Piston 1558178

[ken1007]

I have an R2 avanti with an R1 engine that I want to restore to R2. Part of that process may be to get R2 heads (difficult to find) or use dish pistons to reduce compression, in that regard I found a box of good 1558178 dish pistons but I'm not sure what they are used in and if they would reduce compression sufficiently. Would these work? Ken, Deltaville,Va

6-11: Found out today that piston 1558178 is a cast number and it is used in "standard" 289's. That sounds like low compression (9.5 or less) but question remains as to these pistons working with standard R1 heads and a supercharger. Ken

Edited June 11, 2011 by ken1007

[1963r2]

Ken

I thought R2 heads were easy to find.

I believe they were a low compression head used on other studes such as trucks .

I'm no engine builder but with today's fuel I would have thought lowering the compression with r2 heads and dished pistons might be the way to go.

pb

[Skip Lackie]

Ken

I thought R2 heads were easy to find.

I believe they were a low compression head used on other studes such as trucks .

I'm no engine builder but with today's fuel I would have thought lowering the compression with r2 heads and dished pistons might be the way to go.

pb

Are you sure about that part number? Can’t find it in any of my car or truck parts books. If it’s a good number, then it might be a late supercession of some earlier numbers. These replacement numbers often didn’t make it into parts books.

63r2: Didn't mean to copy your message into this. Response intended for Ken.

Edited June 11, 2011 by Skip Lackie

[ken1007]

Thanks to both of you. The number (1558178) is inside the piston and it may be a casting number, in any case it is dished and would reduce compression,but I do not know how much. The alternative, R2 heads 1557582, are hard to find and when found are quite expensive. Ken

[Jim McCuan]

Thanks to both of you. The number (1558178) is inside the piston and it may be a casting number, in any case it is dished and would reduce compression,but I do not know how much. The alternative, R2 heads 1557582, are hard to find and when found are quite expensive. Ken

The 1557582 heads are used on a variety of Studebaker applications. 1961-1964 trucks, 63V, 64V, and R2

Head Casting by Application

Edited June 14, 2011 by Jim McCuan

[ernier]

The 1557582 heads are used on a variety of Studebaker applications. 1961-1964 trucks, 63V, 64V, and R2

Head Casting by Application

A dished piston should be enough, I ran my R2 with R1 heads, dished pistons and boost of 6 lbs with no problems. I wouldn't buy any pistons untill your block is miced up. You may need an oversize piston after the bores are cleaned up.

ErnieR

[Jim McCuan]

If I recall, part of the reason Stude went with the truck heads and flat top piston combo was to give more material in the top of the piston for boosted applications. If you go with R1 heads and dished pistons, you might want to use forged rather than cast. Probably not a problem for most drivers, but if you plan to be in the boost often it's worth considering.

[PackardV8]

If I recall, part of the reason Stude went with the truck heads and flat top piston combo was to give more material in the top of the piston for boosted applications.

Most of the guys who really knew are long since dead, but the version I remember is so S-P only had to build and stock one short block and it could be used for either an R1 or an R2.

FWIW, I've never had any problems with dished pistons and R1 heads on an R2.

jack vines