Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: tobyker on January 19, 2007, 10:55:55 pm
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Has anyone tried using a four stroke glo engine in a boat? Did you fan or water cool it and if so how? It seems to me that these modern four strokes don't need much cooling, judging by the vestigial fins. I wonder just how little cooling one could get away with. ???
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HI there,
many year ago I had a Merco two stroke aero engine which I managed to watercool successfully with two turns of 4 mm (I think) copper tube round the cylinder and held in place with a jubilee clip. Also wrapped a couple of turns around the exhaust header and had no problems with it at all over two years and many hours on it.
Guess the feasibility of this depends largely on the shape of the cylinder etc on the engine you are thinking of water cooling.
May be that the fan turns out to be the better option.
Is there any particular reason that you want to run a four stroke? You are also going to have the hassle of findong (or in my case making) a flywheel to suit as well as the cooling. May be a two stroke water cooled that is available just ready to be dropped into place...
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I like four strokes; I think they can be silenced better; and I like a challenge.
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:) Ah well, sounds like you are about to start a challenge then.
From memory, OS four strokes have an awkward king of shape to cylinder, (for wrapping copper pipe round!), they are "squared off", and the push rod tubes run in front of the cylinder, so might be good to avoid.
You are right about the noise though, should be reallly quiet in a boat.
Prop size will need thought, as the engine power delivery characteristics will be different to a more conventional two stroke motor.
I (and I am sure lots of others here) will be very interested to see photos of the completed conversion, and to see an update on operational progress.
Good luck and have fun.
Glenn ;)
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Not many 4 stroke marine engines about.But did see somewhere O.S. did one. Maybe S.C. does one but not keen on their quality.
Quieter, smoother, lower revs, less fuel, easier to start, no need for a silencer,a little hard to get and dearer but sounds good to me.
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Not many 4 stroke marine engines about.But did see somewhere O.S. did one. Maybe S.C. does one but not keen on their quality.
Quieter, smoother, lower revs, less fuel, easier to start, no need for a silencer,a little hard to get and dearer but sounds good to me.
As there are plenty of aircrasft four strokes around is there really much difficulty in using one of these in a boat as long as you can cool it?
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Had a scout about for you and can not find any four stroke marine motors "out of the box". There is a page on the OS site about fitting fans to heli engines for cooling them, so that may be a viable option for you perhaps?
Otherwise looking like copper pipe and jubilee clips.
Glenn
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Just Engines import the ASP OS look-alikes (but not cost-alikes) and these start at a .30 cu in (5 cc) but as remarked above, there is very little clearance between the pushrods and the cylinder at the flywheel end, and the inlet tract and cylinder at the backplate end. I am very tempted as this looks like a worthwhile project, but I've still got to do a plank-on-edge (1730 rule) schooner and the pop-pop pre-dreadnaught. If no-one else has tried recently, this might push it a bit further up the list, but it is quite a lot of cash to splash if you ruin the engine. Thanks to all for their contributions.
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Why not buy a pre-owned engine off ebay to ferkle about with, rather than risk messing up a new one?
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Hi tobyker,
I was looking into this option early last year. The one thing worth bearing in mind, is the much lower power output of the four stroke motor, so you would require a larger heavier motor.
There were a few on ebay last year, but they went for a lot of money, and I was a bit dubious as to what the mechanical quality may have been. If I ever have money to spare though, I will fit one in a cruiser style boat.
Good luck
Bob
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I have a copy of a MMI free plan, Ravenna by Jim Pottinger, put by for this project. If i wanted sheer speed, I'd go for a noisy 2T, but I'm thinking of something a bit more gentlemanly.
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http://modelgasboats.com/magazine/index.php?option=com_content&task=view&id=119&Itemid=47
Looks like someone else fancies trying it too, although this one is petrol....
Glenn
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Hi gentlemen, just out of interest I had a discussion about this with Martin last year as I was considering building a fairly large scale Riva Aquarama and we concluded that probably one of the better 'shape' motors to water cool would be one from the RCV range. They offer two types, both rotary valve and either type would be suitable for wrapping copper pipe around (with a little fin modification and removal to clear carbs etc) or machining off the fins and fitting a water jacket.
Heres their site: http://www.rcvengines.com/rcvmodelengines.htm
The 'SP' in line range are also geared down 2:1 by virtue of their design and also has a hexagonal starting dog so would be easy to start and should turn a nice size prop in reasonable fashion, down side is they are mechanically noisy. I have seen these on Ebay for reasonable money second hand so it could be worth a 'play'.
