I'm with OB, looks neater than mine for sure, will look at tidying mine up after new engine is in next week,, welcome to cheaper motoring

Oi, where did my post go? Brilliant job Tony, much better than a lot of professional installs I've seen. One thing that I maybe should have mentioned before is the coolant plumbing. On something like a P38 where the heater is full flow, it's better to plumb the reducer in series rather than parallel. On mine I've gone from the heater feed to the reducer first and then on to the heater. Only one pipe to cut into so less chance of leaks and there's full flow through both. With them in parallel the coolant will take the path of least resistance so you can get a reducer that is slow to heat up or a heater that never gets above lukewarm.

Thank you for yor kind words guys.
Richard that was what I thought too, I had two cons to consider. One, the hose from the pump became a bit long or I had to bend the steelpipe directed to the vapouriser. Same for the hose that goes to the heatermatrix, I have tried different lay outs but was not happy with it. Now I have two relatively short hoses in parallel and have to wait and see what it's like in winter. The screen at the mechanic showed 92º C as coolanttemperature, the vaporiser acts as a heater and I am worrying about the temperature of the fusebox next to it...
If there is no heat in the cabin, I'll plumb them in series. As for the O2 sensors, they are both connected. Is it beter to keep them connected or can I disconnect them (therefore the cheapy connectors)?

In the piccy as it is now, I have still some work to make a nice harness out of the bungying wires.

Thank you all, Tony.

Not quite as easy as it could be as your reducer has both coolant connections on the same side rather, than as most, one on each side. If I was doing it, I'd run a straight hose from the inlet manifold (no 21 below) to the reducer and then the outlet from the reducer to the heater matrix.

As for the lambda sensors, I'd leave them connected if you have the software and cable to look at what the system is doing. If you don't, there's no point as the only reason for connecting them is so they display on the screen. Without them connected you need an OBD reader (or a Nanocom of course) to see what they are doing when running on gas.

Well Richard you covinced me about rerouting the waterhoses, one concern is still the smaller in- and outlet of the reducer which are 14mm OD, the heaterhoses are 19mm ID.
I don't know if it gives a restriction in flow.
Now I'm fabricating the bigger strips for the tank, when I return to the tester I'll buy their cable for the (free downloadable) software, it is read only though, you can't store changes to the ecu. Maybe a bottle of brandy does wonders to the mechanic ha ha.

The photos are really good, thanks for taking the time.

The hoses may be 19mm ID but by the time they get down to the O rings and heater matrix, they are down to 15mm or thereabouts anyway so it doesn't make any difference to the flow (or doesn't seem to on mine). Mine was in parallel when I first got it and in the middle of winter while idling waiting to get into a car park (Christmas shopping), the heater went very lukewarm as most of the coolant was going through the reducer. On a Classic I owned previously, that was also in parallel and, being a single point so would run on gas from stone cold, the reducer would ice up within 400m of setting off as it was all going through the heater. Series plumbing on both cured both problems.

I've got the original 19mm hose going to a 19-15mm pipe connector to feed the reducer and then the same in the return hose to go to the heater matrix.

Thanks man, that's the info I need. I already have the 19-15 reducer pipes, bought them for 'you never know to become handy' and change the lot.
This time of the year I cannot judge the heating capabilities.

Cheers Tony.

Now after a week of driving I notice It's missing a beat sometimes at tickover. On petrol startup (cold) aswell on LPG (warm).
Not always , just now and then. Can it be the sparkplugs that need to be a different type? Now I have the standard Champs as from the handbook, what type of sparks do you recommend on LPG?

I use NGK BPR6ES plugs in my Thor with LPG - I've heard that specific 'LPG' plugs or double platinum or whatever marketing gimmick slang they use isn't worth the extra premium in price for them, and there was one manufacturer that had specific LPG plugs, that were no different to their normal branded ones - but at 3x the price...

NGK's in mine have been good - I haven't taken them out yet to see how they are going, but they've been in there a couple of years which for me is between 6000 and 8000 miles!)

Installed the NGK's, no more hickups!

Below the Champs that came out, they fit a 3.9 Classic but not a P38. Looks like they are dipped in talcum powder, now I remember how they came in, half a year ago I changed heads and they were in already. I thought 'later', on petrol they run ok but not on LPG.

I fitted iridium plugs in mine, then was told to go back to NGK's as these supposed recommended plugs (for LPG) can overheat the engine,, mine runs smooth with the NGK's, a lot cheaper aswell,

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Many years ago I ran big Citroen DS's (I've never been into simple cars) and would always use Champion plugs. After an ID 19 Safari and a couple of DS 21's, I got my first fuel injected one, as DS 23EFi. After running around town I would get out on a bit of open road, give it some throttle and it would cough and splutter down the road for the first quarter mile or so and then clear itself until next time it was run at low speed. I mentioned it to the service manager in my local Citroen dealer (who I was on first name terms with) and was immediately asked what plugs I was using as if I was using the same Champions as in the carb versions, that would be the problem. Stick to NGK or, if you can't get them, Bosch. A set of NGKs went in and no more misfiring. Around the same time I was racing motocross and it was a standing joke that if you wanted to enter the four stroke championship but only had a two stroke bike, fit a Champion plug and it would only fire 50% of the time it was supposed to at best.

Ever since then my preference for plugs has been NGK, Bosch, Denso, Supermarket own brand, cheap Chinese knock offs and finally, if you can't get any of those, Champions......

On a GEMS you need NGK BPR6ES or if you want Iridium BPR6EiX, but different plugs are listed for the Thor engine for some reason NGK PFR6N-11 (according to www.sparkplugs.co.uk) or BKR6EiX-11 for Iridium. I found that on LPG a set of the standard plugs are well worn after 12-15,000 miles so I change them every 10,000 but Iridium will last about 4 times as long. Whether it's worth the extra cost is debatable but it definitely isn't worth getting the 'special' NGK LPG plugs as from the spec they appear to be the same as the standard Iridium but cost about 4 times the price..

The partsstore I got them from also advised me the special LPG plugs, I guessed a tenner a plug. 'Ahem' he replied, between €24 and €32 a piece!
'But I don't sell them that many...'

Lets go for the NGK's and see how long they last. Thanks for the info Richard, I'll write down the partnumbers for future reference.

Think I've had my BPR6ESes in for a couple of years now (bought them before I swapped the engine!). They must be at least due a gap adjustment.