LPG conversion on M30 engine?

[jam172]

Just wondering if any one has experience of converting an E28 with M30 engine to LPG?

Some questions:

1. Can it be done?
2. Likely approximate cost?
3. What is the performance loss?
4. Would the car be dual fuel between petrol/LPG or soley LPG?

As a yearly crusade i always have a long weekend in Cornwall, and i always go in either my E28 528i or my E3 3.0si; but not this year with the fuel prices i simply couldn't justify using them, so i took the E30 Touring. Don't get me wrong i love the Touring, but it's my daily driver.

We usually expect some traffic hold up on the journey down from Sussex and back, this year the roads were clear, and the resorts fairly empty,( on a bank holiday weekend ) i recon everyone is feeling the effects of rising prices, not just on fuel.

Any advice on LPG conversions would be greatly received, at the end of the day, if it gets to the stage where i can't afford to use my cars, i may as well sell them

[gareth]

ahaa, this is why my M30 touring has a half fitted LPG setup!
i do happen to have a complete full M30 LPG setup with a choice of 2 tanks (one half full) in the garage going spare

1. it can be done
2. depends on if you buy used bits... a few hundered nuggets will sort it
3. generally reckoned to be up to 5% on a mixer setup which is all a simple M30 will need
4. switchable while driving!

if you're over this way, you're welcome to pop over and have a butchers at the bits and my part finished installation if you like?

[StuBeeDoo]

It's certainly do-able.
Performance loss is negligible. As Gareth has said, it's dual-fuel.
You can get bargains on eBay as Brian will testify. I didn't want to chance it as it was my first attempt so I bought new for £700. I saved that much in fuel costs in about 9 months/10k miles.
Don't let anyone who claims to be "an LPG specialist" or LPGA member to tell you.....
1) You need an injection (SGI) system.
2) "It's never worth it on a car that age - you'll only get loads of trouble".
3) It's illegal to DIY-fit LPG.
4) Mixer systems are illegal now.
I heard them all (plus a few more....) and they're all un-truths.

Go for it Dude! You'll wonder why you didn't do it years ago.

[Brianmoooore]

You can get bargains on eBay as Brian will testify.

Latest one was £65 for a complete (if very basic) E30 325 system!
Don't get me started on the LPGA! The nearest installer (and LPG member) to me is undoubtebly one of the most arrogant pricks I have ever met! Every time we have met, we have argued within minutes.
Fortunately, after failing to set the world of the BTCC alight last season, with his LPG powered car, he has now cleared off permanently to Spain.

[Andyboy]

Some LPG kits are so good, the performance difference is undetectable. I once drove an E39 535i with the Prinz system and you could switch from petrol to lpg under full throttle and not tell. That's impressive! (and expensive).

[Brianmoooore]

If you build an engine where the compression ratio is increased to take advantage of LPG's higher RON, and optimise the ignition advance curve for LPG's different burn characteristics, then you should end up with an engine that produces noticeably more power than the original.

[jam172]

ahaa, this is why my M30 touring has a half fitted LPG setup!
i do happen to have a complete full M30 LPG setup with a choice of 2 tanks (one half full) in the garage going spare

1. it can be done
2. depends on if you buy used bits... a few hundered nuggets will sort it
3. generally reckoned to be up to 5% on a mixer setup which is all a simple M30 will need
4. switchable while driving!

if you're over this way, you're welcome to pop over and have a butchers at the bits and my part finished installation if you like?

Thanks for everyones replies, Gareth can i take you up on the offer to pop over and chat about the set up that you've got and please PM me with cost details for your spare set up, i would put it on the 528i?

Come to think of it are you going to the America Diner on Saturday night?

[gareth]

i'll pm you in a sec.
not coming saturday as i've got the kids

[jam172]

If you build an engine where the compression ratio is increased to take advantage of LPG's higher RON, and optimise the ignition advance curve for LPG's different burn characteristics, then you should end up with an engine that produces noticeably more power than the original.

Ok, i have had a chat with Gareth that lives 20 miles from me and he has offered me a set up from an e32 to put on my E28 528i, so more questions i'm affraid:

1. Will anything need to be adjusted in the way of timing etc, or does the set up allow for such things, i know it is a stupid question as it is dual fuel?

2. My 528i is mint and so I am worried about cutting too many holes in the body for pipework, in particular the LPG filler, does this have to be external, or can i have the filler neck inside the boot space?

3. I am insured with Aon, is it likely i will pay extra on insurance and will need a certificate from an LPG installer?

Sorry for all the questions, and thanks again.

[gareth]

1. the timing should in theory be tweaked. if you upgrade to an AEB leonardo setup, it has the facility to do this for you when you switch over (i think!). i guess other lambda control setups will do this too?
2. you can't mount it inside the boot space itself as the actual filler point needs to be external. the rear of the filler needs to be enclosed and vented externally in case of leaks. i've mounted mine on the towbar.
3. give them a call?

[Brianmoooore]

I'm afraid the Leonardo, although doing a good job on the fuel mixture, doesn't have any effect on ignition timing.
IIRC, AEB do an ignition processor as well, but it seems to be generally accepted that it's not worth the money for the difference it makes.
LPG is more dense than air, so a leak from an internal filler would fill the boot with an explosive mixture. Not a good idea!!
The filler connects to the tank by 8mm copper pipe or flexible hydraulic hose, so it's easy to fit virtually anywhere legal. Has to be 200mm from the exhaust, within the 'plan' of the vehicle and not in an enclosed space, so towbars, bumpers, behind number plates, or even under the bonnet are all possibilities.
There's only one way to find out about the insurance, and that's to do as Gareth says.
There's absolutely no excuse for charging extra on insurance for what is arguably a 'safer' car, so, if they try it on, insure elsewhere! Most insurance companies treat the LPG installation as an 'extra' , however, and won't pay out anything for the gas kit in the event of a total loss.

[jam172]

I'm still going to do the installation and Brian, i had thought of the idea of concealing the filler behind the rear number plate, that's where the petrol filler is on my E3 I was think that i would use German style plate holders and conceal it behind that

Thanks for all your help eveyone, and Gareth I am hoping to make it over to yours on Sunday, late aternoon?

[gareth]

ahaa... just popped out to the garage and it seems i have an add-on aeb ingition controller so not included within the aeb leonardo itself

sun afternoon is cool with me, i'll be in

[jam172]

ahaa... just popped out to the garage and it seems i have an add-on aeb ingition controller so not included within the aeb leonardo itself

sun afternoon is cool with me, i'll be in

That's good news, i'll give you a ring when we are on our way.

[gareth]

good new for me that is... it's going on my car!