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View Full Version : 2008 X-2 MCX fuel & LPG system


Fab
11-16-2011, 07:46 AM
As requested by many of you in my previous post, here is some pics of the LPG system installed in my 2008 X2. I guess it was installed by the previous owner (in Belgium).

The system is almost full auto, engine always starts on gas, then switch to LPG when you rev over 2000tr/min :

http://img585.imageshack.us/img585/8055/img0059do.jpg

The top button allows to force the boat to run only on gas if you want, or to enter the fuel/LPG mode.

The middle switch is used to choose what LPG tanks you want to run (Left tanks or Right tanks). As you can see the switches are installed on the stock dashboard, which was a lot confusing at the beginning as nobody told me how the system was working !

Here is the tanks :


http://img845.imageshack.us/img845/6477/img0062ym.jpg

2 tanks in each rear compartment, each tank is 27x11inch and around 110lbs full (if i don't make mistakes with conversion!)

http://img830.imageshack.us/img830/5562/img0060eb.jpg

On top of the MCX you can see the LPG injectors on each side of the engine. when engine is started on fuel, LPG injectors stays on idle, then take control when engine reaches 2000tr/min, the engine then stays on LPG even if you go lower than 2000tr/min.

Is anybody here has the same system ? I don't even know how this system is called !!

snork
11-16-2011, 08:27 AM
is there any loss in HP?

Fab
11-16-2011, 10:34 AM
for people in boat or driver we don't feel any loss in HP, but i found on the net there may be like 5 or 8% loss...I think the boat is therefore just reving a little higher to have the same power, as the engine always turn around 2500-3000 when we wakeboard, IMO of course...maybe some members here have some feedback about this...

The only thing about LPG is that you have a very small amount of time between (like 0.2 -0.3 sec) you run full throttle and the moment the engine really starts, it seems the LPG injectors have a little delay compared to the MCX fuel injectors.

Shooter McKevin
11-16-2011, 11:53 AM
A question for you and Holman, how many hours do you get out of 4 full LPG (propane) tanks?

I feel like this system might also have a re-fueling advantage for people who keep their boat on the water with no access to gasoline. Hauling LPG tanks down to the lake seems easier than hauling gasoline. Although lugging 4 - 110lb (50kg) tanks doesn't sound fun either. I guess it depends what the answer is to my rate of consumption question.

Do you guys remove the tanks to fill them or leave them in the boat? Do you have LPG available on the lake?

Also, on your setup Fab, I was thinking it would make more sense to have the tanks split outside/inside instead of left/right for weight distribution when 2 tanks are empty or removed.

How much do the tanks weigh empty?

I drove a Chevy truck running on LPG for a while, it definitely had a good lag in throttle response.

Tomi
11-16-2011, 12:19 PM
One kilo of LPG is equal in energy content to 1,56 liters in gasoline and 1,39 liters in diesel. So 50kg of LPG is equal to 78 ltr (20,6 gal) of gasoline.

Fab
11-16-2011, 12:23 PM
Tomi is right !

Yep i was thinking about splitting the tanks for better weight distribution...

For refilling, here on my lake we just dont have gas station at the lake, so we have to carry tanks of gas or LPG anyways, point is that LPG is faaaaar cheaper than gas in France, so the choice is easy...

An empty tank is around 20kgs i guess...

Holman J.B.F
11-16-2011, 01:50 PM
A question for you and Holman, how many hours do you get out of 4 full LPG (propane) tanks?

I feel like this system might also have a re-fueling advantage for people who keep their boat on the water with no access to gasoline. Hauling LPG tanks down to the lake seems easier than hauling gasoline. Although lugging 4 - 110lb (50kg) tanks doesn't sound fun either. I guess it depends what the answer is to my rate of consumption question.

Do you guys remove the tanks to fill them or leave them in the boat? Do you have LPG available on the lake?

Also, on your setup Fab, I was thinking it would make more sense to have the tanks split outside/inside instead of left/right for weight distribution when 2 tanks are empty or removed.

How much do the tanks weigh empty?

I drove a Chevy truck running on LPG for a while, it definitely had a good lag in throttle response.

