Mating different types of engines and gearboxes

[DavidB]

I've not done this before, and not sure of the correct way of doing it.
If I have a gearbox made from one manfr and an engine from a different manfr, how are these mated together.
I know of changing the bellhousings, etc, but what about input shafts - surely these have to be altered to match different sizes/lengths/spline amounts? I've seen people do this DIY out of their garage (ie a Puegeot 306 with an XE), or is it easier to weld and sleeve the driveshafts?
I have a 4WD gearbox, and want to swap the 3 cylinder, 1.2 engine with something a bit more up to date (not neccessarily more powerful). but don't want to use a 2wd gearbox (as it defeats the purpose of the car).

[colnerov]

Hi, the input shaft is the relatively easy bit, use the clutch pressure plate from the replacement engine and the centre plate for the gearbox. Remake the spigot bearing or an adaptor. The bellhousing is a case of 'clocking' from the crank and mapping the dowel and bolt holes of both engines. Transfer this to a plate, patience and accuracy is needed for this. There is a lot of shared engines across car makers so a better engine may already be available that will go straight on. Good luck.

Colin

[composimmonite]

Have you measured up and checked there is enough room for the proposed engine ? Last thing you want it to work out a way of fitting the engine to the gearbox only to find that the head fouls the suspension strut and can't be fitted.
A quick look finds this pic -

and there doesn't seem much room for an extra pot As a quick check I'd measure the distance between the first two plugs and see if you have at very least that amount between the cam cover and inner wing. That is clear space all the way from top to bottom and anything intruding into that space will also foul if a large engine is fitted.
What about upgrading the original engine - I found a site where somebody fitted a turbo to the 1.2 3 cylinder lump or converting to the later MPi spec

Paul H

[DavidB]

Oops, I forgot the input shaft only goes into the flywheel!
The engine I want to put in is a very similar size (well done on guessing the car though!), it's a Swift GTi engine (it's been done before, but not really documented). I don't want to do any cutting, so it's not going to be outrageous.

[phillipm]

Angle grinder, big hammer.