[rohrt]

First I have seen these.

https://www.amazon.com/Speedmaster-P.../dp/B07L27KFTC

[scott70]

Originally Posted by Steve C.

Iron vs. Aluminum Heads

https://www.hotrod.com/articles/ccrp...er-heads-test/


Iron vs. Alloy
Which Heads Are Better? We Test, You Decide

http://www.superchevy.com/how-to/838...-engine-heads/


Don’t Gamble When Choosing Cylinder Heads

https://www.enginebuildermag.com/201...ylinder-heads/

Hot Topic: Iron vs. Aluminum
On the subject of drag race cylinder heads, there’s considerable debate over which material—aluminum or cast iron—provides the ultimate power advantage. Our experts discuss the merits of each.

http://www.performanceracing.com/mag..._aluminum.html



.

There was a 20hp/20 trq. difference between alum and steel.

[70 bird]

Another vote for aftermarket iron head, I have pro topline iron heads on my 351w. They were $700 a pair new with stainless valves. They have seen 20 psi. with my s480 and have been holding the gaskets for about 10 years now.


I also agree with the others about Edelbrock hosing the Pontiac people for too long! Maybe the china heads will get them to take notice.

[taff2]

New iron heads would be good for a high boost combo, better clamp force with 'just' the 10 bolts means less head gasket problems, but I'm rambling-this is the street section.

[steve25]

Aluminum sucks heat ( BTU ) out of a chamber 4 times faster then iron and a expanding hot flame front is what pushes the Pistons down the Bore!

The place you want to dump heat is out of the Intake Manifold where every 20 degree drop in temp means you lower the octane you need to have in your fuel tank by 2 points!

You can then up the compression ratio more if you care to.

This is way you see many times in the engine masters challenges Intake Manifolds that have been cut back a ton do that thick nylon or plastic shims can be used to far better insulate the Intake.

[Steve C.]

Typically, a normally aspirated engine will see a 1% improvement in power for every 10 degree drop in carb air inlet temperature.


.

[Tom Vaught]

Originally Posted by 64speed

I just bought a set of Edelbrock heads worked over by Butler for 2995 plus shipping. I figured that was the best deal I was gonna get. I think Edelbrock is still made in the USA isnt it?

Since they own a aluminum foundry in California and have owned that foundry for over 50 years, I see no reason why Edelbrock would ever think of producing Aluminum Heads anywhere else 64speed, (Like China).

Tom V.

[dataway]

Remember when the "hot" setup was a box to ice down your intake before a run?

[HWYSTR455]

There's a difference between intake temp drops improving power with a wet intake compared to a dry, air-only intake.

So at 1%, on a 500hp engine, that's what, maybe 1/5hp per 10 degrees? so you need to drop 50 degrees to get 1hp improvement? Hm.

Boost, plenty of folks running aluminum head on a Pontiac with boost. Butler's have gone into the 28+ psi range with no issue. Dropping the piston in the hole a little helps.

My previous comment was regarding SCRs with a potential iron head. So, what would the desired chamber volume be for a new iron head? 72cc? And what would the target SCR desired? Dish the piston, and what happens to the dreaded 'quench' factor?

Asking for an iron head is going backwards.

On price. I suspect Edelbrock, when they first considered doing Pontiac heads, were concerned over the size of the market, and profit margins. To design, setup to make, and prepare, a first small run to 'test' the market, is not a small investment. Sure they calculated how many they would have to sell to cover costs, and start making money, and a line in the sand where they would cut & bail. They met the goals to continue producing them, thankfully. But I bet they are still made in smaller runs than other applications, and that is why they probably cost more. It's overhead.

For Chevy heads, they probably just pump them out regularly, and leave the production line setup for them. And occasionally work in production of other heads, where they can 'afford' to reconfig the production line.

I do agree though, having another option or options will help reduce costs of the E-heads.

.

[steve25]

Towels cable tied around your paired Intake runners and then sprayed down with ice water.

[Steve C.]

Another take from a magazine article...'

Anything you can do to enhance cool air flow into the engine will be good for torque and horsepower across the entire rpm band. Remotely sourced inlet air is almost always cleaner and cooler than engine compartment air. Use an aluminum intake manifold with the carburetor exhaust heat passage blocked off. Manifolds with the runners separated from the valley keep the charge cooler. Duct your inlet air from outside the car and keep the ducting insulated from engine compartment heat. Make your inlet ducting at least 4 inches or larger in diameter, and keep the path as short and unrestricted as possible. Be sure to duct the air through a high-flow air filter prior to entering the carburetor or throttle body. These simple modifications can increase torque from 3 to 5 percent, and they will also increase power at high engine speeds due to unrestricted airflow and a cooler charge.


.

