Aluminum heads worth it?

[rumblefish360]

Thanks. To further explain it, it is a lad to create a quench area. Would that work as well? I figured the work “Dome” would be OK enough to get the idea across. As a basic ....

Yes but different from. most domed pistons... The dome typically is intended to fit into the wedge shaped area around the valves.... A quench pad is designed to fill the open chamber area opposite the wedge shaped area around the valves....

Since the Edelbrock heads are closed chambered a quench pad piston would collide with the head...

 

[rumblefish360]

Isn't the general rule of thumb is you can get away with an extra point of compression with aluminum. So if you're willing to take that chance and save 60 or so lbs off the front end, go for it.

The weight savings pays in racing & not so much in the street. I run a 11-1 - 360 cube engine w/aluminum heads and a 224@050 cam. So an extra point is not what I jumped but 3.2 points up. Runs on 93, with zero issues.

 

[dvw]

I've built 4 Edelbrock headed 440 street motors, 3 at 10-1, one at 8-1. They all run on pump gas. The last one with a Mopar .557 purple shaft. Has been 11.30s. The slowest was the 8-1 with .484 Mopar hyd, stock 11"converter, 12.80s
Doug

 

[70GTX Texas]

Thats a pretty significant gain from just swapping heads. I put all of the engine specs into camquest (for whatever thats worth) and it showed a 70hp gain from just switching heads. Seemed way to optimistic to me, so i wanted to get a second opinion here.

I just upgraded my otherwise stock 70 440 (.40 over and a 509 cam) from cast iron heads and intake with Trick Flow Power Port 240 heads and an Edelbrock Performer RPM intake and TTI 1 7/8 headers this winter. I just got it running and, man!!!! Night and day difference. It’s got flat top pistons but they are .105 in the hole so my cranking compression with the stock 906 heads was 135 psi on each cylinder (only 1000 miles since the rebuild). Now, it’s between 185 to 190 psi. This is the way a 440 should run.

 

[PRHeads]

84cc E street = straight plugs
75cc E street = angled plugs

Not all headers are angle plug friendly.

I don’t even try and push the CR envelope for pump gas street cars.

Your pistons are down far enough so that you’re going to want to run thinner gaskets than the typical Fel-Pro to take advantage of the available quench.

 

[Napoleon1991]

84cc E street = straight plugs
75cc E street = angled plugs

Not all headers are angle plug friendly.

I don’t even try and push the CR envelope for pump gas street cars.

Your pistons are down far enough so that you’re going to want to run thinner gaskets than the typical Fel-Pro to take advantage of the available quench.

I was planning on running .027 gaskets again but i might need to have the heads opened up a little to keep my compression down. If i use them as is, i will be at 10:1 which is a little higher than I'm comfortable with since im currently having some detonation issues with 452 heads at 9.7 CR.

 

[1 Wild R/T]

I was planning on running .027 gaskets again but i might need to have the heads opened up a little to keep my compression down. If i use them as is, i will be at 10:1 which is a little higher than I'm comfortable with since im currently having some detonation issues with 452 heads at 9.7 CR.

By going to Aluminum & getting quench you'll be very safe, detonation won't be an issue..

 

[wyrmrider]

what wild said
452/s ping easy
on opening up your heads ---do it if it helps flow
not necessary for compression
ask PRH

 

[Napoleon1991]

what wild said
452/s ping easy
on opening up your heads ---do it if it helps flow
not necessary for compression
ask PRH

Ok, i will leave them alone then. Btw, what type of timing advance do you think it will handle with the aluminum heads? I've heard that around 35° total is where it should be, would that be too far advanced for 10:1 compression?

 

[HEMI-ITIS]

Ok, i will leave them alone then. Btw, what type of timing advance do you think it will handle with the aluminum heads? I've heard that around 35° total is where it should be, would that be too far advanced for 10:1 compression?

T & T will tell you what the engine likes. What the *** dyno tells you will NOT be what the track will reveal!

 

[wyrmrider]

modern chambers will be less than stock
start easy & t&T

 

[BSB67]

Start with the 35° total. All in at 2500 rpm. Initial at 20°. It'll be close.

 

[Bee1971]

By going to Aluminum & getting quench you'll be very safe, detonation won't be an issue..

Exactly why I mentioned the E Street 5090 s with the pistons that far down in the hole

 

[BSB67]

Exactly why I mentioned the E Street 5090 s with the pistons that far down in the hole

The piston is only 0.023" in the hole. Probably about 6 cc for the valve relief. I'd probably use a shim gasket and get closer to 0.040 quench. Not that it matters once you're this close. That still puts him at less than 10.1:1. But the 5090 puts him at 10.9:1. Personally, I wouldn't go there with his build.

 

[wyrmrider]

bs what shim gasket are you thinking of
thinnest one I can think of are the Mr gasket .028 or some cometics
there used to be steel shim and stainless shim and even rubber coated shims but I do not think anymore and I would not use steel shim on aluminum and we do not know if finish is ok for cometics
just curious

 

[BSB67]

Shim gaskets are advertised from 0.020" to 0.022", depending on the supplier/source. Last set I used, nearly forever ago, measured 0.022". Steel shim gaskets are used successfully on aluminum heads

 

[wyrmrider]

thanks bs i"ll check my suppliers
do you have a mfg?

 

[BSB67]

Mancinni, Mopar Performance, Superformance.

But be forewarned, The aluminum head suppliers/manufacturers will tell you not to use them.

 

[HEMI-ITIS]

I'm pretty sure Greg does not do head & exhaust gaskets.

 

[wyrmrider]

I used to get them from Victor or McCord
lots of choices in the Marine and truck/ industrial catalogs