downunder

I think you'll find it really is chrome but Bob will correct me if I'm wrong .

74SEVEN7

Jim, for more about your shiny Enya 60, see Post # 5350 here - http://www.rcgroups.com/forums/showt...2#post22807233

buzzard bait

Oohh...that's pretty! Must be pretty rare too; all the ones I've seen have the usual matt finish.

jjscott

Yes, that's what I have, nowhere near that nice, but still pretty good.

But, the old girl is still reluctant to give up her rings. I have tried a heat gun, heat gun with PB blaster, acetone with tooth brush, a little heat again, more acetone, etc. Nothing is working so far. I have to be away for a couple of days and will let the piston sit in PB blaster. I am more reluctant than ever to use a hammer since this is a fairly decent example of this model and my success with hammers is sporadic.

Jim

1QwkSport2.5r

Have you tried running the engine on a test bench?

74SEVEN7

Don't give up yet Jim. The trick to Acetone is understanding how it works - merely soaking a locked part in Acetone does no good, BUT if you can get the parts to move (even fractionally) the stuff can work miracles. Keeping in mind that the rings are actually standing slightly proud of the piston's surface, try this. You will need a 3 inch length of 1/4 in. wooden dowel, and (to use as a hammer) a 6'' long desert spoon from the kitchen drawer, or a small spanner. Place the piston in your dish of Acetone, but only have just enough fluid in there to cover the piston. We intend to tap each ring in slightly towards the centre of the piston, using the end of our wooden dowel. Mark a spot with a Texta about 180 deg. (ie. the opposite side) from the ends, and start there but don't tap any closer than about 1/4 in. from either end of the ring. Do this a couple of times, then scrub again with the wet toothbrush. A bit of heat in between (on a dry piston) won't hurt either

jjscott

Stuck ring update: Still stuck!

Couple of days soaking in PB Blaster did no good. Tried acetone and dowel, nothing. In 350 degree oven for 10 minutes, nothing but a bit of seepage at the gaps. Now soaking in carb cleaner. Will give it a few days then try the oven again.

I think part of the problem may be that both rings are fully seated in the grooves. There is only a thousandth or two proud of the piston, so not much space to move in if given a rap with the dowel. Plus, I don't want to make an oval piston.

Jim

buzzard bait

Just ran up an ancient Enya 45 BBTV 6001 using an Enya muffler that has an extension on it, adding about 50% more volume, which should make it less restrictive...

MA 12x4 11,000 rpm

Zinger 13x5 8300 rpm (I think there was a little more to be had; I didn't want to lean it out to the max with such a large prop)

Old TF 14x4 8100 rpm

I want the large prop diameter for a VK Nieuport that weighs 5 lbs 6 oz. and has a huge cowl, plus I don't like the look of dinky props on WWI types. Note that the rpms for the 13x5 prop give 90 oz of thrust, which is plenty for my Nieuport. This is to substitute for a PAW 40 diesel that flew the plane well on similar props. The PAW actually did not turn as fast on such large props. A five inch pitch at 8300 gives plenty of speed potential for this plane.

The torque curves in an old review (on a website by Downunder) show that the engine has a lot of low end torque. So a good diesel substitute, I'm thinking.

I think I probably need a cooling hole in the firewall out the bottom of the fuse. I'm concerned about overheating. Any reason why I shouldn't do this?

Jim

downunder

This may or may not work but you've got nothing to lose so try running the engine with about 3-5% acetone added to the fuel. You may have to use an electric finger at first but take note of how the compression feels when flicking by hand. Use a fuel with plenty of castor in it but a fair dose of synthetic as well. The heat, vibrations and reversing loads on the rings should help free them up. Check the compression feel after each run. Even if one ring frees up you're pretty much good to go because one of the tricks done with the twin ringed Enyas was to remove the lower ring and they eventually went to a single ring anyway in the last version. If you can't get it to run then you're back to square one which could mean sending the piston to Frank Bowman.

I've just recently got hold of an old ETA 29 which has one ring that I can't free up so I'll be trying the run it and see approach too .

74SEVEN7

Take the piece of 1/4 in. dowel described in Post #2256, and fashion one end into a chisel point, the same width as the rings. Try tapping that in when the piston is straight out of the oven

Hobbsy

My Feedback: (102)

Enya-phytes, I got my old, last of the .46's I bought in about 1990 down off the shelf and ran it today. It has a new cam drive pinion bearing by Boca. Here's the skinny.

Enya .46 MKII
Plug==original A3
Fuel==WildCat 15% with 18% syn/castor blend lube
Exhaust==stock with pressure tap added
Graupner 12x5 rpm==11,005
Zoar====11x6 Pictured rpm==11,262

Good numbers, I think.

jeffie8696

Beauty, I want to hear it run.

Thelinks

I picked up 60-4c yesterday for nearly nothing. I spent the evening cleaning it up and after reading a portion of this forum looks like I have a little more to do.
it has great compression and everything feels smooth when hand turned so I believe I have a winner here.

a couple questions as I am brand new to four stroke.

Does this engine require back pressurization to the fuel tank?
The crank port, what exactly is the purpose?

lastly, I need to find a prop nut and washer for it before I can bench test it. I am not confident that the only local shop here would have what I need. Anyone have a good place for these items?

thanks in advance
-links

1QwkSport2.5r

The 60-4C does not need muffler pressure, but it will work fine with muffler pressure if you have a muffler on it. I have a 60-4C myself and I've found it to be a very good running and reliable engine. However, it likes a fat idle mixture. It will be a little blubbery on transition, but it rarely quits. This is running it without muffler pressure. I run mine on 5-10% nitro 20% castor - keep the nitro limited to 10% or less. It doesn't run any better and very little faster on more nitro. I set the valve lash cold pretty tight - .001" is all that's needed. The lash gets wider as the engine warms up. The prop shaft is 7mm X 1 so any Dubro or Sullivan spinner nuts will work. I have a Higley jam nut (thin flat lock nut) behind the spinner nut on mine. Enyas like to rev, don't be afraid to let it rev to 11-12k. The carb will spit a lot of fuel if it's over-propped. Max revs is 13,000rpm.

