how far does 360 piston sit below deck

[morepowertoya]

i would like to know if anybody knows how far the stock piston sits below the deck on a 360 small block , on a average.

 

[dgc333]

When I pulled my 360 apart they were 0.070" in the hole

 

[morepowertoya]

thanks for the information,just trying to get rough estimate on compression ratio on my stock 360 . heads have been milled .020 found compression calculator on other abody site. Found head gasket thickness make a big difference going from thick to thin gaskets.
Thanks again Bob

 

[Sanguine]

it will probably depend on the year, most engines had their compression lowered in the 70s

only way to get an accurate compression ratio is to mock it up and measure

my 340 pistons stick up .008"

 

[whitey]

I pulled a 360 from an 87 van to rebuild for my 73 dart. Those pistons were .13 in the hole PLUS they were dished, LOOOOW compression!!!!
Now they are .05 for all 8 pistons. Now I found out that my compression will be lower than I calculated. In another thread a few guys are saying their magnum heads were cc'd at 64, Ma Mopar advertises 60cc's. My heads were remanned and you can see they were milled, but I used 60 to work out the CR.

 

[moper]

The assumption can always be made that they will be lower than you think, certainly lower than anyone wants...lol. And most printed guides are not really good for much except casting numbers. Sizes and volumes are all over the board...

 

[dgc333]

thanks for the information,just trying to get rough estimate on compression ratio on my stock 360 . heads have been milled .020 found compression calculator on other abody site. Found head gasket thickness make a big difference going from thick to thin gaskets.
Thanks again Bob

FWIW, the bore in head gaskets varies quite a bit from just a few thousands bigger than an 0.060 over bore to over 100 thousands. That will make quite a difference in the compression too. The Fel-Pro head gasket I used had a 4.180 bore.

 

[pagilman]

Hi, I pulled a 78 360 volare roadrunner apart this summer and the pistons were dished and the ridge was about 1/4 inch down in the bore, my 340 is positive deck. Your mopar brother walt.

 

[340mopar]

The ridge is not the compression distance of a piston. It is the top of the ring travel.

Chuck