By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

Small engine tick-over

All Topics | Latest Posts

Search for:  in Thread Title in  
Roger Dyke03/09/2019 15:14:15
237 forum posts
10 photos

Hi All,

I have an old Enya 15 III glow engine which is in very good condition with decent compression. I have recently had it all apart, cleaned everything and reassembled. Fixing it to the test stand and running it I have made the following observations:-

Prop - 9x4 Fuel - 5% Nitro (9x4 prop is for intended use)

Max revs - 10400rpm Tick-over - 2900rpm

Question: What would be the lowest reliable tick-over speed you would expect? I have heard people claim 2000 - 2200rpm but if I reduce mine down to anywhere near those figures I cannot rely on that it won't quit.The tick-over I have is solid and even. If I reduce it more it is still stable and even, but occasionally it will quit. It may be after a few seconds or it may be a couple of minutes but it will definitely quit. I have very carefully tweaked the settings but cannot improve from the figures I have.

Am I missing something, or do smaller engines warrant slightly higher tick-overs?

john stones 103/09/2019 15:25:23
10832 forum posts
1482 photos

Been a while since I had those size engines, 9x4 sounds a lot, I may be wrong, if tickovers stable and would give you landing speeds, do you care what tacho says ?

J D 803/09/2019 15:26:11
1355 forum posts
78 photos

I run a couple of old 15's and recon you are on the money with 2800/2900 rpm.

Jon - Laser Engines03/09/2019 15:45:24
5073 forum posts
217 photos

There are loads of variables but in general about 3k is reasonable for an engine like that on 'normal' props. Fit a big heavy prop and you might get down below 2500 but why worry.

This is something that crops up often when discussing petrol vs glow. Some use 800 or 900rpm idle vs 1800 for a similar glow as a pro for petrol. My question is why? If the model wont trundle forward on its own at 1800 rpm then any lower than that is of no advantage at all. Its a similar story here. If the idle you have is well suited to your purposes then dont worry too much about it

Denis Watkins03/09/2019 16:35:56
4062 forum posts
75 photos

The bench will show you some of the story Roger

In the air is more important, and for landing

2900rpm needs testing for too long a landing run as this may be still pulling at nearly 3K

And 8 x 4 is a more usual prop, until run on the chosen model in the air

Roger Dyke03/09/2019 16:45:31
237 forum posts
10 photos

John, JD8, Jon, and Denis,

Thank you all for your valued replies. It looks like I'm probably on the money then. That's good news.

Denis: I am using a 9x4 instead of an 8x4 to try to keep the revs and noise down. It also appears permissible on the manufacturers instructions. I remember years ago using the engine with an 8x4.

PatMc03/09/2019 16:57:22
4292 forum posts
524 photos

Roger, you may find Peter Chinn's test report on the Enya 15 III of interest.

Roger Dyke03/09/2019 17:37:07
237 forum posts
10 photos


Many thanks for the link. I've had a look and the figures quoted are in general, a little lower than mine. But as the engine in the review is probably a newish one with tighter clearances and slightly better compression than mine I think that my figures are probably okay.

Edited By Roger Dyke on 03/09/2019 17:45:09

Malcolm Fisher03/09/2019 19:24:16
627 forum posts
7 photos

I use a 9 x 4 prop on an old 15 with no problems. The engine, a Chinese copy of an Enya by the look of the exhaust and silencer, was thought to be not much good by most modellers but it does what I need powering my Veron RF5 motor glider.


Roger Dyke03/09/2019 20:13:05
237 forum posts
10 photos

Hi Malcom,

Thank you very much for the info and benefit of your experience.

Jon - Laser Engines03/09/2019 20:31:42
5073 forum posts
217 photos

i wouldnt want to see more than 10500. While i agree 8x4 is a typical prop for a 15 if you can get revs up over 10k with a bigger prop then you are doing just fine.

Roger Dyke03/09/2019 20:48:16
237 forum posts
10 photos

Hi Jon,

I am now reassured that the figures I'm getting for this little engine are fine. Thanks for the info.

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E! 

Latest Forum Posts
Support Our Partners
Sussex Model Centre
Wings & Wheels 2019
Cambridge Gliding Club
electricwingman 2017
Advertise With Us
Latest "For Sale" Ads
Do you use a throttle kill switch?
Q: This refers to electric-powered models but do you use a throttle kill switch?


Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us