Last September Pete and the bike became separated on the track. Ah and he was doing so well. In every good story there is a villain. In this case a cbr600 was in the race. Trying to squeeze to many bikes into a race heat. Pete for qualifying and race one was a respectable 5th. First 3 being rgv’s. Then Petes bunch of cbr250’s. Then the rest of the production bike class. Old mate on his cbr600 was fast on the straight but slow in the corner. Pete saw red. Went wide and defaulted on his agreement with gravity. 30m separated Pete and the now 90° deficient bike. Happily at 3/4 throttle.
Broken. When started back in the pits it was making a ticking noise. As it was a mid week race I was at home. Pete rang, told me the story, game over was my reply.
After tear down I find the tick. The cam idle gear has a sprung loaded gear mated to it. I imagine it’s for backlash dampening at 19000 rpm. 2 teeth were absent on the sprung gear. 1 I found, the other I never did. The mains and rods shells did not look the same as last time I saw them. The MC19 was it trouble.
The bike is an MC22. It’s engine died because the bloke Pete bought it off, said it was only every used to follow the blokes son around… at the race track…on race days…
So an MC 19 engine turned up. $250. Just sitting in a wheel shop. Bargain.
A quick tear down and inspection, valve job, and back in business. MC19 head has bigger ports. And ever so slight piston crown difference from the MC22. The MC22 being the eco friendly model.
Meanwhile a free street bike turns up. Mc22. Crashed and abused.
So it’s carcass now lays like a slain animal. It’s digestive track wrenched out. Front rh fork led and bar torn from its decaying carcass.
Then the fun began. Things NLA. Just about everything. I scored the last 4 main bearing shells on earth for the MC22. It had 2 broken engine mounts, worn bores, with the majority of the bearing shells acceptable.
Getting the wear marks honed out by shop was not going to happen. The crank webbing prevents their hone head making a full stroke. Ceramic coating was out for the same reason. LA sleeves in US would re sleeve, but the cost put that out of the question, and there comment of had some success. Least the bloke was honest.
So , I have a mill, steel and a welder. I built a jig. Ordered an Indian honing head for $100. Modified the honing head, and honed out 0.01 to 0.05mm bore wear, taper and oval, to 0.06 oversized. Man that was slow and challenging. Bore dead at 0.1mm wear.
I double ceramic coated the pistons giving me back 0.01-0.03 bore clearance. Ring gap at mid installation tolerance.
Then on to the crank and rods. Everything measured and weighted to keep reasonablely close to the cranks original set up. 4 pistons, eight rods (MC19. Has a smaller main journals. So there out) 24 Conrod shells, and 20 main bearing shells. All colour coded, some with just microscopic identification paint left. A challenging ordeal to be sure.
After a protracted shell game I got enough good ones in the right place to be good set. Oil clearance 0.022 to 0.064. I scored one at 0.050mm the rest 0.028-0.029-0.032 ish.
On to a quick valve clearances frenzy and open everything up by 0.02 as the tappets went slightly frosty set at the low end.
Finally after eon’s of measurements I bolted it together doing squish, All good at 0.8mm, next final assembly… At 17nm, mid tolerance, one bolts case thread let go. Poot! Stinking M7x1mm thread. Search for helicoil kit, finally find one, it has M7x1x1.5 D inserts, I need 2.D. I ended up with 20x 1.5D,, 10x 2D, and 100 x2.5D. And every sales guy saying are 😉you sure M7, that’s very uncommon! Anyone ever need an M7x1mm helicoil, I’m your man. That’s 2 things in the universe that use M7. Honda 250 circa 90’s and Ducati single rear brake cable. Go figure. Had to make another jig to get drill and tap perfectly aligned. Man, jigs are us hey.
All done and in bike running as of today, heat cycled run in, in the shed. Fresh oil coolant ready for Track day Tuesday apparently. Doesn’t even leak which always amazes me.
Total time 76hrs.
Calculated it can do 215kmph. Around Morgan park it was generally about 14sec slower than a goey 916 I know. With a new engine and a slightly more experienced rider I reckon it could cut that down to 10-12 second slower and give the RGV’s something to consider! 😁
