Gearbox just about ready for final assembly, showing the rebuilt four speed close ratio here. The five speed was original to the X75 but four speed was ordered by the gov on this project. The mainshaft and layshaft are both new along with a couple of other gears and selector mechanism.
Still wondering about using gasket goo on this later type gasket...have been advised to leave the gasket as-is?
I have pillar bolts in all the holes, makes it easier. Presumably you are putting the head on in the frame as it cannot be fit with it. I do not use a gasket on the inner gearbox case. You might want to check the layshaft end float in either case. You did not lighten the crank? A few differences between your frame and the Wenco/North: Both the Wenco and North frames have a loop around the gearbox. The North had the built up sheet metal rear engine mounts and inverted J brace tubes between the front down tubes and top rails. The Wenco had the straight brace tubes and 1/8" plate for the rear mounts. The cross tube under the gearbox was arched to clear the pipe. The front engine plates were not removable. The swingarm pivot tube was the same diameter as the arms. The lower engine mount went through the tube, not on top. The headstock braces are triangular U shaped pieces between the down tube and headstock and another between the top rails and headstock.
This is the same frame Randy / Karsten used for their T150 racer of course reconfigured for the R3 engine. Yes the head can be removed and re-fitted with engine in frame, that is another difference between this frame and the Rob North frame. As mentioned below (I've edited this) the main design is based on the Seeley H2 and the similarity to wenco is only the rectangular section swingarm. As for lightening the crank for what's (now) essentially going to be a street bike I see it as not only pointless but exceedingly undesirable.
I do not think that Dan used rectangular swingarms on the Wenco frames. He made ovalized swingarms by angle cutting round tube and welding it on top of the round swingarm. One of the last frames that he built was for the twin to be used on the shorter circuits.
I suppose a lightened crank is a matter of taste. I took about six pounds of mine. With 20/48 gearing I can keep up with an RG500.
Yes, it is because I designed and built that frame based on the Wenco but in larger, thicker aluminum tube, an inch wider at the rear engine mount, 26 degree head angle, removable subframe, et cetera, et cetera. Yes, a little easier to work with than round for a swingarm.
The framecrafters version was inspired by the Seeley H2 frame and North but closer to the Seeley. You're right I'm not sure if Randy used the box section swingarm for any other reason than Ducati's experience + current thinking in frame theory. Regardless I'm impressed with the workmanship; more gen once I get it on the road. By the way Randy said that with front mount plates removed (of course) the engine can be fitted with head so long as the rocker boxes are left off. Not quite to that point yet...
Finally got the pistone's in and cylinder barrel on, I used a NOS set of BSA kit pak rings this time. All went together very well using the Triple Tecs method. That is to fit the center piston/ rod to the barrel (with center crank journal position near BDC) then lowering the barrel -- with center piston/rod already present in the bore -- on the outer two pistons, those two being on blocks. Last time I neglected to lock the crank which caused an issue when attempting to do up the center rod big end cap so I was sure to lock it this time. Great result! (and no swearing) Thanks Charlie B for this advice. One other thing I found, turning the eccentric on the big end bolts cw (to lock the center rod big end bolts place fully extended in the rod) helps keep the bolts in place when replacing the center rod big end cap