There are 3 types of tanks -steel - composit-aluminium.
Steel tanks are the heavyst(sp?) composit and alu are lightwieght tanks, filled they are under 25kg.
1 ltr LPG wieght 0,5kg and expands 240 times when it vaporizes.
My portable tanks can hold 36ltr but 29ltr when filled at 80%.This is a safety barier for the lpg to expand inside the tank when temperatures rizes.
Modern lpg systems are sequental injected 8x1 pulses and work best on indmar/illmor/pcm from 2006 and up.with a good tune there is no powerloss it is also best to work with double vaporizers and larger injectors.LPG burns different than gas(petrol)so the powercurve slightly changes,but you will hardly notice this.
Keep in mind that the valve seats wear faster on lpg,i still don,t understand why GM does not install hardened valve seats from the factory like on the bi/flex fuel engines.
It,s hard to say when to change the seats,some last aprox 1000 hours some go to 2500 hours.I think it depends on how hard you push the engine.
There is a product called flashlube it helps to save the seats.

Quinten
11-16-2011, 02:29 PM
Is this lpg or an lpi instalations?
Because there is a big differentece, that's what they told me.

Fab
11-16-2011, 02:52 PM
Thx for the tips Holman, you hold the truth !! :P

Do you know how much €€ it is to install this kind of stuff (i bought my X2 with this this system already in, don't even know who mounted that stuff...) ?

BTW my (steel?) tanks are wayyy heavier than that when filled (40L per tank with the same 80% barrier), at least 50kg, that's a good warming before getting on the board !! :)

Holman J.B.F
11-16-2011, 05:45 PM
Fab
Cost on a propane conversion depends on materials that are used,...but aprox anywhere from 2500 to 3500 euro without the tanks.

dihrdskir
11-25-2011, 05:50 PM
LPG has been a popular alternative to Gasoline in Australia for decades with many fleet cars/taxis using it exclusively. Ford even make/made a dedicated LPG only engine however dual fuel is far more popular offerred by GM as well as ford as factory fit options. Our government even offers rebates on LPG installations. What gets up my nose is that our country chooses to sell wholesale to Asia at as little as one cent per litre, yet for us the consumer we currently pay between 55 and 65 cents per litre at the pump. What a rip off. When LPG was first marketed it was almost pure propane with a very high unit energy allowing 16:1 compression ratios or supercharging without risk of detonation. Now its a blend of butane and other waste gasses and more expensive. ie. No more big compression. Biggest disadvantage is the space occupied by the tanks and consumption is typically 30% higher than gasoline requiring big time hours on the boat or miles in the car to justify the installation costs. On the issue of no noticeable power difference, I agree sequential GI is fantastic but the system in my fleet/work car will switch back to petrol under high load conditions eg b/t 5000 and 7000 rpm and when the fuel changes to gasoline it is instant, noticeable and feels like you have just hit the nitrous. Latest trend here is diesel/gas injection. ie. mixing LPG with the diesel. Claims to radically increase torque and lower fuel consumption. Just my .02.

Shooter McKevin
11-28-2011, 03:40 PM
Biggest disadvantage is the space occupied by the tanks and consumption is typically 30% higher than gasoline

This was my impression about LPG as well... the vehicles need to have room for a huge tank.

The other posts in this thread had me thinking otherwise but when I look back at the numbers people have stated it adds up:

"energy of 1 kg LPG = 1.56L gasoline"
"1 L LPG = 0.5 kg"
If these are true then
2 L LPG = 1.56L gasoline = 28.2% more LPG consumption by volume (which is how you pay for it and how you determine the space needed to store it)

If 1 L gasoline = 0.8 kg (internet obtained approximation)
then 1 kg LPG = 1.25 kg gasoline = 20% less LPG consumption by weight (so lighter to haul to the dock but I'm guessing that the heavier tanks will even this out quite a bit)

Fab
11-28-2011, 04:10 PM
interesting stuff...I guess it all depends how much you pay for it compared to gas...even with 28.2% more LPG consumtion...The LPG here in france is 50% cheaper than gas...and even more cheaper in belgium if i'm right...

This conversion is nteresting for EU people, gas price in USA is still very attractive no ?

Shooter McKevin
11-28-2011, 04:57 PM
In Calgary prices are roughly:

$1.10 CAD/L (regular 87 octane), $1.30/L 91 octane (that's $5.12 USD/gal !!) (varies by $0.20/L all the time)

$0.80/L for propane as far as I can tell

Quinten
11-29-2011, 12:23 PM
In belgium
avarange
1L super 95 (gasoline) 1.49Euro/L
Lpg 0.55euro/L