Author Topic: 1951 Royal Enfield drive side assembly - help needed  (Read 3536 times)

Offline T100striumph

  • Advanced Member
  • ***
  • Posts: 16
  • Karma: +0/-0
    • View Profile
    • Email
1951 Royal Enfield drive side assembly - help needed
« on: April 20, 2020, 06:34:35 AM »
Hi, I have a 1951 350cc g2 Royal Enfield and are looking for help in determining the assembly order for the drive side crankcase.

There are two ball bearings separated by a spacer, a cork seal, bearing washer and another washer as per the replacement parts manual from Hitchcocks Motorcycles. The book is not clear on assembly so help or picture would be fantastic.

Regards
Neville
New Zealand.

Offline R

  • Advanced Member
  • ***
  • Posts: 1475
  • Karma: +26/-10
    • View Profile
Re: 1951 Royal Enfield drive side assembly - help needed
« Reply #1 on: April 20, 2020, 08:44:02 AM »
You don't have the old components as a guide ?
And a G2 is a Bullet ?

I think they are a different arrangement to my J, so I'd be reluctant to guess.
If I had to guess !, the felt usually goes on the outside, with a thin steel washer to hold it in place, likely peened.

Also, some bikes are known to have 2 very fractionally different diameters to the bearings,
the smaller one has to go in 1st. Don't know if Bullets follow this practice.
The case(s) MUST be heated and the bearings chilled to install them
Modern bearings may also come with an inbuilt oil seal or more, negating the need for the felt ?
 I'd be enquiring of Hitchcocks, they are usually most helpful.
« Last Edit: April 20, 2020, 08:47:30 AM by R »

Offline Vreagh

  • Advanced Member
  • ***
  • Posts: 42
  • Karma: +0/-0
    • View Profile
Re: 1951 Royal Enfield drive side assembly - help needed
« Reply #2 on: April 20, 2020, 09:59:51 AM »
All my bullets have a single lipped roller as the inner bearing.

Offline T100striumph

  • Advanced Member
  • ***
  • Posts: 16
  • Karma: +0/-0
    • View Profile
    • Email
Re: 1951 Royal Enfield drive side assembly - help needed
« Reply #3 on: April 20, 2020, 09:36:14 PM »
I purchased the bike as a lad 48 years ago and did some non educated work on the bottom end between the four additional bikes as each had a problem. Keep them all for my old age and decided at 65 its time to start restoring.  Thanks for the help will chase up on suggestions.

Regards
Neville

2 x 350 Bullets
2 x 500 Enfields
1 x 250 Enfield side valve 1937
1 x Flying Flea
Aprilia RST1000
2007 Honda CBR600rr
1988 Honda CBR400rr
2007 Kawasaki EN500 ( wifes bike )
1970 Triumph T100s owned since 1973

Offline Mark M

  • Advanced Member
  • ***
  • Posts: 114
  • Karma: +0/-0
    • View Profile
Re: 1951 Royal Enfield drive side assembly - help needed
« Reply #4 on: April 21, 2020, 08:36:42 AM »
Early 350 Bullets had a loose centre bearing on the outside of the d/s crank but nowadays we use 2 identical one piece bearings. So from the outside, cork seal, shim, bearing, spacer, bearing. Of course you will have heated the case as much as you can, you need to do this because the assembly sequence is a little fiddly and can be slowed if there are any delays so you need to retain as much heat in the case as possible. You might even need to pop it back in the oven briefly. I freeze the cork washer as well as the bearings, helps preserve it from the heat. Enfield changed the details of this assembly a couple of times before standardising the design for the big crankcase re-design in 1956 so some workshop diagrams show a slightly different arrangement. I won't list them all here! Any more questions, please ask. REgards, Mark
Sorry I left a shim out, the cork seal is sandwiched either side by the shims.

