1927 ew 350 pistons

[LBHill]

Hi all    need help with 1927 EW 350
just removed engine and dissmantled for major repair
have noticed difference between front and rear pistons the front is a lot lighter and has holes in it and is of cast iron and has two compression rings only the rear piston is much heavier and has three compression rings and one oil ring is this standard or
have i something thats not matching i wish to replace both are they available and where can i obtain them i
also have a serious exhaust valve worn are they replaceble and available please advise on some direction from here desperate to get old girl going but
going well can these parts be obtained in australia if
not from where please help regards LBHill

[LBHill]

I have heard of Honda 750 four pistons being used ounce bores are measured and the correct oversize piston can be obtained if so what is involved with using these pistons as in gudgeon pin size piston crown what machining is required to make then suit
any help appreciated regards
LBHill

[oily bloke]

Hi,
I fitted CB750 sohc pistons to my EW. There is a thread on the forum regarding this somewhere.
You need to rad the top outer edge of the piston and ream the small end eye on the rod to suit the larger pins. I fitted the oil control rings and have done a couple of thousand miles with no problems.
A couple of extra thou piston to bore clearance will be needed as the EW runs hotter than the Honda would.
Dave silver spares in the UK is a good starting point if you cant source them locally.
Cheers
Andy

[LBHill]

Thanks for reply very handy info as i am currently researching Honda cb750 pistons to suit is there a difference between the SOHC pistons and the DOHC pistons as the DOHC type seem more ccommon in oversize from 62 mm upwards can the DOHC type piston be used regards LBHill

[LBHill]

What is the maximum bore size that the EW 350 cylinder can be machined as i have had cylinders measured and the front seems to be standard around the 61 mm mark and the rear is at 62 mm the rear requires machinig due to gudgeon pin scar so i would need to go to 62.5 @ least or more to get both cylinders even using the honda piston method i will also need to replace an exhaust valve and an inlet any method for this would be appreciated also regards LB Hill