915's any help?
 

hello i just purchased a f code hp 440. i cant find to much info about the heads that are on it. i can get a set of 906 or 915s . I was wondering what u guys thought about what heads, would be the best for this motor?
any advice would be great help.
thanks

Back in the high compression days and before modern aftermarket heads, 915's were THE head to have.

How much performace are you planning on? Aftermarket alum heads that are loaded may be cheaper.

i was thinking about a stock rebuild on the HP and maybe throw a few bolt on goodies at it. i have a buddy who has a rebuilt set of 915's for 250$.

That is a pretty good price especially with how you want to rebuild the motor. I'd grab them.

cool. i'll grab them. thanks for the advice guys

the 915 are still the best production head & that price is cheap , when you swap the heads measure how far down the piston is from the deck , if you can keep it in the .040 - .060 range including the thickness of the head gasket you will have perfect quench to kill detonation . it is still effective to some degree up to .080

will i have the needed clearance with the hp pistons? do u guys know what the compression was in this motor. what makes the open vs closed chambered heads different.

How do you feel about a quench distance of .035 to .040? That should work even better, right? How about .020 to .025 distance? Too close? Thanks

The dead part of the chamber away from the valves & spark plugs is raised on the 68 & newer heads / open chamber .....so not a good idea , done for emissions more than anything ! I have seen high 8:1 engines with detonation problems using open chamber heads .
Most will disagree with me but I will run the 516 or 915 heads over any other production heads that are newer because of the closed chamber & they make quench as the dead part of the chamber is flush with the deck of the heads .
The 6 Pack HP piston is a flat top with 4 valve reliefs & work great with closed chamber heads , the piston needs to be close to flush with the deck & then use a .038 thick composition gasket . I have a 512 stroker using 915 heads running 10.6:1 compression with no detonation issues on 91 pump gas .
.038 is as close as I would go , yes it would work better tighter yet but with a minimal amount of rod stretch at 6500 rpm you could have the piston talking to the head , recommended is .040 -.060
I built a 440 for my Duster using 516 heads it was just over 11:1 compression but with a long duration cam , I had 1.81 exhaust valves installed with hard seats , ported the heads & shifted at 7200 for 9 seasons , it would pull the front wheels over 2' ran 1.40 in 60 feet in the mid 11s at 118 MPH & still had stock seat heater etc , was plated & I drove it everywhere . Most people toss out the 516s , I go around & collect them LOL

Thats fast for 516 heads! Did you keep the 2.08 intake valve size on the 516s? I just sold my 516s with stock valve sizes. 1.6 exhaust. But getting some 915s with 2.14/1.81 valves next week. Was considering porting my 516s before I sold them, but thought the 915s would be better. Have done several sets of 915s in the past and always had good results. Do you use the Mopar Porting templates, Chryco? Or just pocket port, blend and port match? I'm with you, I like the old iron heads. But would like to try some Stealths or Eddy RPMs if I was willing to spend $1000.00 plus some. And I dont think you can use the steel shim .020 head gasket on the alum heads.

An F code 440 would be 1970 built? I think. They were around 9.5 to 1 C/R. Advertised. In reality more like 9 to 1. And as the letters go up the compression goes down. Ha ha. The closed chamber head will have the needed clearance on any motor, unless some one has installed step head pistons in it. When you pull the old heads off, just make sure that no part of the piston is protruding above the deck of the block. In most cases, it will be .020 to .100 inch below deck. The 440 6 pak pistons were about .015 below deck. Thats the ideal clearance in my opinion. Then with a .020 steel shim head gasket you have.035 quench. And thats about as tight as you want to get. But I have heard of some motors as tight as .020. Not recommended.

thanks gary. i will make sure on the build to check out piston height. sounds like most everybody likes the 915's idea
thanks again guys

I retained the 2.08 intake valves but did my own bowl port creating a long & short wing shape around the guide to create a swirl flow into the cylinder . I would only use either steel shim or cometic multi layer gaskets with alum heads .

Hey guys I just got a set of 915s with 2.14/1.81 valves in them. I plan to do some pocket porting and blending on them. Plus open up the push rod pinch area. Then put em on my 451 this winter. Cant wait to see how well they work!

So is it ok to use the .020 steel shim head gasket with alum heads? They will seal ok and not damage the aluminum surface? I am unclear on this. Was thinking alum heads needed a copper gasket?

you need a gasket that will not tear with the different expansion rates of alum & iron , typically I use only steel shim or the better choice is Cometic multi layer gaskets