PDA

View Full Version : 350MCX Convert from Liquid fuel to Compressed Gas fuel


eurosysytem0
01-13-2011, 12:19 PM
Hi TT.
I have a 2005 X7 with 350 MCX Engine>
I am in UK so to ensure we have no "english" language problems when I say "Petrol" I meand liquid fuel 95 RON (or as our US Colleagues would say "Gas"). When I say "Gas" I mean compressed Liquid Petroleom Gas (LPG/Butane).

Now to the issue. In the UK our petrol (95 RON) is circa $7.80 per US Gallon. Its becomming unaffordable for cars never mind boats.
I am thinking of converting my MCX from Petrol fuel to LPG

There is a UK trend (particularly with club boats of all makes to convert to "dual fuel" with a small reserve tank of Petrol (5 gallons) but the main fuel being Gas(LPG) stored in a pressurised cylinder in the current petrol tank compartment. This existing MC tank comes out.

QUESTIONS:
Anyone with experience of 350 MCX running on LPG?
Any issues on Engine performance/wear?
Any issues with the trim of the boat- particularly for slalom wakes with full compressed gas cylinder in rear?
Any particular LPG multi point injection system recomended?

Responses from world wide would be appreciated as I suspect USA TTs are still getting their petrol significantly cheaper than europe and therefore LPG operated boats may not be common?

Holman J.B.F
01-13-2011, 01:30 PM
I have done about 50+ lpg conversions on boats the last years.
Stay away from those impco sets,it will run but it will show engine fault codes as a result of the lamda sensors etc.beside that you,ll notice some powerloss.
If you have enough space in the back ski locker,you can instal 2 removable tanks like those forklift tanks,and leave the petrol tank in place.If not you,ll need a small petrol tank incl petrol pump etc.
I,m installing BRC LPG equipment with a double reducer -large injectors etc...it can handle up to 500HP.Works trouble free.
About wear,..it,s thrue that the valves and seats wear faster due lack of lubrication,there are products like flash lube to prevent wear but not enough IMO.Flash lube works with a vacuum,...on WOT there would be less lubrication.
New systems are tested as we speak,..injected flash lube directly on each valve synchronized with petrol injectors,..this lubrication would not be necerarry if these engines were equiped with hardened seats,..like bi-fuel cars.

the dimensions of a removable steel tank is 70cm x 30cm filled it will weight about 35 kg,and hold about 30 ltr each.
There are aluminium tanks or composite tanks with less weight.So if you do not fill up your petrol tank for a 100% it won,t mess up your wake.

Wakeboarders want to opposite,i have 4 tanks and ballast...:D

I would go with BRC Systems,..done a bunch of them and no troubles at all,...but it al depends on the people that do the conversion,..i,ve seen conversions that would make people cry.

If you have any questions just shoot.

vision
01-13-2011, 02:04 PM
I know that compressed natural gas has less energy per unit volume than gasoline and NG converted engines have about 20% less HP than their gasoline counter parts.

Is there a loss of HP/torque when going from gasoline to LPG?

H20skeefreek
01-13-2011, 06:17 PM
You've actually done the conversion? I'm very interested in what it would take to convert a carbuerated 351, both equipment needs and cost.

Holman J.B.F
01-13-2011, 07:19 PM
@H2O
you just need a IMPCO set 425 mixer & Model E reducer.

Vision
yes ,you can notice a different power curve.But 99% of all recreational boaters do not wieght their boat down with 3000/3500lbs,...i do and it takes 1 or 2 seconds longer to get up on speed.
if i need a slightly faster start i can always swich to petrol and swich back to lpg when i,m up to speed.

break even point is at about 120 hours,...after that fuel cost are cut in half.
Gas is cheap in the usa so i think it,s more a european thing,..
in the netherlands gas is $8.20 a gallon (current exchange rate)

http://www.mastercraft.com/teamtalk/album.php?albumid=364&pictureid=2523
LPG injectors and 2 reducers
http://www.mastercraft.com/teamtalk/album.php?albumid=364&pictureid=2522
LY6 Intake manifold Gas & lpg injectors side by side

JLeuck64
01-13-2011, 07:22 PM
Boy! I would be really curious to learn how the efi conversion goes! How do ya get the computer to switch between the different fuels?

H20skeefreek
01-13-2011, 10:48 PM
That's the problem. Everyone makes it sound so easy, but I think it takes more than 2 pieces, and I can't find a step-by-step anywhere. No one I've checked with seems interested in actually setting me up with what I need.

