New heads?

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tony20110

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I have a 360 bored .30 over. I’m at about 385 hp at the fly. I’m not trying race but i would like a little more power so I’m looking at replacing my J heads. What aluminum heads should I consider. Indy? Edelbrock? Brodix?
 
If it was mine I'd work j heads of not already done. I'm not a fan of aluminum heads. I like original stuff.
 
Just curious.... on what are you basing your HP number? I'd guess you have the J heads ported some to get to 385....I ask because if you want more and are starting at a true 385, then you're gonna want to step

  1. Indy with 2.02" (Indy's are iron) and Edelbrock Performers are the next likely step up with rocker's similar to what you have.
  2. Then heads like the W series (iron) and Edelbrock Victors.
You can look at the Hughes site and see a lot of different flow tables for different SBM heads to get an idea of where these are in the 'pecking order' of flow. This is for comparison.... I would not take the HP number presented there as gospel.
 
I have a 360 bored .30 over. I’m at about 385 hp at the fly. I’m not trying race but i would like a little more power so I’m looking at replacing my J heads. What aluminum heads should I consider. Indy? Edelbrock? Brodix?
Where are you located?

I'll port up the power for 400.00
 
Just curious.... on what are you basing your HP number? I'd guess you have the J heads ported some to get to 385....I ask because if you want more and are starting at a true 385, then you're gonna want to step

  1. Indy with 2.02" (Indy's are iron) and Edelbrock Performers are the next likely step up with rocker's similar to what you have.
  2. Then heads like the W series (iron) and Edelbrock Victors.
You can look at the Hughes site and see a lot of different flow tables for different SBM heads to get an idea of where these are in the 'pecking order' of flow. This is for comparison.... I would not take the HP number presented there as gospel.
Stock factory valve job 2.02 j heads are worth 400 hp no problem. These heads he has , well lets hear the valve size and who did the porting along with numbers..m
 
Stock factory valve job 2.02 j heads are worth 400 hp no problem. These heads he has , well lets hear the valve size and who did the porting along with numbers..m

Wait! You know nothing of the build or cam he is running. He should post about the engine and cam specs following your idea.


FYI
If you switch to aluminum, they suck heat outta the chambers, dropping your EFFECTIVE compression ratio.The usual cure is more cylinder pressure.
Maybe you already know this.
That’s BS as already tested and proven differently.
 
I have a 360 bored .30 over. I’m at about 385 hp at the fly. I’m not trying race but i would like a little more power so I’m looking at replacing my J heads. What aluminum heads should I consider. Indy? Edelbrock? Brodix?
Please post up your engine combination. Compression ratio, intake, carb, cam specs @.050, header/exhaust size, etc...
Also your rear gear ratio and tire size and if an auto, what stall converter your running.

As said before, the next head in terms of Horse power potential would be iron eq heads, Edelbrock aluminums.
 
I spent a lot of time comparing heads flow numbers at
Shady Dell Speed Shop
I swung all this on a very budget minded approach. So dont get me on a high dollar shelf.

I jumped on a pair of iron w2 heads when I stumbled on them and never regret it.
I ported them myself and the torque made my throat go out my butt.
Next I looked at w9s but didnt want to get into custom everything. I would love a pair but I cant justify the cost yet.

I would not use an edelbrock aluminum head as they are a step backwards from your current j heads. My thoughts are by the time you work the edelbrock to perform you could of easily went with a uncut w2 head.
Yes everyone says the w2s are expensive because of the one off stuff. But you will likely get new rockers for your edelbrock heads and maybe buy new headers anyways.

I never went down the road of any other cast iron head.

I stumbled on a pair of aluminum indy 360-1 heads a year ago. I had them ported. Had to get the bigger tti headers because the exhaust ports were huge. I have yet to get to a track to test but it sure as hell flies.

I honestly would not play with anything else and jump into w2 heads. The cost up front sucks but if you could swing it you will be a few seasons ahead of the competition.
 
FYI
If you switch to aluminum, they suck heat outta the chambers, dropping your EFFECTIVE compression ratio.The usual cure is more cylinder pressure.
Maybe you already know this.

That’s BS as already tested and proven differently.

