Seann17

Hi Folks (and Lynn I hope),
I'm restoring a vintage U2L Can-Am car that ran in the '80's with a homegrown pp 13B (RX4based). I'm trying to save the engine only because it is part of the cars history. It hasn't been easy...the housings used to make pp were old monster ports with lots hacked out right through the water o-ring lands. I pinned the grooves and got it to seal after a couple of tries. Next problem is the "too short" situation of irons that as Lynn says "should have been thrown out". Anyway the problem with dealing with interference and end float at this point is that as soon as I tighten the rear stationary gear bolts even gently before torquing, the e-shaft tightens up. Shaft moves back and forth easily by hand before tightening. The clearance doesn't go away, it just takes a rubber mallet to move. I've chucked the gear in the lathe and it seems to be true. I even tried shimming the gear back to simulate shortening the gear at the tooth end, but it does the same thing. Anyone run into this?
Thanks,
Seann

Lynn E. Hanover

You are on the right track. As the irons are ground the crank moves to the rear in the shortened engine. The radius on the rear throw starts rubbing on the bearing in the rear stationary gear. The irons may have been "saved" more than once. If nothing is touching the gear face, then you need only radius the front end of the bearing. I have done this for others at the track with a pocket knife. A piece of a beer carton cut out as a spacer under the stationary gear, and back together. If at home, put a small ball of kids model clay on the area around the end of the stationary gear bearing and spray some WD40 on the crank radius. Chill the clay first. Assemble with 2 bolts. The disassemble and inspect the clay. If no clay is left between the radius and bearing or between the gear face and the crank, then more work is needed.

Then check end play. I like .0035" to .0400". Keep in mind that end play needs to be checked with the engine horizontal in the stand. The weight of the assembly is enough to flex the control plate and suggest that there is an amount of end play that does not actually exist. Do not pry. Just push back and fourth with your hands.

Use A cheap conventional oil for at least 2 hours of break in. Then race on Red Line racing straight 40 weight. Mix 1 to 1 1/2 ounce of Red Line 2 cycle dirt bike racing oil 2 cycle in the fuel. I ran 100 PSI in a dry sump system. Not a single oil related failure in 30 years of racing.

I sold the last racer many years back. I support Michael Shank Racing. Indy winner last year. His dad was my crew chief for many years.

Lynn E. Hanover

Seann17

Hi Lynn, thanks for responding...I'll check your theory next. The other "mystery" I'm dealing with is with the final tightening of the bolts in the rear gear. With nothing bolted to the front (so full end float available) and the e-shaft also pushed towards the front (easily moved back and forth by hand), as soon as I make the last 1/4 turn on any of the six short gear securing bolts the shaft tightens up unable to be moved back and forth by hand. Thoughts?