britishtrident
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| posted on 10/5/09 at 05:34 PM |
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LPG tintop conversion finshed -- !
Finally got it finished -- she runs
Would have finish a couple of weeks back but for easter holidays and horrid weather and the family demanding my time.
I used a Stag-4 kit off ebay total cost of the kit including tank ppie and fittings was about £520 but with a extra bits and pieces required such P
clips wire splices and some new tools the real was nearer to £590 which is still pretty cheap..
On first examination of the Stag-4 system I was fairly impressed the ECU case, wiring and connector plugs were of excellent quality. As far as I can
determine the only real difference between the Stag-4 and the Stag 300 is that the Stag-4 uses a much smaller case.
The reason I bought a Stag kit while they are not in in the high end of the market there are a lot of them about and they seem to work without
problems.
For a tank I went for a 60 litre cylinder tank mounted directly over the rear axle behind the rear seats. The Rover boot would easily accommodated a
much larger tank but keeping the weight down was a consideration as the mounting position will also raise the cg height of the car.
A 60 litre tank should give about the same range as the Rover's petrol tank.
Installing the tank took longer than expected because most of the rear structure of the Rover is double skinned so after a couple of false starts the
tank frame was re-drilled and heavy duty brackets made up to mount the tank.
6mm Polyflex pipe was used for the front to rear pipe run running down the right side of the car parallel to main brake pipes clipped at 300mm/1ft
intervals with plastic P clips pop riveted to to the floor pan.
The vapouriser was located high on the right side engine compartment bulkhead adjacent to the power steering resevoir. The Stag ECU was located left
side of the bulkhead adjacent to the battery on the removable section of bulkhead which allows for access to the pollen filter.
The Valtek gas injector rail was mounted on steel strip bracket spanning two pre-existing 6 mm tapped blind holes in the lower side of the plastic
inlet manifold.
The inlet manifold was drilled about 25mm from gasket face with 4.5mm drill and tapped M6x1 for the nozzles.
Viewed from the front the manifold nozzle position were
Cylinder 1 4 o'clock
Cylinder 2 8 o'clock
Cylinder 3 4 o'clock
Cylinder 4 8 o'clock
With this layout the hose length between the injector rail and the inlet manifold was kept to an equal 110mm for all 4 cylinders.
These position allow normal access to the manifold retaining nuts and visual inspection from above without any dismantling.
The inlet manifold did not have to be removed for drilling, only unbolted from the head turned through 90 degrees --- the manifold ports were plugged
with cloth ball pull-throughs and the head ports sealed with tank tape to prevent plastic swarf entering the engine.
The ignition switched supply to the gas ECU and RPM signal were both taken by splicing into the wiring for the coil pack serving cylinders 1&4.
The petrol injectors were rotated 180degrees to allow connection of Stag wiring
harness.
Wiring for the gauge and rear solenoid valve was looped out through the vent hose then back in to interior of the boot via the spare wheel well to run
cable tied to the car's own wiring harness down the left hand sill.
One major problem with wiring this models is that it it uses a BMW style double front bulkhead and I could see no easy route pass wiring from the
engine bay to the passenger compartment. After much head scratching I decided the best way was to roll back the carpet drill the passenger side foot
well close to the centre tunnel just below the bottom of the fuse box cover trim panel. Suitable tight fitting grommets sealed with Dumb-Dumb mastic
were used to prevent possible water ingress.
The fuel filler was fitted in the rear wing just aft of the existing petrol filler, standard 8mm plastic coated copper was used for the filler
pipe.
Now to prepare the car I
(1) Did a compression test --- 180psi on all cylinders.
(2) Fitted New spark colder plugs NGK BKR7ES gapped to 0.7mm
(3) Ran petrol EOBD diagnostic scan to check for any fault codes and made note of live data values of fuel trims, MAP and Lambda values.
After all was ready for the first fill with gas -- I made two classic errors
(1) I left the thumbwheel valve on the tank close
(2) I had forgotten to fully tighten the pipe union at the tank end on the main front to rear pipe.
Fortunately having read of others on the LPG forum making the same mistakes I knew exactly what was wrong.
Put a few litre of gas in the tank -- then a check over revealed no obvious leaks so I filled the tank
Back home connected the diagnostic software entered the sensor and coil parameters and ran the automatic setup --- but it wouldn't run on gas.
So I checked the operation of the solenoid valves and that gas was getting through to the vapour side of the system. But it still wouldn't run
on gas.
After a few minutes thinking I restored manufacturers settings and after setting the main parameters, and I ran the auto set up and it worked. The gas
metering nozzles are currently drilled at 2.1mm and the injector multipliers are between 1.3 and 1.4.
That was yesterday it has been running almost perfectly on gas ever since -- only fault seems to be running a little weak over 4,000 rpm but that
should be easily tweaked when I borrow a laptop.
My first full tank of LPG cost me £26.00 --- and that was from Morrisons who are 10 per litre dearer than a couple of LPG stations in my area.
In contrast a normal petrol fill from near empty costs £55.0
No contest LPG wins
[I] What use our work, Bennet, if we cannot care for those we love? .
― From BBC TV/Amazon's Ripper Street.
[/I]
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zilspeed
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| posted on 10/5/09 at 05:55 PM |
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LPG does win.
If you live near a filling station.
Your local filling station is also my local filling station.
I live about 16-18 miles away from it, you live about 3 miles away from it.
It will be interesting to see what percentage of your petrol mpg you get on gas.
I got between 75-80% with the Golf.
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britishtrident
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| posted on 13/5/09 at 07:29 AM |
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Tried tunning the system -- was a bit puzzled because altering the multipliers seemed to have the opposite effect from what i expected. However did a
reset on the autotune and its is now running perfectly --- on LPG it even pulls a little more smoothly from very low rpm than when on petrol.
Weird it was all just too easy.
[Edited on 13/5/09 by britishtrident]
[I] What use our work, Bennet, if we cannot care for those we love? .
― From BBC TV/Amazon's Ripper Street.
[/I]
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britishtrident
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| posted on 20/5/09 at 06:40 PM |
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After extended road testing I decided it was running lean a wide open throtlle in the 3000 to 4000 rpm band so I fine tuned things a bit but ended
drilling the nozzles out to 2.5 mm and reducing the gas pressure
[I] What use our work, Bennet, if we cannot care for those we love? .
― From BBC TV/Amazon's Ripper Street.
[/I]
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Sprytny
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| posted on 22/3/10 at 10:33 PM |
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Pictures
Hi
Do you have any pictures showing us your LPG conversion. I would be really interested in seeing these as I was considering completing an
installation.
S
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dan__wright
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| posted on 23/3/10 at 04:50 PM |
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there are some in his photo archive
FREE THE ROADSTER ONE
!!
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ken555
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| posted on 23/3/10 at 06:57 PM |
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Do you have someone that can issue a certificate of safety once you are finished?
I know a lot of companies won't certify DIY conversions.
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Sprytny
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| posted on 24/3/10 at 09:31 AM |
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LPG conversion
Hello
Do you have any pictures showing your LPG conversion/ how it was done? Did the conversion allow it to run right away. Also, how did you measure CO
etc...do have a DIY kit to do this?
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