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Hello ZDZ,

I've just finished my 1/4 mick reeves spit. After the first takeoff my zdz 80 rv suddenly stopped after one round. After a emergency landing the piston was completly stuck in the cilinder. I've just send the engine back to Germany (Amelung) they say i did not use any oil in the gasoline but i did!
I used the right 1:30 mixture for running in for 3 hours and 1:40 for flying. I use Bel ray H1R fully synthetic oil! Has anyone have experiance with these kind of things. I suspect it to be a cooling issue but before flight i measured the engine's temperature more than once and it never exceeded 114C (celcius) measured at the opposite side of the exhaust under the first cooling fin. The first thing that i noticed after the landing was that the engine was indeed very dry. Can i be that the oil in the gasoline evaporates by high temeratures?

The cooling of the engine is done by installing a baffle around the cylinder in the lower cowl. The engine is mounted on a large box. The side of this box are also seeled to redirect the cold air from the original inlet through the cooling fins and out trough the scale exhaust pipes. Outlet opening being 5 x larger than inlet! And vacuum behind the scale exhaust sucks the hot air out of the cowl. This way the engine is completly build inside the cowl.

Greetings Ronald.

Take a look at www.kunenborg.nl left menu 1/4 spitfire.

RCSHOWCASE

Very simply it sounds like the engine has overheated. Typical CHT should range from 190-220F.
If the piston has melted down at the exuast port, it has overheated.
Best Regards,

RCSHOWCASE

Sorry, one more thing, please be sure the crankcase and carburetor are getting a supply of cool air as well. Mustangs and Spitfires are the worst. The real ones of course use radiators and were liquid cooled......

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First I would like to thank ZDZ for repairing my engine!

I'm still having trouble with cooling this engine. We've tried various things to bring down the temperature like running the engine very rich, using 30% oil instead of 40%, adjusting the ignition sensor but nothing works. The temperature of the engine is at 2000 rpm about 110 degrees Celsius (230F) but when opening the throttle and running at rpm's ranging from 4500-max the temperature rises very quickly to 160 - 170 (320-338)degrees Celsius and I have to shut down the engine before it brakes down. We tested this at a cold day with outside temperature of 3 degrees Celsius (37F). The engine was tested without a engine hood(see photograph) and it is directly cooled by the air from the propeller. The tests were done on the ground.

Can you please advise because I won't risk my model and I'm afraid to take off with these temperatures.

[link=http://www.kunenborg.nl/img_0909.jpg]Image ZDZ80 mounted[/link]

morro

Having a look at your pic I see you are using a 3-bladed prop, just check it is the right size for the motor, if it is not the right size you could be overworking the engine try a 2-bladed first. with your bottom cowl most spitfires have a " V" letter just behind the spinner, not sure what spit is yours, draw this on to get the right scale then you can cut this out to give you some extra air. check the type of oil you are using maybe try a different brand also try 25 to 1 not 40 to 1. dont lean your fuel mixture out to much engines dont like it. just a few thoughts

Todd

Johns38

My Feedback: (2)

Ronald,

I am in the process of building the Reeves 1/4 scale spitfire. I am interested in the cooling arrangement that you have set up. Were is the in coming air ported from.

I will be installing a 3W80 single cylinder engine in mine. I am planning on using the chin scoop to bring in the air and will be using a live exhaust system, the outgoing air will exit from around the exhaust area.

This is how my flying buddy has his Clark Industries Spitfire set up except he has the in line twin, we fly in the central valley of California were the summer temps are in the mid to upper 90's.

Are you bringing cool outside air into the carb intake. I had a similar sounding problem with my 3W 50 in my P51 Mustang.
The cooling was set up well but the engine would run very poor overheat and finally suffered damage.

Once I ported fresh air to the carb the engine ran like it should. Also be sure your not running to much prop for a new engine.

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Hi John,

Well at first if tried to use the chin scoop to capture incoming air, but the cooling will be insufficient. I've now made a hole in the engine hood?? (sorry i don't know the right word) see new pictures on my website. The hot air is partly sucked out trough the fake exhaust and the space around the exhaust stacks. All the exhaust pipes are hollow and about 20mm in diameter. Because they are angeled at 45 degrees the vacuum behind them will also help in getting the hot air out of the engine compartment. Also yesterday i've drilled a extra hole in the firewall to allow the air from the scoop to go into the fusalage and cool the K&S exhaust. I will have to make some additional hot air exit holes somewhere in the fuselage to allow the hot air to get out. I'm now running 1:25 mixture with the Belray h1r. The engine still run hot but does not overheat anymore. I ve measured my friends 3w75i and his engine reaches about the same temperature when running full throttle on the ground. So i'm slightly more optimistic.

banjbob1

I'm building one with a kolm il 135 and plan to not have any cooling holes cut in the cowl.

Did you get the cooling to work?