Enya .29 model 5224

[John Fitzgerald]

I have two of these I bought used in a box of misc C/L things many years ago and never ran them until lately.  They seem to be broken in and are in excellent condition.  Both are using the low compression heads, but one has a slightly larger venturi opening (cylindrical aluminum venturi). The one with a smaller venturi opening is more manageable, easier to needle than the other.  It turns a 10x5 prop about 9,400 rpm when needle is set to occasionally break from two to four stroke.  The other wants to run away, is hard to needle, and turns the same prop about 10,000 rpm at best setting.  I need to get the smaller venturi for this one.  I used 5% Nitro, 29% castor for the tests.  Does anyone know of a source for parts?
Neither has a muffler, or provision for mounting one.  What about mufflers?
I plan to use one of them, at least initially, on a PT-19 ARF I am building.

Thanks in advance.

[Steve Helmick]

I don't have much Enya experience, only recently exposed to a .15III and a .19IV. Both use clamp on mufflers, so I expect the .29's probably do also. These two are on our club trainers, and they seem to work decently well. Contact Randy Smith at Aero Products, moderator of the "engine setup" forum, as he's the only Enya distributor in the USA, AFAIK. The clamp-on mufflers are not a bad thing if you are crashing occasionally...bending rather than breaking stuff.

The .29 that is less agreeable might just need more break-in time. Getting a venturi bore dimension would help evaluate what's going on. Randy is probably going to be able to help on the venturi insert, either from stock on hand, ordering in from Enya, or by making what you need. You could also try sticking a wedge of spruce or pine into the venturi to restrict the airflow. That will probably tell you if it's the venturi or something else.  Steve

[rustler]

Try the venturi from the "good" engine in the other one?
If using a strap-on silencer do not overtighten, can distort the c/case and cylinder.
The vertical ends of the exhaust duct are quite thick, and probably have a dimple in them. Holes to fix a silencer can be drilled and tapped at these points.

[Steve Thomas]

Enya sell a strap-on muffler (M292) which fits the .29 to .45, but you wouldn't want it - it is very large and heavy.  There was a smaller one that was available for the .29 and .35 back in the day, which is more suitable if you can get hold of one.  Even better would be one of Randy Smith's aluminium numbers.

[John Fitzgerald]

I used my drill press and X-Y vise to drill out the dimples to 3mm and an extra muffler for a OS .25 FP bolts right up, perfect match...not too heavy either. Hope it doesn't rob too much power.  The 9,400 rpm I was getting on the bench with a 10x5 prop was unmuffled.  Anyway, directing the exhaust down and away should keep the plane a little cleaner.  My flying site is about 1,100 feet higher than my home, and maybe that will make a difference too.
Addendum: I ran it on the bench today with the muffler...got about 9,250 at best needle (2cy, a little 4cy) with no pressure, 9,550 at best needle with muffler pressure, so it will be ok, and not so screaming loud.

[George]

John,
You might want to drop the castor content down a little too. Enya instructions call for 20% castor...at least the ones for my old 5224 .29 does.

George

[pat king]

John,
Your engine is an ENYA 29 IVB. that is the Model 5224 with the round venturi inserts. There are three size venturi inserts from the factory. For stunt the #1 (the smallest) is best. Unfortunately, they are not marked. I will have to check to see what the bores are for each insert.

Pat

[John Fitzgerald]

That is correct.  It says IVB on the box.  Unfortunately, there were two engines in the box of stuff (one in box) and only two inserts between them.  I think I "maybe" have the small and a medium.  The engine with the small venturi runs like a stunt engine, at least on the bench.

[Bill Little]

Hi John,

My .35 is about that vintage and runs a nice 4-2 with the low comp. head and small venturi insert.  5% NITRO, 25%-29% all castor, 10-5 paddle blade prop.  Pretty strong and will NEVER wear out unless really abused.

Big Bear