LPG Conversion to '97 Manual Legnum

[adaxo]

[MarkSanne]

Yay!!!

[disco-ian]

Ok so broadband is back up and running. Going to try and add the pictures as previously advised in this thread.

So here is a picture of the LPG nipples in the upper intake manifold. Orginally I had then mounted in the lower manifold the same as I had seen on other conversion on this forum however with my style of injectors it was tricky to get short pipe lengths and the car did not run well. So I revised the fitment like so. You can also see the Magnecor plug leads that I fitted at the same time. Also when fitting the leads I closed the plug gap up to 0.6mm. My NGK Iridium BKR8EIX plugs had not turned up at this point so I left the NGK PFR6B plugs in but just re gapped them.

Incidentally I am not sure if the NGK PFR6B plugs are right as standard as the number if hugely different from the other one listed above. The no 8's have now turned up but I am not going to fit these until the 6's give me issues or due scheduled maintenance.

magneocr_lpg_nipples.jpg

(oh, inserting images, looks like I might have the hang of this :-))

So next you ca see the third manifold pressure take off point that I have added for the LPG system.

Both the MAP sensor and vaporiser will T-piece to this one take off. I also plan to use this take of for my boost gauge when I fit it.

map_take_off.jpg

ECU and MAP sensor fitted beside the battery

ecu_map_sensor.jpg

And here are the injectors connected up to the manifold. I have since made a bracket to hold these securely as well (picture to follow with next batch)

injectors.jpg

I have not yet got pictures of the tank however have a little work to do in the boot soon so will grab some pictures then along with a picture of the vaporiser.

I cut into my petrol injector looms where as some kits come with the correct type of plug so its a simple plug and play loom. The wired looms that I got kind of worked in my favour though for the following reason.

The LPG ECU has two looms one for each "bank" on the engine and the kit then assumes that you will use one set of LPG injectors to fuel that bank of cylinders. Now with my layout of the injectors to nipples on the manifold I have my first three injectors (A, B, C) fuelling cylinders 1, 2, 3 on the engine (of course these are not all on one bank). So if I had the plug and plug petrol injector looms I would have then had to mess around with plugging the correct LPG injector to match the right petrol injector that it was copying. And of course remember this criss cross affaire if I ever needed to diagnose a fault or unplug anything.

However I wired the petrol injector loom for cylinders A, B, C (normally this would be cylinder 1, 3 and 5) into cylinder 1, 2 and 3. Making life much easier for me. - Did that make sense, I'm not sure it does when now reading it back, but it's late so corrections will have to happen tomorrow if needed :-)

I have now managed to get the system to turn back to petrol at full throttle hard acceleration from low speeds. I think this might be down to loss of pressure due inertia as if accelerating with WOT at slightly higher speeds it does not switch back to petrol at all at any rev range. So I little bit of work to do there, not that I drive like that very often ;-)

If anyone has any questions please let me know.

[disco-ian]

OK so been outside in the nice weather this afternoon working on this again.

Been in the boot today just finishing things off and got some picture for you all.

So here we have the filler
Filler.jpg

Then the tank installed and a close up of the multi valve
Tank.jpg

Tank_Valve.jpg

And here (the work I actually carried out today :-) Cutting out the space wheel cover so it will still support the boot floor.
Boot_inside.jpg

Boot_Finished.jpg

[adaxo]

Looking good, even mulitivalve fitted correct way round

Two questions thou, is UK LPG regs not state that filling point must be fixed to metal body??
What did you use to cut plastic tray? ax?

(only joking)

[disco-ian]

I'm not sure about the mounting but it's really secure and the tester was happy with it.

An ax lol. No a 4 1/2 inch angle grinder. :-)


Sent from my iPhone using Tapatalk

[fassi1]

To be honest the nozzles (gas inlets) are fitted in wrong place and wrong possition on the manifold intake.
This reducer will never feed that engine properly and 6mm multivalve is max for 160bhp, not for 280bhp.
Fitting 6 injectors in line with gas feed from one end like on that picture will never work properly, there will be big pressure difference between first and sixth injector, not acceptable.
The other thing is that these injectors are too small for this engine. One of them will do properly max about 40bhp.
This engine runs in open loop for about half of its whole range of the load (from mid to max) so set up based on stft and ltft does note make sens, only AFR.
Below picture with the nozzles in the right possition.
Sorry for beeing so honest

[disco-ian]

Thank you for your comments. But I believe your opinion to be wrong. Thats the nice things about opinions they are not fact based info. And for sure what I have posted in the past is possibly my opinion but also some fact.

I have years of experience with these OMVL, Romano, Tartarini etc kits on many engine types including the 400 bhp Range Rover Sport and the OMVL HP vaporiser does't struggle to supply fuel to that engine with a 6mm feed from the multi valve so I see no issues there through experience and also through other comments from another converter who certified the kit.

The banks of injectors are not piped in series there is a T-piece beside the air box!! Don't post things when you don't know what you are looking at, you can clearly see the blank on the end of the right hand bank of injectors.


I like how you also know the nozzle size that I am running in the injectors????

However, all of the above is irrelative. The engine runs fine on LPG. OK not got the wideband wired up yet, but if the engine was running dangerously lean then there would not be any power there and I have plenty of adjustability left in the system to increase injector timings or vaporiser pressure.

With regards to injector nipple location on the intake manifold I would have preferred to have them closer to the petrol injector location however it was not possible as previously stated in this thread. Keep this in mind though. a carburettor mixes fuel with air miles away from the injectors however ran fine even when forced induction was used. Then we progressed to single point injection. Again no problem here even when turbo charged. Then of course as technology evolved multipoint injection was born which then progressed to sequential injection.

