AmishWarlord

My Feedback: (5)

Guys must be busy flying. I watched the video at 4:38PM and was the first viewer.

1QwkSport2.5r

I just posted it a little bit ago. I'm in the Central time zone, so its 3:45pm here in Minnesota. I didnt expect any replies until at least dinner time because I'm sure a lot of folks are out flying..

It did take me nearly an hour to burn two 8oz tanks of fuel.. Thats something hard to get used to when compared to the thirsty ST S90K that was on this thing before. 16oz of fuel was gone in about 15 minutes.

AmishWarlord

My Feedback: (5)

What fuel type do you run in your Enya's?

1QwkSport2.5r

98% of the time, I run 5% nitro 20% castor in all of my airplane engines. Exceptions are the one 1/2a engine I have that I run 25% nitro 20% castor in, and I tried 20% nitro 20% oil (50/50 cas/syn) in the Enya 60-4C once as an experiment.

I havent ran my SS30 yet this year, that one I feed 25% castor 5% nitro and use a MC59 glow plug.

AmishWarlord

My Feedback: (5)

I'm running
10% Nitro 20% Castor in my BB engines
5% Nitro 25% Castor in the K&B Sportsters.

After run is a clean out with WD-40 followed by a lube job with 3-in-One oil.

1QwkSport2.5r

My sportsters are shelved pending new carburetors... But I am cheap and dont want to burn more than 5% nitro. I burn 3-5 gallons of fuel a summer and if I keep the nitro % low, I can make a lot more fuel.

I'd run FAI if my engines didnt take such a hit on rpm. The ST S90K drops 800rpm on FAI vs. 5% nitro.

earlwb

You may have to up the compression ratio a little bit for FAI fuel. They normally run a little higher compression on them. The USA engine companies used to make special heads or head shims for engines sent to the European market, and conversely the European engine companies had to include extra shims to lower the compression for engines exported to the USA. I don't see that MECOA exports many engines to Europe much anymore so they don't seem to have high compression heads now.
Enya and Fox used to sell high compression heads for some of their engines, you can run across them from time to time too.
I remember running Cox .049's with FAI fuel and they didn't take too much of a performance hit after you adjusted the head shims on them.

Ram Jet

I like your fuel mix. Very nice looking hull. I think I know what I want to do with my 1.55. (The sky pilots are projectile vomiting.) Where did you hide the throttle servo? Where are the air rudders? I want to se her get wet! (that's what he said.) Sounds to me like you've got that engine tamed. It sounds beautiful.

Good job.

Bill

Ram Jet

You a man after my own heart with the fuel mix.

Cheers,
Bill

1QwkSport2.5r

This is the inside of my radio box. The extra AA batteries are in there for ballast only. Two Hitec HS645MG servos, and a JR XS3 synthesized FM receiver, and a 4-cell AA pack is all thats normally up there. The more power the engine has (and subsequently weight) the more the bow porpoises. I have to do a little more balancing work to get it to ride dead smooth.



Air rudders? We don't need no stinking air rudders! LoL I like wet rudders because I prefer my boats to drive more like cars. This boat doesnt turn like my little Minikaze does because its a true flat bottom, but it does drive more like a car than a slide-happy airboat. Nothing about this craft is scale, and it was never intended to be either.

I did make air rudders for it, but I do not like how it handles with them.


Here's how the inside of the hull looks without the skin; I used Sullivan control cables (semi-flex .056" gold-n-rods).


This thing is kind of a pig - 7-8lbs depending on tank size and engine. Closer to 8lbs with either the ST 90 and 16oz tank or Enya 60-4C and 8oz tank. The K&B Sportster .65 made it weigh in at a little over 7lbs. BUT, the ST S90K will get it up to 33mph so far, with 40 in my sights. The Sportster .65 got it up to 29.9mph running a 13x6 APC. I figure the 60-4C is getting it going around 25mph.

I better quit posting airboat pics... I dont want the projectile vomiters to start projecting their vomit at me.. LOL..

