The $600 C clip

[Kookaburra]

What a disaster I have just uncovered. Removing the heads to send away for a top end valve job I discovered a completely wrecked left hand nikasil barrel, a scraped up and deformed piston with the bottom one of the three piston rings fused into the piston and the wrist pin poking out. Out fell half a C clip from the rear end of the piston. There is no sign of the other half but is clear the damage it has done. I am amazed the engine would start and run with such damage. How did this happen ? It may well be that I failed to properly install the new C clip the last time I had the left cylinder apart to install inserts into 2 barrel studs some 1100 kms ago. Whatever the cause (and I can't blame the PO!) it is clear I will need to acquire a new barrel and piston as well as piston rings, C clips and the three cylinder base O rings.  I am considering buying a preloved barrel and piston from MotorWorks but before ordering parts some questions for you gurus:
1. Are left and right barrels identical. (They appear to be and their are no markings to indicate otherwise)
2. Can I replace just one piston? If so should I put new rings in the other one (right hand) given they have only done 6000 kms since new ( I think I will not.)
3. The damaged piston is marked Mahle 138  and 82L41+++.
How important is it to balance the weight of the pistons and therefore do I need to buy 2 matched? (I would obviously prefer not do this)
3. How do you extract pushrod tubes from a barrel or should I just add 2 used pushrod tubes and 2 barrel studs to the shopping list?

I will change the oil, filter and clean and check the sump to try and find the other half of the C clip prior to reassembly.

[Tony Smith]

Do I have a deal for you.....

When I bought my R65 it had dropped a valve on the RHS, LHS cylinder and piston were undamaged.

I was unable to locate a RHS cylinder and piston so eventually I bought a pair of 79 "iron bore" cylinders and pistons and rebuilt it with those.

I've now bought a 860cc kit and will (when I get around to installing it) retain the "iron bore" cylinders and pistons in case I ever want/need to revert it back to 650cc.

So.... How would you like a LHS cylinder and Piston for the price of post?

You will need to balance the pistons but aside from that it should be good to go.

PM me with your post address.

[Kookaburra]

Tony you should be in the Australia Day Honours list however it is too late to nominate you for this year. Thanks for your very generous offer and I will PM you shortly with my details. Many thanks for this yang for my yin and look forward to catching up with you in person later in 2018. I will make a further  contribution to the website costs that have enabled this to happen. Go safely you good thing.

[wilcom]

I love it when the stars align!

[georgesgiralt]

Hello !
If the gift does not make it, I would avoid having the cylinder plated again.
I've checked the French specialist about it and the cost is only marginally cheaper than a new BMW cylinder. I tend to prefer the new cylinder above the salvaged cylinder.

[Kookaburra]

The photo I posted of the barrel bore is only half the story. There is also damage on the other side of the barrel. I don't think replating was ever a realistic option. A preloved barrel with a six month warranty from Motorworks was going to be my next shot. Just for the schadenfreude I post the pic of the deformed piston

[Tony Smith]

I tend to prefer the new cylinder above the salvaged cylinder.

Actually, given the choice I'd go with a re-plated cylinder because the OEM cylinders are done to a minimum cost whereas the re-plater's business reputation depends on every re-plated cylinder that leaves his shop. Also the carbide plating on re-plated cylinders will be thicker than OEM with a potentially longer service life.

[Tony Smith]

I love it when the stars align!

His luck was in that is for sure. Even a year ago I was keeping that cylinder in the hope of finding another to match it with. But it is now kind of redundant.

I thought long and hard before laying the cash down (well pledging plastic) for an 860cc kit, especially given that I have form for putting R80 engines in R65s. In the end I decided that for entirely dishonest (but fun) reasons I want the increased capacity R65 engine to look stock. - I'll explain in a "rants" post in the near future.

[Kookaburra]

So I removed the oilpan in search of the other half of the $600 C clip which was not to be seen. Instead I found a very thick layer of sludge and a small mountain of gasket sealant droppings. This is the first time I have removed the oil pan since I acquired the bike so I can blame the PO for the gasket goo mountain! It seems at some stage a massive amount of sealant had been used to try and reduce the leaks from the rocker covers.
Moving on to an inspection of the oil drained from the oil filter chamber, it was full of bright specks of non magnetic metal.  This is where much of the Nikasil scraped by the piston from the left barrel has ended up.
So I have removed and cleaned the 20% blocked strainer screen and snugged up the bolts.
Now waiting on the arrival of the generosity from Tony Smith OAM and hoping his piston has a minus mark on the crown to match my existing good one.   

[Tony Smith]

I located the parts yesterday and will be going to the PO this morning. If it is clean enough (got to draw the line somewhere) I'll grab the data from the piston crown.

[Tony Smith]

Posted today, expect them in one week according to lady postmistress.

[mrclubike]

O My
That is a lot of silicone in the pan
Personally I would completely remove and disassemble that motor  and wash it out with soap and hot water
Blow out all the passages and check the bearings
It is a small job compared to a car engine
You will still  find Nickasil particulars in your oil even after you have changed it
How did the oil filter look 
Did it  completely clog and go into bypass

[Kookaburra]

Love your work Tony. I hope the lady postmistress is right but I have plenty to do in the meantime and I still awaiting the return of the refurbished heads.

In response to mrclubike. The Mahle Ox35 one piece filter was  only some 1100 km old and it had not collapsed. I have yet to pull it apart for close inspection. How do you tell if the filter was completely clogged and went into bypass?

[Barry]

I suspect it would have collapsed if it had been completely clogged.  The filter goes into bypass to some degree at every cold start in any case.

Look at how thick 20W50 can be when cold. It falls from almost 3000 cSt at 0 Deg C to 18.8 cSt at 100 Deg C. It wouldn't surprise me if all the oil went through bypass when it's very cold.

[mrclubike]

Another reason to go ahead and completely disassemble the motor is to check the timing chain 
The PO may have mucked around in there to

I get a sick feeling Every time look at the picture of your oil pan 
Blackish grey looking oil is not good   
It should be a brown color