Lastly, the fitting on the back of the crankcase is for venting oil out of the crankcase. Run a length of fuel tubing from the fitting outside the fuse.

Use a tach to set the main needle, it's pretty tough to hear when a 4-stroke is at peak revs. Usually it will just quit if you get too lean, but it might backfire and kick the prop off if too lean on higher nitro fuel. If you don't have a tach, start it out really rich and lean it out until it just cleans up and runs smooth. An occasional misfire is fine.

jjscott

Stuck ring update: Unstuck, or rather broken out.

What finally worked was a small steel chisel with the end ground down to a flat about 1/32 x 3/32. I carefully tapped around the outer circumference, keeping the chisel point on the ring only, at first on a soft surface. The bottom ring cracked about 1/4 from the gap, and I was able to go around and pick the rest out. The top ring required another heat. Tapping on the soft surface didn't work. I put the piston on a brass block then tapped close to the gap. The top ring also broke about 1/4 from the gap. It was picked out.

There seems to be no damage to the piston, luckily. It's back to soaking to clean up the grooves, then new rings from Frank Bowman. Thanks again to everyone for the suggestions and encouragement.

Jim

Hobbsy

My Feedback: (102)

I got slammed around some a few years ago when I posted that the .46 MKII you see above would run sloppy rich in the midrange if I tried to use a 12x6 on it. I reasoned that with the larger prop the airflow velocity through the venturi was too slow causing one to set the HS needle richer, then, when you throttled back, the fuel draw improved causing the rich midrange. At the rpm I showed above there was no rich midrange.

1QwkSport2.5r

My R120-4C is horrible about carb reversion; anything bigger than a 13x7 or 13x8 and it makes a huge mess. So I can back you up Dave; Enyas like to rev up and will do so all day long.

I am keeping my eyes open for a 46-4C. I wouldn't mind having one. They're crazy powerful for a .46 4-stroke.

Thelinks

So so what is over propped? I did more cleaning and put a 12-6 on it. I got it running and started to get it trimmed out but it was spewing fuel out the carb as you stated. Not sure if the prop is the issue. How do I get the throttle to close completely? It stops just short of full close.

1QwkSport2.5r

It will run a 12x6 but it would rather turn up more. I think mine turns a 12x6 APC at 9,990rpm. I'm sure it would do fine with an 11x6 or 11x7, or a 12x4 or 12x5 should do okay as well. It will turn a 13x6 as well but for the reasons already mentioned, I don't prop mine that heavy. If the midrange is pretty wet, run the airbleed a tad leaner (backing the screw out leans the mixture. If it cuts out then you went too far.

There is an idle speed screw as well as the idle airbleed trim screw. The idle speed screw is the one just above the throttle arm. The airbleed is in the center of the carb. When your idle mixture is set correctly, the throttle has to be open about 1/4 for the engine to idle at a good rpm. Usually it doesn't take much below 1/4 throttle to kill it.

buzzard bait

Hobbsy's 46 turns his 12x5 Graupner the same as my Enya 53 did on a Rev Up 12x5, i.e. 11,000+. I know props of the same specs but different brands will load engines differently, but still, I'm surprised a 15% increase in displacement didn't make more of a difference. Besides, I always thought Graupners were pretty high load props. Is an Enya 53 not really that different in power from the 46?

Jim

1QwkSport2.5r

I don't know if the .46 and .53 share the same cylinder head or not, but I believe IIRC the .46 has a larger intake valve and thus breathes better than the .60 which has the same size intake and exhaust valves. I think the design of the R120 was modeled after the .46 in terms of valve sizes and breathability.

As I understand, props like Graupner and APC are higher loading props than most wood props and MA black props. Recently I ran an MA 10x6 and an APC 10x6 back to back on the same engine and saw a 400+rpm difference between the two with the MA revving faster.

buzzard bait

Yes, I have always found MA props to rev higher than other brands of same dia x pitch; everyone seems to report that. Zingers seem to load up quite a bit, but I don't know about my old Rev-Ups. Graupners have a lot of blade area, but I've never tested them against other props.

The Enya 53 probably had the same valves, cams and carb as the 46; if so, then I suppose it's no big surprise if the 53 didn't do much better. I have in mind that the 53 was improved at some point, so maybe I had an older one that really wasn't much better than the 46.

Jim

blw

My Feedback: (3)

Tim, that may be true on the ground. Props have several methods to calculate efficiency when flying and that is where everything will change on a prop. The formula is actually easy to understand, and makes sense. The best is if we would all buy onboard telemetry setups to measure rpms. Those reporting with Eagletrees, etc, show unloading to be variable but using a 1000 to 1500 rpm increase is a fair rule of thumb.

1QwkSport2.5r

I haven't been able to discern the absolute differences, but it seems there are two versions of the .53; one with a plain aluminum rocker cover and one with the black cover. The black cover engines mostly seem to be the TN type. I assume the .53 uses the larger bearings that the .46 Mk II uses. The older .46 uses smaller bearings. That's about all I got.

Hobbsy

My Feedback: (102)

The .53 came early on with an airbleed carb, later came the TN carb.