I prize my engines... can ya tell? Is it overboard? Maybe. Do I care? Nope.

edit: Bill - Here is a crappy video of the S90K on the above boat. You can hear it porpoising. I have to move the engine mount farther forward or add more weight to the bow.
https://www.youtube.com/watch?v=5SYlGrDmjYQ

earlwb

I had built one of the Dumas big airboats many years ago. I had powered it with a Fox Hawk ,60 at the time. The engine could get it going fast enough to go airborne if it hit a small wave in the water. Unfortunately it didn't have any control surfaces for flying. But it was a lot of fun to run and play with at the time.

1QwkSport2.5r

I have a great time building these and even greater time running them. This hull shape is really stable even when overpowered. The guy at my hobby shop almost fell over when I told him I was running a sportster .65 on it; he said a .40 was the right size engine for it. He gave me a dirty look when I told him I was putting a .90 on it. It's a handful with the SuperTigre S90K and 13x6 prop.

I ran 4 more tanks through the 60-4C today on the Mississippi river. I have 3 or 4 videos that I'll upload tomorrow. 26.6mph with the Enya turning a 12x6. I peaked it out today and it seemed to like that. On a full tank I set the NV 4 clicks rich of peak. To get a reasonably smooth transition I had to keep the airbleed pretty rich, with the throttle needing to be about 1/4 open to keep the idle stable (2700-2900rpm). I will post vids tomorrow.

Can anyone tell me the reason why 4-strokes have such a high exhaust temperature? Even sloppy rich it's really hot. I expect hot exhaust from gasoline, but not methanol based fuel. The exhaust of full castor fuel smells vastly different from the 4-stroke than from a 2-stroke. It even smelled hot, but the oil coming out of the exhaust was very light in color.

I pulled the glow plug today just to look at it and it still looks shiny and new, and there isn't a spec of carbon on the piston either. (at least what I could see through the glow plug hole). The lack of carbon surprised me. The engine has about 5 quarts through it now, maybe 6. The ring seals amazingly well, and the engine has tons of compression. My .90 size starter has a hard time getting it going once in a while.

earlwb

It is the more complete combustion process going on with a 4 stroke engine. The two stroke engine wastes a lot of fuel which gets pushed out the exhaust. That waste fuel/oil helps to cool the exhaust pipe and muffler a lot. But with a four stroke engine there is not a lot of excess fuel/oil coming out of the exhaust, so with mostly hot exhaust gasses it runs more hot.

1QwkSport2.5r

That's kind of what I expected but figured I'd ask for the heck of it. Thanks Earl.

1QwkSport2.5r

As promised, Here's one of 4 videos I made while boating on the Mississippi River yesterday. I had to make some adjustments in the first few videos, and I havent watched them end to end yet. This one I have and am pretty happy with how it ran. I'm still working on the transition to get it just right, but it was still fun. I had my tripod setup in my boat, and my camera kind of stinks so the quality isn't top notch.. I got really lucky; just as I was ready to drop the boat into the water some schmuck came tearing through this narrow backwater channel at full-tilt making some huge waves.. If I would have dropped the boat in and had it any distance from me it would have flipped from the huge waves... Lucky me.

edit: For some reason, the link I had posted here originally is now dead saying I removed the video. I did not remove anything. I watched the video after I uploaded it and it worked fine, so I'm going to try it again. The new link is in my next post below. Sorry for the glitch.. Not sure what happened here.

earlwb

You tube says your video was removed by you.
Hard to watch if it isn't there. How come you didn't use the USA youtube website?

1QwkSport2.5r

I watched the video after I uploaded it, and now it doesnt work. I'm re-uploading it right now.. I didnt remove anything. I think it could be a glitch because like I said, I watched the video after I uploaded it this evening.. As far as using the USA site, I went to YouTube.com and uploaded it to my account. This is the link it gave me.

This happened once before where I uploaded a video and it didnt work. When I tried to re-upload the same video, it told me it was already uploaded so I went to the video manager in my account and the link had changed for some reason. It should be ready in about 10 minutes at this link, hopefully... http://youtu.be/fANKIgoe65Q

Very strange indeed. My apologies. I will remove the previous dead link.

