I simply can't make my mind up, good grief, seems I've got myself in such debating mood with ever advancing years.

OK, so I'm at the engine mounting stage, it's a transverse mid-mounted 1 litre bike lump, going in the back of a RioT. Originally, the good Mr Phillips had mounted the engine on a rubber bushed cradle going across the rear of the engine, then forward either side to return upwards for the head and block. That cradle was butchered by an intermediate party, to accomodate a pivoting differential frame of immense weight. So, I've dismissed all that, the engine's going lower anyway, I also need to dismiss the forward mounting bit, no room, it has to come from the seat belt anchorage rail above.. So it's all up for review, but I'm going for a shim and bearing mount option, not a pivotting Diff Cradle add-on.

I'm in two minds.

1. Build a rubber-bushed cradle, build in the engine and diff, bolt to car.

2. Solidly mount the engine, solidly mount the diff bracketry.

I'm tending towards 2. Mainly because it's simple, adds very little weight, but also adds structure to the car (though it doesn't need it). I'm hesitating because of crash shockloads going into the crankcase/block/head.

So.... what would you do, what have you done? Solid or Rubber??????????????????

Did your crankcase mounts break when you crashed the car when solidly mounted????????

Car is not for road use, track only.

Comments, experiences most welcome.

My vote is for solid, not heard of any problems with those whose done it this way either.

Cheers

Rich

Depends which engine you're installing - 'litre lump' covers a multitude of sins! Most BECs have the engine hard mounted but I hear there are issues with some newer engines, specifically I know about the later FireBlade (2008 on). It has fairly a sophisticated knock sensor which is likely to make the ECU spit its dummy if hard mounted.

The engine is the venerable GSXR750 and GSXR1000 in K1-K4 vintage (2001-4). The K1-K2 1000 engines are bored to 1080, something you can only do with the early (heavy duty) block. K3-K4 are bored to 1040. It still weakens things compared with a 988, hence my reservations. The GSXR750 is again, bored out to 815cc. Anymore and the pistons would be touching each other.

There's no sensor for knock in any of them, or pretty much anything, just the usual crank sensor.

If no one has any crankcase cracking issues, I'm going solid. Still some time to change my mind, since I'm writing a presentation for a job interview. It and the interview kinda take priority for a while. Back to it...

Meanwhile, any stories, comments, even anecdotals, all welcome.