New 340 should I use X or Edelbrocks???

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Curses, I hope I don't start a big bruhaha here. First, use the X heads. The unported Edelbrocks I have tested don't flow anything like 245 cfm @ .500" OOTB. Have the Edelbrocks ported and use them on a race engine.

Secondly, there are no tests that show aluminum heads need more compression to make the same power as iron. No tests have I seen that show aluminum has a greater detonation resistance than iron, at the same compression ratio, if they have the same COMBUSTION CHAMBER shape.

In iron vs aluminum tests, where the heads flowed the same, had the same combustion chamber and the same compression ratio, the aluminum head in both cases made slightly more power.

Yes aluminum conducts heat quicker than iron, but in a water cooled internal combusion engine it doesn't seem to make a difference in horsepower from a cylinder head material standpoint.
 
I think I have decided to use the X heads and the Lunati 60403. As it is just a street car and if it ends up w 350+ HP that will be a fine cruiser. If I want to get in trouble ill take the Duster out. 450 hp roller 340 in that w 3500 stall and 3:91s
 
Cudafever said:
I when from a set of ported 360 heads to a stock set of 340X heads and picked up (went faster) 1 full sec. And my shift point when down from 7200 to 5800.

Yes these heads were my first attempt to port a set of heads.
All the ET was lost in the first 60 to 80 feet.

I say use the X heads and 404 cam. Eddys would work good to, and with the open chamber(340/360 chamber) The compression would be about the same..........don't you need one more point of compression for ALU ? :-k:-k:-k

P.S you can get new valve retainers that give you more retainer to guide/valve seal clearance.
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From Wild:
cuda, so were the the low lift numbers butchered? or was the cam just wrong for the flow curve?, i have trouble understanding how the car could slow down.
Click to expand...

I when out and look at my notes and.....well the exh flow was when i first got my bench up and had lot of air leaks giving me bogue reading. so i real don't know.
As far as the intake.....rember this was a 1.88 valve head that i dropped a intake valve and had to have one new intake seat and did all the exh seat while i was at it. then i hogged the bowls out, straight down from the hardend seat. On the intake, i made plastic temples that i could match the the intake/blowls The flow was not inpressive at all, compareed to the high RPM it would turn.
It acted like it had a big big duration cam With no compression. (355 gears 3700 pound car on 26" slicks.
When i would leave the line it would almost flat line------- when it got around 4500 rpm it would take of and run grate. I was getting 60' numbers in the 2.7 range and it was another 10 feet before it cam alive
When i when to the X heads "WITH NO OTHER CHANGES" my 60 foot time came down to 2.3 to 2.2. As you can see there was a 1/2 sec gain just in the first sixty feet!!!!

And now here are the ### of my intake flow ports that makes it hard to believe it could really turn 7200.......at least under pulling power......but it did!

.100/56 .200/114 .300/170 .400/199 .500/205 .600/206

Them head were ported some 17 years ago........

My best explanation why they did what they did was that the exh port was so HUGE and velocity was so so slow that the exh would rather run up the intake valve, then out the exh, during the over lap period. My intake manifold was stained black all the way up to the carb. BUT when i got enough RPM aka air velocity threw the exhaust, it started pulling fuel from the the intake instead of pushing exh. out. and is why it would turn such high rpm out of a 200 cfm head with a .474 /280 Hyd cam.

Wild, hope that helped.
 
Ahh....so poor exh flow/velocity and too much 'for that issue' overlap, bummer.
A good test is to reverse flow the int and exhuast ports to see if they make better as the opposite, If ur int port flows better as an exh port...then the shape is all wrong.
 
Someday i will finish my 2.02 conversion and try them out on my stroker.........but i thing the exh port to big for that one as well.

And the stroker need to be finish and, well tested out, before i throw a unknown head like this one on.
 
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