Parts swapping questions

[hools100RS]

Hi all. I'm looking at building up a faux 90S engine from a group of sundry parts and was wondering if anyone could shed some light on a few questions. I have 76 100S crankcase and an 82 crankshaft. They appear to match up beautifully but the end of the crank of course is set up for later clutch carrier and the post 81 lightened 'flywheel'. I don't have an earli:er crankshaft to compare but I reckon that the earlier heavy flywheel will bolt up to the end of later crank without the clutch carrier installed. Any thoughts, encouragement, advice, ideas, anecdotal cautions, misgivings, do's, don'ts or 'no don't try it's will be gratefully received and considered. Thanks, hools.

[Deleted User 287]

I found that to be the case with my R65:

[chasbmw]

My replica 90/s started life as an 82 rt.

The later clutch and flywheel gives a much crisper gear change and the engines picks up revs more quickly, is is to be reccomended!

[hools100RS]

Chas, would using an older style flywheel require fitting a pre '81 gearbox? I was thinking of fitting a 4 speed. Doesn't the later,lighter flywheel setup require a geabox with a shorter input shaft? Why is that?

[hools100RS]

Chas, would using an older style flywheel require fitting a pre '81 gearbox? I was thinking of fitting a 4 speed. Doesn't the later,lighter flywheel setup require a geabox with a shorter input shaft? Why is that?