Rover P6. LPG or not?

Nov 28, 2007 8 Replies

Hello All,



for some perverse reason, I've decided to buy a P6 3500 V8. I'm not that bothered about economy, but I have a feeling I'll end up using a lot more than I am planning to. Well, it's either that, the Xantia or the missus' Mondeo.



It's a 1974 model, automatic running on twin SUs. Has anyone converted one of these to run on LPG. I'm presuming it will be a lot easier than a fuel-injected car.



Thanks for any tips! Cheers



Mike P


Well, plenty of V-8 Rovers have been converted so apart from the actual tank it should be easy?

A 5 speed box from an SD1 helps the MPG too and is a fairly easy fit.

Good man!

I removed a kit from a 3.5 Range Rover a couple of years ago. There was nothing very sophisticated about it at all. Loads of Rangeys have been converted, so there should be a wealth of information out there.

Remember you're not going to have much boot space left. A boot mounted spare wheel would help a bit.

Mike, I've converted more rover V8 engines to LPG than I care to think about, mainly in landrover based vehicles but the basic engine is almost identical bar the shape of the front timing cover and water pump. Your engine is classes as a "pre-SD1" type, which brings about a couple of minor issues to consider when gassing.

  1. Valve seats. The early style heads are not certified for unleaded (although I know of a lot of engines that have run on it for years with no issues) so to play safe, as gas has no lead either, either fit a set of later cylinder heads (late sd1 or early 80's rangerover will fit straight on and have the dual advantages of being both unleaded compatible and slightly larger valve sizes) or fit a "Flashlube" kit (around £50) as part of the LPG conversion. If going the head route, take the oppertunity to have them skimmed 0.030" and use the later composite gaskets for better sealing.
  2. Your distributor will either want replacing with a rangerover electronic type, or some sort of electronic conversion to replace the original points and give a fatter spark for the LPG. Leads, cap, rotor arm and plugs need to be PERFECT - use only genuine Lucas caps and arms, leads from landrover, and NGK plugs. Regardless what you do with respect to carburettor "piston lifters" if indeed you choose to use that system, over time the carb needles and metering jet will wear - not too expensive or difficult to replace though. Badger.

Having owned a P6 in the past, the main problem I would see is where to mount a decent size tank without making the boot unusable.

Yes, I've wanted one for many years, my best mate's dad had one when I was at school. I've finally found one I can afford, it's not perfect but it's got nearly a years MOT and isn't too rotten. Interior is *shocking* though!

Yes, I'll get the spare mounted on the boot and stick the biggest tank I can fit in there. I hardly use the boot in any of the other cars, so I don't see it being a problem at all.

THanks for the reply! Mike p

Thanks Badger, how possible is it to do this lot at home? I do have some mechanical knowledge (ex-citroen mechanic but not since 1991) and I've rebuilt 2CVs and changed engines in Saabs before now..

Cheers

Mike P

No doubt someone will correct me on this, but ISTR that you need more than just a bracket. Stronger boot springs and some strengthening? You may need to find a complete boot from a car that's already had one fitted.

Having just changed some rear suspension bushes on my P6, I'd suggest you take care to retain access to the boot sides where there are two bolt heads, and also the top of the cross member thing where there are two access panels for the diff mount bushes. Check whether any welding is needed around the former area first too. They often go there - mine had a hole I hadn't spotted.

Thanks for the tips guys. I intend to run the car for a few months, to see what fails or drops off, then I've got a unit with a lift in it for 3 weeks in Feb, during which it's going to get as stripped as possible, any welding done, bushes replaced etc. Then I'll go for the LPG..

I'm quite excited by all this. It's the first real "classic" I've had, unless you can count 2CVs, GSs and Capris in that ..

CHeers Mike

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