jetpack

My Feedback: (1)

Any way to contact this company, or learn what they are doing to them? It would be interesting to find out. My guess would be just the timing?

Ernie Misner

Hey guys, are any of you running the Webra .35 Aero engine with the black head and ringed piston? It doesn't seem like many were sold here in the US anyway. I think it was origionally a heli engine and they put a different head on it for the aero version.

I have one that is still new. Any suggestions for a plane for it?

Thanks,

Ernie

proptop

My Feedback: (8)

JP...go to the Extreme Speed Prop Planes forum and search "Weston"...I think you'll find what you're looking for?
There is a Weston U.K. and a Weston USA but a Google search turns up nuthin' for me?
There is (or at least was??? ) a distributor for the U.K. Weston stuff here in the U.S.

NM2K

My Feedback: (14)

Part of "the problem" is that some of us are talking from experiences we had in the seventies and eighties and others are talking about experiences from later time periods. I am talking about engines with the Dynamix carb that were sold as pattern engines. Those engines did require a pump or modification to run properly without a pump in the US market. There were no Webra four-strokes at that time, or they were just on the cusp.

I don't believe that one can issue a blanket definitive statement regarding these engines/carbs and be correct. I'm sure there were variations between different engine lines and perhaps there were differences according to the country in which they were being sold.

I've never heard of a TN carb that required a pump, although that doesn't mean that one never existed.

This is not an either or issue, from my point of view.


Ed Cregger

IGOS R/C

Hi !

Webra engines are good to nitro content from 5% to 15% as per instructions. But if you increase the nitro content above 15% you must increase the combustion chamber volume. It is ease to do. You can see all instructions on www.webraengines.com.

IGOS R/C

Better than one Webra just two Webras !!

NM2K

My Feedback: (14)

Now they are, but they didn't used to be that way.

Some folks here in the US are buying older .61 pattern engines for their replica classic pattern ships. It is these people that could encounter problems with running more than 5% nitro in an old engine. I'm glad to hear that the newer engines are NOT set up with such high compression ratios.


Ed Cregger


***Ooops! Funny how the omission of one little word can change the entire meaning of a sentence. <G> Ed

mk1spitfire

ok here is westonuk website. Alan and steve are very helpful. check out engine section and compare the webras performance against the tuned west/webra modified engines. they sell webras too.

http://www.westonuk.co.uk/

IGOS R/C

Hi everyone!!

You can go to www.webraengines.com and see instructions for all kind of carbs as well as nitro use and running in . Webra engines run without modifications from 5% to 15% nitro content. Install a shim to run over 15% nitro. Dynamix carbs run quite good on muffler pressurized systems since the '70s.


IGOS R/C

Better than one Webra just two Webras!!

jetpack

My Feedback: (1)

Speaking of Dynamix carbs, has anyone reworked the fuel mixture tube so they dont leak?

Only way I can think of is installing an O-Ring inside it somehow, or glue on a rubber boot of some sorts. It lacks a seal, and when they start to wear you have to buy all new, when it really isnt necessary if there was a seal in that area. The idea of grease packing at that end does not thrill me. I've also thought of using a setting tool, and collapse the end opening, but that's still a caveman approach and would require lapping or reaming to hit size and never really cures the problem.

Also, has anyone played around with the rotational angle of the tube to get the best spray pattern? All I've been able to determine from the factory drawing is the top lip should be positioned right at 90 degrees to the barrel, but thats just a guess.

IGOS R/C

Hi jetpack !!

I never try it but an "O" ring could stop the leak. Of course it shall be well installed, say the groove deep for the "O" ring or you gonna to overload the servo etc. Once I got this problem I change the set overall. Anyway post your tries to us.

IGOS R/C

Better than one Webra just two Webras

Motorboy

The groove must be aligned with the spray bar hole.

jetpack

My Feedback: (1)

What I meant was the V notch can be rotated either up or down when it is set and locked by the small aluminum arm that connects the throttle slide.

If it points up too much, it will cause back pressure into the fuel galley and you wont get any spray.

If it is pointed down too much you will get poor atomization.

I was wondering if anyone has ever been through this scenario before and has taken note where the optimum setting would be.

The instructions are clear as to how to set the carb but does not cover or intend you to remove the arm on the mixture tube. It is factory set and not outlined how to go about positioning it if the arm is ever removed.

It is a little difficult to to guess without doing some type of flow test and then recording the position, but once you do it would be easy to say and pass along.

I am at that point where I have rebulit all my carbs but haven't run them yet so I am just asking before I go through the trouble of finding out the hard way.

It looks like the V cut is pointing down a little on the instruction drawing if you look close you'll see the object line on top is straight, and the line on the bottom has the curve which provides a clue. If you had the V set at a perfect 90 degrees, the object lines would be curved both top and bottom due to how the V cut taper cut into the tube. Is this actually the best setup?

