RE: Why not a Webra engines thread?
 

I took a look at he crank pin and measured it with my calipers. Not the most accurate but the pin appears to be round and not tapered. I was expecting to find some out-of-roundness in the crank pin. A new bushing certainly could be made but is it worth the trouble??? I have a small lathe and could do it but a new ring and having the sleeve hard chromed would put me at almost 2/3 cost of a new ST 60 with the same if not more power than the Webra 61. AND, the Webra needs new bearings so now the cost is very close to a new engine. I'm not sure what to do??? :(

RE: Why not a Webra engines thread?
 

Hey Webra Gurus,

Does anybody have any experience with the combination Cline fuel regulator and Dynamix carb?\

Many thanks for any info!

RE: Why not a Webra engines thread?
 

Fuel pumps are something I've had to look into and decided to go with what Webra themselves used to use, the Perry pump. They used to build them into their back plates and came with a seperate one-way valve that it works with.

I think I read about the Cline regulator at the same time I looked into Perry sytems and the only thing that affected that is the price. Clines are expensive.

RE: Why not a Webra engines thread?
 

I stumbled upon this thread when searching for data on a Webra engine I have in my posession. It turned out to be a C/L series 1 Webra 5ccm named BigBen5, produced between 1959 and 1963(series 2). I have no idea when they stopped producing the series 1 in favour of series 2.
It is cross scavenged. The piston slopes up in a straight line from exhaust port to the scavenging ports, where it is cut down again to provide the cross flow baffle.
It seems the engine was plagued by heat problems for RC operation, and production was then discontinued.

RE: Why not a Webra engines thread?
 

I had heard that the Dynamix was difficult to set and operate. Talk of pumps and endless headaches was the norm. They even said there are only two carbs that had to have articles written about them, the Fox, and the Webra Dynamix. I was a little skeptical to try one, but I wanted to see if I could run one of the darned things. I am so glad that I did!


I have never had to use a pump with a dynamix carb. I have used them on Webra Speed .32, .40, .50 .61, and even on a few other brands of engines. They all performed well and had tha instantaneous transition that the Dynamix offers. In fact, I consider the Dynamix my favorite carb. I hope you are able to try one and have similar results.

RE: Why not a Webra engines thread?
 

My Dynamix carb was made in the late Seventies. Put it on a .90 and it had enough air moving through it at sufficient velocity to make it easy to adjust. Put that same carb on a .61 with a pipe and you had to use a pump in most models for it to work properly. I don't know about any other year of carb - just the one I owned. By the time one bought the Webra engine and a fuel pump, you could have spent the same money and gotten the YS .60 which was mostly trouble-free. Yes, I know that there are folks that had problems with the YS .60. I didn't.


Ed Cregger

RE: Why not a Webra engines thread?
 

I have used the dynamix carb with tuned pipe. No issues at all. Of course, turning in the idle mixture screw (clockwise) means richer mixture with this carb.

RE: Why not a Webra engines thread?
 

I recently ordered one of the new Great Planes Dirty Birdy's and planned to power it with a Webra .61 Speed that I picked up on the auction site. I particularly wanted this engine because of the other two Webra .61 Speed's that I own, this is the only one that was factory-drilled for a bolt-on muffler. Well I haven't found a Webra muffler yet so I ordered the Mac's generic muffler and an aluminum bolt-on adapter. All that works as advertised, but found as I finished putting the Dirty Birdy together, that the spinner adapter I used for my other Webras won't fit this Webra. The others are a 1/4" thread, this one is an 8mm thread. Can anyone explain that?

ChiefK

RE: Why not a Webra engines thread?
 

Standard thread engines (1/4-28) were supplied to the USA. The metric thread cranks were sold to europe. No other differences between the two cranks.

RE: Why not a Webra engines thread?
 

So, you think if I were to swap the front crankcase and crankshaft assembly of the 1/4" crank version into the crankcase with the pre-drilled threaded holes, there would be no noticable issues with the connecting rod, or the stroke of the piston, or performance/reliability overall? Naaaa, I'm just gonna get an 8mm adapter.

