A65 rebuild

[Allan G]

Chas, you'll easily loose a thou when you tighten the cases up.

Re the pump, I have been told by a reputable source that the Hepolite and the SRM pumps are made by the same people.

What you get with the SRM pump is a new worm gear, you don't get this with the new Hepolite unit. However it would be good practice to fit a new one with a new pump anyway. Once you have done that the price is much the same.

I have fitted 3 SRM pumps, I've been happy with every single one.

I wouldn't mess about with old pumps.  LF Harris sell very good oil pressure release valves. Consider one of those over any other brand (unless genuine NOS BSA).

Loosen the crank case bolts, tighten the barrel nuts then retighten the crank case again. It should turn easily. The barrel acts as a torque plate and when in this plane is how the line boring should have been done. If those cases weren't perfect on the top surface when it was all machined, then the barrel would pull it out of alignment when it is tightened down.

[Allan G]

Afternoon chaz, when I first stripped this engine there was damage to the cases,replaced  bushes and bearing had a regrind when I tried to reassemble it as soon as I started to tighten the cases together the crank jamed, turned out it was a 66 crank in a 64 engine and it was to long hence £2500  in machining to get the correct end float and balancing so you can see why I'm over cautious about everything.

What did you have machined? The wider crank to fit the narrower cases?

[MITCHELL]

Hi Allan, the crank and the cases were machined + the cylinder. Stripped it down today and found this horror,see photo. Proper depressed now, should have stripped it in the first place. The marking on the shells is not all the way round only on the top and bottom......... Do you think I'm looking at an oval con rod?

[Allan G]

Usually rods go oval top to bottom. Though your machinest should have measured them. I would either suspect:

Dirty rods or shell backing
rubbish shells (Hepolite brand?)
Journals not ground to correct size?

Journals have a 0.0005" tolerance to work within. They should
Ideally be checked with plastigauge before final fit.

Any debris at the back of the shell will prevent it seating properly. always clean with a clean lint free cloth. Assembly onto the crank with engine assembly lubricant.

If rods are suspect, replace with quality new items. Rods from MAP cycle or Thunder Engineering are excellent quality and will outlast you, me and the bike.

[DAVE BRADY]

Hi Mitchell,

Can you post a couple of images of the crank journals?

Dave.

[MITCHELL]

Morning gents, 
  I pretty sure I know the problem and I can't believe I've been so stupid. Been reading the workshop manual again and I can't remember,and I'm pretty sure I didn't lubricate the bearings when I assembled the crank and cases, how can I have been so neglectfull, I'm just about to clean up the journals which just appear to have some white metal marks on them, I'll give them a light polish and see what they look like after. Still can't believe it,what a Muppet. I'll try not to waste your time in future. Cheers Dave.

[DAVE BRADY]

Hi,

Our time is never wasted when helping somebody.  I would imagine that the journals being quite hard have not really suffered as the engine has not been started and run.  I would, however replace the shells.
Also, just ensure that the conrods and the caps have the same number.  They will have originally been machined together so it is important that they stay together.

Dave.

[MITCHELL]

Hi Dave,
The con rods were numbered and marked with timing and drive side so I know the actual parts were all correctly fitted. I think your probably correct re the journalls, here's some photos of them, I'll post some more after polishing them. Cheers.

[MITCHELL]

Hi,
Journals polished,I think I've got away with it.

[DAVE BRADY]

Hi,

They look good. A sigh of relief is in order.  What shells did you use? It seems a bit strange that the contact is in two lines towards the outer part of the shell.  I would have expected a wider contact area from a dry assembly.

Dave.

[MITCHELL]

Hi,
I don't know the make, they came with all the parts when I picked them up from the machinest. It does seem odd the they only damaged on the very edges but the machining was done by T L and they have a spotless reputation so I don't think it's anything to do with the crank,maybe inferior shells. I've ordered some new ones from C&D which should be in tomorrow and I'll have another bash, this time with a bit more thought.

[DAVE BRADY]

Hi,

The ones from C&D should be OK but I always ask for Vandervell, it looks like Burton Bike Bits may have them, or modern equivalent which is Clevite, stocked by SRM. 

Dave.

[Allan G]

+1 to the SRM shells I only use there's and never had an issue

[MITCHELL]

I'll see what Mark has tomorrow, checked the invoice from T L but no manufacturer detailed. Interestingly I scraped a new stanley blade over the shell to see if it scrapped more on the edge than in the centre but it shaved the same all the way across. Still a bit weird though.

[Allan G]

What was written on the back of the shell?

Also have you put a micrometer on the journal? Can you tell us the measurement?