OK so of course the most up to date injection system a full sequential multi point injection system is going to give the best overall results for power and efficiency. However this does not mean that any of the previous ways of delivering fuel to the engine were wrong!!!!

Please do not take this as a personal attack however your post above seemed like an attack rather than I positive post that might have been trying to be helpful.

Please try and keep thread posts positives as negativity simply drives members away from clubs.

[disco-ian]

I have just noticed that you are an LPG installer. I fail to see how you could throw such negative comments towards me when you could have simply offered advice and asked questions.

[fassi1]

Don't take this post as a negative comment, i agree it sounds like it, it wasn't my intention, sorry. I offer my help to everyone at this club.
From my experiance most of the LPG components are highly over valued and never perform as manufacturer guarantee.
My intention is always convert car to LPG and make it performing as well as on the petrol so still reckon that 6mm inlet multivelve is too small for VR4 engine.

[disco-ian]

Hi Chris,
Thank you for your reply and I'm glad that there is another person on the LPG band wagon :-)

If the option was there to me while ordering I would have had a 8mm outlet on the tank however the option was not there (I can of course always change things later if I need to ) I have already covered all of this in previous posts on this thread. I am already running a 8mm pipe front to rear so am ready for it if I find I need it.

However as previously stated decided that it would not cause a major issue to me as have run 400bhp Range Rover sports on the OMVL kit with the same vaporiser and feed to it without issue. So fuel supply to injectors is tested to at least 400bhp by my own hands, however of course the Range Rover sport is a V8 so used 8 injectors (again the same type as I have fitted) which works out to 50bhp per cylinder. And of course on our engines (standard setup) we have about 50bhp per cylinder.

This is the logic that I was working on along with discussions prior to installing with the supplier (not just a third party installer but the actually importer of the OMVL kits)

Again I do appreciate you posting on my thread however it did come across to me the way I read it as being very negative. However water off a ducks back mate.

I often post on this forum and state that I am just throwing the idea out there for it to be discussed as I am a strong believer that two heads are better than one. Other people outside of projects often have great ideas as when working on a project yourself you can very easily get stuck on one train of thought and are too close to the project to see other things.

[fassi1]

No offence mate. I love discussion about LPG as i reckon that car can perform as well as it does on the petrol with the right converssion.
Have u tried: from 20-30mph 2nd gear, WOT, 3rd gear, WOT and up to about 130mph?
What is ur gas pressure, petrol timing and gas timing at the idle, what is ur gas timing at WOT and 6000rpm, what is ur max gas pressure drop from the value at the idle?

[disco-ian]

Figures I can not give you as I am not able to look at the computer screen whilst driving. Although I have tuned the correction map at idle to ensure the petrol injector timing do not adapt away from what they are when running on petrol. Not that it took much adjustment lol

LPG injector pressure is set at approx 2 bar however I have not checked this since the first install so it might have settled down a little now.

Drivability I can talk to you about.

Any gear from 1000rpm WOT pulls just as well as on petrol. There is a slight miss (or lean spot) through about 2500 rpm which passes in a second and I hope when I get the wideband installed I can see whats going on and adjust fuel accordingly. The car will pul 5th gear on LPG from 20/25 mph without a problem. 2nd gear up to 60mph (rpm limit nearly) no problem.

I was able to get to an airfield the other day and got her up to 120mph without issue on LPG.

WOT gives no problem if already rolling however if you go WOT from a junction (i.e. 0-60mph run) then she will switch back to petrol at the moment if the fuel tank is not full. I believe its because the fuel is moving around a bit much in the tank however again I can confirm more when I can look at the screen while running (I need some screen logging software really). Interestingly thinking about this now (again why I like discussing things out loud) if the car was on a rolling road it would not switch back to petrol on WOT as there would be no inertia there to throw the fuel around :-) so just rolling road tunes should always be backup up with a actual road test / tune ???

[disco-ian]

Out of interest what LPG system do you normally fit?

[fassi1]

I normally use AC Stag or LPG Tech and they can log the data, great stuff. Can set ut many others.
Missfire caused by lean mixture. From mid load up to max load ECU doesn't control fuelling on this engine as it runs in OL so proper set up can be done only with wideband as this engine can run very rich with AFR even 9. Do u get duty cicle overlap under the WOT and max load?

[disco-ian]

Like I said I do not have the ability to look at the injector timings etc while on WOT or driving at any speed at the moment.

Am looking forward to getting my wideband installed though.

Sounds like a nice feature on the stag ecu to log the data. Maybe I am not looking in the right place on my software for it. I'll take a closer look next time I'm "plugged in"

[adaxo]

Ian, make sure you come on next Sun to Japfest, we (myself and Chris) will be there so we can have a proper chat

on serious note, I hope we all can meet at some point on dynoday and then we can see/discuss/share all aspect of LPG in real life.

[disco-ian]

Unfortunately I can't make next Sunday. Chrissy's work (my partner) have an open day (extravaganza) so will be going along to that and my parents are possibly bringing there '68 Daimler down so had better turn up to see them also lol

Seems like I'm going to miss the local mini meet happening later this month also as I'm going to Ten of the best in york. lol.

Hopefully I will make a meet at some point as like you say I would love to meet up and chat, discuss ideas. See how others have done things etc.

[disco-ian]

on the dyne note once I have it tuned on the wideband I do want to stick it on a dyne to get a petrol and lpg graph and know what I'm starting with in terms of tuning if I ever have the funds to do something more with the engine.

[fassi1]

Yeah that would be great to meet up.
I mentioned duty cycle overlap cause when that happens AFR is uncontrollable, injectors suddenly start throwing out a lot of gas and if the gas pressure drops too low it gets too lean what may cause misfire. In this situation we have power loose and poor economy.
It's great to be able to log all the data so u can keep an eye on all the parameters.