Royal Enfield Hepolite piston 3495 or 8510,plus 0.060" wanted

[albert]

Hello,
I am looking for this piston 85,5 mm 0.060" oversize.
Thank you for searching!
Yours sincerely

[R]

For what year and model is this ?
A lot of those pistons were about the same, for a very long time.

??
http://www.vintage-motorcycle.com/index.php?language=en&site=4&pid=118&id=10824

[albert]

For Royal Enfield 1931 570ccm SV Sloper.
This motorcycle was only made in that year!

[chaterlea25]

Hi Albert,
Send the details  of the piston  required to,  johnharding197@live.co.uk

or phone, Sheffield British Motorcycles ( Bantam John) Chesterfield 00 44 1246 29002

HTH
John

[R]

Enfields made bikes with that 85.5 mm bore for quite some years, so it would be surprising if the pistons were all different for different models and years ??  Do you have a sample of the original piston to measure or compare ?

[rogerwilko]

Gudgeon to deck height might be different as in M21 and M20 BSA's.

[33d6]

According to a prewar Piston catalogue I have the 570cc SV piston was shared with the K series 1140cc vee twin. Unfortunately the catalogue only goes back to 1932 but I'd be very surprised if it didn't fit the earlier 570 engine, sloper or not.

They do show differing compression heights between various RE engines sharing the 85.5 bore. The 570cc piston you want has a compression height of 1 & 19/32" .

Cheers,

[albert]

Piston no.3495 is the piston for the early 1140 engine,1933 to 1936, (export models) which is in fact an early 976ccm engine with enlarged stroke to 99,25mm and alloy spacers under the cylinder barrel flange!
This piston (piston skirt is too long to use in the 976 ccm-engine) is totally different to the 1140 KX pistons used from 1936 to 1939.(four oil pumps engine).
Therefore I am looking for no.3495 as replacement for the original 570 piston.

[rogerwilko]

Piston skirt length is easily fixed in a lathe? B33 BSA's have an 85mm bore.  Check out their specs for comparison? Give me the gudgeon pin height to top of piston and i can check.