ChiefK

RE: Why not a Webra engines thread?
 

Nope, everything should be fine. It was just Webra's way of catering to the US market the best they could.

RE: Why not a Webra engines thread?
 

I would get another adapter. The 8mm thread is longer and more sturdy.

Best,
    /Magnus

RE: Why not a Webra engines thread?
 

Another Webra.....I found a Webra 35cc Bully engine. It came in 2 versions= Gas or Glowfuel. Made in Italy....very nice engie and it was new in box. Capt,nhttp://www.rcuniverse.com/forum/js/f.../thumbs_up.gif

RE: Why not a Webra engines thread?
 

This is getting a little bit of a pain in the a**. I got the 8mm adapter, but it didn't come with a spinner cone bolt, and now I see I also need a metric prop reamer. I bought this engine (used) from a USA seller who failed to mention that it was not a US standard version.... now spending this extra money on an engine I haven't even run yet. I hope it's worth the delays and extra cost.

ChiefK

RE: Why not a Webra engines thread?
 

ChiefK,

What engine is this?

The only .61s I have with 8x1.25mm thread are 1033 (long stroke rear exhaust with red or green head). Great running engine, but not exactly suitable for a dirty birdy. All other good old .40, .61, .70 and .80 with side or rear exhaust and front or rear induction in my possession are 1/4x28 thread and most of them are bought in Europe.

Cheers,
/Magnus

RE: Why not a Webra engines thread?
 

The box says "WEBE 1024 + S", "Speed 61F Aero". It looks like a standard Webra Speed .61 side exhaust with TN2 carb. It does have factory drilled and tapped holes (3mm) in the exhaust stack., but the crankshaft has this 8x1.25 thread shaft. If this was intended to be a special purpose engine, I'd like to know what that special purpose was.

ChiefK

RE: Why not a Webra engines thread?
 

ChiefK,

Sorry, I don't know enough to give you a straight answer about the engine.

What's written on the box, however, indicate that you should be happy with the combination as long as the engine correspond to the box.

Cheers,
/Magnus

RE: Why not a Webra engines thread?
 

This might help you out.

http://web.archive.org/web/200609230...r=AERO&lang=EN

If you go to the spare parts section you can see that they made a few different models.



AERO

WEBRA 60
SPEED 61F
RACING 61F
SPEED 61 LS
Racing 61F C

RE: Why not a Webra engines thread?
 

CaptinJohn

Webra Bully's don't just come in gas and glow.

Long before there was a 3.5 engine. The first Webra Bully.

RE: Why not a Webra engines thread?
 

Broken Wings,

Your link suggest that the crank thread is a question of age: older engined most likely have 1/4 inch thread and newer would have 8mm. Indeed my engines are old.

Cheers,
/Magnus

RE: Why not a Webra engines thread?
 

Thanks BW... do you (or anyone else) have an idea where I might find gasket sets for this engine?

ChiefK

RE: Why not a Webra engines thread?
 

I always thought the weird threads on Webra's were for the Heli engines. Do you have a photo?

Cody

RE: Why not a Webra engines thread?
 

You can use the method here:

http://www.airfieldmodels.com/inform...ate_gasket.htm

Used it without problems.

The head gasket is different; it's rather a shim to control the compression. You'll need one with thickness to suit your favourite fuel and glow plug. I can't give you guidelines since I never played with it but I am sure others in the forum can.

Cheers,
/Magnus

RE: Why not a Webra engines thread?
 

Not for sure, but I think the early ducted fan units were 8mm I believe.

Here is a nice Webra engine you don't see every day. Webra was way a head of everyone else in small gas engines. this one has a steel rod needle bearing on both ends. P5-90i

RE: Why not a Webra engines thread?
 

I don't think that is that far ahead. There were small gas engines even before then. I don't know if they had needle bearings on the rod. But Fox had them on 60 sized engines in the 60's. Still a very nice engine!