PVL ignition upgrade?

Chris Hatch · Joined: 02 Mar 2004 Posts: 405

I tighten my flywheels around 90-100 ft pounds. I also will lap the crank to the flywheel as well as add a washer between the nut and the flywheel cup. There is some minor matching up issues between the flywheel and crank, at least there was when they first came out and once you do something to eliminate a problem, you just keep doing it. However, at only 50 ft pounds, I would expect to shear that key on the stand.

Alan Sheidler · Joined: 09 Aug 2001 Posts: 471

Nationals is over, a generally successful run for the family WF engine. Son Colin pretty much proved that the Briggs can run competitively with the KT-100 in autocrossing, even being 40# over the minimum on the scales. If it weren't for a couple of pesky cones, he'd have had 2nd place. He posted the fastest scratch time on the West course.

Following some really good advice, I used lapping compound to get the crank and flywheel tapers to mate very well, after cleaning up some rough spots. Thinking about other press-fits I'd dealt with in the past, I left the flywheel (without cup or fan) in the oven at 225 for an hour, then put it on using a homemade holding tool with the nut and a washer to 75 lbs. I took the nut/washer back off, and installed the fan and cup, this time torqueing to 100 lbs. Checking for true, it had virtually no runout. Fired right up, and ran strong through all laps of the practice course, as well as the longer and faster Nationals courses. The oil issue was apparently my fault for blocking the original vent, and never reappeared again after I installed a catch can (which did not see even a drop of oil).

We had an absolute blast. Very Happy

My thanks for all the help and advice I got here, and also to Bill at Stony Creek karting for taking the time to talk on the phone.

Alan