Vintage Motorcycle Eccentrics

Stripped and cleaned the rear engine cases and measured the main bearing bores today. The bores are hammered so will require a sleeve insert.The drive side is from a 1960 T120 and since the case mating numbers don't match I can only guess from the casting number on the timing side as to what year that may be. Good thing is that both cases use the same bearings. Some pre-1962 engines used smaller bearings which wouldn't be strong enough for a load of nitro.


The pre 62s had two different cranks. One was a 3 piece, bolted together and one that was a solid casting. I found two of them so they will be cleaned, measured and magnifluxed to makes sure there are no stress fractures. If all is good they will be sent out for regrinding the rod journals.

The clutch started life in a ironhead Sportster but was modified to take extra plates, stronger springs and a custom pressure plate. The rust wasn't too bad so it cleaned up great. What would life be without a bead blaster.


The jack shaft that the clutch and output sprocket ride on will need new bearings and a left hand nut to hold the sprocket on.
Not sure why this nut is left handed unless the shaft is from a gearbox that had the output sprocket on the right side of the bike. It was loctited on such that it was a real job getting it loose. The sprocket has been modified with 1/4" offset so the chain would clear the tire and line up with the sprocket on the rear wheel. When the bike was built back in the 60s the only drag slick available was a Avon 400-18. M&H finally came out with the cheater slick that looks more like a road racing tire.

I found the sprockets needed to do the primary drive as well as the #35 ASME triplex chain for the clutch and also some duplex British chain to go from front engine to the rear engine. Now I need to weld the sprockets together for the rear engine as the end of the crankshaft has splines only long enough for one sprocket. Actually the photo isn't correct, it will look like the second photo.

My friend John Stein produced this video. Also published a nice book on the history of motorcycle drag racing. They both show TRUTH the V8 bike and the Auger Lightning.

Made some progress today on the front end. The baby Ceriani forks were disassembled and cleaned up. Surprisingly clean inside. All the bolts were rusted so will get the 'cad' treatment. The trees had some heavy scratches so took the time to polish them rather than going back to paint. The polished Tomaselli clipons look nice too.


The front wheel spokes were quite rusted so the wheel went into the blaster. They appear to be cad plated now and will get a clear coating of polyurethane. The rim cleaned up ok for now. The staging disk which is screwed to the rim had some major dents but after hammered out ok. Had to make a new brake torque arm.


Next will be getting the frame parts off to the powder coater.

Who do you use for a power coater?
    I don’t know yet if I’ll paint or powercoat the frame on the sei. Original is certainly paint- but this is no show bike.

I used Kitsap Powder Coating on the Triumph. Very pleased with the finish. http://www.kitsappowdercoating.com/
A little on the expensive side but high quality.

Thank you.
It is likely I will powder coat the frame/swingarm, so I’ll contact them.

Mark

Cleaned and reasembled the sprocket and brake disk in the rear wheel. I still don't have a Hurst Airheart master cylinder but found the caliper. I want to mount it rigid with the frame so will have to make a bracket that also slides as the wheel moves to tension the chain. The frame will have to be modified to clear the caliper. This frame was made for a 4" wide slick but it's been modified to accept a 6".