- Tue Dec 23, 2014 2:17 am
#42895
OK, you'd better get yourself a beer and get comfy.
The original plan was to get one of Henry's Indian contacts to modify a 500 Machismo engine to take a full set of timing gears and a contact breaker and ship it over for the proj. Long story short, that never reached me, so after some discussion with Henry we hatched the 500 AVL/classic engine plot. The classic 350 cases were chosen because a) they already had the timing gears, b) Henry had a stock of reasonable used ones, and c) he'd already converted some for 500 use, so this wouldn't be a lot different. Ahem... The beefier cam followers weren't the catalyst, but a very welcome bonus, nonethless. If you look closely you'll see they're the extra-thick stem Samrat items with phosphor-bronze guides.
The crankshaft is Electra-X, originally from Tiny Tim's bike before it failed @ 15,000 miles/24,000 kilometres. I knew Henry had this kicking around after Tim got a replacement crank, so it was rebuilt for he proj. This needed an Alpha big-end pin, new needle roller assembly and a bored and sleeved big-end eye in the conrod before reassembly and truing. Ah, how do you get the AVL timing side crank to work with a classic timing cover? I didn't, we used the AVL cover, as I like the large capacity gear pumps. OK, so how does THAT work with the classic cases and timing pinions. The alloy bosses for the idler pinion spindles are already there, the upper one has already ben drilled, that just leaves the lower one to drill out and both to be faced off for the correct end float for the pinions. If you're using adjustable cam spindles it will now fit straight on, if you're using fixed spindles their holes need drilling/reaming out from 15mm to 5/8". With more recent AVL timing covers only one oilway doesn't line up, that's the upper one on the scavange side. Late classic Bullet cases (2000-on?) already have the blob in place ready to drill, this one needed some alloy weld to get the blob in place. If you look at my last picture the circled 2 is the new oil hole to match the AVL timing cover, the circled 1 is the old oil hole drilled and tapped to 6mm for a slotted grub screw to seal it off. OK we now have a recon bottom end with full oil circulation, thanks to a 350 Machismo rocker oil feed pipe. Are we having fun yet?
Nearly done. With the change in cam followers and a set of "S" cams the push rods are now too short! Inlet was easy, just use the longer one from the exhaust (remembering to swap to classic Bullet adjusters). To get a longer exhuast push rod I modded one from a classic 500 to suit, I made a bronze bush for the hollow rod to take an AVL pushrod top. That's not quite the end of the story, but from there it was a case of time the igntion, fit the Dell'Orto PHF36 carby and see if works. Fired first kick. The crank also has an electra-X alternator inside a set of home-market 350 Electra primary cases, complete with TCI trigger still in place, though that's a fall-back option if the mag that's on there now ever goes belly-up.
That's not the whole story but any more would send everyone to sleep. Congrats if you made it this far.
Regards,
A.
