stunthanger.com
Engine basics => Engine set up tips => Topic started by: michael battley on February 12, 2009, 10:07:36 PM
-
Recently bought one of these engines and it seems to be down on power. Enya recommends props in the 11x6 to 12x6 range, I've tried a few and none seem to yield more than 0.87 BHP.
This is well below Enya’s claim of 1.3 BHP.
Last start it ran an Apc 11x6 @ 10,800 rpm, Air density = 1.1604 kg/m3, fuel was 10% nitro and 24% lube, plug was an Enya No3. Venturi is 7.5mm, No Muffler,No head shims.
If anyone else has this engine what sort of RPMs is it turning?
Regards,
Mike.
-
Mike,
I can't respond directly with experience on that engine as mine is still NIB. However it is not uncommon for a ringed engine to take awhile to develop full power. In Enya's it is not uncommon for the break in to take about 3 hours total till you can say it is truly up to par.
Dennis
-
Thanks for taking the time to respond Dennis; I've put about a gallon and a half through it already, so I'm not sure if I'm going to waste any more fuel on it until I try a few things. I believe there could be a problem with the piston to cylinder fit as compression is non existent, I will be ordering a Frank Bowman piston ring for it and will also try the larger 8mm venturi.
Hope you have better luck with yours,
Mike.
-
Michael,
Perhaps there is a problem with the ring, after a gallon you should have some compression cold, but these engines will built up compression with more time running.
I have no reference of peak rpms but over 10k RPMs with an 11x6 it doesn't sound tooo bad.
My friend has an Enya 45 and I have the SS50 and the ring, like Franks rings, needs more then a gallon of fuel for the ring to seat properly. At least my older Enya 45 6001 with Franks ring took about 3 gallons to achieve peak power and smoothness.
The Enya SS45 has the same case and piston of the Enya SS50, just a little shorter stroke so I think they are not too much different.
The original muffler could be robbing some good power. I have seen new SS45 coming from factory with the exhaust hole enlarged from stock and other just stock. I did enlarge mine as much as I could with a round file and it helped. But what really worked was the Aeroproducts Muffler, venturi bored out to 7.8mm. With the APC 12.25x3.75 I got an UNBELIEVABLE STUNT RUN in high RPMs, generating massive power for a 60 size ship.
I'd like to try a Bolly 12x4.25 3 blade or a Brian Eather 12x3.75 3 blade.
If you like to get a classic 4-2-4 with a 6" pitch prop, you get the engine re timed. A friend raised the the intake ports almost to the same height of the exhaust and his engine run a smooth 4-2-4 with a 12x6 prop. But it did not generate as much power as the stock engine with the low pitch prop and higher RPM.
Martin
-
Hi Mike,
My flying buddy and I have 4 (or maybe 5) of these motors that we use regularly. I have one in a Trophy Trainer profile, and another in a Nobler.
The one I have in the Trophy Trainer is the newer of the two but has had more than enough power available for the trophy even allowing for the normally windy conditions we have to endure here and appearing to have no compression when turned by hand when I installed it first.
I run 25% all castor 5% nitro fuel. Prop is an APC 11x6 or a Zinger 11x6. At my level I can't tell the difference in performance between either of these props, but I can tell the difference between these and other 11 x 6s. Takeoff RPM is 8700 or so. I use a home made uniflow tanks, with no muffler pressure and get 6:30 on 90 cc of the above.
I'd have to say that for me, this is my no brain setup, I can guarantee a full pattern every time I fly with this configuration. I fly pretty close to sea level, it never gets particularly hot here, but flat calm is almost unknown.
Of late I've realised that I should be able to get a lot more from these motors, but why break something that isn't broken?
Chris
-
Mike,
I forgot to say both of my models in the post above are porkers - over 50 oz each.
Chris
-
A gallon-and-a-half and still no compression? Your ring is definitely suspect. Can you partially disassemble the engine to check the ring end gap? IF not, I'd say send the piston and cylinder to Frank Bowman for a new ring.
No, or low, compression is quite normal in a new (or newly rebuilt engine), but it sounds like you have 4 - 5 hours on your new Enya, and that's definitely not good.