Can anyone tell me how much clearance there should be between the frame and the back inspection cover on the Rocker Box on a Matchless G3/WO? I changed the box over on my G3 recently and it was a very tight squeeze. The bike has had a compression plate fitted at the base of the barrel that is about 3mm thick, could this be taking up space and making the rocker a tight fit?

Bill they are tight for room. A 3mm plate will only aggravate the situation! Do you need it?
It is quite possible to remove the rocker box and head in place. But one of the bolts can't be fully removed as it comes up under the top tube. You have to wiggle the rocker box around to get the push rods out, before the box can come off..... Even more fiddly on assembly.
The Triumph type rocker caps are just ornaments and deleted for later G3 and G3L Engines. Ron

email (option): ronpier@talk21.com

Thanks for that Ron, just what I needed to know. From what I can find out, the compression plate seems to be a later army fitting, but is probably not needed and not right for a 1940 G3. I've got to replace the lower pushrod tube gaskets very soon as it is leaking oil everywhere, so when I whip the engine to pieces again, I think I'll remove the plate and see how I get on. Lovely bike by the way Ron and what's that behind it, is it a Morris?

Well done Bill! Yes it's a Morris. Bet you've never seen another one like it? Ron

email (option): ronpier@talk21.com

Blimey Ron, it looks like it's got the wrong back on it!! If I didn't know better I'd say it was a very early 4 wheel drive pick-up, but I've never seen one before and if you'd asked me I would have said that none had survived? Is it a recreation or are there survivors after all? It's a wonderful old beast whatever it is!

It's a bit off topic on here Bill, but I'm sure no one will mind. It's a PU8/4 which is a four wheel drive version of the 8cwt PU truck. Only 1200 built in 1940 and I know of only one other survivor, which is sadly unloved in the Victory museum in Auburn USA.
It's the bottom right in this page from the Fighting Vehicles Directory. Fortunately there is a motorcycle in one of the other pictures. Ron

email (option): ronpier@talk21.com

We are digressing a bit Ron, but hopefully nobody will mind as it's such a rare and wonderful old truck. I've always been a big fan of the old military Morris Commercials and they don't come much better than yours! I've heard of these before, but as I've never seen or heard of one in the flesh I assumed they were extinct. It just goes to show that you never know what's out there and you never know what folks have got in their sheds!

I couldn't resist it, I've just been out, stripped the Matchless down to within an inch of its life and taken the compression plate out. Everything seems the same as before except the Rocker Box slipped on a treat with no wriggling, banging about or swearing. Cheers Ron.

Well even without the compression plate (or should that be...decompression plate). There was still some gnashing of teeth and swearing coming from my shed.
I am not happy with the clatter I seem to be getting from these new high lift cams I fitted. I am going to put back some standard cams that Ed Abbot is going to send me. Mine were so bad I flung them in the bin.
BTW. Can I introduce you to Private Spoons? He was absolutely useless when it came to helping with my rocker box.

Ron

email (option): ronpier@talk21.com

I think it should be 'depression plate' as it's caused me so much anguish! I was lucky that the chap who owned the bike in the 1970s got a load of NOS parts together ready for the restoration he never did. Amongst these were new cams, pushrods, rings and so on, so I am very pleased I didn't have to mess about with that sort of thing. Is Private Spoons acually the proud occupant of a Radio Eqippied Morris Commercial? That's even rarer! Even the strap on Morse key is like Hens Teeth. What a lucky chap he is.

Ron, when the cams get consigned to the bin, err.......could they be consigned to my bin?!!!

email (option): davmax@ntlworld.com

Private Spoons may not be much help but from the photo you have to admit the 'sun shines out of his arse'... ...Ian

email (option): ian@wright52.plus.com

Yes Ian. I jambed a light bulb in his crotch to illuminate the wireless for another forum.

Dave, I'll remember that in future.

Ron

email (option): ronpier@talk21.com

Ron how many standard cams do you want? I've got quite a few, some are very nice, but only one inlet one I think

email (option): davmax@ntlworld.com

Email sent Dave.

Ron

email (option): ronpier@talk21.com