compression on a 360

[dart67]

I have a chance to buy a running 1981 360 out of a van,($350) and was wondering what the compression of the engine is?I would like to build a 350hp street car,would this engine be worth it or find an early 70's motor?
Thanks

 

[abodyjoe]

stock compression? your lucky if its 8.1.


yes the motor is fine to build. your gonna change the pistons and machine the block anyway.

 

[rumblefish360]

350 is doable thopugh I'd seriously recomend a head with small chambers to bump up that ratio. It's probably somewhere around high 7's -1. The slugs are a bit down in the hole.

you'll need not port the head for this, but a milling is what your after.
(About .060)

 

[Toluene56]

dont' mean to highjack..but does anyone know the approx dome CC of the factory style dish pistons?

 

[DadGum_Teen]

I have a 360 out of a 77 Dodge van with some Speedpro Hypernuetic pistons. I don't know if the heads were milled, and I'm not for sure how much the chambers were messed with, but it measured out at 9.3:1 static compression. Hope that helps for comparison.

 

[rumblefish360]

Factory pistons are cast aluminum. Not sure of the dish cc amount.

The Hyper-U pistons are replacements. Factroy pistons were down the hole .050 or .060. I'd have to look it up, but generalllly, you could here an echo when they were at BDC cause there down so deep.

 

[mod5v]

All the stock blocks I checked were .100+ in the hole. Speed pro makes some nice hyper pistons reasonable and you don't have to run extra large ring gaps. I'm useing the "405" ones 1.637 dh should be right at 9-1 with .053 head gasket and 62cc heads. The "116" ones are .05" taller for 9 to 10-1 with open chamber heads depending on gaskets and chamber cc and block deck. They have plenty of valve relief also. I got mine off the bag with rings for 137$ to the door.

 

[Toluene56]

the pistons in my 360 are .040 that are factory styled dish.. they measured about .070 or so in the hole.. don't know what brand they are... So if calc's are correct and i use a -10.00cc dish with the .040 compressed thickness of my headgaskets... It says my compression is about 8.66:1.. assuming that the dish is 10.00..that is also using a 66cc chamber.. If teh chamber is 62cc then it's 8.98:1 according to calc's (but i doubt that's the case.)




I guess we'll see.. new pistons are goin in eventually.. kb107's or something after I get the car together. 8)