soarrich

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I bought a couple of these engines which I have a few questions about.

It says Made in IOM, where is that?

I'm assuming the threads are going to be metric, is that correct?

I'll try to put some RC carbs on them, have any of you done this?

Are they a quality engine? The castings seem so so, but the machining looks nice.

[email protected]

IOM Isle Of Man

GrahamC

IOM is Isle of Man built by Moore Engineering Ltd. at Peel on the Isle of Man


Based on it's pedigree and age I would say the fittings are most likley BA threads (or BSF or BW or... ) but I am sure someone in the know will correct that if I am mistaken.

cheers, Graham

[email protected]

A fellow modeler has a couple 1 cc Heron diesel engines from the same IOM. I have run one of these and a nice easy to start and adjust engine with good power from the 1960's. I would guess the 1.5 cc Snipe would be similar. The Heron diesel engines were sold in th USA by Hobby Hideaway in Delavan, Illinois during the 1960's into the 1970's. Other small imported diesel engine suiatable for scale free flight models were sold by Hobby Hideaway. Jack

soarrich

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I hope it runs as well as my PAWs...BA threads[sm=cry_smile.gif][sm=cry_smile.gif][sm=cry_smile.gif][sm=cry_smile.gif]

Thanks guys.

ffkiwi

The 'ME' engines first appeared in 1960, with the 1cc 'Heron', and was followed by the 1.5cc Snipe shortly afterwards in 1962. As previous replies have noted, IOM stands for 'Isle of Man' , located in the Irish Sea between Britain and Ireland. It is something of a tax haven, which is why a lot of UK companies relocated there in the 50's and 60's. The Davies Charlton engines (Allbon, DC and Quickstart brands) were produced there from 1953 onwards, as were the Frog engines from the mid 1960's when DC took over the production.

The ME engines were produced intially by Marown Engineering, and the first series had red anodised heads and fuel tanks. Subsequently Moore Engineering took over production and dropped the anodising, and used nylon fuel tanks. The 1.5cc Snipe was also available with an R/C carb, and both engines were available with silencers and in watercooled marine versions.

The 1cc Heron is a sport motor, and not terribly powerful-it was designed for easy starting and long life. The 1.5cc Snipe was a more potent engine, in comparison with its comtemporaries, than the Heron-but not in the same league as a PAW. Better than a DC Sabre, and comparable with a Frog 150 or AM 15. Their main distinction was being the first British engines to have a really effective silencer developed for them by the manufacturers.

The Heron is quite common here in NZ,. being used for FF scale by some of our leading scale modellers-the Snipe less common-I can't comment on how effective the throttle might be, but the R/C Snipe was tested in the Jan 1966 issue of Aeromodeller-this review noted that the power of the R/C version was down in comparison with the standard engine tested about 3 years earlier. [not an uncomon occurrence, when std engines were converted to R/C] The throttle seemed good for about a 50% reduction in revs, depending on prop size.

Still a useable engine-but no ball of fire. The threads are definitely NOT metric-this engine belongs firmly in the BA era [BA=British Association thread series]. The choke tube threads in on the Snipe, and can be locked in any NVA position with the thin nut-just like a Cox TD. This may provide a bit of a challenge/obstacle in fitting an R/C carb. I'd suggest an equivalent PAW, or an Enya 09. Either way you'd still have to come up with some kind of threaded adaptor to fit it to the intake. At a guess this intake boss thread is NOT a BA thread, but one of the ME series either 32 or 40 tpi.

ChrisM
'ffkiwi'

soarrich

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Thanks guys for all the information.

I took one the engines apart[X(], it has evidently been run with a lot of castrol oil, lots of "varnish" and black carbon. When I removed the finned barrel from the cylinder it seemed to have a gasket between the barrel and the crankcase. It might of just been a lot of carbon, I'm not sure it was a gasket, does anyone know if one goes in between the finned barrel and the crankcase? Is the prop drive pressed onto the crankshaft?

I'm going to soak it in some kerosene for a couple of days do soften the gunk up before I continue to disassemble it.

qazimoto

My Feedback: (1)

Like many of the respondants above I too have a ME Heron in a Free Flight Tomboy. It's a delightful motor. There is a page on the ME Heron on the Model Engine News web site at:

http://www.modelenginenews.org/cardfile/ME_heron.html


The above source also mentions the Aeromodeller engine test on the Snipe:

Chinn, P: Peter Chinn tests the M.E. Snipe 1.5 c.c. Diesel Motor, Model Aircraft, Volume 21, Number 255, September 1962, Percival Marshall & Co Ltd, p272.