[tom s]

Here we go again!First a cheap block,the cheap iron head rears its ugly head again!We have very smart capitalists in our aftermarket hobby.Im sure many have looked at how much is used by our beloved pontiac part of the hobby and figured out there would be no ROI in making either in iron.I hope it happens someday!JMHO,Tom

[HWYSTR455]

Yeah, it's well known cooler intake charges do make more power, and I try to take precautions to help intake charges. What the actual gains are vary, a lot depends on the setup/config.

I've seen guys' times drop off at the track when they don't 'cool down', so that's proof enough for me. And sure the term 'hot lapping' came from somewhere.

.

[Slick]

Originally Posted by HWYSTR455

There's a difference between intake temp drops improving power with a wet intake compared to a dry, air-only intake.

So at 1%, on a 500hp engine, that's what, maybe 1/5hp per 10 degrees? so you need to drop 50 degrees to get 1hp improvement? Hm.

Boost, plenty of folks running aluminum head on a Pontiac with boost. Butler's have gone into the 28+ psi range with no issue. Dropping the piston in the hole a little helps.

My previous comment was regarding SCRs with a potential iron head. So, what would the desired chamber volume be for a new iron head? 72cc? And what would the target SCR desired? Dish the piston, and what happens to the dreaded 'quench' factor?

Asking for an iron head is going backwards.

On price. I suspect Edelbrock, when they first considered doing Pontiac heads, were concerned over the size of the market, and profit margins. To design, setup to make, and prepare, a first small run to 'test' the market, is not a small investment. Sure they calculated how many they would have to sell to cover costs, and start making money, and a line in the sand where they would cut & bail. They met the goals to continue producing them, thankfully. But I bet they are still made in smaller runs than other applications, and that is why they probably cost more. It's overhead.

For Chevy heads, they probably just pump them out regularly, and leave the production line setup for them. And occasionally work in production of other heads, where they can 'afford' to reconfig the production line.

I do agree though, having another option or options will help reduce costs of the E-heads.

.

1% of 500 is 5. So, ~ 5HP/10* on a 500HP engine. If the power gain were linear (and it surely is not) then 50* would equal a 5% or 25HP gain.

[HWYSTR455]

Originally Posted by Slick

1% of 500 is 5. So, ~ 5HP/10* on a 500HP engine. If the power gain were linear (and it surely is not) then 50* would equal a 5% or 25HP gain.

Dyslexia gets me again! Heheh!

.

[azbirds]

I often imagine what it would be like to have an iron head with modern chambers and increased flow, and considering what a set of RA-IV heads cost these days I don't see why a replacement head wouldn't make money. Doesn't everyone want a RA-IV?

[Tom Vaught]

A cast iron Ram Air IV head PORTED by a EXPERT PORTER in the old days (like Butch Elkins of Diamond/Elkins Racing Engines) might flow 300 cfm.

Other porters might hit 280 or 285 cfm but Butch could get that extra 15 cfm out of his ports. A 366 cid Pontiac engine with Elkins heads in 1971 could run mid 10s in a 63 Tempest body.

Today with a light touch-up most porters can get 300 or 310 cfm without a cnc program from a very basic Edelbrock Aluminum head. And there are a Bunch of other heads that will flow a lot more air.

I suppose that there would be Pontiac guys who would want to run 10s with a set of as cast RA-IV Stock Looking Cylinder Heads (especially if they were trying to pass them off as factory originals). Outside of that were is the market?

For the same effort you could cast up Pontiac Cast Iron RA-V heads that would have a lot more potential. but we already have some very good Aluminum RA-V heads out there.

Again the market seems to be already covered on the RA-V .

Tom V.

[Stan Weiss]

I must be missing something here. Yes I know the RAIV head can flow just over 300 cfm when ported. The"E" is a copy of the RAIV head with some improvements and can go 370's cfm when ported. So then why can't an improved cast iron version be able to be ported to the 370's cfm range also?

For a number of people cast iron offers a number of advantages over aluminum.

Stan

[Steve C.]

I don't keep up but it used to be in order to reach 370 cfm it required widening the ports enough that pushrod relocation is required. More difficult with a service replacement iron head design ? Also in doing so some are going to yell the intake runner volume is TOO big !


.

[JLMounce]

I think the idea being thrown around here is basically a service replacement head instead of an iron copy of an e head or the like. Basically people want to be able to buy a set of heads in the 700 range and have them delivered to them, ready to bolt on. Maybe it has a modern chamber and some slight flow improvements, but that's it. Basically the "vortec head" equivalent for Pontiac.

I could see that being a decent seller if it was priced in around 800 for a complete head that had a modern combustion chamber and a slight flow increase over a stock head setup for a HFT cam. Whether there's money in that is another story.

The obvious critique of that is that you can go get any of thousands of heads out there and have them built to suit. This is a barrier to entry though if you're on the fence about chucking your poncho motor for a chebby. This type of person doesn't typically want to go source the correct head he needs, find a shop, have them done etc. It's going to cost more as well.

The guy that wants or needs 300cfm+ flow has plenty of options already.