[GTOLou]

Looks like this ends at midnight - midnight, cyber monday, etc.

1114 is shipped - no tax on my order. Pretty crazy.

[74Grandville]

Originally Posted by phil400

I'm not a real player compared to you guys on here but I could see a couple of things holding the sale of these heads back from a street car perspective. And its has nothing to do with who made, quality or whatever.

They are round port, the majority of guys are running d-port, so to run these you're talking new headers as well.

They are only available in 72cc, guys running 455+ cubes with Iron heads and flat tops can't just plop them on now and go and still run pump gas.

Ironically the 72cc heads would be perfect for a 400 but they have big 215cc runners which isn't ideal for anyone still running 400s.

If they had a head with a 215cc runner at 87~90cc
And a 72cc head with a 175cc runner at these prices in d-port, bet they'd sell alot more.

Some theoretical Dyno numbers to consider for a street engine (DD2000 so take it with a grain of salt of course). If i install these heads on the W72 i'm planning for my TA, the numbers look pretty good. Rods are stock with ARP bolts, TRW Forged pistons, and Early crank. The cam might be a little small, but I was hoping the nice chambers and aluminum would make it be OK for Detonation. I will need to swap the springs for Flat tappet.

[maxpowerta]

Originally Posted by phil400

I'm not a real player compared to you guys on here but I could see a couple of things holding the sale of these heads back from a street car perspective. And its has nothing to do with who made, quality or whatever.

They are round port, the majority of guys are running d-port, so to run these you're talking new headers as well.

They are only available in 72cc, guys running 455+ cubes with Iron heads and flat tops can't just plop them on now and go and still run pump gas.

Ironically the 72cc heads would be perfect for a 400 but they have big 215cc runners which isn't ideal for anyone still running 400s.

If they had a head with a 215cc runner at 87~90cc
And a 72cc head with a 175cc runner at these prices in d-port, bet they'd sell alot more.

This poses an interesting question, my intended application for these heads is a 455 with flat top pistons according to the compression calculator on the JBP site a 72cc head on a 455 should come in at around 11.6:1 my thinking is that being aluminum and with careful selection of the cam this should be workable should it not?

[P@blo]

Originally Posted by Murf

Point taken. This is the Street section. I was actually thinking of a Street/Strip setup. Car under 3500 lbs probably 3:73 gears and an OD trans. Still to big?

Thanks
Murf


Sent from my iPhone using Tapatalk Pro

I'm not 100% sure Murf but it port volume does have an impact and always try to put it out there for information purposes. One could probably use the factory as a guideline for compression, transmission, and rear gear ratio in the round port offerings.

A factory D-port intake runner volume is considerably smaller and can get a ported iron port with a runner volume ~170cc has better flow, use a the headers I have and factory bolts. If someone out there is listening offer a efficient cast iron d-port head and you will sell truck-loads but instead we have Pro-Comp Chinese knock-offs of a Edelbrock product that was already available.

[krisr]

Originally Posted by Murf

Is a 215 cc intake port really too large for a 400 + CID engine?
I have seen this posted several times recently.
Are there any builders that have had success with E heads on 400 based engines?

Thanks
Murf

Yes, they work fine even on a heavy street car albeit the combination has to work which is where lots of people fail and start pointing blame. The heavy pig of a car in my signature is a legit 3.75x4.120 400c/i with round port e-heads and a victor intake believe it or not. Still working on going faster too, plus it see's many MANY street miles!

[P@blo]

Physics does not lie and port velocity is an important consideration in head selection on a street driven car. If it's not I'll eat crow and never mention it again. Sometimes this form is more about parts pushing and commerce then it is about information exchange.

[63gpman]

So it has the exact same port size as the E-heads but flows better if I am understanding everything? If that is the case, it has better velocity flow than the E-head, no?

[Bruce Meyer]

Originally Posted by P@blo

Physics does not lie and port velocity is an important consideration in head selection on a street driven car. If it's not I'll eat crow and never mention it again. Sometimes this form is more about parts pushing and commerce then it is about information exchange.

Start eating because it looks like krisr proved you wrong. 11.4 in a street driven heavy car with a 400 is very impressive. When Pontiac engineers wanted a more powerful 400 they made RA4 heads. They had larger ports and no one complained about velocity. Just because a port is larger and flows more air doesn't mean the velocity suffers. Sometimes its just the opposite. Ive seen flow sheets where E-heads had more flow AND velocity than a stock d-port.

[Formulajones]

This question comes up from time to time. 215cc intake runners just isn't a ton of port volume, especially for a 400 cubed engine.