Murphey

My Feedback: (11)

Enya Guys: I recently acquired a VT-240 that I would like to get in running condition. Its fairly gummed up but otherwise looks OK. I took the back plate off to clean it up and lubricate the cam gears and you guesses it...I got the timing off. I noticed the 2 timing marks, but can anyone tell me how they line up? Also, there is 1 cylinder head that has a broken fin...any idea where I can get a used head? Thanks for the help!
Murphey

earlwb

I can see your videos this time. Yeah it looks like it is running pretty good there. It is zipping along quite nicely there.

1QwkSport2.5r

Thanks Earl. I have a feeling the bigger 13x6 prop is going to end up going slower because of the rpm drop, but at least for now it seems to be running pretty well. I will keep running it to get some time on it and I'm sure as with any ringed engine, the engine will only run better and better with more time. I am using an 8oz tank on it and I easily get 15-20 minutes of runtime on that with an ounce or two still left in the tank. Of course a boat needs to be run with a lot more throttle than a plane would so I probably use more fuel on the boat than I would a plane.

I do wonder though.... That I might have it set wrong still. As it was running in this last video, The throttle is open about 1/4 with the airbleed nearly closed. This is where it seems to throttle the best. Do I have it too far out of whack or is that about normal? It will idle at 1600 with the throttle nearly closed but to get the idle mixture rich enough to transition good, it will not run that low. 2700-2900rpm seems to be the butter zone, but again, I have to have it set pretty rich for a decent (though sluggish) transition thus the 1/4 throttle setting for it to idle.


I tore the ST S90K apart that was on this boat to clean it up and find out why it started running all funky. New gaskets, cleaned the carb out, and reset the spraybar to the factory position and it runs great without quitting now. The transition was really good as well. For some reason I want to say I've gotten 13,600 from it on a 13x6 previously, but today it only mustered 12,600rpm on the same 13x6 prop and 5/20 fuel. My memory might be a little fuzzy though. I might be thinking of the 12x6, too which I might try on the 90 for the heck of it. The Enya 60 turns a 12x6 at about 10,000rpm peaked and a 13x6 at maybe 9400-9600rpm or so. I'll have to double check it again with the tach. Sunday I was adjusting it by ear only.

NM2K

My Feedback: (14)

I have "a few" Enya 60-4C and 80-4C engines. It was a pleasure watching your video and hearing a 60-4C sound again (same as the 80-4C). A 13x6 is a good prop for this engine, as is a 12x7 to 12x8 and a 14x4 to 14x6. This is an early four-stroke design that was designed to operate while swinging large, low rpm props. It has always amazed me how well the Enya four-strokes of the early era fared when revving up a bit. I.E., few broken valve springs when compared to some other brands when revved.


Ed Cregger

1QwkSport2.5r

I'm getting happier with it each day. It's a beautiful looking engine and it is running better and better too. I just keep it below the "critical rpm" and so far it seems happy. I check the valve lash every hour or two I run it and reset it as needed. I certainly want to treat it as it should be treated.

Thanks for the compliments Ed, I appreciate that.

earlwb

Many years ago, we were racing the smaller 20 size airboats, and it was always a challenge to select the best prop to use on them. If you went with a bigger prop, you got more thrust for better acceleration, but a smaller higher pitch prop would give you more speed but weaker acceleration. So it made it interesting depending on how we setup the race course that day.

earlwb

Ken Enya at Enya engines likely has the parts. But if you are going to use the engine, the broken fin likely won't make a difference.
Shtterman who sells Enya parts on Ebay also can order the head for you too. He orders parts fromEnya often so it can save you a little on shipping costs.
I think we have some pics of the valve timing setup farther back in this thread for a single cylinder engine. But the twin would be the same, except you have to align the second set too. But is is done the same. If I find the post number showing the pic of the timing I'll post it here. But it is back a ways in this thread.

Ram Jet

Thanks for all the pictures of your hull under construction. Nice work. I love the sound of that little Enya. Sounds like your have the low speed to high speed transition nailed. As far as the porpoiseing thing goes could you add trim tabs at the trailing edge of your hull bottom or change the angle of your crankshaft in relation to your hull or simply add weight to the front of your hull? It's not porpoising badly in your last video. All would cost some speed but it would save you hacking-up a beautiful hull to move the engine forward. On an outboard motor (engine) boat changing the angle of the prop shaft in relation to the hull bottom kills porpoiseing.

Just a thought.

Cheers,
Bill