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LPG conversion
Posted: 25/09/2004 02:26 PM |
| Has anybody tried fitting a sequential injection gas kit on a modern, multipoint injection, ski boat engine? I know a couple who have tried and failed with remote sequential (where the gas in injected at the air filter end of the inlet manifold), but has anyone tried one of the new systems that inject into the inlet manifold next to the petrol injectors ? |
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Re: LPG conversion
Posted: 25/09/2004 11:04 PM |
Post the same question on planetnautique.com and correctraftfan.com. These are Nautique owners sites, the members seem to have come across just about every problem related to a boat, be it mechanical, electrical, or anything else you care to think of, I understand a couple of the main contributors work for Correct Craft.
If you are not a Nautique owner, I'm sure they won't hold it against you.
Good Luck |
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Re: LPG conversion
Posted: 26/09/2004 09:09 PM |
| Thanks, I'll try. |
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Re: LPG conversion
Posted: 26/09/2004 11:45 PM |
Nick, We use a local installer for cars and trucks. They might be able to help.
GAS 01483728300 BARRY READER
GAS FAX 01483729300 sales@dualfuelsystems.co.uk |
Ski-Ya Rich
http://www.glse-southern.co.uk |
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Re: LPG conversion
Posted: 07/10/2004 02:33 PM |
Nick
I have no immediate need but would be interested in knowing what you have found out from your continued research. I used to own, (until it was recently stolen) an MC with an MPFI engine. I toyed with the idea of LPG conversion but wasn't able to get any satisfactory answers from within the boating community about systems specifically for use on MPFI engines.
Would be grateful for any info you can provide. |
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Re: LPG conversion
Posted: 25/01/2005 12:28 AM |
Nick
I've been looking into this again as a subject area. I have collected a variety of conflicting stories and explanations as to what is possible and what works and doesn't work.
Have you found a workable (and cost effective) solution yet? If so, would appreciate your input.
Regards
Jeff |
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Re: LPG conversion
Posted: 25/01/2005 10:39 PM |
| It seems that to do the job properly with a sequential systen means removing the whole inlet manifold to drill for the injectors. I have also had conflicting advice on whether the software needs the lambda sensor input that we haven't got. In the end I have decided to go for a standard Impco 425 based system but "engineered" to fit! I placed the order today & will happily let you know how I get on. The other benefit for me of going this route is that the boat will feel identical to the boats I compete behind. The plan is at the moment to go dual fuel. Have you found anything else I ought to know - its not too late yet ! |
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Re: LPG conversion
Posted: 26/01/2005 04:59 PM |
Because I am not actually in the market right now, I don't like consuming a lot of a supplier's time if I'm not potentially about to put some business his/her way. From your post, it sounds like you are futher forward than me and will know most of this anyway but this is what I have gleaned so far.....
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In the main, LPG conversions work around the old manually aspirated system whereby a mixer unit is installed on top of the intake and gas is drawn through as a vapour through the normal inlet manifold. This type of system can be fitted to all TBI engines and the very latest MPFI engines fitted to boats.
A common feature of MPFI engines in boats is that the intake manifold air intake is not in a central position with respect to the eight cylinders. For engines with a front intake and long manifold, the gas mixture leans off towards the rear cylinders and could cause overheating and engine damage. In such cases, an MPFI gas system needs to be fitted and there are a couple of ways of doing this.
Liquid injection system
This can be a dual fuel system and is around similar pricing to the manual system. The advantages are optimum power performance and good economy. There is a school of thought that very cold liquid gas injected directly into hot cylinders may be detrimental to long term engine life.
Vapour injection system
The latest systems are vapour injection. These allow for very good comparable power without the potential risk to engine life. However at moment they are expensive.
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Sounds like you are adapting your inlet manifold in order to use a standrd TBI-type system?
I have had an exchange of e-mails with George Hazlewood of Malibu who claims they have fitted "simple" systems to MPFI engines and they work fine. He quoted 1500 incl VAT to fit one to the LT1-engined MasterCraft I used to have. Here's an extract from one of his e-mails:
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We use the Impco system which does introduce the gas at the air intake. This
system is fitted on our 380HP hammerhead and has had no problems so far (900
hours). Our Malibu's have a phlenum chamber on top of the engine which helps
as the air and gas get more evenly mixed than a TBI system. There is a lot
of rubbish associated with LPG systems and we have found a properly fitted
system used on a well serviced boat is fine. The MPI LPG systems (liquid or
gas) I have seen are not capable of meeting the HP rating current boats
have. This may change as time goes on but as there are very few 300HP cars
around I can't see a system being brought on to the market at present. We
also use an additive injection system to cool any hotspots.
