be...LOL

My good friend, and other racing 71-72 GTO stockers (in the early 80's)(specifically 455 HO's) found out that when they decreased the primary tube sizes, the cars went faster...Hmmm.
Thanks again

[ponjohn]

PHR is done?

[900HP]

Originally Posted by 77 TRASHCAN

I've got the PHR magazine, the last one...I guess ever...and have read the thread.

The end of the collector looks like about 2-2.5" dia...LOL

I've seen Tri-Y headers on a successful pontiac stock elim. car recently, close to what you guys made, but they appeared to go more for the equal length effect...
Thanks for the attitude adjustment on what size primaries, HAVE to be...LOL

My good friend, and other racing 71-72 GTO stockers (in the early 80's)(specifically 455 HO's) found out that when they decreased the primary tube sizes, the cars went faster...Hmmm.
Thanks again

Headers are 1 3/4" step to 1 7/8" primary tube with 2 1/8" secondary tube. The collector choke is 2 1/2" tapering out to 3". All lengths were within an inch of target. Not shown in the photos are the 3" collector extensions we used, I *think* they were 11" long..... Not mentioned in the article was the 8" of crankcase vacuum we could pull with the pan-evac setup

[900HP]

Originally Posted by ponjohn

PHR is done?

Deceased. PHR and High Performance Pontiac along with 10 other magazines have been absorbed into other rags. PHR and HPP become part of Hot Rod Magazine now. Those with subscriptions to PHR and HPP will get a Hot Rod subscription instead to finish out the contract. That is how I understand it.

[900HP]

Originally Posted by 900HP

Headers are 1 3/4" step to 1 7/8" primary tube with 2 1/8" secondary tube. The collector choke is 2 1/2" tapering out to 3". All lengths were within an inch of target. Not shown in the photos are the 3" collector extensions we used, I *think* they were 11" long..... Not mentioned in the article was the 8" of crankcase vacuum we could pull with the pan-evac setup

Here they are semi-finished

[AC445]

I'm trying to get more info on these heads. I called edelb. but tech couldn't tell me the distance from the top of the seal to the bottom of the retainer. Tech said the valves would handle 650# open solid roller springs. any thoughts?