abufletcher

OOPS. Deleted my prior post since it's 2am and I wasn't really the scale correctly! See correct weights below.

****

I just weighed the entire assembly of engine, mount, exhaust ring, and propeller...and came up with about 3.2kg. The engine and mount together weigh 2.7kg, the ring weighs 320g, and the 24x10 propeller weighs 146g.

abufletcher

Following Kelvin's advice, I bolted the engine back onto the test stand so that I could use both hands to massage (muscle?) the ring's headers into place. After getting them all roughly aligned, I applied firm counter-clockwise pressure on the tailpipe and could just manage to get the lip of one of the headers into the cylinder. Then with a bit of effort, I got a second one just barely in (and the prior one slipped just a hair further in). I needed to use the piece of wood to leverage some into position...but not too much pressure on the stick. It's sort of like fiddling with one of the metal puzzles where you have to get the two pieces together and it seems impossible, but there is a way...one that doesn't require brute force.

And then they are all in. The next challenge is to get the nuts seated right. I'm still battling with that as it's hard to know how they are supposed to feel. Some seem to thread in easily enough for the first half or whole turn, but then get really hard to turn by hand. I'm hesitant to use a wrench yet.

chasrb

Great progress!! You may need to wiggle the exhaust tube while you are trying to threads the nuts in.

abufletcher

It took a LOT of patience, but I finally got all the nuts threaded. Part of the problem is that when you do this for the first time (and basically everyone will be doing this for the first time) you don't know how it's supposed to feel. I needed to loosen some of the cylinders a bit more and then it was a matter of wiggling (the cylinders) and trying and trying again. Three nuts went in pretty effortlessly but the other four were difficult to get started. It helped to turn the engine face down (but being careful not to let it rest on any of the push rod tubes).

Anyway, that's done...AND I'M NOT DOING IT AGAIN!

geezeraviation

My Feedback: (3)

I think Don Has encountered that unusual condition of "this morning I could hardly spell mechanic and now I are one"
Congratulations and never say never again.

chasrb

Hoooooo RAYYYYYYYY!!!

invertmast

My Feedback: (23)

So whats prop manu, size and rpm is everyone running? Ive been having a heck of a time finding the right prop.

Menz ultra 24-12 = 5200rpm
Above cut to 23" dia= 5300rpm
Cut down to 21" dia = 5700rpm
Cut down to 20" dia = 5900 rpm

JC Super props 20x16 = 5600 rpm

Im About to pull this motor off my fw190 as its life expectancy is only as long as it takes one cylinder to die shortly after takeoff. So bcof that, im going to put it on a 1/4 geebee R2 that will weight around 22lbs.

geezeraviation

My Feedback: (3)

Sorry to hear that Thomas. Multi cyl glow engines do seem to have thier problems. What I find a real bother is once a cyl drops out even reducing the throttle to where the glow lighter comes on (if you have the altitude and room to do so) they still dont come back to full power.
Doc

abufletcher

Are you running an on-board glow system? If so, what would make you suspect that you might have a cylinder "die" on take-off? I did have one "cold" cylinder (the bottom one) during some early break-in runs but they all seem to be running now. In the model I'll use the MICROSEN controlled on-board glow, which should keep all cylinders going even at near idle.

The recommended break-in prop for the 770, according to the manual is a 22/10 and that's what I've been using. My engine is still undergoing break-in but I've had it up to 5500. I picked up a 24/10 (XOAR) to see how that works.

Spuetz

Hi Thomas,
Your rpms sound about right. And I have never had a cyl. Die on me. I, too, use the microsens GLOW 7 LP and it is great!
Cheers, Martin

invertmast

My Feedback: (23)

Im using the mcdaniel onboard glow system. I havent had a cylinder die once they all came on line after warmup and start. The problem, is the airplane is so marginally powered right now, that if anything happens power wise from liftoff until 1 lap into the pattern has been completed, the airplane is going to be a right off. Because of that (and other projects) my 190 is being sold w/o the motor and im planning to put the motor in thd geebee.

