How bad is this!?! **UPDATE**

[RichardL]

Bob,

I suppose the roller conversion is done by more than one shop here in the US, but the one I know for sure does it will get no more of my work. If I were to do have it done, I think I would only be truly comfortable using SRM (no offense to fabulously talented machinists on this forum who do such things and put me to shame with their knowledge). Most of the decision as to what to do will depend on what I find inside the engine. If my timing side bush and journal are in good condition after some 3700 miles, and the inner drive-side race can be stabilized, I think I'll probabaly go with reshimming. If not, well, that's another issue.

Groily,

Did you have your fat tailor-made shim ground to thickness? Getting rid of shims that a are couple of hairs thick would be a good idea.

Richard L.

[groily]

I had the shim made up by T&L Engineering as a single item, when they were sorting out the first 'ahem', to avoid that wafer-thin shims thing Richard.
Chances are after so few miles your other bits will be in good shape I'd have thought. The needle-roller conversion is assuredly a good thing, but to be honest, I've done a lot of miles on my engine, not treated it especially kindly (or unkindly), and the timing side has held up well. What I don't do much of is 'down to the pub' type riding, most runs are an hour or more non-stop which does reduce wear per mile, and always under light load until things are nice and warm. And nor do I run at Musky speeds!! - 60-ish suits me just fine on non-4-lane roads, it"'s only a Flash-spec engine after all. If I'm in a hurry i'll go a bit more quickly, but again, under 70.
The only time I was really pressed - about 3 months back - I had an exhaust valve seize at 75-ish on a dual carriageway, which was very noisy, inconvenient and required a van to rescue me. My own fault, I'd made a new lh exhaust valve guide when I had the motor apart to do the crank thing, and must have been too mean with the clearances for when things got good and hot. That'll teach me. Luckily, despite the pushrod leaping out and the piston ramming the valve shut again (well shut!), causing huge flames back through the carb and near enough setting it and me and the battery alight, it all survived and has done an uneventful couple of thousand miles since then. Tough beast, I reckon, and as reliable as ever, warts and all.
Here's hoping you haven't got any other nasties to deal with apart from the mainshaft and the race. Bill

[RichardL]

Groily,

I hope you meant that for laughing, otherwise, my sincere apologies. (Edit: This probably doesn't help,  but I was laughing about the near fire,  not your grief with the mechanicals.)

It didn't occur to me until you mentioned "Musky speeds", but I was pushing a little harder than usual the last time I was out, but nothing over about 72 mph. Regardless, I don't really know when the tender shims decided to depart the shaft.

Richard L.

[coater87]

 Richard,

 Yesterday while hanging out at the magazine rack while my wife shopped, I came across an ad for another company here that does the conversion. I am taking it they are like an SRM sponsored company- but I cannot be sure. They do the conversion for $1199.00 U.S., and that includes a brand new SRM oil pump.

 The place is called limeylucasmotorcycles.

 Maybe you could ad a link? I am using a Linux computer, and am still on the steep side of the learning curve.

 Lee

[RichardL]

Lee,

Yes, I seem to remember having seen these guys and this offer before. Maybe it was on the Cafe Racer TV program that I first saw them (not really sure). Thanks for the reminder. The good news is this is not the company I have ruled out. The bad news is, now I have to seriously consider spending the money.

Richard L.

http://www.limeylucasmotorcycles.com/

[morris]

The bad news is, now I have to seriously consider spending the money.
Richard L.

Don't worry Richard, it's like my wife always says. Money is made for spending 

[muskrat]

G'day Richard. If the nut is torqued up correctly the shims should not escape even with a loose inner race. If the shaft is only a thou or so small I'd use loctite on it and the nut.
Cheers

[a101960]

CRAP! My turn to discover twisted shims sitting on the sump screen.

The most worrisome aspect of this, is the fact that had you not decided to remove the sump plate you, would have been completely oblivious to the fact that anything was wrong with you engine. This particular problem seems to be quite common. If an engine has been properly put together how, and why does this occur? I get quite paranoid about this sort of thing, and I remove and clean my sump plate and screen every time that I change the oil and the filter. I use Fuchs (Silkolene) Comp 4 20/50 fully synthetic oil in my engine and I change the oil every 1000 miles. It is quite expensive at £39.66 for 4 litres. However, I like to use the best oil that I can get. Will it make the engine last longer? Who knows, but I like to think that I have done as much as I possibly can to keep the engine well lubricated, and to help it stay as clean as possible internally. Contrast this with the days of my miss spent youth. I suppose that ignorance is what engenders confidence. My first bike back in the sixties was a BSA C11. I never changed the oil. I did not know any better. I did keep an eye on the oil level though, and topped it up now and again if  necessary. I had that bike for 3 years and thrashed it mercilessly, and despite all that it proved to be totally reliable. Come to think of it, I never carried so much as chain link with me, and it goes without saying I did not have any break down cover. None of my friends had any trouble with their old bikes in those far off days either. The bikes all got the same treatment. The only Achilles heel that I can remember was battery failure. Back then batteries did not seem to last very long at all. Isn’t it strange how these days all our pride and joys lead such a cosseted life, and yet there always seems to be problems with them. Back in the old days a complete lacking in any mechanical empathy, and also for that matter, not knowing any better, I for one rode around as fast as I could everywhere that I went totally oblivious to any ideas about maintenance. It has been said many times by many people, that modern bikes are totally reliable, and that our old Brits are very high maintenance. By today’s standards I cannot argue with that sentiment, but roll back the years to around 1963 and things were completely different or so it seemed. Such was the impetuosity and optimism of youth. I can never remember listening for odd knocks and rumbles. I just used start the bike up, and rode off with not a care in the world. And I always got away with it! I know that none of this is very helpful to you Richard. Just a bit of Irony really.