Other engine range is more conventional but not having pushrods to get in the way would mace copper pipe cooling easy to fit, they also have a low profile so should fit below deck better.
Maybe a line to RCV identifying a gap in the market could kick off a range or new ic fourstrokes...who knows....?
Braders.
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OS used to make one.....
(http://i136.photobucket.com/albums/q168/MBmayhem/OSengine.jpg)
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Seen an O.S. like above on Ebay last year,should have bought it.
Do I remember that there was A Fox 4 stroke engine to mate up with the famous Spearfish Cabin Cruiser.
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The RCV are very interesting - thanks for pointing me at them. the CD version in particular looks as if it is just waiting to be machined down to take a water Jacket. However, the smallest available is 10cc, and they are a bit pricey. I wonder if they'd do me one cheap, for proof of concept of water-cooled version?
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http://cgi.ebay.co.uk/OS-FS-26S-CX-Four-Stroke-Recoil-Start-Car-Engine-New_W0QQitemZ190079578908QQihZ009QQcategoryZ34062QQrdZ1QQcmdZViewItem
Here is a four stroke glow car motor, did not know they made such things but there you are, every day's a school day, my work for your boat OK and no water cooling required, I presume the engine has additional cooling fins on it.
Not sure what size motor you are after, this one is a .26
Glenn
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Might need to cool it it by wrapping coil around the body get it from a model shop. I know that an O.S. 20 was around 3.2cc many years ago.
There some out there keep looking.
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Thanks Glenn, (and for your PM) I'll have a pop at that. (4.4cc acording to the OS web site) Its interesting that the advt Martin found shows a tiny cooling jacket on the barrel only - I think these things are designed to run pretty hot, and don't need all that much cooling.. Certainly with the 2-stroke car engines with the enlarged fins I reckon you could drill a few holes through the fins, interference fit for some copper tubing and run the water through like that. The car engine might have more finning than the aero ones, it's difficult to see.
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You are most welcome. I would be interested to see the results if you get it.
Good luck.
G
:o
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im sure if you wanted to you could make a water jacket yourself if you can weld aluminium? or solder it.just cut some thin sheet to desired length and bend it round then attach a bottom and top and bend another larger circular peice to make a jacket then drill and attach inlet and outlet nipples.ive seen this done on homelite engines(petrol).in fact you may be able to buy a jacket depending on which engine you get.the jacket just slips over the head and cools it but the easyest way is the copper or brass tubing i used this method for my .61 size sc engine for a boat hers a pic i used the zip ties to hold it till i soldered the coils together and it worked great.this pic was before i also attached the new fly wheel from prestwich models.
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The car engine on e-bay is now up to two thirds of the cost of a new ASP aero 4-stroke. I think I could have more problems fitting a flywheel to the car engine than an aero so I'll let it go, but thanks Glenn for pointing it out to me. Cooling a four stroke is going to be complicated by the proximity of the pushrod tubes to the cylinder but I will keep it on the list of things to do.
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can you not get a pull start for the car engine?? Also the car engine wont need water cooling if you run it in an open hatch boat.
just checked that engine out and it has a pull start so you dont need a fly wheel either, just stick it in a boat thats designed for an open hatch like the one i built !!.it will get more than enough air to cool the engine that way.
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If you don't fit a flywheel the motor won't run, no momentum to turn the engine over the non power stroke... :(
I see your point Tobyker, getting a bit too dear now. Never mind.
G
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what i meant was he wont need the usual marine flywheel for the v belt !!it will have a standard fly wheel on wont it?.
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Doesn't appear to. Normally they are part of the centrifugal clutch on the cars.
G
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Hi All,
Just thinking about the no fly wheel won't run theory.
How do plane engines run then? ;D
Bob
(Cat Pigeons etc).
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Put your finger in the way whilst one is running you will soon find out :o :o
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The propeller does the flywheel business
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Hi Seaspray,
Sorry, but I can't except that the prop does the fly wheels job. I'm not saying that you're wrong, but I can only see the prop giving resistance, and not inertia.
I would like one of those technical explanations, similar to the one given on electric motors '16 TURN 10 TURN WHAT'S ALL THIS ABOUT' thread.
Even then, I will still have my doubts. ???
I'm a very inquisitive person, and I have already forgoten more than I ever learned.
