V6 LPG engine and overdrive gearbox transplant.

Liking the wheels ... what are they ? size etc.. and how did you fit them ?

Engine conversion looks well cool

The performance is extremely rapid to 50mph, then slower on to 70'ish as a top speed due to running out of revs thanks to poor gearing in the rear axle. I've established pretty much that the rear axle is 4.1:1. Which is good for acceleration but not cruising with this engine. So, by putting 16" rims with 205x16 tyres on it raises my rolling diameter from 26.92" to 28.92". This gives an effective axle ratio of approx 3.7:1. This together with the overdrive mods should do the trick. Losing some of the acceleration won't be an issue because at present it will spin it's wheels into second gear from a standing start! This is no good as I wanted a van that would cruise all day at a relaxed 70mph and be economical, not a drag racer! So the mods should sort this. I can also go bigger on tyres to 225/75x16 if needed too which will give me another half inch. We hired a big Iveco the other week for our business and it was fast, but the V6 LT left it for dust up to 60mph, when it ran out of steam. The bigger wheels will fix that. Incidentally, my other LT is a 1979 2 litre petrol, and that was slow too 'till I rebuilt the engine with a slight over bore and some Porsche 924 oily bits instead of LT spec. Now, it's still not a sports car but it is faster than this 6 cylinder van was as a diesel. I also have loads of pictures of that full rebuild as well if people are interested and are not fed up of me yet???!!

Unfortunately Andy, I don't have pictures of the engine being built, just what's in my head! Also mine is a low top van. If you have a high top or a camper, of course the engine struggles that bit more. I have loads of pics of body resto though if you want them I can email them to you. If you think they're worth it, and if you don't mind again perhaps you could upload them to a new thread? Up to you... Out of interest, I also measured my old van up for an engine transplant before I decided to rebuild. As you're aware, the floor of the old van's is significantly different to the newer 6 cylinder ones. However, the engine I settled on was a Montego Turbo petrol engine, running LPG. If you remove the front drive stuff off the engine, turn it the proper way and mate it to a Rover 3.5 5 speed gearbox with 2 litre petrol Sherpa van  rear engine plate and bellhousing you're in business! It fits in real well and gives an easy 160bhp and suitable torque, while still retaining the all important 2 litre engine size for insurance purposes. And, all the aformentioned bits just bolt together like they're meant to be there. You also use the Sherpa van clutch and flywheel which is much bigger and designed for commercial use. Sorted!

Hi Paul, A small block Chevy is a fine engine.... but rather big, wide and very heavy! You'd probably be into some serious structural  mods to get in in place, and you'd have to have some serious cooling system to keep that running cool inside the cab. I 'd love to see that fitted though! Scorpio 2.9 would be fantastic as long as you're handy with wiring. It gives out a lot of power and torque.

There is also the proble that you don't want to make a van too fast if you are still planning on using it as a van as it becomes very hard to control. The best conversions to anything I've ever done, have always been the ones that have achieved the best balance, and not necessarily the ones that looked best on paper or in my head! Incidentally the smaller Chevy engines are not worth having. They generally weigh the same, achieve similar (poor!) MPG and take up the same room. Also parts for the 350 (5.7 litre) are dirt cheap and the sky is the limit for power. Still don't recommend one in an LT though... Although you are correct when you say the instal would be the same from a connecting up point of view. Also, although Chevy engines are still reasonably cheap here, 5 speed gearboxes are definitely not.And, if you go the auto route, you once again have the revving it's nuts off at 60mph that you won't be able to do much about.

Hi Jam-man,

as an owner of a 2.0l i would be really interested in the re-build info that you worked out from your van and quite what you did! Love my van as i do, its engine really could with help...

Cheers,
Andy

Sounds like for us 4cyl guys that the montego turbo option is the best bet.
Trouble is I haven't seen one for years, a mate of mine had a 1.6 which did well over 200k without any major issues so I assume the basic motor is fine.

Jam-Man can you give us an idea of how available the parts recommended are and at what cost please.

Cheers

Andy

Hi guys. I actually meant the 2.0 turbo petrol unit, but as BeJay points out quite correctly the 2.0 turbo diesel is also an extemely fine unit and still plentiful. I just bought a whole Montego TD just for the engine and box to upgrade my trusty old Maestro van from diesel to turbo diesel. The whole low mileage (but rusty) car only cost me £350 on Ebay. My Maestro diesel has done 320 000 miles and still uses no oil. In that time it's had one head gasket... The TD unit, is indeed a Perkins Prima, but is infact a modified petrol unit effectively. It is extremely strong and durable and has no major flaws. As you can see from the Landy boys, these engines are good, and are also beautifully made... The same gearbox options as explained for the petrol one would work. While the petrol versions are not exactly plentiful now, they are still available, particularly in later (even more powerful) twin cam versions in the Rover range from 200 series up to 800 series. Although these have more complex wiring with fuel injection whereas the Montego/Maestro turbo is simple and runs a pressurised SU carb. As I say, they are not exactly plentiful, but are around. I mentioned it only as it is a perfect engine and the only one I measured up at the time. The 2.0 litre petrol injection engine would still be a good unit at around 120hp and is far more plentiful. The wiring is again fairly simple even though it's injected. So, as you can see, anything from that family petrol or diesel would be a good choice I think. Especially as the gearboxes are still very reasonably priced on ebay. For the diesel option you simply use the 2.0 sherpa gearbox instead of the Rover one. All engine conversions take work and lateral thinking, but it does help if the engine fits the hole in the first place without significant modification to the van's structure. You'd be amazed how much time and trouble that saves. 

Looks like a few of us on here have got the engine swapping madness!! Fantastic.... It's incurable you know when you get going!

The gearbox linkage is definitely the hardest part. but we've managed to make it work ok. Better than it was as a VW in fact. It just takes a lot of minor adjustments, refitting and testing. It also depends a lot on the type of gearbox you use and the gearchange it has. Don't forget, your existing gearbox is way back there under the bed as well, so it's 'only' a case of modifying the existing arrangement to fit your new box.