Gasket betwen crankcase halves/ 350 single

[SPRIDDLER]

Started as a stuffed barrel due to the gudgeon pin circlip dropping between the piston and barrel and now I've the whole engine in bits on the bench. Gawd!.
On dismantling there was a gasket between c'case halves but cannot find any ref to this in literature or spares scheme parts list.
Much else to be replaced - oil pump plunger, valve camshafts bushes (all four), timing side main bush (Loose on axle and in its crankcase housing). And loads more. Yawn.
Is there a workshop manual for the engine - e.g. there was a washer on the drive side axle, between the flywheel and the inner ball bearing. From the scant drawings/parts lists that I have it seems that only one or two washers (depending upon whether Hoffman or Skefco bearings are used)should be fitted, and then they should be between the two (inner and outer) main bearings.
I can tell I will need to draw upon a lot of \Forum experience........
Neville

[Biscuit]

A gasket was never fitted between the crankcase halves, I do it on twins, but hesitate to do it on singles due to the possibilty of a leak around the cylinder barrel.

[laxy]

Spridler Looks like your starting from scratch with this engine. Nobad thing as only when you have rebuilt it yourself can you be confident that everything has been done and done properly.
First you must get a workshop manual and illustrated parts book such as those offered by B.M.S. In the jampot. Keep it by the bed and read it every night before going to sleep.
Re the washers on the drive side fly wheel axle I dont know what year your bike is but on my single[51 G80] they do indeed fit between the two main bearings. I seem to remember reading somewhere that in the early fifties skefko bearings were in short supply and American Hoffman bearings were used by the factory.It is important that the correct size washers are used dependant on the make of bearing to ensure there is no oil starvation to the outer bearing.
Re the bush in the timing side case. This must be "pinned" after fitting to prevent it spinning in its housing like yours appears to have done then reamed to size.
From what you have described do not assume that your engine was assembled correctly by its previous owner. It clearly wasnt.
Im sorry if all this sounds alarmist but these engines realy are easy to work on and if you use the correct parts and assemble correctly Im sure you will be well rewarded.
Dont forget Spriddler help is only a keyboard away!

[SPRIDDLER]

Hi laxy
I have the workshop manual and BMS illustrated parts list, plus other publications , Mick Walker, Roy Bacon, W F O'Neil, Haycraft etc. etc. and know them all like the back of my hand but none of them shows a 'proper' exploded diag or provides dims or a descrip of the assembly. The feeble pic in the Workshop Manual is only an 'artist's impression of the crankcase and big end assy etc. In fact that 'Workshop Manual' is not much more than a service manual. I built and tuned competition Minis and campaigned a Greeves Starmaker in the late 60's so have agood idea what to expect.
I have realised that the engine has been assembled wrongly by a bodger. There was a 2" dia x 30 thou washer between the drive side of the flywheel and the inside of the inner main bearing, which has been chewed away down to about 5 thou, allowing that flywheel cheek to rub on the inner face of the crankcase. There is also a 20 thou washer between the outer face of the outer main bearing and the crankcase recess. It's edges are razer sharp. I don't think it should be there.
There is only one spacing washer between the bearings.
The timing side main bush is loose in the housing, has worn so much (and is breaking up) that it has enabled the oil pump drive gear to run low and almost wear away the oil pump plunger splines.
And there's too much more bad news to list.
It is a sad sight and I really can't be arsed to spend time on it as I only have weekends when I'm not at work and can arrange repairs / speak to / visit repairers. I'm tempted to get rid and buy something ready to ride. Shame as I enjoyed riding it.
Having a bad week.

[lawrence]

Been there, done that, several times and I know how you feel. you certainly have my sympathy.

Why not put it to one side for a week and then look at it again. Suprising how much more inviting it looks after time to reflect. Like Laxy says, they are lovely bikes once done properly and it is not as if it is work transport and you have to rush it.

Good luck

[Biscuit]

The answer, Neville, is to have at least two bikes, then the busted one won't have to be rushed. Unless of course you manage to er...um...ah wear out both!.

[laxy]

HI Neville well you certainly seam to be having a bad hair day/week/life.KEEP THE FAITH!!!
You appear to have a good old selection of manuals there,
Now back to the plot. The washer between c/case and outer bearing should never be there.The only washers you should have are fitted between the two bearings.These washers, and in the case of 55 - 57 Engines single washer,are on my 51 single two different diameters.
The part no. in my case is 010628 [for skefko bearings] they are listed in the club spares catalogue £2.57. The part no. for Hoffman bearings spacer is 014830. If you are mixing the bearings then the Hoffman bearing must have the spacing washer against it thenspacing collar 017194 fitted so that it abuts against the skefko bearing.
What I would do if I was you is buy twonew bearings from the club[yours are going to be shot anyway] along with the correct two washers for that year.
Timing side bush: as mentioned on my earlier post these must be pegged into the c/case to prevent them turning as yours have done.It must then be line reamed to size.If the crank/case half is damaged where the bush fits a new bush with an oversize outside dia. needs making.Not a big job if youve got a lathe and a bit of [phozzy] bronze.
Crankcase end float: when c/cases are assembled end floatshould be12 thou min. 25 thou max.this is with the shock absorber spring removed and will be taken up when the spring isfitted.
Neville all this info relates to my own 51 G80 but should be relevent
to your bike do please check part nos. etc against your manuels
Remember.... there are no problems with our bikes only chalenges. are you up for the chalange?

[SPRIDDLER]

Thanks all of you. Two bikes sounds very sensible as I'm seriously missing riding (even this weather), and also to take time, fit new parts (there aren't many inside the engine, it's pretty agricultural, bless it), and not rush it. It's my prime interest and although I'm no lottery winner, cost is not an issue.
Laxy, thanks for the info - feel a lot better as I had a gut feeling that there were too many (misplaced) washers in there. Mind you, anyone who's so expert as to refer to a "bit of [phozzy]" makes me envious (so would "a bit of totty" come to that). As said before "When it's been put together wrongly by someone else it's very difficult to rebuild correctly without drawings or knowledgeable help".
Ordered the Neill Workshop Manual today. Hopefully I will soon experience 'The Joy of Spec's' (aka 'How to put your bits together properly').
I'll make enquiries with fellow fettlers at my Sussex AMOC section - There must be an engineering shop that understands these old bikes fairly locally.
Deep breaths, fresh mug of tea. Where's that Spares Scheme order form?
Edited by - SPRIDDLER on 03 Nov 2005 4:57:35 PM