series 1 / exhaust mounting

[tea5ive]

Just doing a bit to a series 1 engine and have just realised that the exhaust mounting points on the engine case are m6. Will these be ok to hang an expansion pipe on?,will they be strong enough?. Cheers Simon

[bristolmod]

as Innocenti quickly revised those attachment points to a larger fixing, I would say "no".

TBH even the revised larger studs tend to take a battering with a standard exhaust AND the later under crankcase fitting.

Chris

[byron]

you can drill those out and tap to M8, keeping the drill straight, not a lot of room to wander off course
[and then you may need to enlarge the holes on the side casing of course]

[dapper]

You can buy M6 to M8 studs from MB. Not cheap but do just the job

[DigDug]

I don't see the point you still have an M6 stud in the casing don't you?

[tea5ive]

I don't see the point you still have an M6 stud in the casing don't you?

I was thinking the same

[Grumpy225]

Just doing a bit to a series 1 engine and have just realised that the exhaust mounting points on the engine case are m6. Will these be ok to hang an expansion pipe on?,will they be strong enough?. Cheers Simon

Drill them out to 8mm and retap.

It's not hard but having a drill press and some guides come in very handy.

When in doubt get a grown up to help.

[DigDug]

That leaves the casing very thin so a bit of extra ali is the way to go.

[Donnie]

M6 for both series 1 and 2, as to will it be ok with an expansion?

If the studs and casing are good, cant see why not. I've had 2 clubbys, a scootrs, a JL3 and a taffy copy all on mine over the last 10 years and the studs and casings are still good.

[Yanker]

Agree with Donnie here. There is not nough material in the S1/2 main case to tap to M8 without making it easily your weakest link. The expansion will presumably be rubber mounted/floating stressing FAR less than solid mount exhausts, and possibly have extra support points also. The studs are not expensive h[url]ttp://beedspeed.com/fastener-repair-stud-40mm-long-p-6820.html[/url]. In your shoes I would be trying that. If it fails then you need to get the main case welded and the chaincase drilled (which is the only alternative option) .

Gotta fess-up to being a bit perplexed (easily done) by Dig Doug's chaincase weld pics in relation to this (belt and braces? as the main case stud drillings are main failure prone spot)