Author Topic: Royal Enfield 1931 crankshaft wanted  (Read 803 times)

Offline albert

  • Advanced Member
  • ***
  • Posts: 27
  • Karma: +0/-0
    • View Profile
Royal Enfield 1931 crankshaft wanted
« on: September 20, 2017, 11:55:48 AM »
Hello,
I am looking for a 1931 RE crankshaft (or flywheels) for model J 500 ohv  or H 570 sv ,sloper , 99.25 mm stroke,
or complete bottom end.
Flywheel Diameter 8 inches: 203,2 mm
flywheels are marked with numbers: 15172 drive side, 15171 Timing side.
This is the first dry-sump engine with integral oil tank in front of the crankcase.
The piston has a diameter of 80 mm (because of the longstroke engine) instead of 84 mm piston on the ordinary model JA and H.
Thank you for looking.
Yours sincerely
Albert
email: axel.winklbauer@gmx.de
« Last Edit: August 02, 2018, 03:33:22 PM by albert »

Offline albert

  • Advanced Member
  • ***
  • Posts: 27
  • Karma: +0/-0
    • View Profile
Re: Royal Enfield 1931 crankshaft wanted
« Reply #1 on: August 02, 2018, 03:34:16 PM »
Hello,
I am still searching!!

Offline mini-me

  • Advanced Member
  • ***
  • Posts: 775
  • Karma: +14/-19
    • View Profile
    • Email
Re: Royal Enfield 1931 crankshaft wanted
« Reply #2 on: August 02, 2018, 06:09:01 PM »
A long search ahead, have you tried Hitchcocks? about the only place that could help or advise.

Offline vintage_keith

  • Advanced Member
  • ***
  • Posts: 19
  • Karma: +0/-0
    • View Profile
    • Occasional blog
    • Email
Re: Royal Enfield 1931 crankshaft wanted
« Reply #3 on: August 23, 2018, 08:38:42 PM »
Hi Axel
Those early 30s engines occasionally turn up on ebay. I had to correct one guy who thought he was selling a New Hudson bottom end!
I'll keep an eye open in my areas of interest/events, you never know.
That's the same stroke as the 1140 KX, could the flywheels be the same? - not that they will be any easier to find (but Alan Hitchcock does replacement flywheels I believe, due to the cracking problem)?
The original part no. is certainly different, but often the casting no. is different to the part no.
Don't have an engine open at the mo' so can't check.
Cheers Keith

Offline john.k

  • Advanced Member
  • ***
  • Posts: 239
  • Karma: +1/-0
    • View Profile
    • Email
Re: Royal Enfield 1931 crankshaft wanted
« Reply #4 on: August 25, 2018, 12:08:15 PM »
making your own flywheels isnt rocket science.....oxy torch and a bit of 1" thick plate.......another tip is matchless G3/G80 flywheels are 8" dia,stroke a bit short.......The racers use hard plate ,like Bisalloy 360 for flywheels,but I would think that mild steel would be OK for a rally bike .Add a current ebay Indian crankpin for about 10 quid,and youre well on your way.


Offline vintage_keith

  • Advanced Member
  • ***
  • Posts: 19
  • Karma: +0/-0
    • View Profile
    • Occasional blog
    • Email
Re: Royal Enfield 1931 crankshaft wanted
« Reply #6 on: September 09, 2018, 02:33:59 PM »
No cranks or bottom ends at Netley/Beaulieu, but this side valve was up for sale with no spares to speak of.
The guy reckoned it was a 500, but I'm not sure, looks smaller, and only single down tube. It's the same sloper/bulbous crankcases/integral oil tank range.
« Last Edit: September 09, 2018, 02:58:40 PM by vintage_keith »