Welding on my engine plates

[guest27]

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

[guest7]

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

[Steve H]

I'd use spacers, but make them reasonably thick otherwise it will be tricky to get them aligned making a pig to assemble.

[beeman]

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

[Steve Lake]

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.

[guest27]

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

[guest207]

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.

[guest27]

Mmm - added bother now but maybe..  The Rotax I have has the balancer shaft.

R

[guest207]

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