[slowbird]

Originally Posted by Gach

Got a friend I’m doing a 505 for and he’s about ready to pull the tiger. Oh 72 cc chamber Text me if you prefer.

Keep your phone on you, I'm sure Paul will be contacting you very soon.

[Formulajones]

Originally Posted by PAUL K

These are great heads for a serious effort high performance Pontiac. They are copies of what we consider our "standard pushrod location race head". They differ from other commercially available CNC heads in many ways. But what we are most proud of (other than their power producing potential) is the lack of pushrod tubes and head bolt sleeves. For years I've rolled my eyes looking at ported heads that slice away the head bolt boss. The loss of integrity of the casting and potential for sucking oil far out weighs any power gain found from removing the head bolt boss. The pushrod tubes are almost always in the way of the pushrod or a shop installs a tube that is excessively large and reduces the CSA area at a critical point. These heads have made over 800 horsepower on stock block builds and have run 5.0 in the 1/8 on a 3300 lbs. street driven nitrous car.

The port volume is close to 250 cc.

Port window has been optimized to work with a Victor manifold.

That's a modified cast 72 CC chamber in the picture. We have done these heads with the Edelbrock CNC chamber and 87 CC ports. Valve size can be varied per application.

Delivery times are a mess due to parts availability, folks not wanting to work and the people that are willing to work being over loaded.

Been wanting to order a set from you for quite a while Paul, disguised as a stock head of course But I know you've been busy with your move and talk of maybe semi retiring. Hopefully this supply chain garbage gets turned around soon and we can get back to maybe a little bit of normality.

[Stan Weiss]

Originally Posted by PAUL K

These are great heads for a serious effort high performance Pontiac. They are copies of what we consider our "standard pushrod location race head". They differ from other commercially available CNC heads in many ways. But what we are most proud of (other than their power producing potential) is the lack of pushrod tubes and head bolt sleeves. For years I've rolled my eyes looking at ported heads that slice away the head bolt boss. The loss of integrity of the casting and potential for sucking oil far out weighs any power gain found from removing the head bolt boss. The pushrod tubes are almost always in the way of the pushrod or a shop installs a tube that is excessively large and reduces the CSA area at a critical point. These heads have made over 800 horsepower on stock block builds and have run 5.0 in the 1/8 on a 3300 lbs. street driven nitrous car.

The port volume is close to 250 cc.

Port window has been optimized to work with a Victor manifold.

That's a modified cast 72 CC chamber in the picture. We have done these heads with the Edelbrock CNC chamber and 87 CC ports. Valve size can be varied per application.

Delivery times are a mess due to parts availability, folks not wanting to work and the people that are willing to work being over loaded.

Paul,
What bore size was used for the numbers Brian posted?

Stan

[Dragncar]

Originally Posted by slowbird

I have been looking for cnc heads to put my dad's GTO back on the street. And decided to go with Paul Knippens cnc version. Very nice looking and have proven performance. Hoping for well over 700hp on 92 octane. With the parts we have plus these new heads.

Heads like these were what I had in mind in a earlier comment about being more than good enough to do what I want to get done and not dealing with any fitment issues like the High Port. Brake boosters, wiper motors ect.
The flow numbers are almost exactly the same as my High Ports.
I think he is going to sell more of these.

[PAUL K]

Originally Posted by i82much

do you have a different program for someone that wants to run a T2, RPM, or Northwind?

We don't have a CNC program for the smaller heads, all those get done the old fashion way. The Torker II and RPM need a considerable amount of work to keep up with our 318 cfm heads, the Northwind would be a better choice.

[PAUL K]

Originally Posted by Stan Weiss

Paul,
What bore size was used for the numbers Brian posted?

Stan

Hi Stan, 4.25

[Stan Weiss]

Originally Posted by PAUL K

Hi Stan, 4.25

Paul,
Thanks. I know even shops that do a lot of head porting still have a limited number of bore sizes. With that bore size I would guess they will lose very little or nothing flow wise on a 455 +30 or +60.

Stan

[Steve C.]

head flow vs. bore size

https://www.yellowbullet.com/threads...e-size.615123/



.

[PAUL K]

Originally Posted by Stan Weiss

Paul,
Thanks. I know even shops that do a lot of head porting still have a limited number of bore sizes. With that bore size I would guess they will lose very little or nothing flow wise on a 455 +30 or +60.

Stan

Very little Stan. If we set everything up there is almost no flow loss with a 2.11 valve on a 4.185 bore.

[blueghoast]

Originally Posted by PAUL K

Very little Stan. If we set everything up there is almost no flow loss with a 2.11 valve on a 4.185 bore.

Can you do this with a Speedmaster head also and maybe a 2.19 valve
I've got a set of bare heads is why I'm asking.

GT

[PAUL K]

Originally Posted by blueghoast

Can you do this with a Speedmaster head also and maybe a 2.19 valve
I've got a set of bare heads is why I'm asking.

GT

Possibly, we are going to look into that as soon as we get our heads (the other heads) above water. Valve size is not an issue.

[i82much]

Originally Posted by PAUL K

We don't have a CNC program for the smaller heads, all those get done the old fashion way. The Torker II and RPM need a considerable amount of work to keep up with our 318 cfm heads, the Northwind would be a better choice.

