Thumper Club Forum

Technical => Bike Problems/Questions => Topic started by: guest27 on May 14, 2007, 09:06:49 AM

Title: Welding on my engine plates
Post by: guest27 on May 14, 2007, 09:06:49 AM
Cannot decide so thought I would ask for views.  Need to get the new engine plates welded to the TZR frame, should I make these snug to the engine or should they stand off a little and use spacers.  The former sounds the strongest and probably the best way, the latter suggests room for error or moving the engine slightly at a later date - or even rubber bushing it.  Any thoughts?

R
Title: Re: Welding on my engine plates
Post by: guest7 on May 14, 2007, 09:11:29 AM
The manufacturers seem keen on using spacers, it also gives you room to get the engine in.

I'd say weld the plates with a gap for small spacers.

GC
Title: Re: Welding on my engine plates
Post by: Steve H on May 14, 2007, 10:13:23 AM
I'd use spacers, but make them reasonably thick otherwise it will be tricky to get them aligned making a pig to assemble.
Title: Re: Welding on my engine plates
Post by: beeman on May 14, 2007, 04:35:10 PM
Spacers everytime, gives you more room to get the engine in(and out) and for minor adjustments if needed. If it is bolted up tight shouldn't make any difference to rigidity etc.

beeman
Title: Re: Welding on my engine plates
Post by: Steve Lake on May 15, 2007, 01:30:13 PM
what engine are you putting in?
I've got an SRX6 lump in a tzr chassis, the 2 rear mountings are an (almost) exact fit, the rocker cover mounting is also a snug fit, the front engine mountings bolt onto two struts which in turn bolt onto lugs welded on the underside of the spars (i.e. the engine sort of 'hangs' from them) these struts are fitted after the engine is located into the rear and top mountings, it gives good clear access for what is a pretty tight fit.
Title: Re: Welding on my engine plates
Post by: guest27 on May 15, 2007, 07:15:18 PM
Putting a Rotax SOHC 500 in to it.  Have had to make new rear mounts, a cross piece and head mounts and a down tube for one set of front mounts - cannot bring myself to make a cradle - may have to though - will have to see whare the exhaust ends up.

R
Title: Re: Welding on my engine plates
Post by: guest207 on May 15, 2007, 07:25:08 PM
Mate of mine solid mounted a DR650 engine in a TZR250 chassis some years ago he suffered with a fair bit of weld fracturing, the option of maybe being able to bush it like you say may be best, especially as its going to be a road bike. I think the Rotax engine is a bit more vibey than the DR also.
Title: Re: Welding on my engine plates
Post by: guest27 on May 15, 2007, 09:39:38 PM
Mmm - added bother now but maybe..  The Rotax I have has the balancer shaft.

R
Title: Re: Welding on my engine plates
Post by: guest207 on May 15, 2007, 09:59:05 PM
Mmm - added bother now but maybe..  The Rotax I have has the balancer shaft.

R

Nah just do as the others said and use spacers, and keep an eye on it. If it becomes a problem just look at bushing the spacers... might never trouble you tho :)