Why not a Webra engines thread?
 

Hi everyone !!!

I'like to suggest a thread about Webra engines. They are very powerfull and longlast. They were a success in the '70s handled by multi TOC and F3A Champ Hanno Prettner. They're still powerfull. Just to mention compare a Webra aero R/C .55 specifications (2,1 PS/1,54 kW - 360 grams - 11 x 7 to 12 x 6 props, all with straight fuel (no nitro) and .46 size mount with any other brand.
In time: I'm just a happy owner.

IGOS R/C

RE: Why not a Webra engines thread?
 

Nice, I have two .50 's and a 91P5 which is quite impressive. All of mine run great, are reliable, light and powerful engines.

RE: Why not a Webra engines thread?
 

Lets do it. I have the following, a SilverLine .40, SilverLine .61/roller upper rod bearing, .61f, 3 .91s, two ringed 1 ABC, a P5 .91, a .50 with Dyles ring and a 1.20 with a Dykes ring.

RE: Why not a Webra engines thread?
 

Here are the P-5 and the 1.20 Picture #3 is my .50 wearing a Davis Diesel head turning a Graupner 12x7 at about 9,400 rpm.

RE: Why not a Webra engines thread?
 

Webras!

RE: Why not a Webra engines thread?
 

Hi everyone!!

Good to know about Webra happy owners!!

My power fleet includes a .61 speed (purchased in '71 and still in the box), a .40 speed, a .61 race and Webra tuned pipe, a .61 speed (all in good condition) and two .55 recently purchased. Some are equipped with dynamix carburetors. The .40 has more than 200 flights and powered more than four models (Kaos .40, Gator Flea and some own design) and still keeps the high performance. I will publish some pictures in a near future.

IGOS R/C
Better than one Webra just two Webras !!

RE: Why not a Webra engines thread?
 

Is that an original Dynamax carb? 25 years ago when I had mine, I couldn't get the blasted thing sorted out.

I currently own only the big blocks, 145's and 160's. Guys in the Pattern World in this country were not able to figure them out.... I have however and love the power these engines make.

MattK

RE: Why not a Webra engines thread?
 

My Webras are:

A handful of used (4 or 5 from worn out to nearly new) 1024s and two NIB. Two NIB rear exh. 1030 Racing (1 ABC, 1 ring). Three 1027 SE Long Strokes (new to nearly new) ABC & ring. One used grey head (faded black?) 1020 w/ roller rod (top).

One NIB 1037 .90 Speed.

Five 1055 Speed 120s (two NIB).

One 1034 .40 Speed (used).

Mostly TN/TN2 carbs with a few slide valve carbs.

Terry in LP

RE: Why not a Webra engines thread?
 

Nice triplets, 8178!

Cool collection, Hobbsy.

I have a Speed .61 RE, 10ccm Blackhead, 6.5ccm Blackhead and a Silverline 6.5ccm. I'm always on the lookout for more.

David

RE: Why not a Webra engines thread?
 

Quote:

---

ORIGINAL: MTK

Dynamix carb? 25 years ago when I had mine, I couldn't get the blasted thing sorted out.

---

Matt,


The Dynamix™ carburettor needs a relatively high fuel pressure to function properly.

A fuel pump is almost an imperative requirement, since exhaust-pressure is relatively low.
Getting it high enough would require so much back-pressure, the engine's performance would be compromised.


The manual says this, but most people follow this rule; "Only after all else failed, RTFM"...

That's 'Read The Manual' for you...

RE: Why not a Webra engines thread?
 

do they still make Webra engines ?

RE: Why not a Webra engines thread?
 

I and just about every one in the club ran a Webra Speed 61 during the early-mid 70's.
20% caster, 0% nitro... wonderfully.
I don't know if there as powerful compared to todays offerings, but they where certainly hot in those days.
And what fun it was back then.
I can see those little springy needle valves vibrating away as clear as day.

RE: Why not a Webra engines thread?
 

http://www.webra-austria.at/download/en/motor.pdf

Scroll down to the DynaMix carb and item 5 says the DynaMix carb will operate with muffler pressure or a pump, just like any other engine. For anybody with Webra engines tht page is well worth printing. Nobody caught it but the Webra .50 running as a Diesel is wearing an MVVS 7mm carb.

RE: Why not a Webra engines thread?
 

Dave,


Who says no-one noticed the MVVS carburettor?


As to the fuel pressure issue with the Dynamix; the manual does state exhaust pressure can be used, however, experience of people that used this carburettor with the Webra #1024 and #1030F was that with exhaust pressure, you have no chance to land with the engine running...

The engine will invariably quit during flight, often during a pattern maneuver...

Using a Perry (or the then available Robart) pump made completing the pattern sequence possible...


Just to understand the difference in engineering, Dave, an MVVS #3219Q Quickie carburettor, despite its huge 9 mm bore, can run on venturi suction only; although exhaust pressure is recommended.
The smaller bore Dynamix requires pressure and the level provided by the exhaust is borderline...

It is simply not designed to run on venturi suction.

RE: Why not a Webra engines thread?
 

My experience with Dynamix carburator in Webra T-4 works very well without fuel pressure either it is a pump or muffler pressure.

If in doubt, i can take a movie of the engine running without fuelpressure and add in the youtube next time i get "negative" answer..

RE: Why not a Webra engines thread?
 