Holman J.B.F
01-14-2011, 05:07 AM
http://www.brc.it/public/TA01Z043I_P&D_EN.pdf

i,ll shoot some pics today,maybe you will understand it better.

Plave
01-14-2011, 05:26 AM
Lots of converted boats over here now.

Fueling on the lake here is near $10.00 a gallon for petrol (gas to you US guys) and LPG is around $5.30.

Makes one hell of a difference over a season.

eurosysytem0
01-14-2011, 01:49 PM
First thanks to all who have contributed. it really does make you feel part of a community. Does anyone have a photo of a 350 MCX with a LPG conversion installed. photos of the engine and the storage tanks would really be appreciated

JLeuck64
01-14-2011, 02:09 PM
http://www.brc.it/public/TA01Z043I_P&D_EN.pdf

i,ll shoot some pics today,maybe you will understand it better.

Yup I get it, thanks. That really does look like a plug-n-play system all right.

CNG is used for heating in my area, very few vehicles or refilling stations. Always thought it would be cool to have the ability to refill a vehicle at home using the CNG but the compressor needed to do that is really expensive!

Holman J.B.F
01-14-2011, 08:38 PM
today i took a set of a 2009 supra ,the owner bought a new boat and wants his LPG set installed on his new boat.So a good oppertunity to take some pics.

One reducer will not be enough to supply the engine with enough lpg mixture ,so 2 will do the job.As you can see the system has a own ECM that calculates how much mixture is needed.It does this by a signal from the Gas/petrol injectors and the info from some sensors -like map - temp - lpg pressure etc. The LPG ECM and its software duplicates the petrol values and converts this info to the ingintion values of lpg.
Hot water is send thru the reducers to vaporize the Liquid gas into a ...gas, that will be injected directly into an inlet port.So no more backfires or what so ever.

With the software you can install almost every combination you want.
For example change over times in cycles,..temp...rpm...idle...wot
Say you want the engine to run on Petrol under 1500 rpm and on gas above 1500 rpm and change over in 10 cycles one cyl at the time,it can.(just an example)
well that,s about it,..in a nutshell.

http://www.mastercraft.com/teamtalk/album.php?albumid=364&pictureid=2525

http://www.mastercraft.com/teamtalk/album.php?albumid=364&pictureid=2529

http://www.mastercraft.com/teamtalk/album.php?albumid=364&pictureid=2526

Crap..
see my album,something went wrong with the pics

eurosysytem0
01-18-2011, 07:36 AM
Where can i find your album?

eurosysytem0
02-09-2011, 12:28 PM
TTs,
I am still checking out systems to convert my X7 to dual fuel. It seems to be comming down to two options The BRC solution and the Prins Solution.

Both have multi point direct injection and both have a small petrol (gas) tank to support the LPG main tank. Both use the petrol to start and reach temperature and then auto switch over to LPG.

Does anybody have experience/recommendations of the two systems?
Regards

eurosysytem0
02-09-2011, 12:31 PM
today i took a set of a 2009 supra ,the owner bought a new boat and wants his LPG set installed on his new boat.So a good oppertunity to take some pics.

One reducer will not be enough to supply the engine with enough lpg mixture ,so 2 will do the job.As you can see the system has a own ECM that calculates how much mixture is needed.It does this by a signal from the Gas/petrol injectors and the info from some sensors -like map - temp - lpg pressure etc. The LPG ECM and its software duplicates the petrol values and converts this info to the ingintion values of lpg.
Hot water is send thru the reducers to vaporize the Liquid gas into a ...gas, that will be injected directly into an inlet port.So no more backfires or what so ever.

With the software you can install almost every combination you want.
For example change over times in cycles,..temp...rpm...idle...wot
Say you want the engine to run on Petrol under 1500 rpm and on gas above 1500 rpm and change over in 10 cycles one cyl at the time,it can.(just an example)
well that,s about it,..in a nutshell.

http://www.mastercraft.com/teamtalk/album.php?albumid=364&pictureid=2525

http://www.mastercraft.com/teamtalk/album.php?albumid=364&pictureid=2529

http://www.mastercraft.com/teamtalk/album.php?albumid=364&pictureid=2526

Crap..
see my album,something went wrong with the pics
Thanks for input.
What was the engine in the 2009 Supra?
Who manufactures the system you described?
Hows it going?
Whats the impact on boat performance, economy. ?

Any downsides to installation?
Pictures would still be appreciated