AuthorTopic: LPG hints?  (Read 1996 times)

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Offline Andy C

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LPG hints?
« on: April 24, 2006, 20:32:35 »
So many questions, so little space! Anyway,  does anyone have any hints for getting the best out of a carbed LPG v8 RR engine? Tuning and setup hints cos its running a bit rough at the minuite. Thinkk its the timing but what do I set it to??? :?:
Thanks again
Andy

Offline murph

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LPG hints?
« Reply #1 on: April 25, 2006, 00:18:14 »
Sounds just like mine was the other day, come to that still is.

I checked my timing and it was way out, so retimed to 4 degrees before and it made a big difference.

I still have a problem which has to be fuel supply, over 3k revs it will not pull, will reve out sitting still no problems.

I have taken some advise and the next step is to strip and clean the cards, SU's don't like LPG or so I'm told.

How does it run on petrol??
Murph
98 P38 V8, RPi chipped, 18" alloys 2001 lights, privacy glass.

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Offline Range Rover Blues

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LPG hints?
« Reply #2 on: April 25, 2006, 01:48:37 »
SUs don't like LPG because they run dry, eventually they will wear out and not run on petrol so you need lifters for the variable venturi ie the piston.  Also think about a lubricator, these are about £35 and the oil protects your valves etc.

If it's runnin out of steam at 3500 revs then either the evaporator, the big black thing , is too small or the gas ring is too small, or it's set up badly.  It's not uncommon to see V8s with inadequate LPG systems that restict power at the top end.

LPG will also run with a CR of about 12.5:1, but you'll damage the engine runnin gthat on petrol, as you will with the ignition advanced beyond the recomended 4 or 6 deg depending on year.  I have an ignition advance module that, although water shy, works by advancing the timing 4.5 deg when on gas and running above idle, it gives the car a bit better torque too.

You also need to check it's not runnin g lean as LPG is much harder to ignite so at higher engine speeds when the spark is weaker you may get a missfire. Have you closed your plugs up by about 3 thou?
Blue,  1988  Range Rover 3.5 EFi with plenty of toys bolted on
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Offline Greybeard

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LPG hints?
« Reply #3 on: April 26, 2006, 13:20:07 »
You also might want to try changing your plugs. Recommendations seem to be NGK BPR6ES.
Is it on electric ignition or points and condensor. If the latter try a new condensor.

Steve
1999 Disco V8i  mmmmm  nice. LPG Conv.
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OMVL LPG Kit, 10 Bolt Heads, 2" Body lift.
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Offline Andy C

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LPG
« Reply #4 on: April 26, 2006, 22:22:34 »
Yea I think the timing is all over the place, it pinks a bit on petrol although it seems to have a bit more power. Still not as quick as I had imagined tho. 120 odd BHP from a V8? :cry:  Wheres the rest of them :?:  Its going in to an LPG specialist next Wed for a setup. Apparently its a BRC kit which is a good one and can cope with up to 6 - 7 litre engine.

Offline Greybeard

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LPG hints?
« Reply #5 on: April 26, 2006, 22:38:53 »
Dont forget the weight the V8 has to pull. 120bhp is not a great deal in todays terms, not when you consider a Suzuki Hyabusa GSXR1300 produces 174bhp to propel a motorcycle that weighs less than 500lbs. A RRC weighs nearly 6000 lbs.
1999 Disco V8i  mmmmm  nice. LPG Conv.
1990 3.9i Vogue SE offroader.
2" suspension lift including Shock mounts.
OMVL LPG Kit, 10 Bolt Heads, 2" Body lift.
265 x 85 x 16 Grizzly Claws. MPS 4x4 Steering Guard.
SuperWinch EPi9, First 4x4 Winchbumper.
Braided brake lines. Sraight Thru pipe instead of back box for that delicious noise , mmmmm !!!!

Offline Range Rover Blues

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LPG hints?
« Reply #6 on: April 28, 2006, 16:10:53 »
Quote from: "Greybeard"
You also might want to try changing your plugs. Recommendations seem to be NGK BPR6ES.
Is it on electric ignition or points and condensor. If the latter try a new condensor.

Steve


Go for BP6ES if you can get them but either are good plugs.  If you can find the £65 then fit platinum plugs :shock:

Coming to the pub on Wed?
Blue,  1988  Range Rover 3.5 EFi with plenty of toys bolted on
Chuggaboom, 1995 Range Rover Classic
1995 Range Rover Classic Vogue LSE with 5 big sticks of Blackpool rock under the bonnet.

 






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