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I have also been quoted £2,700+VAT from a firm claiming to be the UK's biggest supplier of LPG conversions for cars. That was a vapour injection dual fuel system. They wanted a deposit of £200+VAT plus another £200+VAT for a survey to ascertain if the conversion was possible. The deposit could be credited against the installation but not the fee for the survey. Nice work if you can get it!
I don't put enough hours on a boat to justify that level of expenditure - the payback would simply be too long.
Apologies if the above is all old hat to you.
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 sjwskier
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| Joined: 31 May 2004 |
| Total Posts: 20 |
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Re: LPG conversion
Posted: 26/01/2005 08:39 PM |
| Why dont you try brian or graham at tv ski all our nautique club boats have been on gas including the new generation injected engines and we have had excellent service and no problems |
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Re: LPG conversion
Posted: 26/01/2005 08:41 PM |
| Thanks for the info - I kept meaning toi talk to Hazlewoods. The system I am going to use is very similar to theirs. I am going with twin tanks to get 140litre capacity. I will take pictures when its done, if you are interested. If you are keen for what looks like very high quality and high power capacity, look at the Iwema system - but its expensive for a conventional system. |
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Re: LPG conversion
Posted: 27/01/2005 09:06 AM |
sjwskier....
I've already spoken to Graham at TVSki. As I understand it, TVSki fit a simple throttle-body type system on all boats and, as you indicate, appear to have have no problems.
Indeed, with the latest generation of engines one would not expect to have any problems because they have centrally located inlet manifolds hence don't suffer from the potential problem of mixture strength differential between front and rear cylinders. They are easy to convert and can use a relatively simple system.
Most EFI boats sold in the mid-90's thro to 2002/3 time period were fitted with single point (throttle-body injected) systems and these are also easy to convert with a simple LPG system. It's the MPFI engines produced in that period that are the most difficult and challenging to convert satisfactorily. Boats fitted with these engines are relatively rare.
When fitted to older style MPFI engines, simply throttle-body conversions completely by-pass the advanced fuel metering provided by the MPFI engine management system. Given that most of this is aimed at increasing economy and reducing emissions, you can argue that with the fuel half the price of petrol, it doesn't really matter if the system isn't running as efficiently as it might. Also, harmful emissions from LPG are lower than from petrol. All fine and dandy if the mixture runs richer than it should - you just waste gas. Not so if it runs weaker than it should. Your engine overheats and can get severely damaged. Having seen (and repaired) the damage caused to an engine by a weak mixture, it's something I would prefer to avoid having to do again.
So, what this all says is that unless it's a very new boat, it's pointless opting for an MPFI engine if you are going to run it on LPG. You're either paying for an engine management system half of which you by-pass (the electronic ignition and timing adjustment still work) or you pay through the nose for a vapour injection systems where the economics don't make sense. Unless, of course, you are a club, puts hundred of hours on a boat in a season and can swap the conversion from boat to boat as you replace them, thereby paying only once for the hardware.
If anyone knows more or can present a better case, please chip in!
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Re: LPG conversion
Posted: 27/01/2005 09:19 AM |
Nick
As I've previously said, I'm not in the market immediately as my boat was stolen last year and I'm in two minds whether to replace or simply team up with another boat-owner. But my boat had an MPFI engine and I really liked how easily it started, how smooth and powerful it was, etc.
However, if I do buy another (used) boat in the near future and LPG conversion is a serious consideration, knowing what I do, I would avoid buying one fitted with an MPFI engine. In 5 years time when the latest generation of boats are in my price range, the argument will be different. But that's 5 years away!
Would be really interested in any techy stuff and photos you are prepared to send me. Even details of the various systems and suppliers you have investigated and considered. You can e-mail to: boats@salesteamfocus.com
It's a broad band connection so file sizes are irrelevant.
Thanks in advance. |
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baggioli
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| Joined: 21 Aug 2008 |
| Total Posts: 15 |
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Safety guard for ski handle
Posted: 21/08/2008 04:05 PM |
| Nick, all considered what happpened yesterday to Aidan ... could you please advise me where to purchase the handle guards you and Jemma use? Thanks, Marco |
Marco |
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Re: Safety guard for ski handle
Posted: 23/08/2008 09:47 PM |
Contact Thomas Wayne - twcues@gci.net - I checked and he is still making them. He hopes to have a website up and running later in the year.
As you can imagine all our best wishes go out to Aidan. |
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