Engines

[andrewa]

Thanks for all for replying to my last post, now I have another quandry. I have a 1993 Sea Ray 270 Sundancer powered by the mighty Mercruiser 7.4L (mighty in CC capacity and thirst for fuel though it sounds lovely) I am off to the show tomorrow to look at the kit especially engines diesel and petrol however after reading alot of the posts I am fast coming to the conclusion that diesel could be a liability, the amount of posts in the past asking for advise on diesel problems and in this months MBM about diesel fuel is fast putting me off and servicing costs seem higher than the petrol equivalents as well. There are posts for petrol engine problems but not as many as diesel. Could someone explain why this is, is it because more diesel boat owners are using the forum or are they more unreliable in general than there petrol equivalents of similar power. My engine has been faultless all season so far and my mechanic charges £21.00 an hour and thats on the South Coast.

 

[tcm]

If you're happy, leave it as it is?

You know the disadvantages re fuel availability, but if these don't put you off, and the cost to change is gona take a long time to recoup, stay as you are. Converting to diesel will leave you attempting to recoup money on resale that you may not - you would have to justify it on running costs, IMHO. At least one poster has a diesel engine which may as well have been petrol cos hardly used it, and expect same applies to many.

That said, I think many diesel probs are reported here cos most crusiing boats have diesels. Also, not many posts brag on bnoringly about their incredibly reliable diesels.

There's a safety isuue, and a cost issue, and a performance issue, all of which you seem to be fine about. There shouldn't be a reliabilty issue (and a diesel *should* be reliable) - but if your petrol is faultless- it won't be any better with a diesel and it could be worse...

 

[andrewa]

Thanks for reply, I don't do huge hours probably 80 this year so far, I will see what deals I can get on both flavours of juice and do my maths.

 

[longjohnsilver]

Calculation

80 hours running, let's say you use approx 12 gals ph on petrol and 8 gals using diesel. Assume petrol £4 per gallon x 12 = £50 per hour x 80 = £4000 per year.

Diesel @ £1-50 per gallon x 8 = £12 x 80 = £1000 approx (allowing for extra oil changes) Cost of conversion probably £14000, therefore it will take almost 5 years to break even, assuming you keep the boat that long and continue to use it as much.

Why not think of converting to LPG, big fuel cost savings to be made with low conversion cost, also keeps the engine you're happy with.

 

[andrewa]

Re: Calculation

Thankyou LPG is underconsideration my engine is mechanically sound though only problem being MGS which would be my preferred supplier is no more, though there fitters have bought all the equipment from Calor and are continuing to do conversions and cheaper than MGS used to charge.

I really posted to see if I was correct in these powerfull diesels being less reliable, and more expensive to maintain who better to ask than people who own them though.

 

[hlb]

Re: Calculation

No you've got it all wrong.Diesels are prity bome prouf. As long as the engine gets fuel it goes. Problems mainly arise from dirt or water in the fuel filters. So realy very easy to fix. (Should not have been dirty in the first place). It's only because nearly no one has petrol engines. So not many complaints about them. Deisel is much better for all sorts of reasons. Agrea with others though. Not worth changing yours. Less flog it and buy one with diesel in it.

<font color=red> No one can force me to come here-----------
----- I'm a Volunteer! /forums/images/icons/smile.gif

Haydn

 

[oldgit]

Re: Calculation

Agreed.Stay with present cheap to maintain engine and just use it.Look for noisy smelly vibrating but cheap to run oilburner for next, much bigger better boat which you will be buying.. err.. about next spring.

Just hold tight dear it will not be so rough when we get round the corner,trust me.

 

[Xenopus]

Hi,

Re LPG, MGS went to Aus in the middle of our conversion and we're now dealing with Marine Solutions. MGS did our last boat and it was lovely but so far the new lot seem even better. Try calling Richard Neville on 01438 715388 or see him on the Calor stand at Soton. We have found LPG to be great and would recommend it highly if you're in an area where its available. The 7.4s seem happier on it than petrol and you don't lose performance if the timing's altered.

Happy boating!

 

[tr7v8]

Re: Calculation

Hate to disagree but.....most people feel comfortable with petrols because they are in their cars. Diesels may in theory be more reliable BUT they are very finicky to things such as clean fuel, air leaks in the feed etc. This seems to be what generates most of the "how do I do this..." type questions.
Another point is that diesels require more servicing and that servicing needs to be more skilled, also a broken diesel costs loads more than a petrol. With the rising complexity of a lot of the diesels (to give petrol type power outputs) this applies even more, intercoolers, superchargers, turbo's & EDC's fancy having this broke in some out of the way place?

Jim
-------

 

[Iwema_LPG]

Hi Xenopus,

I got some photos from Richard Neville from Marine Solutions (our UK importer).
He installed 2 of our Tornado 450 systems on a Hunton.

You can see the conversion photos on our web-site www.iwemalpg.com.
Look under: "marine index" => "installed systems" => down on the page "Hunton".

This is a very powerfull conversion!!

Regards,

Hugo

 

[nicho]

Unlike petrol engines that rely on electrical sparks to keep running, just about the only thing that will stop a diesel engine is contaminated fuel/filters. As long as these are meticulously maintained, and you use a decent diesel additive, you should not have a problem. I would guess that the reason more forum users discuss diesel, is that there are likely to be many more of them with diesel engines. Petrol, and sea going speeds/distances do not lie comfortably together due to the high cost of marine supplied petrol. On my last trip to Guernsey from Southampton (when we had a Sealine S37), we used 320 litres (approx 71 gallons) of diesel, which cost £73.20 at Guernsey prices. Had that been a twin petrol engined boat, the cost would have been more like £280.00, or a prohibitive £550.00+ for the return trip!!

I don't know if servicing cost are more expensive than the equivalent petrol unit, but in the marine environment and major engine manufacturers service agent is going to rip you off anyway....I wouild certainly go for diesel, if for no other reason than the cost.

Mike N