Piston-cylinder clearance

[Pvo]

I just had my cylinder re niked, new rings, and piston and am ready to put the motor back together.  I have an 86 500 and in the factory service manual the standard clearance between the piston and cylinder is .002-.003.  I measured my clearance to be .005 by slipping a feeler gauge between the piston and cylinder.  I've built a few motors and this seems a bit loose to me.  The shop I bought the parts from said it's normal and to run it but I'd like some opinions. Thanks.

[kaw rider]

what piston do you have.

[Motorrad]

what piston do you have.

Exactly..
Stock cast pistons run a tighter clearance than Forged....   But they should have asked you this before they plated it.....

[Pvo]

I have a Pro-X piston.  I don't have the box with me but the dennis kirk description describes it as being a cast piston.

[kaw rider]

that is loose for a cast piston

[madmick]

correct me if i am wrong but can you not get an a/b/c and d size pistons,and pvo just get a matching size for what his size bore has measured after plating.?.

[Friar-Tuck]

 The pistons should be avail in the alphabetic enumarations from the OEM, but I'm just curious about the way to measure the piston to wall clearance... I was under the impression you had to use bore (snap) gauges and a mike.
  the feeler gauges are used to measure the ring end gap after pushing the ring down in the cyl squarely.
         When I send my stuff out the the machine shop I send them the piston and rings also,
                Tuck \o/   

[Speedway73]

Divide that by 2...because you're only measuring 1 side. Think about it. You're running clearance is .0025...within spec according to your manual.

[kaw rider]

Divide that by 2...because you're only measuring 1 side. Think about it. You're running clearance is .0025...within spec according to your manual.

He needs to measure the right way.

[Friar-Tuck]

 I apologize for not being able to figure out how to line the pages up in order..
  You can find the following pages in this batch of pics. (click on the thumbnail for a larger pic)



and here:
http://s69.photobucket.com/albums/i75/Friar-Tuck/service%20repair%20maitenance/?start=20

And here:
 Tuck\o/

 

[Rd]

Divide that by 2...because you're only measuring 1 side. Think about it. You're running clearance is .0025...within spec according to your manual.

Speedway 73 is correct.

[kaw rider]

im talking about he needs to use the right tools to measure the piston and cylinder. and he didnt say where on the piston he measured it at.

[Pvo]

im talking about he needs to use the right tools to measure the piston and cylinder. and he didnt say where on the piston he measured it at.

I agree with this and will when I get home.  I was in a hurry to get it somewhat assembled before I left for Bonneville.

[Big Yac]

Divide that by 2...because you're only measuring 1 side. Think about it. You're running clearance is .0025...within spec according to your manual.

wouldnt you multiply by 2 instead?  if it was .005 on one side, would not both sides added together equal .010?

[YUNGGUNNAZ]

think of the piston being centered in the bore not against one side.that being the case then u would divide his measurement by half(2).but where the piston is measured makes a world of difference since pistons are tapered..imo