The $600 C clip

[mrclubike]

make sure you balance the pistons
do no rely on the markings
A small digital scale is cheep

This the scale i used
What you want is repeat ability and it was very accurate

[Tony Smith]

I get a sick feeling Every time look at the picture of your oil pan 
 

Here's one for you to really worry about then :-)

(Sat for twenty years, sump full of silastic and large pieces of what used to be RHS Piston crown)

[mrclubike]

I get a sick feeling Every time look at the picture of your oil pan 
 

 

Here's one for you to really worry about then :-)

(Sat for twenty years, sump full of silastic and large pieces of what used to be RHS Piston crown)

O my I think I am going to have to sit down
I am felling light headed  :-/ and sick to my stomach

[Kookaburra]

Mrclubike I replaced the timing chain and associated bits about 5k ago. It was very carefully and properly re-assembled with minimal use of the recommended sealants.
That's a very scary graph Barry's has posted. Only saving grace is ambient starting temps in Australia are likely to be on the upside of 10C!
At the initial oil and filter change I did on acquiring the bike, the filter was collapsed. With the benefit of hindsight I should have pulled the pan then to see what was going on. Anyway we learn as we go along.

Phone call today saying my reconditioned heads are on the way back from the Queensland guru shop with not only new valves and bits but the faces machined, the exhaust nut threads and the rockers refurbished. Starting to get excited and a little anxious.

 

[Tony Smith]

Phone call today saying my reconditioned heads are on the way back from the Queensland guru shop with not only new valves and bits but the faces machined, the exhaust nut threads and the rockers refurbished.
 

Out of curiousity Mark Morrisey or Ray Peake?

[Tony Smith]

O my I think I am going to have to sit down
I am felling light headed  :-/ and sick to my stomach

And here, for the "finale" is what I found when I removed the brown oil, sludge and piston remains.....Yes my MPO was a clever guy, he managed to crack the sump and instead of having it properly repaired, he reached for the trusty tube of silastic.

And you know the truly funny thing?

This is probably the only legitimate use I've ever seen for silastic on a BMW. That leak patch had held for at least 20 years and you know what? I put it back on the bike with a clear conscience and a mental memo to avoid grounding the sump anywhere.

I've had a replacement sump for a couple of years now, but just haven't got around to fitting it - I will when the 860cc kit goes in, along with a offset mount oil cooler.

[Kookaburra]

Tony to satisfy the curiosity, Ray Peake, who was highly recommended by a number of people, got the gig to refurb the heads. He reported telephonically they were a mess.

I arrived back today from a flying trip to Melbourne to find the well trained posty had hidden a box on the verandah. It contained a left hand cylinder and piston for a BMW R65 with a negative mark on the crown (which is actually a very positive start if you get my meaning given the undamaged piston on my machine also has a negative marking.) The stars still seem to be aligning....

 I am still writing the submission for the new years Honours list but I need to find others besides myself who can attest to your communitarian spirit if not your good character (which I suspect may be a little more difficult.) 

In the meantime a million thanks and blessings to you and I will get to the delicate business of weighing and balancing pistons tomorrow.

[Kookaburra]

Have now managed to overcome internet connection problems, pay Tony for the postage and clean up both the donor piston and the good one . Both marked negative but using the electronic kitchen scales the donor piston was 0.4 gm lighter than the original. Much careful filing later I have got the weight difference down to 0.3 gm which by my calculation is 0.9% difference in weight. Now getting concerned about where to take further material off the piston.
So gurus, is 0.3 gms a significant difference in weight and if so, from where should I file further material?

[Tony Smith]

Payment received - thank you.

Here is a "balancing Pistons 101" youtube to waste your time
https://www.youtube.com/watch?v=_YMMQnBdVW4

[Kookaburra]

Watched the youtube posted by Tony and there is no way I am going anywhere near the inside of the piston crown with a drill and I do not have a drill stand anyway. I have recalculated the % difference in total weights (now including the wrist pin) and it is 0.65%. I think I can live with it but could not live with stuffing up the piston.

Cleaning Tony's cylinder barrel up to fit I notice there is a small amount of damage to the nikasil liner very near the top of the stroke. Looking in the mouths of gift horses comes to mind but I will be using it. 

[Tony Smith]

I'm embarrassed. I've never cleaned that pot up and didn't realize the damage.

[mrclubike]

I wonder what causes that type damage to the cylinder wall
Corrosion maybe from sitting?

[Tony Smith]

I wonder what causes that type damage to the cylinder wall
Corrosion maybe from sitting?

Given other things I've found, I'd suspect the MPO simply ran it until bits of ceramic fell off the spark plug.

[Kookaburra]

'Two steps forward one step back' is a  quote from a guru in a much older forum than this but which sums up progress on the $600 C clip saga. Having cleaned up the Tony Smith benefit cylinder with matching piston and then attached the Ray Peake beautifully refurbed head I was in a careful  process of  four stage torquing of the left cylinder when the upper inlet side stud went soft on me at under 11 foot pounds.  So it was another call to the peripatetic thread doctor to come and helicoil the stud without blocking the oilway that feeds into the stud channel.  I swear the thread doctor could find his way to my place blindfold. This was number 4 of 4 studs on the left side that have required fettling over the last four years. 
So finally all re-re-assembled and torqued up to 23 ft pounds, (even more conservative than Snow Bum) the valve lash set and with a clean sump, Penrite 20-60 oil and a new filter I turned the engine over until the oil light went out. I turned the petrol on and using minimal choke I hit the starter. It always seems such a miracle to a shade mechanic like me when the bike actually starts after being in many bits in boxes.  15 seconds at 3000 revs and a further 30 seconds at 3,500-400 revs and then immediate shut down for a leak check. No leaks and more than enough excitement for one day.

With the various comments of Mrclubike on balanced pistons, dirty sumps and potentially fouled oilways ringing in my ears I am preparing for the 30km running in ride with some trepidation.


 

[Tony Smith]

Congratulations!

Looking forward to the "1st ride report".