General Category > Bike Builds, Rebuilds And Restorations Only
1975 850T Survivor Project
cmice:
A little overkill perhaps, but CNC cut the blanking-plate for the original screened oil-pickup (ie. non-filtered flow), and installed. I added nylocs on the back side just for safety, and we'll see if there's room once the crank is installed...I think there will be no problem. Now that all the machining on the block is done, and it is clean, we can start building it up again.
cmice:
Short update for today. Rear main lip-seal changed, and the rear main bearing is in the freezer waiting for the "big day" when the crank goes back in.
In cleaning up the rear main bearing, I forgot that there was still the old gasket stuck to it. I don't know when whoever was in here was in here, but they used some sort of gasket sealant that got super hard and really stubborn over the last 30 odd years (can't be 50, surely). Anyway, spent some quality time with a steamer with a brass-bristle brush attachment, and the almighty razor blade, and those stubborn things finally relented and came off nicely. New gaskets will get hylomar - doesn't harden, cleans up easily, love that stuff.
New rear main lip seal went in with only oil - no sealant. Old seal had I think shellac type sealant, and was a bear to get out.
Some arbitrary engine shots.
cmice:
Update from last post - freezing the rear-main is the bees' knees. Dropped right in without a fuss. Lip seal was a little stiff to get over the end of the crank, but gentle coaxing with non-sharp things got it to slip over and it went home with the gentlest tap of a dead-blow hammer.
Ok - today's question, and I'm sure it's a boneheaded one as it's been covered before....but this just doesn't make sense.
I'm reusing my existing conrods and kept track of how they came out (plus end caps, etc) - but I don't trust anything that's coming out of this motor now given someone else has been in it. Looking at the oil squirt hole orientation, all the references say that the milled flats and the oil squirt holes should face to the right (which means one squirter points up, the other points down).
Oil Hole in question...
But that doesn't make sense if the role of these is to squirt the underside of the pistons. It seems like both should squirt UP, but instead, all facing right means one side gets squirted underneath and the other squirts the sidewall of the engine case? Am I overthinking it? Using new bearing shells so previous run-in is ignored.
This is how I would THINK it would go, but this would be incorrect.
Also, looking at the two conrods, one side looks like something funny happened - unclear if this is from the factory or field related damage. Is this just a manufacturing thing or is this rod suspect? Underside of the cylinder skirt looks ok. Thoughts?
Looks like a hand-grinder was taken to this???
[Post-lunch edit...] Everything I see says left-up, right-down. I don't understand why, but that agrees with how they come out so that's how they're going back in.
cmice:
Ran the heads through the ultrasonic. Had to put the valve keepers in a press to get them to pop. Gotta say, never had to do that before - but this motor has been a long time sitting. Valves cleaned up nicely, valve tips looked like this:
Couldn't catch a finger on it, but still peace of mind wanted them cleaned up. My local VW hot rod shop chucked them into the grinder, and in under a few minutes cleaned them all up up (only 2 of 4 shown of course).
The kicker, he said "have a great holiday" and sent me home f.o.c.! Refused to take any payment despite my insistence. Love old school places who like doing old school stuff. Gotta figure out how to keep them in business.
Started the cylinder build up - and let me just say - when the Italians say "everything is pre-sized", what they MEANT to say is they INTEND for everything to be pre-sized. After putting one cylinder and head together, torqed it up - engine was pretty tight with only one cylinder installed and that was not a good sign. Pulled it back apart, and found the oil control ring gap to be 0.0025". That's not going to work.
Now we check them all. Luckily, no wall scoring and this should be better once I get it back together again. Thankfully I've got a spare head gasket.
cmice:
Ring gaps set - that cylinder now moves like it should. Since I had to pull a cylinder back off that put me short of a base gasket so I'm waiting for another gasket to turn up.
While we're waiting, as they say, "if you've got time to lean, you've got time to clean." Front cover went into the ultrasonic - it's slightly too big for the cleaner so I had to do it in halves. Yeah, baby.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version