VETDRMS

I've decided to can the nitrous idea, and am instead going with a better pair of heads. I have to keep it under $1000 and am debating between these two pairs of heads. The price difference is ~$100. Would I be better off with the RPM's? They have smaller intake and exhaust ports, but i can run higher compression. If i went with the iron eagles, i would run 9.8:1, and 11:1 with the RPM's. Also the RPM's are good too .575" lift.

Any help would be appreciated.

Thanks :cheers:


[edit] I'm selling the GM 041 64cc Heads Here: http://forums.corvetteforum.com/zerothread?id=472066


[Modified by VETDRMS, 5:15 PM 1/14/2003]

1979toy

I would be inclinded toward the Iron Eagles for a street car, and about one full point less compression with whichever heads you choose. Shoot for 9 to 1 compression ratio with steel heads and 10 to 1 for aluminum with 92 octane pump gas. With any more you are going to have to start backing off the timing or use a camshaft with enough duration to bleed off excess cylinder pressure.

VETDRMS

Thanks, i just like the 50lb weight savings and the extra compression with the RPM's. I currently have a Comp Cams XE268 Cam 224I 230E


[Modified by VETDRMS, 5:16 PM 1/14/2003]

GrandSportC3

The Iron Eagle Heads are some of the best steel heads available.. I have those on my 383/465HP engine.. They outperform the Performer RPM Heads by quite a bit... They are also available with much larger runners.. My heads have 215cc runners... You can go up to 10.2 :1 compression without a problem if you use good gas.. I run approx. 10.2 : 1 compression and run 93 octane pump gas with no problems... (Chevron)

:cheers:

Olivier


[Modified by GrandSportC3, 7:18 PM 1/14/2003]

GrandSportC3

especially if you go with a radical cam - you can go with higher compression... Longer duration cams bleed off some of the compression.. With a mild cam - you shouldn't go higher than 9.7 - 9.8:1 compression...

:cheers:

Olivier

VETDRMS

Oliver Thanks for the heads up! I was wondering what heads you have. What cam are you running? Also, what are the specs on your heads: (valves/valve job angle/porting/springs). Also what intake/carb combination are you running? I would love to even approach 300rwhp with my new setup.
Thanks again. :cheers:

GrandSportC3

Here are the specs on my cam:

Custom solid cam:
Lift: .525/.540
Duration: 238/248 degrees @ .050
107 degrees centerline

The combustion chambers on the heads are ported. (from 64cc to 68cc)
The runners didn't need porting.. Big enough for over 550 HP...
Don't remember the exact part# of the springs.. but they are dual Comp Cams springs

Intake:
Edelbrock Tarantula.. fully ported and matched to intake gasket..
(This is the early version of the Victor Jr. - 3500 - 8000 RPM range single plane intake - looks just like the original Torker.. but with bigger runners) .
I also use a 1/2 inch spacer for a better ram effect..

Carburator:

Holley 80528 - HP series 750 double pumper (drag race carb) with 72 primary and 82 secondary jets.

If you use those heads together with a nice solid cam.. you should easily get above 300 RWHP.. My best dyno run was 365 RWHP.. without reaching peak HP (dyno shut off at 5300 RPM)...

:cheers:

Olivier

69stingray

It is my understanding that heads create torque through port velocity. Which ever head flows more cfm through a smaller intake port. Some of the heads with larger intake ports have nice looking flow numbers but the port velocities are not as high. You have to ask you yourself if your application even needs the extra flow of the Iron Eagle heads. I say go with Edelborck. I think you will get better port velocity and same some weight on the alulminum.

VETDRMS

I am using a comp cams Extreme Energy 268 cam [224I 230E]
I was looking at going with the 180 or 200cc Iron Eagle as this
motor is primarily for the street and to be used with a 2400rpm stall and
dual plain intake.

