elmshoot

My Feedback: (6)

There is no need to hook the tank vent to the Kelo exhaust. I did it just because I need some place for the fuel to over flow that isn't in the cowl.
Its a pump style carb so fuel draw shouldn't be an issue if the fuel line melts from the high temp I seem to recall having the fuel line melt last year.
I know how many turns it takes to full tank so I go a few short of that and when I complete a flight I empty the tank the refuel to a know quantity not until it overflows.
I'm running a Xoar WW2 23X10 and it turns 6100 RPM ambient temp is close to 90F
Three flights completed today the engine is running flawlessly. NASA Scale contest. I think its called the Hoosier Scale Classic.
Talk about score inflation...
ill see if some one can get a video.
Such a sweet sound!
My team mate had the wing strut fail on his Decathlon only 8 flights. It's a write off.
Sparky

cathurga

ForcesR,
Yep, they are all the same similar/carbs, and all have the same problem. I dont like the 'cure' from Saito, which seems a bit 'sticky-tape & glue' fix....I am nervous enough flying warbrids that are not designed for rolls and loops all the time (aside from the lack of skills on my behalf) and just seems ridiculous that we have to do this on expensive engines in expensive planes. Fix the damn thing at your factory...That said, my FG40 burps and farts occasionally until the carb is clear, but even when its doing this, its never stopped. My heart skips a beat when it does this, but it doesnt stop.....until one day when it does! Then its like being in the property market....location, location, location.....dead stick on a low slow pass will likely end badly!

Brad, flying in the face of Ray English advice....you dont need the pipe from the nipple to the tank. Leave it as it is. They are all 'pumper' carbs, and provided your plumbing is good and tank not too far away, you shouldnt have any problems. No disrespect to Mr English...I just dont think its necessary.
Sparky, if the pipe melts closed, and there is no vent to atmosphere, you will start getting a vaccum in the tank, and eventually the pumping wont be able to overcome the vacuum, and the engine will start to lean up, until it cannot draw anymore...and stop.

Glad your event is going well, if you cant get video, get PICS!! :-)

In making the changes on Frankensaito, we changed from 30Deg BTDC to 34 BTDC, and as you suggested, no changes to any 'numbers' we got, but to the 'ear' it sounded worse! So that will be changed back to 30Deg BTDC, and left there.
We have never had telemtry rpm on the plane, but installed it, and did one flight before the timing change, and another after. Numbers were about the same...
Static RPM on the ground - 5200RPM
Dynamic, full speed in flight - 7150 RPM
Thats a massive difference, around 35% increase! I expect partly because of the 4-bladed prop. Not based on science or numbers, but I dont know if a 2-bladed prop would have the same difference or not, but for those on 6500rpm on the ground, beware...LOL!
Bewteen the flights, while changing the timing, I opened exhaust rocker cover on Cyl-1, and to my immense surprise and pleasure, the valve train was soaked in oil! Remember, this plane has been dormant for 3 weeks, and any residual oil would have dropped into the crankcase as its stored in normal orientation. So, after 1 flight, lots of lube up there!! very happy about that, and lends some kudo's to the crankcase mod, and doing its job of keeping things oily in there. I dont care if it shlurping oil into the intake....its doing what it should do, and keeping the moving parts oiled. I am a believer in this mod!

We also ran Mike's Hangar 9 Corsair with the FG90 in, with the MMM timing hub, and it went VERY well. 24x12 Falcon prop. Temps got a little higher than we would have liked, but its a new engine with maybe 5 flights on it, so has a lot of loosening up to do. I will post a video on the FG90 thread, so as not to derail this thread. After the flight, I noticed the 'squeak' of the valve that was mentioned by someone on this thread ages back, and I suspect the same problem of not enough oil getting to the top, so eventually will look to do the crankcase mod on this engine too.

Sparky, sorry to hear of your mates 'undoing' of his plane....it does hurt when you maintain a plane well, and then still have structural failure, unavoidable or not.

elmshoot

My Feedback: (6)

5 Flights over the weekend the engine ran perfectly all weekend. 4th place! Not bad i have two more events this year so I will have a great handle on the engine if things continue as it has.
I did pull the plugs Friday night before the weekend and I was only getting 5700 RPM down 400 or so. I pulled the plugs they were NOT oily but still very black. I considered better that the last time I looked at them. I sprayed them
with brake cleaner. Is there any gap specified ? I figured the spark is so hot that the gap isn't super critical. With the engine at 1000 RPM waiting to taxi out it is impressive.
I had a flight that I got a 10 in flight realism. That I attribute to the engine and its sound......
Sparky

cathurga

Nah! You dont win event's like that with the sound of an engine, you gotta know how to fly, so well done. Good to know the engine is running well. But...

WHERE ARE THE PICS!!! :-)

elmshoot

My Feedback: (6)

Im waiting for my buddy to FWD some still shots over to me.
Any thoughts on proper spark plug gap?
Sparky

Smotherb

cathurga

Smotherb

cathurga

ForcesR

Sparky, the spark plug gap should be from 0.5 - 0.6mm or .018 - .022 thousand.

slither

If memory serves me, Ray said that you have to use silicon tubing on the Keleo ring pressure tap or the tubing will melt...

Chris Nicastro

My Feedback: (3)

cathurga

Chris, did you only adjust HS? Put the HS at 1.5 and if it isnt getting top end, richen up the LS and get it to 2500rpm stable, then follow the process I mentioned earlier. I find it is a reliable way to get a close tune.

Before you do any of that, since you took the plugs out, are you sure you put the leads back the right way?....it wouldnt be the first time thats happened to a radial user :-)

And as you mentioned, check the plugs and gaps again to be sure. Also check that there is no fuel system blockages.

