940T LPG conversion

[SalvadorP]

I am strongly considering converting my car to LPG. Gas prices in Portugal are just stupid. Price of the conversion seems to be around 1600€. According to calculation, and considering i do 20k km a year, i would pay the investment in less than a year and a half.

I know that some of you have/had 940s converted. Do you encourage other people to do it? What are the advantages/disadvantages that might not be so obvious?

[classicswede]

All my cars are LPG converted or at least the ones I use anything much. I have been installing LPG systems for over 25 years.

The 940 is a little more fussy on system and really wants one that copes with full group injection. The AEB systems do this as does KME, there could be others

The clear advantage is the lower fuel price. Oil does not get contaminated as much. Engine life can be increased

Disadvantages
1) ignition system has to be in good order and needs to be serviced more often
2) the lack of cooling makes LPG a bit harder on valves and valve seats
3) loss of spare wheel well
4) increased rear end weight


loss of space for the spare is no issue. Most modern cars do not have a spare. It is easy enough to carry the spare in the boot and take it out if you need the space

With the extra weight I would fit cargo springs


Range - you want as big a tank as you can get. A 77ltr tank fits easy but it is possible to get a 95 ltr tank in do not take anything smaller than the 77ltr (water capacity LPG fill is 80%)

[Rversteeg]

In the Netherlands there are still a lot of 940s on the road and I would not be surprised if the majority is running on LPG. My 940LPT was converted when new and has covered 730K km on LPG by now of which I did 550K km myself. I have a liquid LPG injection system from Vialle, but with the bankrupcy of Vialle this system is no longer available. This system has a pump in the tank, giving a net volume of about 54 ltr and a usuable range of about 350-400 km. More than sufficient for the LPG station density we have in The Netehrlands.
Like classicswede is saying, fuel price is much lower. However, as a liter of LPG only contains 75% of the energy of a liter of petrol, your fuel consumption will be 25% higher. The price advantage is therfore 25% less than it seems by just comparing prices.

A spare wheel is usually standing upright to the right side of the boot area.

I never noticed additional service requirement for ignition parts. What I did notice is that the building quality of the LPG system does not match that of the Volvo itself. The majority of the issues I had over the past 20 years were usually LPG-system related in some way. On the plus side, it has saved me over 25K Euro by now and when you do have a problem it does not leave you stranded as you can always switch back to petrol.
Most issues were specifically Vialle LPi system related though (eg. 4x fuel injection inhibit relay, 2x in-tank pump seizure, 2x LPG injector).

I would say the major drawback is the continuous wear of the exhaust valve seats. I check the valve clearance every 15K km and usually have to adjust one or more valves every 30K km. Shims start at over 4 mm when new, thinnest ones Volvo sells are I believe 3.3, but thinner ones can be sourced elsewhere. You reach the limit when the cam hits the bucket in which the shim is located underneath the camshaft (2.9 - 3.0 mm). Some will oppose, but I have had a few exhaust valve stems grinded shorter, giving me another 200K km without cylinder head overhaul.
Note this valve seat wear is mostly due to the slower burning of LPG compared to petrol, so at high loads and engine speed the combustion is still ongoing when the exhaust valve opens. Also contrary to petrol at full load, a richer LPG mixture actually burns hotter.

Finally running on LPG is much better for the environment. Relatively less carbon and more hydrogen in LPG produces less CO2 when burned. You see the higher water content in the exhaust gasses as white steam especially during colder periods.

[SalvadorP]

Thank you both for the incredible input.
I don't know any brands really, and I guess what is available in the NL and UK might not be the market leader in Iberia, but I might be wrong.

Seacrhing online I found a company that seems to be a good specialist in this conversion and they happen to be 5km from my house.

They use BRC equipment, which seems to be an established Italian brand.

This is the website of the guys that install it, and there is a list of different kits they use, I guess depending on the car's type of engine. The list of parts included does not mention a tank though...
https://www.ussegpl.pt/produtos-brc/

[classicswede]

The weakest link of BRC has always been the electronics, they always tended to be over complex. By the look of the Alba32 ECU it is the AEB32 so should have the full group filter.
Vapouriser is the BRC unit and they are decent enough
Injectors look like rail or Valtek injectors - not great but should they prove to be a issue not hard to change for something else
BRC are now part of Westport who have most of the LPG equipment supplier in their portfolio including AEB, OMVL, Valtek and others.

Tank manufacture does not really matter provided they fit the right size. The easy fit tank is a 650x270 0degree or 4 hole tank
best thing is to go and see the installer and see what they can offer

[SalvadorP]

Originally Posted by classicswede

The weakest link of BRC has always been the electronics, they always tended to be over complex. By the look of the Alba32 ECU it is the AEB32 so should have the full group filter.
Vapouriser is the BRC unit and they are decent enough
Injectors look like rail or Valtek injectors - not great but should they prove to be a issue not hard to change for something else
BRC are now part of Westport who have most of the LPG equipment supplier in their portfolio including AEB, OMVL, Valtek and others.

Tank manufacture does not really matter provided they fit the right size. The easy fit tank is a 650x270 0degree or 4 hole tank
best thing is to go and see the installer and see what they can offer

I can also look around for other installers. It's just that this one has website and seems to be one of the bigger ones nationally. But what are the best makers in terms of LPG kits in your opinion? If I know what to look for I can just phone a bunch of places and ask what equipment they work with.

[classicswede]

Prins tend to be considered the "best" system. The vapouriser is very good, The keihin injectors are possibly the best on the market. The electronics are its weak point, well made but basic. the big put off is only a Prins dealer can access the ECU. BRC has the same issue with the BRC produced electronics

KME from Poland make very good system. Electronics are good, Vapouriser is good. injectors opt for OMVL rather than the Valtek they most come with

OMVL, AEB electronics imo not as good as they used to be, injectors are probably the best budget injectors, vapourisers are ok but not a first choice

With Westport now owning almost all the Italian stuff the systems are mix and match more than they used to be the same parts can carry multiple brand names


You want a installer that is not too far away, has a system that works with full group like any AEB based ECU or KME that can filter the injection pulses.