Help Cylinder Wall Clearence

[surfunc]

Hi everyone new here first post. I am doing my first build. I picked up a 1970 cb750. I am putting a 836 kit in it and just dropped off the jugs to be bored.

Here is the info I have on the new pistons I got.

69-77 HONDA CB750K 836cc BIGBORE PISTON KIT W/ GASKET

*69-77Honda CB750K Piston Set (set of four pistons) With Head gasket
New Aftermarket 65mm Piston and Head Gasket
*Set includes: pistons, pins, clips, and rings
We produce this product in reference to (OE Number: 13101-300-030)
Therefore, the design and performance resemble the original one (Except outer diameter)

The crown measures 2.535
The Skirt is 2.556

I need to know what the piston to cylinder wall clearance needs to be.

Please help and thanks in advance.

 

[dirtdigger]

What brand are the pistons?

"We produce this product in reference to (OE Number: 13101-300-030)
Therefore, the design and performance resemble the original one (Except outer diameter) " To me this makes me think they are cast pistons and are recommending standard piston clearance.

Standard Honda piston clearance spec is .0004" to .0016"
Wiseco 836 piston clearance spec is .002.

 

[surfunc]

Thanks dirtdigger will let my guy know hope he can figure it out. Got the pistons off ebay contacted the seller and he said they are generic no name brand so hope I'm not screwed.

 

[dirtdigger]

No problem. The ebay 836 pistons are cast. Not the best for high performance and or racing but will work ok on the street. I have heard OK things about them but I have also heard some really bad things about them. They seem to be very inconsistent as far as what your compression ratio will work out to be when done. Some of the pistons end up even with the deck and give good 10.25 to 10.5:1 compression but others have reported the piston sit down in the bores .010 to .020" and drop your compression to the 9:1 range. If it is just a basic street motor you will more than likely be OK.