Bob
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Hi Bob,
You won't believe me, and right now I can not be bothered to do loads of typing reference momentum and inertial mass etc., but, when a prop falls off an aero engine - guess what - it stops. :(
Really - it does. The prop on an aero engine if you think about it has a fair bit of momentum in it when it gets going, as does the flywheel on a marine or car motor. :)
Technical explanation to follow...... :-\
Glenn
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O K Chaps,
My next project will be to start one of my engines which are fitted with a recoil starter, but with the fly wheel removed!
As it's 1.06am, I will leave it for a few hours. After I have walked the dog and had breakfast, I'll strip down my Cachalot and give it a go.
I'll post the results latter this morning.
Bob
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Hi all,
Just down from the modeling room, where I have been running my OS 32 with no fly wheel.
Unfortunately it's raining cats and dogs, and blowing a gale, so I had to do this in doors, as I have no shed.
It started as easily as usual, but with the exhaust and fly wheel removed was out of tune. Because of the noise smell and smoke, I did not have time to re tune it, but from fast tickover and upwards, it ran OK.
I also have a Thunder Tiger Out board motor, and the fly wheel on that is tiny and made of alloy, so virtually no fly wheel action. That also runs and ticks over with no trouble.
I wonder with regard to an aero engine stopping when the prop falls of, wether this could be because with the prop on, the throttle will be open wider to keep the motor running. So when it falls off the loading changes, as will the throttle setting to keep the revs the same. With no resistance, it would require a lower throttle setting. If you see what I mean.
I wait with interest.
Bob
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Hi all,
I just had another thought. Unlike with a plane and perhaps a car, (talking models) the loading on a boats prop varies, especially if it's a speed boat. The fly wheel does controll the time it takes the motor to rev up or down. With a cruising motor, the heavier fly wheel keeps the motor and varying changes of revs smooth.
With a racing motor, the fly wheel is much lighter, to enable the motor to increase or decrease revs quicker. Smooth running especially at lower revs is not required.
As I have said in the past. I reserve the right to be wrong at any time.
Bob
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Only me,
I have just realised that this thread is about four strokes, so all of the above ramblings, are referring to two strokes. Can't test the four stroke theory, as I don't have one.
Bob > :( :-X :'( :-*
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Interesting. I'm surprised it ran at all, but there is probably some mass in the bit of the recoil starter that is attached to the crankshaft, and assuming the engine is forward induction through the crankshaft, there will also be some in the diameter of the shaft. But as you say, would that amount of inertia be enough to get a 4T round two revs and over compression, and would there be any slow tickover?. The acid test would be an aero engine started with an electric starter on a very light spinner but no prop. One then wonders if you could build a super-light racing boat sans flywheel, but could you ever get it into the water with the engine running? Thank you for sharing your experiment with us.
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I bet this would convert easy, round head and space .Peter
http://cgi.ebay.co.uk/model-engine-condor-91_W0QQitemZ160082872173QQihZ006QQcategoryZ34055QQrdZ1QQcmdZViewItem
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Hi tobyker,
There is no mass in the recoil starter. It uses a one way bearing. The crank just locks to it when the starter is pulled.
It did occur to me that the motor itself is a fly wheel. The mass of the crank and attached parts etc. as you suggested.
I only did the test out of interest, and not to prove any one wrong or right.
Bob
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Hi BobF
http://www.infoplease.com/ce6/sci/A0811114.html
Rotation tends to cause these forces.
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Hi Seaspray,
Thanks for that.
Loads of words for me to try and understand. ??? :(
As I once said to someone.
I know you think you understood what I just said. But do you realise that what I said, wasn't what I meant.
Bob
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Try and find an engine the doesn't have a flywheel,centrifugal clutch or propeller fitted and you'll find it to run erratic. Just click on the highlighted underscored words and they'll give there meaning.
Then there is the Wankel engine
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i Sean this in a photo once on the end of the engine thee is the bit that covers the crank witch is held on with 4 bolts in the picture someone had put a piece of 1/8 aluminum over this and put and taped it to take 2 nipples so the inward bit would have water ruining throo it this would help cool down the engine
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Something like this.....
(http://i136.photobucket.com/albums/q168/MBmayhem/cooling.jpg)
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Yup thanks it sorta explanes it better.
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There you go Bob, Seaspray said in his link exactly what I could not be bothered to type out last night!! :D
I must say, you are keen to test a theory, I was really suprised that you got a motor to run with no prop / flywheel fitted. Must be the crank moment forcing it round and keeping it going.
Thanks for sharing the experiment result. Thinking further down the line, guess that an assembled boat motor with shaft, coupling etc etc will have even more inertial mass resulting in increased momentum. Maybe this will be the kick off of the flywheel less race engine.