It should be possible to get a copy of that review. It is very likely that there was a gasket under the liner. Simply make another from a coloured magazine cover although it might run fine without it.

Edit: The pic below shows a gasket under the exhaust flange on the ME Heron. It's likely that there was one in a similar position on your Snipe.

regards Ray

ffkiwi

The usual arrangement with this sort of structural setup (also common to the DC Merlin/Spitfire/Sabre series) with the cylinder liner located by a flange sealing on a shelf in the upper crankcase, retained by the fins screwing over the top of the liner into the top of the crankcase, is a gasket UNDER the exhaust flange of the liner-to seal the transfer path from blowby, and the head fins screw down ONTO the exhaust flange. which bears down on the gasket underneath. It would be unusual to encounter a gasket between the upper side of the flange and the underside of the screw-in fins-unless this was intended to resist the fins unscrewing during running. If there is a gasket it is likely to be paper-or possibly a red fibre one 1/32" thick or less (much less if paper, ~ 1/32" if fibre). Unfortunately the AM 66 Engine test I mentioned earlier does not show any photos of the fully stripped engine, only a shot of the new and old piston cylinder units, and another separate shot of the carb components.

'ffkiwi'

AMB

Sort of a varient of PAW instead of screws holding on the cylinder it screws in.On my paws with muffler they do use a thin fibre gasket
I used Koppercoat sealer on the surfaces and no oil ooze. it dos not get super hard thus you do not get a seal that is not hard to unscrew
On my sharmas I did the same stunt using paw mufflers and gaskets . the rear fins on the sharmas had to be filed for clearance
I would guess cutting a thin gasket (even cardboard should work and rubbing in oil to it would do fine). then use the sealer
They run ok, but still partial to my OS and TT10s davis conversions martin

ffkiwi

Nasty looking crack in that liner of yours, Ray..........

'ffkiwi'

qazimoto

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There certainly is! I hadn't noticed that. The good news is that it isn't mine, it was a picture from the article on the MEN site. I should have noted that in my reply above.

The ME Heron is a nice little engine too!

Ray

soarrich

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I cleaned one of my engines up tonight. Lots of soft carbon gunk. I bought a PAW09 carb and made it press fit into the ventura of the Snipe, so it's a RC ME Snipe now.

I'm going to make a carb for the second Snipe.

soarrich

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I took my second Snipe apart this morning, and yes it has a fiber washer under the cylinder. I then took the first one apart and rapped some Teflon tape around the lower cylinder to make a washer, I just don't think I could cut a washer very easily, so the Teflon should work.

qazimoto

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How about you cut you "washer" out of a playing card. It's remarkably easy to do with a sharp hobby knife or a scalpel. You get your liner and place it over the card and rotate it into the surface a few times. Cut the centre out first then the outside. Much easier to do than describe.

Teflon tape isn't going to last very long.

Otherwise you may be able to fit a fibre water-tap washer or something similar from an Auto parts retailer.

Ray

soarrich

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Good idea, I'll give it a try. Thanks.

soarrich

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I ran my RC Snipe today, I love it. I got 9000 rpm with a JZ 8x4 wooden prop. It would idle at 3000 rpm slowly coming up to 4100 rpm, then it held 4100 rpm for over 15 minutes.

A few questions for the gurus:

Does the top rpm sound right for that prop?

Why does the rpm creep up from 3000 to 4100 rpm, I'm 99% sure the throttle didn't move.

After extended idling, it puffs white smoke for a second when I give it throttle, what's that telling me?

Is there an antidote for the diesel smell?

peterburford

No antidote for diesel smell.
Once you're hooked, you're hooked!
Peter

AMB

After extended idle the engine cools a little bit, the Puff of white smoke may be a little unburned fuel , of course when it come up to full operating temperature you get a complete burn, at an idle you also may get a tiny excess of fuel in crankcase that does not get get up the bypass ports. or a combination of both it is not really an issue, the idle speed jump in rpm do not know,maybe one of the guruhs can explain that one, I am assuming you have not adjusted the needle or compression martin
that dual exhaust looks neat

soarrich

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No, I never touched the needle or compression.

