Compression bump.

[Burns69RT]

Hey guys so I have a 440 out of a 75 to 78 trail duster or motorhome of the guy who I bought it from says it was out of a 76 trail duster I am looking to bump the compression up as much as I canwithout changing the Pistons I will be running 906 heads a performer RPM intake and a Lunati voodoo cam with 513/533 lift duration 279/287 110LSA 106 and duration at .50 234/242. And I'll be running a gear drive. Eventually in a year I'll swap for some 10.5.1 pistons and a forged crank with eagle rods. But right now trying to bump up the 8:0:1 comp ration from the 440 as best as I can. Thanks again, Jon

 

[ykf7b0]

If no parts are going to be swapped then steel shim head gaskets and or shaving the heads are your only options.

 

[Burns69RT]

No parts will be swapped, just the top end. What size? Where can I get them, how much do they cost?, and for installation do I just put them on and torque them? Or do I have to use a special sealant?

 

[ykf7b0]

No parts will be swapped, just the top end. What size? Where can I get them, how much do they cost?, and for installation do I just put them on and torque them? Or do I have to use a special sealant?

Size: .020 Supplier: Mancini Cost: $21.95-35.95 depending on the brand and your bore size. Put them on and torque them to spec. I always use a spray copper coat sealant.
My opinion is that this cam will need lots more compression than this gasket swap will provide. Closed chamber heads would be your greatest compression boost without a piston change.

 

[Burns69RT]

Do I spray the copper coat sealant on both sides of the gasket? And how much would it bump my comp ration to?

 

[lewtot184]

if the engine is stock then it should already have steel shim, .020", gaskets. yank the heads and cut .060" off them with a .020" gasket. should get you in the low 9's on compression.

 

[ykf7b0]

Do I spray the copper coat sealant on both sides of the gasket? And how much would it bump my comp ration to?

Spray both sides. Lewt is right. It might already have steel shims on it.

 

[Burns69RT]

Okay, I'm curious to my hp/tq ratings will be with the combo so far when I do the .020 steel shim head gaskets. What do you guys think? My combo is above.

 

[moparcrazy]

i would pick up closed chamber Heads 915 or 516 maybe you could Trade your 906 ? also pick a cam that could build compression by opening the valve slower or keeping it closed longer as the pistons come up.

 

[Burns69RT]

i would pick up closed chamber Heads 915 or 516 maybe you could Trade your 906 ? also pick a cam that could build compression by opening the valve slower or keeping it closed longer as the pistons come up.

I will eventually throw a forged crank and higher comp Pistons, probably in a year. 906's will stay till I get a set of trick flows and the cam will definitely stay that new Lunati one that I listed above untill I go solid roller.

 

[66Satellite47]

I've taken ..080 off my 906's which brought the CC's down to 78 as I recall, then use the .020 steel shim & Kopper Kote both sides as stated above. That should gain you a full point. Make sure to mill the intake side too in the proper proportion.