If nobody knows but Webra on this, it might be I would have to rig up some sort of flow meter bench and play around a bit...something I rather wouldn't have to monkey with if there was a clear cut answer...

Communication with Webra for me in the past with more simple questions than this have turned out to be quite choppy and hard to understand, so I don't even think I want to attempt going through this with them.

Anyways, not wanting to kill the thread with just a question, lets see more motors [8D]

Bone

OK, the call went out to show more engines Here is the one & only Webra engine I have - the Glow-Star 3.40cc. Purchased the Glow-Star 2nd hand, it runs well albeit with modest power. The engines of this era were designed with a rotating baffle baffle over the exhaust port, but mine came without the baffle - seems the previous owner lost it [] By the way, the OS 702 muffler & strap is quite a reasonable fit on the engine & is effective in taming its bark.

rainedave

My Feedback: (1)

Nice example Bone. I just got one myself. It was also missing the exhaust wiper (or butterfly, or baffle, or whatever it's called). I had some extra OS Max .20/.25 baffles in a box, so I attached one of them. It fits well enough. I will try a spare #702 muffler on it, too.

I'll try to run mine this week. I'm thinking a 9x4 might be a bit too much, so I was planning on spinning an 8x5 or 8x6. At the same time, I don't want to over-rev it. I will be using Powermaster GMA 5% nitro, 29% straight castor oil fuel.

David

rainedave

My Feedback: (1)

The OS push rod from the throttle arm to the baffle was about 2 or 3mm too long. So, by bending in an elbow I was able to adjust it to the perfect length. It also seems to have improved the geometry a bit, too. It works very smoothly.

David

Bone

Yours is looking pretty good too Dave - and cleaner as well. When time permits I'll try & make mine shine a bit more. Seems I will need to fashion a baffle come butterfly exhaust thingo out of some sheet metal & see how it goes. Those polished spinner nuts add a pleasant touch.

I ran mine earlier in the year, dont recall the RPM exactly on the APC 9 x 4 prop using my standard home brew (for this type of engine) : 10% nitro, 20% Castrol M castor & 70% BP Methanol. Next time, I will leave out the nitro & increase the oil to say 22% to 23%.

The Webra started easily & was very well behaved. I'm very pleased with it [8D]

rainedave

My Feedback: (1)

Be careful with the head gasket and cylinder to case gasket if you disassemble yours. They are brittle. The head gasket in mine is made of some strange material that reminds me a bit of mica. It's sort of shiny with a kind of mineral look to it. I cut new gaskets for the cylinder to case and the backplate out of brown automotive gasket paper. You can see it in the photos. Mine has very good compression and should start pretty easy. My experience with these old carbs is that they act more like high/low throttles. These engines would be good in something with the decalage of an old Class I or II model... climb and dive.

David

DarZeelon

Hey, this is a Webra thread...

Get those old OS Max baffles out of plain view...

rainedave

My Feedback: (1)

Where do you see an OS? That's a Webra 3.5ccm (with an OS exhaust baffle).

See, "Made in Germany."

David

Bone

Dave - I've just notice something (perhaps this is old news to some of the "in the know modellers") ) - your engine has "Made in Germany" under the exhaust whilst mine has "Made in Austria". Seems that some Webra engines were made in different locations ? [:-] The 2 countries share a common border & perhaps the engines were / are made in neighbouring factories. Anyway, this all adds to the pleasure of owning a Webra [8D]

rainedave

My Feedback: (1)

Well Dar, I guess you'd have to call my engine a Deutsch-Nippon hybrid. The glow plug is an OS, too.

Bone, I also noticed your mounting lug doesn't have the etched-on serial number like mine does.

David

NM2K

My Feedback: (14)

-


The baffle piston engines, like the 10cc Blackhead, were made in Germany. The schneurle ported engines were made in Austria.


Ed Cregger

Bone

Yes Dave, interesting indeed. No serial number on the mounting lug BUT I did own another example of the Glo-Star that DID have a serial number on the lug (but can't recall if it was Austrian or German manufacture). I sold that engine during a brief spell of stupidity. Also, the engines have 3.5ccm on the transfer port casting but my box says "3.40ccm" - refer my pics in earlier post.

And another thing that makes tuning the needle valve difficult (when the OS muffler is attached) is that the needle vavle is on the exhaust side of the engine. The hot muffler gets in the way & it's so easy to burn your fingers [&:] Oh well........... [8D]

rainedave

My Feedback: (1)

It started by hand a lot easier than I thought it would. The A3 plug seems to be a good choice.

David

BobHans

I was just given a Webra 10 CCM (Speed 61), but missing the muffler and spray bar/needle valve. Does anybody have theses parts and willing to sell at a reasonable price ? The Webra site shows this engine uses the TN II carb.

I might be able to use an OS 61 muffler - it has the same hole spacing, but the port is smaller than the Webra engine. Will that be a problem? Do you know of any other makes that will work with the Webra?

Bob H