4 replies to this topic

[JDImini]

Hi,

 

I'm stripping a 1098 as a learning experience and cleaning one of the pistons it shows AT6J34 +40

 

   IMG_4903.jpg   96.37K   0 downloads

 

would this be the standard piston?

 

measuring the bore diameter appears to be approx 65.6 mm

 

any info much appreciated

 

thanks

Darren

[GraemeC]

No, it’s 0.040” (40 thou) oversize

[JDImini]

Thanks GraemeC,

 

um interesting so it's had a 40 thou rebore a wonder what the capacity would be? suppose it depends on piston dish, block skim and head work

Edited by JDImini, 14 October 2019 - 09:07 PM.

[GraemeC]

Bore = 2.543” + 0.040” = 2.583” = 6.560cm
Stroke = 3.30” = 8.382cm
So swept volume = pi*((6.56*6.56)/4) * 8.382 * 4 cylinders = 1133cc

The piston dish, block skim and head work have no impact on the cc as they are constant.

[JDImini]

Bore = 2.543” + 0.040” = 2.583” = 6.560cm
Stroke = 3.30” = 8.382cm
So swept volume = pi*((6.56*6.56)/4) * 8.382 * 4 cylinders = 1133cc

The piston dish, block skim and head work have no impact on the cc as they are constant.

Thanks GraemeC that's great!