Just purchased some RPM Heads, need input.

[Sweet5ltr]

I just purchased some 84cc Performer RPM Heads. I know the '440 source' Stealth Heads are a better deal, but I do not knowingly buy any products from China; unless their is no other alternative :angryfire: I don't think I could even look myself in the mirror if I was to buy knockoff Chinese heads and install them under the hood of my AMERICAN MUSCLE CAR!

As far as headflow, these heads have seemed pretty consistent in almost all the major magazines and have flowed 270-278cfm @ .500 and 290cfm @.600. Realistically this is more than enough for ANY street engine (IMO) and could handle an access of 600HP out of the box.

My questions are;
Should I stick with the Performer RPM dual plane for a motor that is only turning 6,000RPM or should I take advantage of the flow and opt for a victor.
Here is a Mopar Muscle intake comparison: http://www.moparmusclemagazine.com/techarticles/mopp_0701_mopar_intake_manifold/photo_21.html

Would buying a set of 1.6 rocker arms be worthwhile, in transferring my .509 mopar camshaft into a .555 lift grind (if my math is correct with 9% increase from 1.5-1.6)? or would the 5cfm increase @ .550 lift with the heads be worth the hassle of going to possible "un-reliable" valve train gear?

How much power can I expect (flywheel) out of a 451, 10.75CR, Performer RPM Heads/Intake Combo, .509/292 camshaft, and a highly modified 750DP Holley? The engine also has less than a thousand miles since being built by CME (balanced, blueprinted, etc.), so its still fresh.

Thank you for any and all input.

 

[wedgie]

I am with you 100% on not buying foreign goods if at all possible.
What heads are you running now and how big are the combustion chambers?
What is your current compression ratio?
The reason that I ask is that I am thinkin about doung the same head swap to my 906 head 496 stroker 9.9:1 ratio. If I can keep the 9.9 with the Eddys, I believe that there will be no further need for premium gas.

 

[IQ52]

I just purchased some 84cc Performer RPM Heads. I know the '440 source' Stealth Heads are a better deal, but I do not knowingly buy any products from China; unless their is no other alternative :angryfire: I don't think I could even look myself in the mirror if I was to buy knockoff Chinese heads and install them under the hood of my AMERICAN MUSCLE CAR!

As far as headflow, these heads have seemed pretty consistent in almost all the major magazines and have flowed 270-278cfm @ .500 and 290cfm @.600. Realistically this is more than enough for ANY street engine (IMO) and could handle an access of 600HP out of the box.

My questions are;
Should I stick with the Performer RPM dual plane for a motor that is only turning 6,000RPM or should I take advantage of the flow and opt for a victor.
Here is a Mopar Muscle intake comparison: http://www.moparmusclemagazine.com/techarticles/mopp_0701_mopar_intake_manifold/photo_21.html

Would buying a set of 1.6 rocker arms be worthwhile, in transferring my .509 mopar camshaft into a .555 lift grind (if my math is correct with 9% increase from 1.5-1.6)? or would the 5cfm increase @ .550 lift with the heads be worth the hassle of going to possible "un-reliable" valve train gear?

How much power can I expect (flywheel) out of a 451, 10.75CR, Performer RPM Heads/Intake Combo, .509/292 camshaft, and a highly modified 750DP Holley? The engine also has less than a thousand miles since being built by CME (balanced, blueprinted, etc.), so its still fresh.

Thank you for any and all input.

If this is ment to be just a raucous street engine, run the PRM Performer intake. The Victor is a nice manifold but will reduce hood clearance by about 3/4".

The 1.6 rockers will increase the lift to .543" and will not reduce reliability. I personally wouldn't run any $250 rockers.

Power? I'd look to see some 500 HP.

 

[IQ52]

I am with you 100% on not buying foreign goods if at all possible.
What heads are you running now and how big are the combustion chambers?
What is your current compression ratio?
The reason that I ask is that I am thinkin about doung the same head swap to my 906 head 496 stroker 9.9:1 ratio. If I can keep the 9.9 with the Eddys, I believe that there will be no further need for premium gas.

What is your current combustion chamber size, 88-90cc? 13cc dished pistons? Deck height? Gasket thickness? What cam are you running? I suspect the head swap would take you to 10.3-10.4:1.

 

[Sweet5ltr]

I am with you 100% on not buying foreign goods if at all possible.
What heads are you running now and how big are the combustion chambers?
What is your current compression ratio?
The reason that I ask is that I am thinkin about doung the same head swap to my 906 head 496 stroker 9.9:1 ratio. If I can keep the 9.9 with the Eddys, I believe that there will be no further need for premium gas.

If society doesn't wake up and realize that we are half the problem by supporting China (walmart, etc.) then we will never get out of this slump we are stuck in. How can we create more jobs and retain our freedoms if we are shutting down American businesses and running sweat shop' induced mega-monopolies. I buy from Edelbrock because they are one of the few companies that proudly still retains their integrity and stayed in the USA.

Just a wildcard guess, somewhere in the 90cc range. They are 73' 243 castings (HD Motorhome) heads that have mild portwork. the engine was pulled from a highway patrol car.

My current compression ratio is 9.8:1, if you were to go with the 88cc version the jump would be minimal if not non existent (if all else remained equal.) their are some great CR calculators if you have all the information from your current build, If you are looking for a precise number. Anywhere under 11.0:1 is (what I've been told) fine to run with pump gas and aluminum heads on today's horrid fuel.

The way the economy is, I don't blame you for wanting to save .30 or more cents a gallon. I have a Z06 corvette that runs premium as well, so I can't seem to get away from it. $4.30 a gallon last night for 93 in Florida.

 

[IQ52]

I am with you 100% on not buying foreign goods if at all possible.
What heads are you running now and how big are the combustion chambers?
What is your current compression ratio?
The reason that I ask is that I am thinkin about doung the same head swap to my 906 head 496 stroker 9.9:1 ratio. If I can keep the 9.9 with the Eddys, I believe that there will be no further need for premium gas.

The heat transfer properties of aluminum do not have the quantities of detonation resistance as normally ascribed to them. You may find, that in Chyrsler aluminum heads, the detonation resistance of the aluminum head comes from the combustion chamber shape rather than heat transfer. The Edelbrock RPM Performer is an aluminum head that can purchased with both open and closed combustion chambers.

Therefore, the closed chamber 84cc head may be a better choice for your purpose rather than the 88cc head which has a combustion chamber shaped like the 906 heads and factory iron heads in later years.

Popular Hot Rodding and HiPerformance Chevy Magazines have done tests on small block Chevy engines using the same cylinder heads in aluminum and iron. With the same compression ratios, combustion chambers and flow rates, there was no difference in detonation resistance or horsepower.