CRG

My Feedback: (3)

Except the FG-60R3... We are out of stock so did not include it this time.

Improved induction would be accepted well by most, I agree.

Craig

V2rider

My Feedback: (4)

The pics of p51fw190f4u's install is on Page 116, posts 2891 and 2892. The pics of the install done on Bearbow's plane is on page 131, posts 3264 and 3272 with some more pics on page 133 past 3323. Cutting the firewall back looks like a pain, but without doing it one or the other mixture screw will line up with the firewall and be a real pain to get at.

jagdpanther9

just an update guys, my FW is ready to start tune and fly hopefully that easy. the 70cc twin made G/G perfectly with just removing the two factory installed weights. the air mains and servo operated tail retracts seem to work perfectly. I will post some pictures when I am tuning .
it looks cold and rainy for the next 5 days .just can't get a break on the weather : /

dasintex

My Feedback: (10)

Appreciate the update, how did you make out with the cowl, any major cut outs other than for cooling?

jagdpanther9

i will get some pictures up soon, but I made the two holes for the exhaust slightly larger to help move air. also I made a slight gap in the cowl "hoods" by using nuts held in place with ca on the 6-32 bolts . this leaves a 3-4 mm gap to the rear of the cowl to help move air as well.
I am wondering how hot this twin will run or if I will need to make baffles in the cowl or more cut outs .

sparky4lawndart

My Feedback: (10)

it's all about the 3 to 1 rule... 3 times exhaust to the amount of air coming in... I had to fiddle for a long while to make sure the amount of air coming in was getting out of this giant cowl... use louvers, bigger holes, but do something... the DLE111 I stuffed into the cowl (yes it fit) cooked both cylinders in a single flight...

this is how I baffled mine

jagdpanther9

ok sparky, thanks for the heads up. i will take your advice and build a baffle . i have seen others with similar set ups . i also have a heat gun i will be using to read the temp as i break in my 70cc twin. i am thinking that 180-200 deg. should be what i want. what would you guys think a good temp would be?

kwik

That depends on where you measure. If you think this could be problem, then how/where you measure is important.
In a 70cc twin with the "lawnmover-style" cooling fins (big ones !), I reckon baffing will solve the problem anyways.

So, If you plan on pointing a gun towards the engine, and measure, make sure to measure on the same spot every time.

Otherwise there will only be more confusion, than before you measured. The temperature increase a lot towards the top of the cylinders.
So if you measure here and there, you get different results.

I mention this because I just had a baffling exercise with my typhoon, and decided to measure on the middle area of the cylinder.

It stays on 65 to 85 degrees Celcius. 85 deg on idle, and drops to 65 on max rpm.

The baffling leads more cooling air to the cylinders on high rpm, than on low rpm. Therefore you can check the cooling on the ground; Let it run on max for at least 5 minutes.

If you see that the temperature just keep climbing up towards, say 120 Celsius (on the middle of the cylinder), without stabilizing, you know you will have a problem up in the air.
You should then stop the engine, and do something about it.

It is just a matter of how long your flight is. Somethimes you are lucky, and land before it seizes, somethimes not.
But if it stabilises on, say, 85 degrees, nomatter how long it is run, you know there is no problem up in the air.

But of course, one only start doing these things if there is a problem....in most cases it is okay, anyway.

In my case, on theTF 190, it was the petrol that was the problem. "Global Warming" additions that the oil companies
are forced by law, to put into the mix. This results in lots of "Local Warmings".

sparky4lawndart

My Feedback: (10)

Kwik, have you ever used "white" gas or camping gas? I guess its a no-additive version of pump gas

kwik

No, I haven't heared about that. I guess the naming is different from country to country.

Here, they sell something called for example "Aspen" , based on acylate.

It doesnt smell, and runs cleaner. But the price is, well, here you can multiply by 5 nowadays.

When I tried it some years ago, you multiplied by 10. So it is getting better.

Maybe I will try it this summer, since it doesn't smell; There will be less complaing from my wife.

SrTelemaster150

True "white gas" or Coleman camp fuel has no anti-knock additives & isn't suitable for internal combustion engines.

As a side note: I have used unleaded pump gas in Coleman lanterns for nearly 40 years. The only ill affect was that I would have to spin the generator cleaning crank periodically. Now Coleman has (dual fuel) versions.

dasintex

My Feedback: (10)

Another name for White Gas, Camp Fuel or Coleman Fuel is Naptha Gas; Right?

jagdpanther9

good info gentlemen.
I think I will run my twin on 91 octane with a 30:1 mix. I run klotz in many of my other 2 strokes and probably will in this one as well. I should make a baffle from light ply and epoxy it into the cowl and be done with it. 20 + mph winds today and for the next 5 days !!! I just cant get a break on the weather.

sparky, 111cc dle twin in your FW... you animal ! any flight footage??

CRG

My Feedback: (3)

You're on the right track with baffling. The 3:1 "rule" is hogwash, but still widely perpetrated as gospel. It doesn't matter how large the exit area is if the air doesn't pass through the cylinder fins. It still has to have a way to exit, and that is driven by pressure differential, not the ratio of inlet to outlet.

jagdpanther9

a few pictures of my cowl with baffling. sorry about the image quality, I will get more pictures when I have it on the bike lift tuning and breaking in my engine.

dasintex

My Feedback: (10)

Looking good, quick question, why the hinged/split lower cowl with the square hole cut outs on each half, exhaust pipe clearance?

jagdpanther9

yes, the holes are for the twin pipes to exit. I may have to cut the holes a little bigger to move more air if the gap between the split lower cowls and the plywood lower cowl ring isn't enough.

hpergm

Dear All,

Getting close to finishing the bird; pics to follow in the thread.

One question regarding CG: The Top Flite instructions give out a number (139mm from the LE "break") but depict the bird with the landing gear DOWN.

So, at which CG do you fly yours, and do you balance it there with the gear tucked-in or extended?

Thanks to anyone for a quick reply...

Hector.

dasintex

My Feedback: (10)

Gear Up(tucked in)

hpergm

Hey, thanks! You fly @ 139mm??

slembones

My Feedback: (1)

you may want to double check the cg. I am using the fg57 which weighs 2500 grams. Your engine I believe weights 1800 grams. I have the weights on and the model balances level at 139 mm. I am using the electric retracts and balanced with the wheels up. Obviously every plane of the same model is slightly different. Just a thought. Does your twin have a starter? Does that make it heavier?

i only point this out because I would like to jettison those weights too but found the model was tail heavy.

happy landings!

kwik

I balanced mine according to manual with gear down. It has the FG-57.

It behaves wonderfully in the air, so it must have been good.

slembones

My Feedback: (1)

Kwik

Does that mean you took the weights off? do you use the stock wheels or are you using something heavier like the williams bros.?

I have the williams bros and the plane is much more nose heavy with the wheels down.

I know the manual shows the wheels down but I thought it was customary to balance planes of this nature with wheels up. I'll have to look at the manual and see what it says.

Happy Landings!

kwik

No, didnt take off the weights. And yes I have the Williams wheels.

dasintex

My Feedback: (10)

Kwik;

How are those Williams Wheels working out?

Thanks.