Ok, say I believe you.......
So
how come I can run near 200psi on 87E10 with no detonation?
Whereas with iron, the limit is down around 160/165
Both at WOT/optimum timing, and otherwise identical
 
Last edited:
I spent a lot of time comparing heads flow numbers at
Shady Dell Speed Shop
I swung all this on a very budget minded approach. So dont get me on a high dollar shelf.

I jumped on a pair of iron w2 heads when I stumbled on them and never regret it.
I ported them myself and the torque made my throat go out my butt.
Next I looked at w9s but didnt want to get into custom everything. I would love a pair but I cant justify the cost yet.

I would not use an edelbrock aluminum head as they are a step backwards from your current j heads. My thoughts are by the time you work the edelbrock to perform you could of easily went with a uncut w2 head.
Yes everyone says the w2s are expensive because of the one off stuff. But you will likely get new rockers for your edelbrock heads and maybe buy new headers anyways.

I never went down the road of any other cast iron head.

I stumbled on a pair of aluminum indy 360-1 heads a year ago. I had them ported. Had to get the bigger tti headers because the exhaust ports were huge. I have yet to get to a track to test but it sure as hell flies.

I honestly would not play with anything else and jump into w2 heads. The cost up front sucks but if you could swing it you will be a few seasons ahead of the competition.

I’ll second that. An as cast W2 (or W5) outflows most ported OE heads. Ported W2’s (&W5’s) are capable of 600+ HP.
Rocker gear cost is the draw back. But it is much better. Used intakes are available inexpensively.
A Indy 360-1 or -2 is the other option.
Many are eagerly awaiting the Trick Flow small block head. The early reports about them look promising.


Ok, say I believe you.......
So
how come I can run near 200psi on 87E10 with no detonation?
Whereas with iron, the limit is down around 160/165
Both at WOT/optimum timing, and otherwise identical
AJ, do the test yourself. I did the iron J to Edelbrock head swap. Never looked back. Remember, Squeeze his squeeze.
I started with a zero deck .030, 360. The J heads ratio was 9.8-1. 72 cc’s. Swapped on a Edelbrock 63cc head. Same fuel, went faster, no other changes, no problems.
 
I dont have to know, and I mentioned it in a way as such to point that out.

Still the cam is tiny or the heads dont flow.
 
Go aluminum..and don't look back we use iron heads for "doorstops" around here!!
 
FYI
If you switch to aluminum, they suck heat outta the chambers, dropping your EFFECTIVE compression ratio.The usual cure is more cylinder pressure.
Maybe you already know this.

AJ, do the test yourself. I did the iron J to Edelbrock head swap. Never looked back. Remember, Squeeze his squeeze.
I started with a zero deck .030, 360. The J heads ratio was 9.8-1. 72 cc’s. Swapped on a Edelbrock 63cc head. Same fuel, went faster, no other changes, no problems.

FWIW and IMHO..... The above 2 posts are apples and oranges.
  • Hotter iron chambers make more cylinder pressure inside (prior to the start of combustion)? Yes. But that value of cylinder pressure is not 'compression ratio'. It reflects both compression heating, AND the absorption of heat from the chambers, which are 2 independent contributors to the heating of the mixture.
  • The effects of cylinder pressure on torque/HP all depends on the difference between the starting and ending pressure during the combustion and power stroke cycles, not by the absolute numbers themselves.
  • More HP? Not just based on a different cylinder pressure (piror to combustion) by itself. I agree, I've looked and looked for definitive results showing a difference going from iron to AL and have found none published; the trick in such testing is to always make the other factors identical.
  • BTW, RF, your positive experience with the head swap does not zero in on the exact cause of the difference you found unless you flowed both heads and found them identical. I'd guess you got some benefit from flow (but that is truly a guess); but you certainly got some benefit from more efficient combustion (partly from the higher CR, and partly from the smaller chambers), better cylinder clearing, and better extraction of power at the higher CR due to a bigger start-to-end pressure difference.)
I'd change AJ's statement to say that, rather than 'curing' anything, the cooler AL heads ALLOWS more CR without getting into detonation. AL heads widen up the operating range for CR and cam selection by reducing an undesired factor in the engine operation (extra mixture heating during compression).
 
Ok, say I believe you.......
So
how come I can run near 200psi on 87E10 with no detonation?
Whereas with iron, the limit is down around 160/165
Both at WOT/optimum timing, and otherwise identical
You tested identical heads? Both in exact design and combustion chamber shape, except one was aluminum and the other iron? What were those heads?
 