I was hoping to get around 6100-6200rpm static so as to get as much performance from the motor as possible. But currently, my home made cut down prop is the only thing i have found that works well with the motor. And since that prop is no longer made, im stuck in a tough spot if it ever breaks

abufletcher

The 770 has always been rated more about 5500rpm.

invertmast

My Feedback: (23)

Weird the spec sheet for mine says max rpm at 6500rpm

BobH

My Feedback: (2)

Thomas, have you ever considered a 3bladed prop for the FW? Just wondering here is all. I have yet to run mine..

invertmast

My Feedback: (23)

I tried the Solo 3-bladed prop w/ the FW-190A blade profile.. it worked Horribly. All other 3-blades don't have the pitch necessary to get the flight speed needed out of the prop per my calcs..

Spuetz

HI Thomas,

I remember us talking on this forum before about it. Just seems like a bad fit. Biplanes, slow flying monoplanes that are built in a very light way are about the target group for the Seidel. Their power-weight-ratio is horrible!

If you want to go radial and WWII warbird, MOKI is the way to go! the guys fly Corsairs, FW190s, Grumman -cats, Lavochkins here in Germany with that setup. Absolutely awesome sound and performance. They even fly Sukhoi aerobatics with it and hover them! How about a small MOKI for your FW 190?wouldn't that fit?
Also, I saw that MOKI is making a 7 cylinder radial now.

Cheers, Martin

abufletcher

I've also come to realize that my BIG engine doesn't equate to POWERFUL engine. The Seidel 770 is probably in the 45-50cc class, and weighs close to twice as much as comparable gas engines. But for slow-flying WWI biplanes with relatively short noses, where you can see the engine in that big old round cowl, there's nothing better.

invertmast

My Feedback: (23)

Martin,
Unfortunately the seidel 70 is the only radial that will fit in my 190. The cowling is only 9.22" in diameter and the seidel is 9.128" at the rockers. Like glyou say, i think the seidel will do better in a lighter plane or a slow biplane. Hence the reason for trying a geebee

Mein Duff

Sorry Don... the "best thing" would be an actual Rotary engine in a WWI bird !!! lots of machinists have home built them don't think anybody is mass producing....what a dream that would be... ehh??

Just think of having to muscle with all that torque on take off like the real thing..

geezeraviation

My Feedback: (3)

I have seen a Clerget a Gnome and a Le Rhone but all in 1/3 scale. Never seen one as small as 1/4.

Teus

Doc,

You need to take a look [link=http://www.modelbouwforum.nl/forums/vliegende-schaalmodellen/84686-rotarys-bij-phantasy-blue-9.html]HERE[/link] on a dutch forum [8D]

Two 1/4 scales Gnome's are currently build and almost finished. One intend for a "Brik" (pusher version) and one for training on a Proctor Fokker E.III [8D]

geezeraviation

My Feedback: (3)

WOW that's beautiful, I try but I cant keep track of all of them LOL
Doc

abufletcher

[X(][X(][X(]

Teus

Doc, How about this, a 1/5th scale [X(]



[youtube]http://www.youtube.com/watch?v=oLW_6XCvBWI[/youtube]

DeeCee 57

Just read all the pages of the thread, phew!
Woz like reading a thriller, enjoyed every bit of it, thanx to the authors

I love 4 stroke, even more so if they're radials. Still have a "50cc" 220cm (86") GW Yak-55M in the box, looking for an adequate, but non DA, DLE, RCGF, etc, engine. It has to be 4 stroke, minimum of 2 cylinders, the more the better.
The Seidel/UMS would provide adequte weight, size and power for limited 3D, mostly scale aeros type of flying.
The big - is glow... decide a few years ago not to go back to them... but who knows...
The big + is the cost. The Seidel also seems reliable, power output is good, and it is pretty easy to set-up and operate.

Also had a look at the RCS/Mokis, problem is that their smallest radial starts at 150cc which would be slightly oversize....

invertmast, loved your 190 with the Seidel. Beautiful video (ok, the pilot is way better than the cameraman).
The 190 looks really scale, also performance wise. The take-off run, the climb angle and the speed look very realistic. Guess I'm a bit fed up with scale looking planes leaping of the ground in a couple of feet and then climbing at unrealistic angles in the blue yonder....
Looking forward how the Seidel performs in the Geebee.