Yea, the dual exhaust looks cool, and the outlets are sooo tiny. I really like this motor. With my diesels I really don't care too much about getting tons of power, I want the planes to fly on the wing, not the prop.

AMB

If it flys the plane thats all that counts, I would also guess rather quiet with that muffler set up and not screaming at 15000 rpm
at 9000 it should be almost inaudible say at 200 ft or so martin

Rifleman1853

Rich - ref. your question about the gasket between the cylinder and the crankcase.

I came across the background to this only recently, on another forum;

"A note for Merlin owners; there is a red fibre gasket that fits under the exhaust port band of the liner. This gasket not only seals the crancase for primary compression, it also sets the 'deck' height of the cylinder, and thus, the transfer / exhaust ports. If it is missing, or too thin, transfer does not occur, and you've no chance of ever starting the engine."

If you raise or lower the cylinder, which has ports cut in it, relative to the centre line of the crankshaft, you also affect the port timing. Omitting the gasket will lower the cylinder in the bore. Even if the exhaust port is still completely uncovered by the piston at the bottom of its stroke, this will still delay exhaust port opening and restrict the free escape route of the exhaust gases, causing a drop in power - mainly from trapped exhaust gases contaminating the incoming charge.

More critically, lowering the cylinder will also, at least, delay the time interval in which the transfer ports are open, as the ports will open later and close earlier. At the very least, this will restrict the transfer of incoming charge enough to cause a significant drop in power, and may be sufficient to making starting difficult or even impossible - as noted above.

All of which makes me wonder about the effectiveness of the PTFE tape you have used in place of the gasket. From my experience of using the tape on plumbing jobs, whilst it is brillant at moulding itself into gaps and nicks, PTFE is so soft as to squash down under heavy pressure, and just extrude out of the joint. This suggests to me that, even if your engine is running fine at present, it may not stay that way in the long term. If the PTFE thins down too much, the cylinder head will not be pinning the cylinder liner firmly between itself and the crankcase - and that liner is not something you want working loose on you at 12,000 rpm!

9,000 rpm for a 1.5cc Snipe sounds about right for a 8 x 4 prop; I haven't found a datasheet for the Snipe, but the one I found for a 1cc ME Heron says it will do 8,000 on an 8 x 4.

One thought about the engine speeding up when on slow speed setting. When you have the engine running at 9,000 rpm, the cylinder head will settle at a certain temperature - roughly down to heat being produced in combustion as against the cooling effect of the airstream. If you then throttle right back to 3,000, less fuel is being burnt per second, but the hot gases are staying in the combustion chamber for longer, which may cause more heat to be transferred to the cylinder head, and (for sure) the cooling effect of the airstream from the prop is greatly reduced - and by a lot more than 2/3rds. If so, this could lead to the temperature of the cylinder head rising at tickover - and thus, effectively, raising the compression ratio, so causing the engine to develop more power, and increasing the revs accordingly. Until, of course, everything sorts itself out, and the temperatures and airflow come back into balance at 4,100, and the engine steadies at that speed. The fact that, once having reached that speed, the engine held it steadily for 15 minutes suggests you're not into some kind of thermal runaway problem.

What do you think?

By the way, I recently came across a company in England which does spares for all sorts of engines, and their list includes the ME Snipe. In case you find it useful, here's the link to their website;

http://www.modelenginespares.co.uk/

HTH, and best regards,

Jack

Recycled Flyer

Although its been 7 months between replies I find that Riflemans reply to be very helpful indeed, well done!

And it is interesting regardless of the engine type.

Thanks.

soarrich

My Feedback: (98)

Yes, thanks Rifleman.

I haven't run the engine since I wrote last. I ordered a Micro-Telemaster from Hobby Lobby 11/25/09 and they keep saying it's on back-order, it's in transit from the kit cuter, on and on, but no kit yet. I my just scratch-build something for it.

fiery

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Mayglen Engineering Ltd M.E. Snipe - R/C with silencers.

Looks unrun, NIB and with spare P/L and rod assembly.Unfortunately the natty nylon tank with built in feed, fill and overflow tubes is cracked from over tightening.