Before I go any further, I have a nervous system disorder which severly limits my earning abilities, so I (very slowly) build all my own parts. Buying in off-the-shelf solutions really isn't an option.
I've got an offroad only SJ413 which I've been slowly modifying. It's got the 1298cc G13B in it, and I'm concidering a G16, and/or bike carbs.
I'm leaning towards buying a 1.6, and while it's out of the car do a full rebuild - perhaps porting and polishing the heads, making the intake manifolds for bike carbs etc - then drop the engine in and tune it up a little.
I've already swapped out the original G13A for a G13B (the original engine smoked like crazy, and I damaged the head whilst removing gasket residue during a rebuild - DOH!) so the thought of swapping in a G16A doesn't daunt me at all. It's got a homebrew side-draught carb setup (SU HIF44 clone).
With the engine up high, swapping in a heavier engine is a no-no (asking for trouble when I'm regularly at about 45 degrees with 6 inches of lift).
However, I really would like more than an extra 20ish ft-lb of torque. HP doesn't bother me all that much (like I said, it's an offroader - HP isn't *nearly* as important as torque) so the 75ish of an 8v is probably fine.
The engine will probably only power the car for a couple of thousand miles in the rest of it's lifetime, but they'll be relatively hard miles - 4 lo, often at high revs for short bursts. *ALL* offroad (in mud, shock loads won't be too high).
So my questions to you lot are:
1) Are a set of bike carbs going to react ok to the strange angles that my SJ spends a lot of its time at?
2) What kind of power increase am I likely to see (being conservative) from bike carbs on a 1.3?
3) and 1.6?
My goal is to eventually have a 120ft-lb engine. That may be unrealistic, but hey - a man can dream!