RWD Engine Conversions

It would be hard to make a "comprehensive" list, as it's going to be different for every engine/gearbox combination, and again for every combination of drivetrain/car

What car are you using? And what gearbox have you got in mind?

Propshaft should generally be inclined 5 degrees, whilst keeping the engine/gearbox and diff straight. So either the diff needs to be offset (most usually are by a couple of inches anyway) and then the engine shifted to one side too, or the front pointing upwards, to tilt the back down.

Mounts again, depend entirely on the engine, and the chassis/shell you're using

Thanks for the replies chaps, both very helpful.

I was a bit vague because I was hoping to find peoples methods for carrying out this type of work and maybe compile a list of do's/don'ts, hints/tips and useful info for people like myself.

A bit more background on what I personally want to do; I have a Mitsubishi Starion with the 2.0 8v turbo engine (4G63) which I brought off a friend after he completed a forged rebuild. However the engine is horrendously complicated, 000's of vacuum lines everywhere, strange duel point injection etc. no one knows anything about them and I just don't like it.

I previously owned a S13 200sx with a CA18DET and loved the engine, it feels keen and likes being rev'ed. It just sort of 'suits' me, so I want one in the Starion. I could also buy a rusty S13 donor car for very little and hopefully use everything including transmission.

So far I have found some good info here:

www.4xshaft.com/

And a good picture:



So starting to get my head round it but if anyone would like to add any more it would be really helpful.

Thanks

From what I have read this is to keep the CV joints happy, Is that correct?

Is there more room for error with a two piece prop Or are there other potential difficulties?

It seems to me that with a two piece prop getting the crankshaft and diff pinion parallel is not quite so critical, although it is still best to have it somewhere near. When I originally installed a KA24DE into my Datsun, I had that a few degrees out initially with a one piece prop but it didn't suffer driveline vibration because of it. I later, remounted it to get it exactly right though.

My first swap was a Rover V8 into a Datsun 280C and that was miles out of alignment, mainly because the engine was a pretty tight fit so I was stuck with mounting it at a certain angle. That was a two piece prop and had no driveline vibrations at all. On the other hand, my lowrider did suffer a little vibration but with that the angles were all over the place due to the need for extreme travel between full drop and full lift. I had the nose of the diff angled such that it would drive well just of full drop but lifted it had vibration. That's an extreme example though. in a normal engine swap you'd never have the angles anywhere near as far out as that had.

Getting an S13 engine running in a car isn't hard. I've done 3 conversions and helped others do there. It looks daunting on the wiring diagrams but it's not all bad.

Only thought I've got regarding the Starion is that the exhaust is on the other side of the engine. Other things like how does the speedo work? (elec or mechanical). I like to use original gauges, so assuming the rev counter is electronic, there's some simple work that can be done to get this working assuming it works on a -ve coil basis. Temp gauge can still work if you try to utilise your original sender.

Other than that it's the mechanical fitment of the engine which is actually the hardest, main thing would be the prop.

As for engine alignment on a 2 piece setup I generally consider one half of the prop to be an extension of the gearbox or the diff. The part that needs aligning in almost the same plane is the half with the opposing UJ's.

Thanks to everyone for the replies.



What methods do people use to find the exact pitch of the engine and diff? How can you accurately make sure they line up? I.e. the bottom of the sump may not be parallel to the crank, so you shouldn't use it to take your measurements. Do you just measure down from the center of the crank at each end? assuming everything else is completely level.

The more I think about it the more I think this is probably something I will find easier to get my head around with the problem in front of me.



*Already a member from when I owned an S13.
*I would do a light rebuild, metal HG, ACL shells and a gasket kit.
*Electronics not my fave but I think I can manage it. I have the Starion electronics workshop manual and there is a wealth of info on CA18DET stuff online, including a lot of other people who have used them in conversions. I have read that once the harness is stripped down there are actually very few wires needed to get them running.

I already have a project log, although not updated for ages. I have completely changed direction with the project now too, but have a clear vision in my head of what I want the car to be.



Good to hear you have CA18 swap experience, although you probably shouldnt have told me that lol, keep your inbox empty

I'm sure the exhaust problem is something I could get over with some creativity. The speedo problem is something I'm a little more scared of. How have other people overcome this problem? I wonder if it would be possible to graft the back of the S13 clocks to the Starion's. Or maybe a basic digi dash could be used.




It's a good idea but I can see it ending up more complicated and expensive (after a mapping session) than a conversion. Especially considering after its done I should have a fair few S13 parts and a forged 4G63 to sell.

In my experience there is very little knowledge or support or parts available for the engine. I recently had to buy some parts from america where there is still a good following.

Thanks again everyone for the input. If anyone in the south east area is carrying out a conversion of this type would like a hand one day let me know. Seeing the methods in practice would be massively beneficial.

Cheers.

I like the fact that you're thinking in engineering terms about lining up engine and diff. Surprisingly, I'm not sure how exact you need to be in that department.

Take a look at a bike engine installed in a Locost or Westfield. The engine often runs parallel with the side of the engine bay, putting it way out of line with the diff. They have to do that to get the drive flange in line with the transmission tunnel. A 2-piece propshaft is used to ensure the UJs aren't running at too extreme an angle. But other than that, it works with these cars without issue.

Best pic I can find, though this one doesn't have the engine so twisted off centre.

The angles in that picture look pretty extreme to me Is that what 5° looks like in practice?