Thanks :cheers:

GrandSportC3

Here is the direct comparison between my 215cc Iron Eagle and the Performer RPM Head:

I used all the specs of my engine:

IRON EAGLE 215cc:

PERFORMER RPM:


Performance was calculated with DD2000
The Iron Eagle oupterforms the Edelbrock PERFORMER RPM Head by 13 HP..

:cheers:

Olivier



[Modified by GrandSportC3, 11:11 PM 1/14/2003]

GrandSportC3

That's a pretty mild cam (for a performance cam) but pretty good performance for a street cam... I still would go with the 200 cc Iron Eagle heads... just in case if you are planning to upgrade the cam one day.. The 180cc Heads would be fine with this cam.. but - if you want to upgrade the cam later.. you would have to change the heads too..

:cheers:

Olivier

VETDRMS

quote:
--------------------------------------------------------------------------------
It is my understanding that heads create torque through port velocity. Which ever head flows more cfm through a smaller intake port. Some of the heads with larger intake ports have nice looking flow numbers but the port velocities are not as high. You have to ask you yourself if your application even needs the extra flow of the Iron Eagle heads. I say go with Edelborck. I think you will get better port velocity and same some weight on the alulminum.
--------------------------------------------------------------------------------

I understand the application of port velocity vs flow on the street, and this is a concern of mine.

Oliver I was looking at the 180 or 200cc head for my engine. At this level would the benefit of an aluminum head actually be worth using the edelbrocks?

GrandSportC3

Well - if you prefer bottom end torque to top end performance... then the Performer RPM is the better choice.. The Performer RPM shifts the peak HP to a lower RPM and adds a lot of bottom end torque... Both heads are great heads and should work fine for your application.. Even with the Performer RPM and your cam.. you could get to around 400 crank HP and over 300 RWHP... The main advantage of the Perfomer RPM's is of course the weight reduction.. Iron Heads are pretty heavy...

:cheers:

Olivier

VETDRMS

Oliver Its kind of a toss up at the moment. My setup may like the power at the top end offered by the Darts (2400stall/3.70gear) But the added torque and 13hp less offered by the RPM's may be beneficial as well.
The iron eagles are at 52lbs to the RPM's 24lbs, So there is over 50 lbs of weight savings. How much HP is 50lbs worth? I will talk to the local shop about a pair of RPM's, and what machine work they do with them. A complete set is $929 compared to $844 for the Darts.

Smitty's75

Save your money,,if you want a set of heads that will go to 400 HP use the same GM heads they used in the 1970 LT!,,they cranked out 370 HP with them without a real radical solid cam,,everyone seems to forget the potential of the camel hump heads,,except me, and I'm going to save money and still have a decent set of heads for under $500. They're on E-Bay all the time,sometimes at less than $300, just clean em up or replace the springs with higher lift ones if so desired, but remember the LT1 specs are easy to follow and the cam is still available through GM.

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2400230610

Alwyn678

I agree smitty

GrandSportC3

Well - weight savings doesn't increase HP at all.. it improves ET's :D :D
Usually each 100 lbs in savings result in .10 faster ET... Don't know exactly how many hp it takes to decrease the ET by .05 (which would be the approx. improvement with aluminum heads)... I personally like the DART Head, but I've never had the Edelbrocks so I only know what other people tell me about them... Considering that you are not going too radical - I don't think that a .1 - .2 difference on the strip will make a big difference for you.. so I would go with the cheaper heads.. Both heads are good heads for sure...

:cheers:

Olivier

GrandSportC3

That's actually not too cheap... If you get a good set of springs and have them installed.. those heads will end up almost as expensive as the Dart Heads...

:cheers:

Olivier

GrandSportC3

For your application - I actually would actually get following Heads:

WORLD PRODUCTS SPORTSMEN II Heads with 200 cc runners.. They are $100 cheaper than the Iron Eagle 200 cc head and have basically the same performance...

:cheers:

Olivier

VETDRMS

Oliver I know weight has no bearing on HP, I was curious about the needed HP to drop ET by .05. 10 maybe?
Thanks again for your input, I'll consider my options a bit longer. :cheers:
I have 4 months till spring... :(