Topic: Standard pistons - Honda or aftermarket?

[PeWe]

Piston diameter is often measured at the skirt.




The total tolerances I have mentioned is the bore dia minus skirt diameter.

Bore dia where mostly worn.
(Measure the lowest, middle and  top position for piston to be sure.)

Cruzinimage cast pistons max 0.025mm
Forged pistons have often 0.05-0.06mm due to the alloy.
Dynoman recommends 0.0025" (0.0635mm) for their JE forged pistons.

Old used bore is no longer round. Hone to correct that can end up in the smoking clearance.


But, I had a horrible wide clearance on my 836cc latest setup with NOS RC cast pistons. Bores had been honed several times. No smoke. Maybe good oil with anti smoke additives?

I rebuilt it to save the good pistons for another cylinder with tighter clearance for future use.



I used a Mitutoyo bore micrometer and similar brand micrometer for piston  I could borrow from my job.
Lowest -mid-top part of bore where piston have contact and cause wear.
Piston dia a std micrometer.

Important to calibrate both with the test bit that is included in the package.

[RAFster122s]

The aluminum in the cylinder cooling fins allowed the cylinders to drift out of alignment slightly as the heat cycles initially settled the cylinders, this lack of alignment ribs you of about 5% of the ho and torque possible. So an align bore to reset the cylinder liners to be in alignment with the crank restores that power loss.
You won't listen to reason, so my and other's input has been dismissed as you are going to do your own thing. Why did you even ask for input if you won't consider it and ask more questions to learn?
Guess I'm in a crotch old codger mode today, pain makes ya that way sometimes.

Likely you bought from 4 into 1, not a recommended source as you often will find the cheap Chinese crap they sell to not work or simply not last.
Forget about returning or any service after the sale...

Sorry to others for my rant...just pissed me off sometimes to see people ask questions then argue with you or ignore any investment of others attempts to help wasting their time and effort to do so...

[HughL]

The aluminum in the cylinder cooling fins allowed the cylinders to drift out of alignment slightly as the heat cycles initially settled the cylinders, this lack of alignment ribs you of about 5% of the ho and torque possible. So an align bore to reset the cylinder liners to be in alignment with the crank restores that power loss.
You won't listen to reason, so my and other's input has been dismissed as you are going to do your own thing. Why did you even ask for input if you won't consider it and ask more questions to learn?
Guess I'm in a crotch old codger mode today, pain makes ya that way sometimes.

Likely you bought from 4 into 1, not a recommended source as you often will find the cheap Chinese crap they sell to not work or simply not last.
Forget about returning or any service after the sale...

Sorry to others for my rant...just pissed me off sometimes to see people ask questions then argue with you or ignore any investment of others attempts to help wasting their time and effort to do so...

It doesn't seem like you've read my original question either, I did end up getting the answers I needed though. I wasn't asking about specs or sizing, simply a piston manufacturer/retailer.

I've already ordered my pistons.

Thanks for the input

[dave500]

if your doing a cb500 you can use XL/SL 125 pistons,they have the same gudgeon(wrist pin) height etc but they are domed,youll need to check your head clearance etc,ive used them on a 500 build and had to have the head combustion chambers milled out somewhat for clearance,then depending on your cam reduce compression further or leave as is.