Cheers,
Glenn
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I remember watercooled crankcase backplates. I seem to remember they were used in conjunction with w/c heads. I reckon these modern engines don't need anything like as much cooling as the old ones, so maybe any part of them you can suck heat out of will help. I suppose to some extent they are oil cooled since they operate on a total loss ("dead loss", Sandy Skinner used to say) oiling system. Good point, EE, I'll bear it in mind.
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HI edible
My ole O.S. 20 has a factory fitted cooling crank/back plate fitted.
The cooling tube runs from the pick up scoop to the bottom nipple on backplate out the top backplate nipple up to a head nipple out the other nipple returning the the water via the output on the side of boat.You can adjust the temp of the output water by squeezing the cooling tube a little till the temp you require is obtained.
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Hi Bobf
Did your test engine run smoothly on tick over speed ?
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Hi Seaspray.
I was running it in doors, so could only run it for a few seconds. Noise smell smoke etc.
I had removed the complete exhaust system to get the motor out of the hull to remove the coupling and fly wheel.
When it started, it would rev OK but would not tick over. I assumed this in part to be caused by the mixture settings being out.
Bob
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Hi BobF
Lets know how it goes.
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http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=150090857609&ssPageName=ADME:B:WNA:UK:72&isfrommerc=1&refitem=190079578908&itemcount=8&refwidgetloc=watch_reminder_email&refwidgettype=osi_widget
Here's another 4 stroke on ebay Tobyker.
It's a long way away
Glenn
(http://i136.photobucket.com/albums/q168/MBmayhem/f414_1.jpg)
(http://i136.photobucket.com/albums/q168/MBmayhem/1308_0.jpg)
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That would make a great boat motor....
Roy
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Certainly is a rare one a 60 that 10cc is it.
Looks like a wee bit of wear on the flywheel grove or is that with just not being used
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Hi Seaspray,
I can't run it on the pond as the fly wheel and coupling have to be fitted together.
I have a lot of other projects on the go at the moment, so can't really afford the time.
There again, now you've mentioned it I may have to make up a spacer, and give it a go.
Bob
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That OS 60 with exposed rockers (very Vintage - possibly Edwardian style ) does look nice, but words like "rare" and Collector" tend to put me off. But one of these days....
That car engine went for £160!!!
Further to backplate cooling, this would probably be more appropriate for a two stroke, as it would tend to give the new charge a nice cool trip through the crankcase, retaining its density and mass and contributing to adiabatic efficiency (which I read about once in a book about supercharging!) Though if I get to modify a 4T and can't get much cooling in the top end, I'd certainly add backplate cooling.
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I also looked into the 4 cylinder 4 stroke some years ago. You could buy them in kits ready to assemble or with a little lath work to complete But I was into 3.5 and 5inch model steam loco then.Only thing against 4 stroke was I felt that it would need a gearbox to increase the output revs. You then had the option of fitting a reverse gear
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Hi All,
Been talking to a chap today that specialises in making water cooled heads for any engine you want. He is a true boat man, builds and races them.
Try Paul Firmin at www.nimrifmodels.co.uk
Regards
Simon
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Think I've got a SC52FS off the bmfa classifieds site. Will report progress if any, but I have other projects on too!
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Think I've got a SC52FS off the bmfa classifieds site. Will report progress if any, but I have other projects on too!
Hi Tobyker, is that the aero engine? Guess you have a plan to cool it?
I will be interested to see photo's of how it progresses.
Glenn
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Just Spotted an OS .40 four stroke marine engine on ebay, new in box.
If anyones interested in it.
Regards to All dazzle
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Have you got the listing please?
Regards
Simon
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http://cgi.ebay.co.uk/OS-40-FS-Marine-Glo-plug-engine-New-in-box_W0QQitemZ160120335767QQihZ006QQcategoryZ140972QQssPageNameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting
Peter
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Thanks Peter, I dont know how to do that listing bit yet.
dazzle bob
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dazzle
Its easy .. cut and paste
Left mouse swipe over listing at top or anything you want to transfer.. this highlites it .. Right click scroll to copy....move pointer to where you want to put it ..(it can be in another window or document)..right click ,,scroll to paste right click on it ,,,and it should be there .. sorry if it does not make sense... my spelling is awful , if you get stuck just PM me and ill find an article for you but this may help Peter
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Interesting... I wonder how much it'll go for. I'm just looking at my 52FS for a while, pondering water jacket designs. It is useful to see that the jacket on the .40 is pretty small, and there's no cooling on the head or backplate either. I was surprised to read in the instructions for the .52 that there's no provision for lubrication of the internals, including valve gear and camshaft, other than a squirt of oil into a nipple under the crankcase, and "turn the engine upside down so some runs into the pushrod tunnels and up to the valve gear". I think we might have to do something about that - I wonder if I could arrange a drip feed into the head space, and scavenging from the nipple?