AJ, do the test yourself. I did the iron J to Edelbrock head swap. Never looked back. Remember, Squeeze his squeeze.
I started with a zero deck .030, 360. The J heads ratio was 9.8-1. 72 cc’s. Swapped on a Edelbrock 63cc head. Same fuel, went faster, no other changes, no problems.

IMO
Poor test
for a streeter.
First; because the smaller chamber Eddies jumped your compression up a full point, compensating for some of the heat loss,and so not an apples to apples comparison. And,
Second; because at WOT, for 11/12 seconds the heads can't get rid of all that much heat, compared to what is being created under it. And,
Third; for a streeter that mostly spends just a tiny tiny part of it's life at WOT and rarely more than 3 to 5 seconds atta time, and almost always from a too-low rpm, and often stuck at too low an rpm for most of the run, your test is meaningless. Throttled and at low rpm, the heads pump vast amounts of heat into the underhood, and need the pressure just to break even.
This is why, with aluminum heads, I ran a small cam, at near 200psi, and a minimum water temp of 205*F, and just rev'd the nuts off it at the top to stretch it out. Well that and 32mpgs US. I may be down on power at the race-track,but the fabulous lower register is waaaay more useful on the street, especially with a manual trans or street-friendly stall.
With a regular A833in low gear and 3.55s,20 mph is still only ~2300rpm. I'd rather have a boatload of torque there, than at some higher rpm and much higher mph, cuz every time I take off I will be going thru the lower register to get anywhere, and will be stuck below peak torque, all the way to ~34 or more mph.
And Lord help the poor guy that lets his carb ingest all that super-heated underhood air.
Maybe I misunderstood and this is for a drag-car. But I checked the Forum header............. this time;
HomeForumsMopar Technical ForumsSmall Block Mopar Engine
 
FWIW and IMHO..... The above 2 posts are apples and oranges.
  • Hotter iron chambers make more cylinder pressure inside (prior to the start of combustion)? Yes. But that value of cylinder pressure is not 'compression ratio'. It reflects both compression heating, AND the absorption of heat from the chambers, which are 2 independent contributors to the heating of the mixture.
  • The effects of cylinder pressure on torque/HP all depends on the difference between the starting and ending pressure during the combustion and power stroke cycles, not by the absolute numbers themselves.
  • More HP? Not just based on a different cylinder pressure (piror to combustion) by itself. I agree, I've looked and looked for definitive results showing a difference going from iron to AL and have found none published; the trick in such testing is to always make the other factors identical.
  • BTW, RF, your positive experience with the head swap does not zero in on the exact cause of the difference you found unless you flowed both heads and found them identical. I'd guess you got some benefit from flow (but that is truly a guess); but you certainly got some benefit from more efficient combustion (partly from the higher CR, and partly from the smaller chambers), better cylinder clearing, and better extraction of power at the higher CR due to a bigger start-to-end pressure difference.)
I'd change AJ's statement to say that, rather than 'curing' anything, the cooler AL heads ALLOWS more CR without getting into detonation. AL heads widen up the operating range for CR and cam selection by reducing an undesired factor in the engine operation (extra mixture heating during compression).
Here is one iron vs aluminum..........I'll find another.
Comparing Aluminum And Iron Cylinder Heads - Car Craft Magazine
https://www.hotrod.com/articles/ccrp-0602-iron-versus-aluminum-cylinder-heads-test/
 
Yep.......... here is another.

Iron vs. Alloy Engine Heads - Tech Article - Chevy High Performance Magazine

These two were the only tests of the same casting and air flows that I ever found.

Anybody else found anything similar?

Oh, excuse me for awhile, I must go elk hunting!
Those are what I have seen.....I can't recall anything else but I can well have forgotten. Neither test was perfect but their conclusions were the same.

IMHO.... the broad statement in the first article of 'heat kills power' is the kind of broad statement that gets misunderstood and misinterpreted as to the specific's of why. I would expect it is all in the heating in the intake tract that lowers density, not in the chamber after the valve is closed.

Good luck with the hunting, Jim! Man, I wish I was there... I would be your 'gun carrier' and call you 'Bwana' LOL
 
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