Thanks!

[slowbird]

Got the heads from Edelbrock, now I just need to get the cnc program ran on them.
If anyone is interested the supplied valves and springs (hyd roller) along with related parts from Edelbrock will be up for sale soon.

[Cliff R]

"Why not use the heart shaped Eddy chamber versions?"

Early Edelbrock round port heads used the wider "bathtub" chambers and in heavily ported versions made great power.

I was involved with several engine builds that made over 730hp with that style combustion chamber and around 330cfm intake flow.

The smaller heart shaped chambers have a slight advance with combustion efficiency and a good choice for lower HP builds at higher compression ratios on pump gas, but when you start moving a LOT of air laying back the combustion chamber and unshrouding the valves proves to be a better choice in the big scheme of things......IMHO......

[PAUL K]

Both chamber designs have their place. Both chamber designs are "good enough" to make over 1k HP NA. Best bet is to choose the chamber design that will work best for your application. However due to the Covid debacle and other reasons sometimes one has to choose between using what's available or sitting on the sidelines and waiting.

[Cliff R]

Ya, it's probably tit to tat with these high HP pump gas "street" engines.

Even so, WAY back when KRE released the aluminum "D" port heads I built one of the test engines for them. It was 10.5 to 1 compression and used the Crower 60919 cam.

It made 502hp/467tq on the dyno with peak HP around 5500-5600rpm's nearly as I can remember.

A few months earlier I built and dyno'd a near identical engine with Edelbrock round port heads. I'll add here that neither the KRE or Edelbrock heads were ported in any way, but I did have to mill quite a bit off the Edelbrock heads as they showed up with 92cc chambers instead of 87cc.

The 455 with Edebrock heads cranked out 505hp/551tq with peak HP at 5100rpm's. The intake ports as cast in the Edelbrock round port heads are notable larger than the KRE's. So with more port flow you'd think it would not only make more HP but it would be at higher RPM's.....hum?

The other main difference in those engine builds and head were the combustion chamber shapes. The Edelbrock using the large "bathtub" chamber variety and the KRE's using more of a "heart" shaped chamber. About all we got out of the testing was that more port flow and bigger chambers was good for a few more peak HP, but made less torque and average power than smaller runners with the heart shaped chambers.

Of course completely different builds that what is being described here but obviously combustion chamber shapes play a role in power production (torque) with these engines.....FWIW.....

[Steve C.]

The KRE dyno sheet for the engine Cliff refers to in the above post:

https://pontiacstreetperformance.com...455MikeG2.html

Engine specs for it:

https://pontiacstreetperformance.com...d455MikeG.html


.

[Cliff R]

Thanks Steve. I knew I was off a tad on the numbers but having bad cases of CRS these days and even worse cases of DGS (Don't Give a Sh*t)......LOL....

[AG]

Originally Posted by Cliff R

"Why not use the heart shaped Eddy chamber versions?"

Early Edelbrock round port heads used the wider "bathtub" chambers and in heavily ported versions made great power.

I was involved with several engine builds that made over 730hp with that style combustion chamber and around 330cfm intake flow.

The smaller heart shaped chambers have a slight advance with combustion efficiency and a good choice for lower HP builds at higher compression ratios on pump gas, but when you start moving a LOT of air laying back the combustion chamber and unshrouding the valves proves to be a better choice in the big scheme of things......IMHO......

A few reasons in my opinion. Less timing needed to make the same power and better flame propagation. But, my race motor has the old bathtub style Eddy chamber and MAKES 700 Hp with a small roller cam.

[rohrt]

Originally Posted by Cliff R

Ya, it's probably tit to tat with these high HP pump gas "street" engines.

Even so, WAY back when KRE released the aluminum "D" port heads I built one of the test engines for them. It was 10.5 to 1 compression and used the Crower 60919 cam.

It made 502hp/467tq on the dyno with peak HP around 5500-5600rpm's nearly as I can remember.

A few months earlier I built and dyno'd a near identical engine with Edelbrock round port heads. I'll add here that neither the KRE or Edelbrock heads were ported in any way, but I did have to mill quite a bit off the Edelbrock heads as they showed up with 92cc chambers instead of 87cc.

The 455 with Edebrock heads cranked out 505hp/551tq with peak HP at 5100rpm's. The intake ports as cast in the Edelbrock round port heads are notable larger than the KRE's. So with more port flow you'd think it would not only make more HP but it would be at higher RPM's.....hum?

The other main difference in those engine builds and head were the combustion chamber shapes. The Edelbrock using the large "bathtub" chamber variety and the KRE's using more of a "heart" shaped chamber. About all we got out of the testing was that more port flow and bigger chambers was good for a few more peak HP, but made less torque and average power than smaller runners with the heart shaped chambers.

Of course completely different builds that what is being described here but obviously combustion chamber shapes play a role in power production (torque) with these engines.....FWIW.....

Am I reading this correctly.
KRE D port = 502hp/497tq @5300 heart" shaped chamber
Edelbrock 505hp/551tq "bathtub" chamber Larger cast intakes

It doesn't seem like the Heart shaped chamber did much at all. But you did say they were completely different builds.