Speed 20, 40, 61 Marine

All reworked from new with ceramic hybrid bearings with stainless steel races and phenolic cages. All parts have been deburred, polished, hand spotted, lapped, ect. fully by hand. assembled with stainless screws, and have their own line-up of new spares, shims, gaskets, plus original manuals and spare rear covers with pressure taps.

Each will be put into its own size of Dumas Drag N' Fly hydroplanes to make a matched family of boats, and also have their choice of a TN, MC, or Dynamix carbs each.

I love Old School! Webra's are wonderful engines, and sure like the idea of a low-nitro diet.

The engine collection has taken over three years of effort, and definently not leaving anytime soon. [sm=tongue_smile.gif]

BTW: Ya'll can have your eBay back...I'm done for now.:D

Thanks to Webra-Austria and all that have helped with my questions along the way, this is the best bunch of banana's on the planet.[8D]

RE: Why not a Webra engines thread?
 

Hi!
Webra are still going strong!
The Webra GT .40 is the most powerful standard sport engine on the market (on 80/20 fuel) and has been so for decades.
The GT .40 has been the dominating engine in newcommer Q-500 pylon (424 to you americans) over here in Sweden for many years, only recently has an equal competitor shown up...and thats the Kyosho GX .40, better known as ASP.40.

RE: Why not a Webra engines thread?
 

Webras are supercool. i'm running West engines (weston uk), 50V1, 36v1. These are super tuned webras. Weston modify the webra to get more power out it and works.
Look at the success of the MagnumR plane with west 50v1 and their genesis tuned pipe set up. Awesome power plant.
I've run them only on fully high quality synthetic fuel(prosynth). Sometimes on super competition prosynth with only 7.5 oil. The engine after is so cold you could chill your beers on it!!

RE: Why not a Webra engines thread?
 

Hi!
Webra are still going strong!
The Webra GT .40 is the most powerful standard sport engine on the market (on 80/20 fuel) and has been so for decades.
The GT .40 has been the dominating engine in newcommer Q-500 pylon (424 to you americans) over here in Sweden for many years, only recently rivaled by the Kyosho GX .40, better known as ASP.40.

RE: Why not a Webra engines thread?
 

Daves, plural, when you have a box of mufflers like I do there is no tellin what you might find. Picture #1 & 2 is very likely a muffler some of you used back in the day. Picture #3 is a K&B .61 Twister muffler that bolts right onto the SilverLine .61. Pic. #4 is most of my muffler collection.

RE: Why not a Webra engines thread?
 

Hobbsy...that muffler in your 1st two pics is a Silenceaire (or some similar spelling ) made sometime in the early 70's.

I have an old 1.5cc Diesel...1950's vintage...it has red (or now sort of pink ) anodized fins.
4 .50 GT's and 3 .61 Speeds...and one 1.20
Love 'em all [8D]

RE: Why not a Webra engines thread?
 

Any Enya .25X mufflers in there?:D I will probably have to try and get someone to machine an adapter for me that will bolt to the 24mm wide case holes and have outer holes spaced for another muffler, like an ASP/Magnum or GMS .25 muffler.

David

RE: Why not a Webra engines thread?
 

The reason Webra never took off in this country was the lack of instructions written clearly in English, plus a lack of explanation regarding the high compression ratio that would lead to preignition and overheating if conventional US nitro amounts were used without reducing the compression. Why Webra put up with this kind of behavior from their US distributors has always puzzled me. Webra engines are among the best on the planet, as far as I'm concerned.


Ed Cregger

RE: Why not a Webra engines thread?
 

I have a Webra 145 I came by second hand, seems to be in good shape, pipe & header in the package. I haven't installed it in anything, but would like to fly it next year. Anybody have experience with this engine, recommendations for fuel, prop, header length, head shims? It has high & low needles, no mid-range adjustment.

RE: Why not a Webra engines thread?
 

Quote:

---

ORIGINAL: Motorboy

My experience with Dynamix carburator in Webra T-4 is that works very well without fuel pressure, whether it is a pump, or muffler pressure.

If in doubt, I can take a movie of the engine running without fuel pressure and add it in 'YouTube' next time I get "negative" answer..

---

Jens,


I am here to discredit, or to cross, neither you, nor Dave Hobbs...

I am sure any Webra engine can run with the Dynamix carburettor and as to T-4 engine; perhaps its Dynamix's bore is 'reshaped' to provide some suction.


I am only telling about such carburettors that I actually faced and what the Webra instructions actually say about it (and also about UltraMix and ProMix carburettors).
"It is not designed to work on suction feed"...

The TN/TN II is a pretty good carburettor (perhaps not as good as the new MVVS #3216/3219, though :D...) and its instructions do not state pressure is required.

RE: Why not a Webra engines thread?
 

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?

RE: Why not a Webra engines thread?
 

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

RE: Why not a Webra engines thread?
 

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.

RE: Why not a Webra engines thread?
 

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

RE: Why not a Webra engines thread?
 

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 !!

RE: Why not a Webra engines thread?
 

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

RE: Why not a Webra engines thread?
 

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/

RE: Why not a Webra engines thread?
 

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!!

RE: Why not a Webra engines thread?
 

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.

RE: Why not a Webra engines thread?
 

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

RE: Why not a Webra engines thread?
 

The groove must be aligned with the spray bar hole.

RE: Why not a Webra engines thread?
 

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]

RE: Why not a Webra engines thread?
 

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 [:o] By the way, the OS 702 muffler & strap is quite a reasonable fit on the engine & is effective in taming its bark.

RE: Why not a Webra engines thread?
 

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

RE: Why not a Webra engines thread?
 

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