We build small block chevys with 220cc heads, as thousands of other people have, and it actually works very well if the rest of the combination of parts are happy together. Look as LS engines since 1997, and how small those engines are. A few years later GM even went to a 260cc square port intake runner on stuff as small as 364 cubes and look how efficient those engines are. They have a very broad power curve.

Hell I'm running 315cc intake runners on my 454. 100cc bigger runner on an engine that's only 54 cubes bigger than a 400. It has no trouble at all making torque any where in the rpm range.

If it helps answer the other question, starting with a bare set of heads it usually costs me right in the $1,000 range to rebuild. That's new hardened seats, stainless valves, springs, guides, valve job as well as machining for positive seals if the head isn't already equipped to accept it. No porting.

[P@blo]

Fair enough Bruce I have a few good recipes but aren't there just yet.

http://www.superchevy.com/how-to/eng...ons-measuring/

[slowbird]

Runner cc tells you absolutely nothing about port size. Comparing a Pontiac runner cc to a Chevy runner cc is apples to oranges

[Murf]

I know I don’t understand this very well but, Wouldn’t it be very hard to compare port volumes of different heads? I would think the design, physical size and maybe other factors would make a big difference.
I assume a SBC 220cc port would be bigger than a 215cc Pontiac port if they were equalized for length, is that incorrect? If so, wouldn’t the whole intake tract effect velocity? It’s all very interesting but kinda confusing to my old mind.

I have always been a fan of Jim Hand & built a couple engines using his style.
I just read Paul Sandoval’s book & found it very interesting. I enjoy trying to understand all this.

Thanks
Murf


Sent from my iPhone using Tapatalk Pro

[P@blo]

Originally Posted by slowbird

Runner cc tells you absolutely nothing about port size. Comparing a Pontiac runner cc to a Chevy runner cc is apples to oranges

Fair enough but what a comparison from a speed master 215cc port to a ported factory d-port heads? I thought the edelbrock heads were patterned after the factory roundports.

[NeighborsComplaint]

Originally Posted by maxpowerta

This poses an interesting question, my intended application for these heads is a 455 with flat top pistons according to the compression calculator on the JBP site a 72cc head on a 455 should come in at around 11.6:1 my thinking is that being aluminum and with careful selection of the cam this should be workable should it not?

If it were workable, I would think Edelbrock would not be selling 87cc heads for 455 applications.

[Stan Weiss]

Port volume from different makes / manufacture is hard to compare. Even from head to head for the same make / manufacture maybe a problem. If you know the port length then you can using the port volume to calculate the average CSA. Using the average CSA and intake flow (CFM) at different lifts you can average port velocity. All of that said, cam it wrong and it still does not work.

Stan

[RocktimusPryme]

Originally Posted by NeighborsComplaint

If it were workable, I would think Edelbrock would not be selling 87cc heads for 455 applications.

There is always someone who chimes in and says how they ran 13:1 on 87 octane and its all about dynamic compression etc etc.

At the end of the day, while Im sure you could 11.5 to one safely under optimum circumstances, your margin of error gets smaller. You better get the cam perfect, timing perfect, and hope you never catch a bad tank of gas.

Juice isn't worth the squeeze IMO.

[PAUL K]

Originally Posted by RocktimusPryme

There is always someone who chimes in and says how they ran 13:1 on 87 octane and its all about dynamic compression etc etc.

.

LOL!

[72projectbird]

Originally Posted by maxpowerta

This poses an interesting question, my intended application for these heads is a 455 with flat top pistons according to the compression calculator on the JBP site a 72cc head on a 455 should come in at around 11.6:1 my thinking is that being aluminum and with careful selection of the cam this should be workable should it not?

I'm in the same boat.

.060 over 455 with flat tops. I really would like to try a pair of these heads, but the 72cc kills it.

[shaker455]

Originally Posted by 72projectbird

I'm in the same boat.

.060 over 455 with flat tops. I really would like to try a pair of these heads, but the 72cc kills it.

I can help you boys in that dept if you want to go that route

[Sirrotica]

If you want to run small chamber heads on a 455 all you have to do it run dished pistons, I've been using small chamber heads on 455s with dished pistons since the 70s. One advantage of small chamber heads is they usually have a little longer short turn radius, said to help flow.

Detroit adjusted compression 2 ways for years, either piston configuration or the changed the combustion chamber size. Fine tuning was done with head gasket thickness, Pontiac factory head gaskets came in different thicknesses according to how high the intended ratio the factory wanted.