Hello again,

A new question reguarding my top end rebuild from an earlier post.

I had a stock bore fl350 that lost the piston skirt on the intake side, And managed to find a OEM PISTON 0.25 OS P/N 13102-VM0-315 and rings on Ebay. Iniatially it was thought that the bore wouldn't clean up for that piston. Which in turn it did( I lucked out). So it has been bored for that OEM piston and the exhaust port bridge has been relieved.
No on to my next question which is : Should oil holes be drilled in the Honda Piston (ART) or does that only apply to the wiseco pistons? If it should be drilled what size holes and at what location on the exhaust side. Im sure the wiseco pistons have paperwork, but is this neccessary with Honda pistons?
Thanks Im learning.

YES do it on the stock piston too, it adds more lube and a little more cooling to the bridge.

Tech sheet



The piston broke the skirt because it was run too long or because the piston to cylinder clearance was too great, PLEASE check your piston to cylinder clearance don't ASSume it was done correctly.

viewtopic.php?f=2&t=3115


Make sure your ports are properly beveled, have detail pics of your cylinder?

viewtopic.php?f=2&t=3399

Thank you for the info.

The service manual states a piston to cylinder clearance of .0023 - .0037 and a service limit of .006 .

What do recommend for clearance for a Honda piston, I see other posts with clearances for the wiseco piston being larger.

I would say .004 to .0045 for stock piston.

What is everybody else running?

i have a question about clearance

do you think that after you bore and hone your cylinder set your clearance and then torque it down to spec - is there a possibibility that the roundness of the cylinder might change?

I saw somewhere that other people were running .005 clearance with wiseco's because of the expansion rate. I have been so many places searching I'm getting confused, I need to just stick with one site. :)

Mine is set at .004.(Stock piston)

I need to drill my piston holes yet, not sure if I need 2 holes like the green sheet you showed me or three holes like the diagram shows. i saw a post of a picture here from Turbotexas's piston he had three holes drilled.
I have to wait for wrist pin and bearing before I can mark holes for drilling purposes.

Thanks

Yes no maybe, lets put it this way not enough to worry about building a torque plate for the FL250 FL350 FL400's if the stud placement was a problem you would plainly see it in wear on a cylinder during your rebuilds, Macdizzy thinks this might be an issue on the 300cc big bore kit I got for my ATC250R because of the wear patterns seen on the cylinder walls, I will see of the wear he sees matches the stud pattern, we cant discount some mutt over torquing the head some time in the past either, one of the studs threads is messed up not sure what caused the damage but the stud is junk.

I have not seen it as a issue on the Pilots or Odysseys under normal wear and tear, I am more concerned about how clean the air is coming into the Engine, I have seen more abnormal wear because of dirt ingestion than anything else, next would be over heating of the air cooled engines, if I owned a FL350 the first mod would be air blowing on the front of the cylinder where you always see aluminum pistons stuck to.

Only two holes are required if you read the tech sheet it tells you 2 holes but the picture shows 3 holes, more stupid wiseco crapola they cant even write directions without confusion.

You can add a 3rd hole if you like dunno how much more effective it would be I don't see how it could hurt anything.

I usually drill 3 holes in mine and have done 4 in the past. The number is not as critical as having cooling/lube holes on the bridge. I would stress relieving the bridge a few thousandths too. Do not forget to check for sharp edges on all ports and the piston too.

Gary