TomH

My Feedback: (4)

he called me last week and asked me why I had mine plugged off on my 60R3, I sent it to him to do the timing mod, he told me to use the silicone tubing as well. I know its not compatible with gas I guess the spent fuel is more oily residue than gas. I use the neoprene black tubing with a twist of wire to hold it on. I had one blow off and it took forever to clean the mess up. I don't want to pressurize the tank with that black junk either. It ran fine without tank pressure.
I got a question, how do you have your tank plumbed, three lines or two lines. When I had my engine in the EF 91" Yak, I used two lines. it was easy to clamp off the line between the tee and carb when filling the tank.. I'm thinking I might go to three line in my next application because I don't think I will be able to pinch off the carb side of a tee setup.

elmshoot

My Feedback: (6)

Tom,
Two lines on mine with a Tee on the fuel delivery line. I can't clamp the fuel feed line in the Hellcat but I discovered that if i can jam the carb fully closed it will seal off the carb and I can fuel the plane without issues, Maybe its just how my carb is set up. I'm not talking about just idle it down so the engine quits but jams closed. I have mine set up on the fail safe so when I turn the TX off it runs the carb fully closed likely stalling the servo so I make sure I shut the RX off right away. Walbro carbs with the way they are pumping fuel will close off the line so fueling in the delivery line doesn't require a clamp. the Saito pump will allow fuel to seep by during fueling unless you use my trick. My method seems to prime the engine making for easier starting as a benefit.
The tank vent is on the nipple from the Kelo exhaust ring it is at the top of the collector ring so it get a minimum of goo backwash into the tank. If I had the space I would loop the vent line around like the 3D guys so the fuel doesn't leak overboard when it is nose down being taken to the flight line. I have seen lots of my two stroke throw more gunk into the tank. I did melt the line last year and its replaces with high temp line now.
All my connections are secure with.012 stainless safety wire. The safety wire pliers are from harbor freight.
The vent from the engine ejects into the exhaust stream about 1/4" from the exit of the Kelo Pipe.

As an aside I pulled the cowl last night and opened up the #1 rocker covers. It wasn't soaking wet like I see my glow Saito's so I added some YS after run oil just to be certain all was well.

Sparky

TomH

My Feedback: (4)

thanks Elmshoot,, I use the TechAero for ing. kill and mix throttle kill with it so it closes the throttle completely. so what I will do is activate that switch which will totally close my carb. before i fill the tank. I made a dump tank for lack of better words that the crankcase residue goes into, it is filled with dental gauze which absorbs the mess, I have vent holes in the top so it will breath. works well and I clean it out each year.

cathurga

Yeah, I am still of the opinion that they dont need tank pressure to run properly....just my opinion, the pumper carbs are good enough. Might be worth asking Mr. English how he treats the engines that come for refit, that DONT have a Keleo? The Saito ring doesnt have a tap, the stock pipes dont, and neither does the Morris one, or the Meier one. Maybe a good way of pushing Keleo sales :-)

Filling the tank with a two line setup might help get fuel up to the carb, and help starting first up in the day. As long as you are not flooding the engine, so keeping the throttle closed might help. Sometime, if the engine hasn't started in a while, I purposefully close the fuel tank breather pipe to build up some pressure while cranking in gas, and then flick the prop through a few rotations, seems to purge the air out, and it starts pretty easy... Since I am running the negative pressure crankcase, it IS a little harder to start.....but then, I have a nice oily exhaust rocker, so that cancels out my starting problem..lol.

Great to hear engines are all going well, the timing is the big killer on these things, so good to see people have adopted that. I really hope, for all of our sanity, that we see a lot less, or rather, NO MORE FAILURES!

Chris Nicastro

My Feedback: (3)

Chris Nicastro

My Feedback: (3)

elmshoot

My Feedback: (6)

[QUOTE=cathurga;12541889]Yeah, I am still of the opinion that they dont need tank pressure to run properly....just my opinion, the pumper carbs are good enough. Might be worth asking Mr. English how he treats the engines that come for refit, that DONT have a Keleo? The Saito ring doesnt have a tap, the stock pipes dont, and neither does the Morris one, or the Meier one. Maybe a good way of pushing Keleo sales :-)


Agreed the tank (probably) doesn't need the pressure It was convenient to plumb mine that way.
Sparky

TomH

My Feedback: (4)

When I sent my engine 2 weeks ago to Ray, he called before he even started on the timing mod, to ask why I plug off the tap on the Keleo ring. that I need to remove it and connect it to the tank. His reasoning was it would prevent a lean run while inverted. I won't argue with him, but I won't be hooking up and run the risk of that nasty stuff going in my tank. my lines are short , in line, and tank feed is level with the carb. I never had any lean runs. plus my style of flying does put hi demands on my engine anyway.

Do you think that we would have these issue with the new 73R5, five cyl. engine. we can now pre-order, I asked Ray if he was involved with it, he said no, he hasn't seen one yet.

khoysagk

My Feedback: (2)

Not trying to offend anyone but Ray strongly suggesting to hook up the exhaust tap to the tank of a gas engine with pump carb makes me think his expertise is a little overrated. So many people spend hundreds of dollars to have him modify an engine that may or may not need it. My FG84, supposedly the one with the biggest problems, has been running fine for years without Ray English mods.
I have a few DLE35's, will they also run lean while inverted? Sorry but I've never heard of feeding exhaust back pressure to the tank on an RC plane gas engine. Correct me if I'm wrong.

khoysagk

My Feedback: (2)

Another thing, I bought a Keleo ring for my FG60 last year and it doesn't even have the pressure tap. Of course it's possible they forgot about it.

slither

Ray adds them, himself.

khoysagk

My Feedback: (2)

Did not know that. I just assumed because the ring of my 84 came with the tap.