Old BMC engine for a boat?

[Henri]

Well, having had the idea for using a VW aircooled engine pretty well trashed, for some very thoughtfull reasons, and still thinking about a small modest econ engine for a modest coastal boat, me thinks - why not an old BMC OHV 4 banger from a Morris or the like, say an 850-1275cc or so in a smaller displacement boat like WB has been headlining. Now I've done a few of these (including a full-load Derrington)and know thier good & bad points; seems they will grunt quite reliably with good oil in thier pan.

[seafox61]

Hi Henri
I have a old vw engine I was going to try and build a plane around but looking like I will use it in a small tractor, and use the V8 out of a chevy impala to power a houseboat, though I may change my mind. one thing is if you enclose the engine their is the anti flash back ( backfire) screen in the carb and non sparking electrical devices required for marine use. ( distributer aulternater fan ect)
A thought I had was to place the engine room on deck sealed from the bilges open at the sides but with a front wall and roof so sound might be lessened. a small say 3/4 inch high drip pan to catch spilled oil might be good under the engine but as long as the side are open I think (???) you could claim the engine is "outboard" and does not have an explosion risk so you do not have to have the stuff mentioned above for inboard engines.
here in utah most of the airboats I have sceen rin with VW engines
jeffery

[ion barnes]

Much as I like 'outside the box'thinking, it has to be used with some knowledge or end up in serious trouble.
The VW and BMC engines are not to my knowledge, have a source of marinized parts to draw from, or have features that promote safe marine use. Even an older auto diesel has to be marinized by way of changing the starter and altenator to ignition protected units.
Even the rotary engines discussed here earlier, need a marine makeover.
Best to stick with something common. the more of them, the more parts at a reasonable price. Ion

[seafox61]

that was one electrical spark maker I missed, the starter. But if the engine is not enclosed in a room or other closed space where the fumes could gather and then be idgnited I do not see a problem any more than in a car.
in starting a car I had sitting in the drive way for a year or two it cought on fire from the eather I sprayed in the carb fortinutely I was able to blow out the flames, come to think of it same thing happened with my frends VW and with the magnesium parts that a lot more dangerious. was able to blow that flame out also before my friend could come rinning from the drivers seat in responce to my cry of " fire!"
jeffery

[Ron Williamson]

My neighbour was working on a car in his backyard,just steps up from the mighty Saugeen river.He had poured some methyl hydrate down the carb and was still under the hood,when his son turned the key.Apparently,it was quite a sight,to see someone running down the hill flapping his arms like he was on fire :eek: (he was,but alcohol flame is invisible in bright sunlight)and dive into the river,in April.
R

[ion barnes]

Just to clear a few things; VW engine cases are aluminum alloy not magnesium, A car, because of it being 'open bottomed' gas fumes are able to escape, but when you have liquid fuel laying about or the engine coughs back and spits out gas and flame... thats a different matter again.
Back to basics, any engine, no matter what space it occupies, has determined the requirement of everything else in that compartment to be sparkproof! No if ands or buts, thats it, cut an dried. Ion

[seafox61]

Respectfully disagree.
in outboard moters and in land vehicles distributers aulternater and starters are not spark proof. I think I am missunderstanding when you say what ever space the engine ocupies determins that every thing in that space be sparkproof? do you meen that in a boats engine room everything must be spark proof? I agree if it is an enclosed room this is why I am sugesting an open sided space, seperated from enclosed spaced like bilges saves the need for spark proof items.
Thankyou for helping me understand

one story in perticular might iluminate things. when I worked on the golf course at hill afb we used toro work vehivles with 14 horse engines under the seat in that space were the mattery and the fuil tank one night a vehicle that had lost its air cleaner was dripping gasoline out the carb down onto the transmission cooler lines it had also broke the exust manifold at the block providing idgnition for the fumes driving that piece of junk back to the shop ocasionally the fumes would flash out from under the seat and I would take of running then after seeing that it did not catch fire perminately back on I'd climb and drive down the road till it lit off again.
on a boat the only reason to have a lip around the catch pan below the engine is so that spilled hydrocarbons won't flow overboard and polute the water.

it is intresting to note that liquid gasoline will not burn, a lit match pushed into liqquid gasoline will put it out. the trick is to keep from idgniting the evaporated gas just above the surface of the gasoline <g>
a trick I should note I do not wish to deministrate
jeffery

[ion barnes]

You must read the coast guard regs to get the whole story but in a nutshell, as I had said, the auto senerio shows that because the car is not enclosed underneath, the heavy fumes are able to escape and disapate. I totally agree with your statement that liquid gas will not ignite but that where you get your vapours from!
Some years ago there was an excellent article written in WB about marinizing a Subaru engine and the next issue had an indepth article about the safety precautions to be taken when using gasoline aboard.
I am not entirely sure of the requirments of outboards, but the ignition parts are magneto based rather than make and break points(sparkless) and it would not surprise me if the starter is spark proofed too. It may not appear so.
When i purchased a older Bayliner with a Chev 350, I found a electronic distributor in place of the original, better but not marine rated, and a carb with a repair of aluminum-epoxy to the stainer body. When I took it to the local shop for replacment I was told right away that it was an auto carb, because it did not have the vent tubes that face into the carb throat and something else that I cant remember. When I went home, fist thing I did was roll into the bilge and check the starter, yup its was the right one and I was aready replacing the existing marine altenator so that was covered.
All of this comes down to legallity, insurance, and your persoal safety. If the CG or an insurance adjuster find your vessel not to be compliant your could face all sorts of court issues.