Offline T100striumph

  • Advanced Member
  • ***
  • Posts: 16
  • Karma: +0/-0
    • View Profile
    • Email
Re: 1951 Royal Enfield drive side assembly - help needed
« Reply #5 on: April 21, 2020, 10:49:07 PM »
Mark,
Thanks for the reply, I have had an email from Adrian at Hitchcocks and he and your assembly is the same so that's great to have it confirmed. One step closer to having it back on the road after long time ownership in storage. Original number plate which I have managed to register is 250TT shame it wasn't 350TT :)

Keep safe with this virus stuff.

Regards
Neville

Offline Rex

  • Advanced Member
  • ***
  • Posts: 1509
  • Karma: +11/-69
  • I love YaBB 1G - SP1!
    • View Profile
Re: 1951 Royal Enfield drive side assembly - help needed
« Reply #6 on: April 22, 2020, 09:28:30 AM »
250 TT is still pretty good though. Is Terry Thomas still around? ;)

Offline Mark M

  • Advanced Member
  • ***
  • Posts: 114
  • Karma: +0/-0
    • View Profile
Re: 1951 Royal Enfield drive side assembly - help needed
« Reply #7 on: April 23, 2020, 09:01:54 AM »
Neville, congratulations on the number retention, not easy to achieve these days as DVLA are quite tough. And that's a great number, it will probably considerably increase the number of "I had one of those" bystanders when you finally get to go to an event! I've built a few Bullets over the years and I'm currently working on a late Bighead 500 special so feel free to contact me at trials59@yahoo(DOT)co(DOT)uk if you need any assistance. My last one (a 1955 350) was finished and sold last year.
REgards, Mark

Offline T100striumph

  • Advanced Member
  • ***
  • Posts: 16
  • Karma: +0/-0
    • View Profile
    • Email
Re: 1951 Royal Enfield drive side assembly - help needed
« Reply #8 on: April 26, 2020, 07:45:24 PM »
Mark,
Thanks for your help, looking to heat case and put drive side together, checked oil ways were clear and found three bits of broken ring in crankcase return, something must have gone bang when I was a lad :)

I have assembled and aligned crank, however the two 3/4 BSW nuts an the crank pin are not aligned to allow the small lock screws, can you advise torque setting for these two. My readings indicate 98 ft lbs can you confirm.

Regards
Neville

Offline Mark M

  • Advanced Member
  • ***
  • Posts: 114
  • Karma: +0/-0
    • View Profile
Re: 1951 Royal Enfield drive side assembly - help needed
« Reply #9 on: April 27, 2020, 09:03:15 AM »
Neville, there never were any torque settings quoted for British motorcycles at this time and in the case of a crankpin, very subjective anyway! Your figures sound reasonable and I'd try to tighten until the nut flats align with the lockscrew. I have seen both nuts and screws filed to meet up, probably as a result of meeting the end of the thread!
REgards, Mark

Offline T100striumph

  • Advanced Member
  • ***
  • Posts: 16
  • Karma: +0/-0
    • View Profile
    • Email
Re: 1951 Royal Enfield drive side assembly - help needed
« Reply #10 on: April 27, 2020, 11:38:30 PM »
Mark,
Thanks for reply, I have used drill type impact driver with metric socket ( bit loose fitting) to tighten. Currently waiting on delivery of the correct socket BSF 7/8 from Australia. I have had a read on a number of BSA and other sites, torque settings up to 180 ft lbs based on type of steel, others just tighten with a strong arm :)  Attached the Indian Enfield 350cc torque settings for crank pin which is 13.8kg /m  or 99 ft lbs.

Once again thanks for your expert help.

Regards
Neville

Offline R

  • Advanced Member
  • ***
  • Posts: 1475
  • Karma: +26/-10
    • View Profile
Re: 1951 Royal Enfield drive side assembly - help needed
« Reply #11 on: April 28, 2020, 01:22:19 AM »
98, 99  ft labs.
You'd wonder why they didn't go the whole hog and make it 100 ft lbs. !!

As someone said, back then they didn't have torque wrenches, so a good heave would be sufficient.
Or "really tight", and if it broke, then back off half a turn....