Hitchcocks Forum

both the classic 350/500 engine indian enfields have the same size oil pumps but a 535 thunderbird has larger why ?

I think you mean the 535 Lightning, the Thunderbird is a 350 AVL model with gear-type oil pumps (though there's also a UCE version).



The Lightning is a home market model and I seem to recall something about it struggling with Indian conditions, and the factory introducing bigger displacement pumps to circulate a greater volume of oil in an attempt to improve reliablility. Has anybody heard different?



A.

The 535 Lightning has several internal engine differences (It's not just a bored out 500). I suspect that these differences added up requiring extra oil.

Apart from the 87mm piston what else was changed? A.

Apart from uprated oil pumps & the larger piston & barrel (& pick up for the rev.counter), the only engine difference I'm aware of is the larger alternator, (hence the deeper primary cover).
Most of the changes are frame 'cosmetics' Though with significantly more torque than the standard 500, the bike suffered electrical/instrument gremlins & more significantly numerous engine siezures in the home market. The piston was expensive to replace so most bikes in India have now been fitted with standard barrels/pistons. I have a Lightning 535 (my second) & like the individuality & extra oomph, but can't say mine have been without issues! REgards Mick.

I've had a quick look at the parts catalogue. The 535 had a different crankshaft. Different rocker arms and bearings. Oh. The tacho is electronic, so there's no mechanical pick-up for it (My tacho has packed up, due to electrical gremlins).

This motor was developed by Fritz Egli,so he must have determined they were worthwhile.
colin