Lots to think about while I work on the charter schooner.
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Thanks Peter, that was a crystal clear explaination,
Me know now, how to.
cheers dazzle (bob)
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Thank goodness that .40 is now more than I paid for the a/c .52. Getting some better ideas about cooling and lubricating now. Good to have something to think about and take out of its box every so often.
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I must not reply to the better ideas about four stroking cooling lubricating & scavenging for nipples,
or martin will ban me the same as he did miss sinbad.
dazzle
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;)
Martin
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Thank goodness that .40 is now more than I paid for the a/c .52. Getting some better ideas about cooling and lubricating now. Good to have something to think about and take out of its box every so often.
Hi there,
I ran an FS40 four stroke in an aircraft for quite a while and there is no issue with top end lubrication, I would jsut do what it says in the instructions and don't worry about it too much.
Glenn
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Just a thought to use a small 6 or 12 volt fan simular to as used in pc' s
they take very little current & should provide enough cooling.
plus it would also keep the engine in its original form.
dazzle
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just found this its got alot of pics of engins and some 4 stroke marine engines
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.....is there a link missing edible_engine .... ???
just found this its got alot of pics of engins and some 4 stroke marine engines
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wops here it is http://translate.google.com/translate?u=http%3A%2F%2Fe.a.t.chez-alice.fr%2FAAmoteursminiatures.html&langpair=fr%7Cen&hl=fr&safe=off&ie=UTF-8&oe=UTF-8&prev=%2Flanguage_tools
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One on Ebay! - OS FS-80 Four Stroke Water Cooled RC Engine
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=150276131906&ssPageName=STRK:MEWA:IT&ih=005 (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=150276131906&ssPageName=STRK:MEWA:IT&ih=005)
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Hello chaps!
I would be cautious about this FS-80 four stroke on ebay. First of all, if OS made a marine version engine, it came from the factory with a flywheel and not an airplane propeller drive washer. Also, this engine on ebay has an aftermarket prop spinner hub attached.
If you look at a factory photo of an OS FS-80 you will see the cylinder fins are rectangular, not round. Also, the water jacket on this engine is unlike any water jacket that OS installed on its factory marine four strokes. Notice this one has a stepped shape.
FS-80:
http://www.osengines.com/history/osm640/osm-1982-fs-80.jpg
Various OS Factory four stroke marine engines:
http://www.osengines.com/history/osm640/osm-1982-fs-40m.jpg
http://www.osengines.com/history/osm640/osm-1979-fs-60m.jpg
OS Engines Timeline:
http://www.osengines.com/history/ostimeline01.html
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Converting an aircraft four stroke to marine use is not hard. I converted a Saito FS-40 to marine version and have tested it on a bench with complete success:
http://www.youtube.com/watch?v=IzSygqHvLPY
(http://www.fototime.com/6B8168A750F1DFE/standard.jpg)
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One on Ebay! - OS FS-80 Four Stroke Water Cooled RC Engine
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=150276131906&ssPageName=STRK:MEWA:IT&ih=005 (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=150276131906&ssPageName=STRK:MEWA:IT&ih=005)
Sold for:
238.00 GBP = 456.818 USD :o :o :o
If I ever put some of my engines up for sale they are going onto eBay UK!! lol... O0
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Been looking at my SCFS52 again - did some research on crankcase suction through the vent nipple using a tube from the nipple to a jar of white spirit. Discovered fluid spraying out of the side of the engine. The blind side of the camshaft tunnel is cracked. Too long since I bought it to complain, so have sourced a replacement ASP crankcase from JustEngines (ordered Sunday, arr Tues first post). Will re-build and get to know the engine with an aircraft prop. Interestingly the new crankcase came with the bearing in the blind side of the camshaft housing already installed. I wonder how many get bust when people try to put them in themselves! The old one dropped out after heating the case with a hot air paint stripper, so it can't be that difficult. At least I now have a spare crankcase to file fins off to see where w/c pipes might go. I'm wondering about fitting a water-cooled gasket to the rocker box cover, though to go by the old OS engine cooling the backplate and the cylinder is enough. I did say this was along term project!