John

[RichardL]

John,

That was a good read.

Given the loss of one very thin shim, it might have been a long time before I noticed anything obvious. I did consider riding through the end of the season, then I decided to follow my own good advice: "I'm afraid it must come apart, mate."

Up until last weekend I was a convinced user of Castrol GTX 20W/50, then, at the antique motocycle show and swap meet in Davenport, Iowa (100 degrees F. in the shade, felt like 108) I got schooled/spanked for how little I knew about the importance of zinc (ZDDP) in motor oil. Seems that its protective benefits with respect to our type of tappets are rather important. Because I didn't know about it, I didn't know that manufacturers have been reducing it over time to add longevity to catalytic converters. In the US, the standard now allows for 600-850 ppm. According to my friendly lecturer, 1400 ppm used to be typical and now cams and flat tappets are subject to scalling. I looked at the website for your Silkolene Comp 4 and it is pretty high at 1100 ppm. Also, Silkolene commented in a Q&A exchange:

 As for this ZDDP business, you may like to wade through the attachments if you've got a couple of days to spare! It suffices to say that oils with adequate, but not unnecessarily high ZDDP levels are fine, especially if the load-carrying is boosted with synthetic ester and the oil film thicknesses are maintained by shear-stable polymers. It's not just a simple 'high zinc good, low zinc bad' thing! Zinc level in the Pro and Comp grades is 1100ppm.

Unlike Castrol, Silkolene is forthcoming with their numbers. I also found an independent article saying Castrol was safe for flat tappets. Not sure yet if it's true. I'll know better tonight after I lift off the barrels.

Richard L.

[RichardL]

Barrels off and lifters and tappets are quite good with no spalling. Good news for Castrol GTX, but still changing to Valvoline VR1 for the ZDDP. On the other hand, showing some piston overheating (or overexpanding?). Worse on the left side, as right side only has it on the rear surface. Bores look very good, with this piston issue barely having an effect that shows on the barrels. My inclination is a very light sanding for the pistons and a very light honing for the bores and Bob's your uncle! Maybe. (Not you, TopDad.)

Richard L.

EDIT: Should I add "under-oiling"?

[Rocket Racer]

If you're going to dress those pistons (hard to see how bad from the pic's) use a file rather than sandpaper which will leave nasty abrasive grit embedded in the pistons, whereas a file will remove unwanted piston if done carefully.
If its been nipping up, I'd suggest giving the bore a hone to clean it up and ease clearances.

Barrels off and lifters and tappets are quite good with no spalling. Good news for Castrol GTX, but still changing to Valvoline VR1 for the ZDDP. On the other hand, showing some piston overheating (or overexpanding?). Worse on the left side, as right side only has it on the rear surface. Bores look very good, with this piston issue barely having an effect that shows on the barrels. My inclination is a very light sanding for the pistons and a very light honing for the bores and Bob's your uncle! Maybe. (Not you, TopDad.)

Richard L.

EDIT: Should I add "under-oiling"?

[muskrat]

G'day Richard.
As RR said it looks like it has nipped up (probably un-noticed). Never use wet & dry sandpaper on a piston but I think even a fine cut file might be a bit too aggressive. A light buffing with a soft mop and white wax should be enough. You don't need to completely remove the scores, just smooth them over. A very light hone and some new rings will do the trick. Piston to bore clearance should not exceed 6 thou measured at bottom of skirt at 90 deg to the pin. Any more than that and you will hear piston slap, 4 thou is standard. As for oil, I use cheap 20/50 but add Nulon, gives the innards a teflon coating like a fry pan.
Cheers

[RichardL]

Hey Muskrat and All,

Thanks for the advice. Not having the pistons loose, I haven't had a chance to measure the existing (pre-honing) clearance. I suppose it doesn't matters much but, considering the almost invisible affect on the bores, might this have been a one-time short duration event?

Richard L.

[chaterlea25]

Hi Richard and All,
I believe the pistons will clean up ok, "tuning for speed" recommends a "Swiss file"
Make sure your replacement rings are compatable with the pistons, lots of crap out there!!!!

Re oil,
I use straight 40 classic Castrol , before that I used Duckhams 40 (Fleetol??)
I use the Castrol in all the customer classic Brit bikes except Tri T120/40's with common oil for the engine, primary/clutch
I use the "Comp 4" in my modern B*W bit wouldn't if I had to pay £40 for 4 litres 
Seek out a trade deal and save almost half

Musky,
I am not a fan of adding additive to engine oil which have roller bearings, especially needle roller ones
The additive as you say adds a coating to the rolling components,
This reduces the working clearance and can cause bearing failure, It was a common cause of failure to the intermediate shaft needle bearings on BMC Mini's and the like

Best of luck with the repairs
John

[muskrat]

 G'day John. I don't want to turn this into an oil thread. I've used Nulon in ALL my&friends engines, gearboxes and diffs in cars, trucks, 4x4's and bikes (except wet clutches) for over 30 years. Not one bearing failure yet. I would never use any of those sticky thick additives like Lucas or Morleys, they rob revs.
Cheers