Considering LPG conversion for your XC70 - then read this

[kat]

Being based in the UK and looking to an increased use of the XC70 I have been seriously considering an LPG upgrade to take advantage of the rather cheap fuel £0.97 for petrol per litre vs £0.49 for LPG as it stands at the time of writing.

I enquired with a few companies as a number of different sytsem available. Guide price ranged from £1500 - £1900 plus VAT.

BUT, one company who do a lot of fleet conversions checked back with one of the suppliers how good the conversion would be for the engine, below is a cut and past job from the email they sent me.

latest information from Prins NL, our preferred supplier, states that the 20-valve 2500 Turbo (2003 onwards) as used in the XC70, suffers from valve seat recession on LPG. This means unfortunately without expensive cylinder head modifications (hardened valve seats) you will have a very expensive bill looming after conversion. Should you wish me to provide a detailed quotation for the head mods, I will do so, but to give you a rough idea, expect to pay circa £1500.00 + VAT on top of the conversion which would be £1900.00 + VAT.

My car is MY04 and therefore counts the car out which is a shame but the benefit was marginal anyway so I am not too bothered about it. Guess this would apply to XC90 owners as well and somethnig to be aware of if buying second hand.

[AWD*V70XC]

That might be so for LPG but would CNG fall into the same boat? Maybe you could go back and ask them if CNG (Compressed Natural Gas) would have the same effect, if there is a difference you can have British Gas install a pump on your property and fill away, I think the costs are about the same as LPG.

[ashpee]

Hi,

I have LPG installed in my MY'01 XC (Vialle LPI). It's combined with a valve saver system, which diffuses a regular amount of oil through the intake onto the valves. This should do the job, but I've also been told by a Volvo (truck)-mechanic that I could run into troubles after about 60000km, when the cylinder head is not modified. Now I've only covered 10000km with the system and I can say it's realy nice, no difference in 'LAUFKULTUR' of the engine, nor performance loss.

The mechanic told me that Volvo can supply a set with tougher valves and valveseats as they were mounted untill MY'97 or '98. After this date, they used weaker items, but they would be interchangeable. I didn't verify myself yet, but I intend to do so. After all, the only alternative is Diesel, and although I don't dislike the D5, I'm afraid that governments will strike back once all the new sold cars are diesels (As it is almost now in Belgium). First they promote, then they punish. And also I like the purring sound of my 5cyl gaoline engine.

CNG will, in my opinion, have the very same effect on the valves as LPG. After all, it's not the product itself that causes extra wear, but it's the physical effect of evaporation and the lack of greasing ingredients that makes the valves more vulnerable.

Hoping that I never have to share my griefs about heavy engine repairs and other costs, just look around and talk to people who use these systems (the Dutch and Italian are known to use LPG very often, so this would be the best references for you).

Bye, Hans

[Willy]

Hello,
Any idea why Volvo opted for softer valves/seats on the newer engines?
Willy

[ashpee]

That would be cost off course.

Engineers make heavy calculations to see how they can make the cars last forever, but marketeers don't want them toi break at a certain mileage. I hope Volvo expects them to last very long, but they wont bother to put in pieces that survive the car twice or three times, when items exist that, under normal circumstances (read: no LPG if not factory-fitted), do the job as well and cost less.

And, they gain twice if they can sell the car and the heavy-duty valve set separately. No one will even try to blame them or put in a warranty claim if cause for the failure is the LPG.

Sad, but how would you reason if you were in mr. Volvo's shoes? :rolleyes:

Greetz, Hans

[peterjam]

I have installed Prins LPG in my 01xc70. Since then I can hear a whisteling sound, especially around 2000 rpm - and I suspect the LPG. Does anybody have a simlar effect?

[MD-Daddy]

[QUOTE=ashpee
Greetz, Hans[/QUOTE]

Greetz back at ya! Thanks again! You...and the hundreds of silent (maybe silent for now, but when their topic comes up they provide EXCELLENT opinions) others is why I love this community! Thanks again. MDD

[ashpee]

Hi,

first of all, must say I'm flattered with the encouraging words. Thanks to you, MDD.

As to Peterjam, the whistling sound could be the gasoline pump. It always produces a kind of whistle, but if you block the fuel-flow to the fuelrail on the engine (which is done to allow the LPG to do its magic instead of gasoline), the fuel must circulate internally. This makes more noise, but won't harm your pump. I've been told they don't shut the pump down anymore (as they did on my old 740 on LPG), because the pump suffers more of standstill.

Why this would be more noisy at 2000 rpm, no idea. But if it came from e.g. the turbo, then it would be the same running on gasoline or LPG (which isn't the case as I've understood).

Good evening to you all, Hans