m20b25 S-52 crank stroker

[dwight]

On the above should or could the pistons sit above the top of the block?
I'm using an s-52 crank and con rods with CP-vac custom pistons and the pistons sit a hair above the top of the block, is that normal. Any input would be appreciated.
Thanks for your in-put
Dwight

[2mAn]

try the M20 forum, they will know better.

[SkiFree]

No, something like this needs to be discussed between your machine shop and VAC, bringing in a message board that doesn't know the parameters of your pistons is a recipe for confusion and frustration.

[dwight]

Done

try the M20 forum, they will know better.

Thanks for the advice, but I have gotten my answer I needed.
Dwight

[dwight]

No, something like this needs to be discussed between your machine shop and VAC, bringing in a message board that doesn't know the parameters of your pistons is a recipe for confusion and frustration.

Ya your 100% right I should no better.

Thanks
Dwight

[MR 325]

Thread moved. Next time please post a M20 question in the M20 section.

[Sirotto]

,4 extrusion if anybody cares about factory spec.

[dwight]

Pistons

,4 extrusion if anybody cares about factory spec.

86.368mm OEM

[Sirotto]

86.368mm OEM

Extrusion homie, the height above the deck or into the headgasket and head.

[dwight]

Piston height

Extrusion homie, the height above the deck or into the headgasket and head.

Above the deck..about.025 I was told to use a MSL metal gasket and ARP studs.

[dwight]

Piston height

Above the deck..about.025 I was told to use a MSL metal gasket and ARP studs.

[E30-325iS]

Looks like you have a 91mm stroke crank and your pistons were designed for an 89.6mm crank.

[dwight]

Crank

Looks like you have a 91mm stroke crank and your pistons were designed for an 89.6mm crank.

[dwight]

Crank

The crank was an s-52 do they make a 91mm?

[digger]

it is not unusual to have pistons sitting proud of the top of the block on those style if it sits flush the CR might be relatively low?, any competent machine shop/engine builder will know what to do to get it to work but probably how it supposed to be.