[ion barnes]

Clarrification; the magneto ignition is the sparkless variety, the make and break point type is not, the electronic ignition is sparkless.
The important thing to remember is the components have to be physically identifiable as marine grade to satisfy the regs. Such things that live in the same compartment MUST be rated as IGNITION PROTECTED meaning they will not cause flamable fumes to ignite.
And last the fuel pump has to be properly vented too!

[Dan McCosh]

You seem to be starting about where a marine engine manufacturer does. That is, with a small auto block, and then you have to add all the stuff to make it a marine engine. This means water cooled manifolds, pumping systems, electrical, etc. It would be a lot simpler to find an old marine engine such as an atomic 4 or Graymarine and rebuilt it. It's kind of tough these days to find a new gas marine engine, hence this is probably the best route. All in all, rebuilding the block is probably simpler and cheaper than modifying a car engine for marine use.

[Henri]

Well I was hoping one of the Brits might speak up regarding usage of the old 3 main Westlake chambered BMC 4 banger such as was in the Morris. Its a very small engine, and a fuel mizer. I think its light enough to go outside the hull on a transom step; this avoids lots of spark problems.

[Dan McCosh]

And I nearly finished without once making some crack about Lucas electrics or leaking oil....

[TomRobb]

I was thinking that if you can live with a Toro mower's periodic hot-seat, maybe, in an exploding boat, oil weeping BMC motors with Prince of Darkness electrics is the least of your problems. :rolleyes:
As was suggested, there seems to be plenty of Atomic Fours out there. Why not do your family a favor and go with something that has a known record?

[ion barnes]

What do you call inexpensive? Get an old outboard but dont cobble up something that you will regret or not have the chance to

[seafox61]

"Court issues?"
leaving aside the bit about weather or not this is still a free country <g>...
reading the coast guard regs ( admittadle something I have not done for about a year) the backfire preventer in the carb requirement is stated to be needed for inborad engines only which brings up the question of what is an inboard?
when I called the coast guard to ask what constuted an inboard vrs an outboard the young man on the phone's most coherent statement was "the builder will tell you if it is or it isn't"
when I said I was building the boat for myself I fear he became totaly lost and was unable to supply any definitions but did helpfully confirm what the pamplet said that backfire preventers were needed for inbords but not for outboards.
another thought here, in enclosed compartments where fumes could be a problem halon fire supression systems are used. if your engine is outside an enclosed space is your choise prettymuch fixed and hand held foam fire extingushers?
thankyou for your thoughts
jeffery.

ps Henri could you email me at seafox@xmission.com?

[ion barnes]

I can only hpe that logic and common sense will prevail. Get the outboard or an established older marine engine. That my final remark ion

[Henri]

Personally, I think these "older marine engines" were obsolete the day they were designed and are very little more than scrap metal today. They simply will not produce a contempory bmep or specific fuel consumption. The "old" Westlake chambered BMC will do both of these at about 1/2 to 1/3 the weight of an older marine engine. I have a pair of Gray 152's and would not consider them effective at today's/tomorrow/s fuel prices.

[Dan McCosh]

The old sailboat standbys are holdovers from pre-WW II designs--L-head engines with lwo compression ratios. The Gray also is a 5-main bearing engine based on a Continental block which is still in production, mainly used for fork-lift trucks, hence parts are still being produced. There's no question that the L-head is inefficient, but the engine is very strong. The BMC engines were notorious for wearing out quickly even in the light cars they were used in. I doubt that they would do well as a stationary engine. (I've been using a 35-hp. Gray in a 26,000 lb. boat for about 18 years.)

[hoss]

Why a BMC motor, even without the marine safety stuff, I don't think an engine out of an old British car would be a good choice. The only thing they have going for them is that they are very simple to work on, also the hull of your wooden boat would never rot because it would be soaked in oil. (they ALL leak). You also might want to check out the weight issue the 1800 cc motor in my MG weighs more then most modern V6s and some V8s, and puts out less then 100 horsepower. (just wait untill you have a go at adjusting the carbs) All of the above might indicate that I don't like British cars, well I love them (I own 2 MGS) as a package they are cool, but when you get right down to it there is reason that Toyotas sell so well.