morecashthansense

Hi Matt,
The Carb in question is a wyk33 sorry for the typo. Will try and post photos soon.
Available here http://www.arrowshark.com/WYK-33.php
The motor has had another tankfull this evening and is starting to settle down a bit, yes the throttle is a lot more linear and a lot easier to set the needles.
I have now to get used to reading the plug colour to see if the mixture is correct. And try to determine where the needles swap over on the revs range.
Interestingly my research into ignition timing has found out that with a proper tuned pipe I should be retarding the ignition an extra 2 to 3 degrees, setting it to exactly 35 btdc meant high revs also high temperature's on the head and possibly a bit more 'peaky' putting in the extra 2 to 3 degs had lost a hundred revs but brought the head temps down considerably and smoothed out the throttle response apart from a little more mixture tweaking after swapping to 50 to 1 oil I think I'm happy with the set up and can't see getting anymore from it just need to finish the airframe now.

MTK

Rob,

I ordered one to play with. A 15+mm venturi will be interesting. That's the same size as on the 55cc's.
How are you planning tostart itwithout a choke? Finger access in the plane doesn't always work well. I have an extra choke mechanism from SAP that is basically a sliding cap.
I can appreciate a marine app and this carb, particularly since the marines are turning, what? 18K? It will be very interesting how this works on a plane engine which is propped to turn in the low 7's

Standard Walbro carbs can be primed using choke and simple spinner rocking against compression which actuates the gas pump. Do you think the same applies in this carb?

If I read you correctly you retardedignition by 2-3 degrees, to about 37 degrees BTDC and that helped smoothen response and reduce head temp?

morecashthansense

Hi Matt,
Yes retarded the ignition from 35 to 37 and this smoothed out the response quite nicely this is on a full tuned pipe though not sure if your carbon ones will react the same plus it has reduced the running temp a lot.
The DLE has started quite easily without a choke, even with the low needle being on the lean side ie it won't transition until warmed up a bit just by using the method you mention. Warm starts are usually one finger flick quite surprisingly.
I have made a new adaptor plate to transition from the dle square port on the reed cage to a 15mm round port also I rotated the Carb to give better access to the needles, the Carb in the link seems to use an extra pulse port mine works well cross drilling the pulse port to line up with the new Carb, I'll try and send some photos to explain it better.
I was a little worried about the 15mm venturi when you see it it looks like it could swallow your thumb however it just works so well.
Mine is hitting 7650 on a Mejzlik 19*11 tonight right on target to get just a little over 4hp when I can swap to 50\1 oil. The 32\1 I'm using at present (for safety) does develop a little burble (4 strokeing)at 3500 rpm which I can't tune out just yet, hopefully the rest of the first gallon at 32 then swap to 50 will enable me to lean the low end a little further . There is no other jump in the revs range just a constant increase in revs with the throttle opening right up to full.
I have fitted one of these as the intake noise now is the loudest noise however I am disappointed that it has done little to quieten down the noise but it is good practice to help stop things being injested into the 15mm venturi, I havent used the choke assembly that comes with it as I have not found it necessary.
http://www.ebay.co.uk/itm/3906101943...=p5197.c0.m619

Regards Rob

MTK

7650 on a Mezjlik 19x11 is tremendous output. I am getting only 7100 on a 19x10 Xoar laminatedwood. Xoars are quite the load but the difference seems too much to me. That difference has to be the larger throat, making breathing easier.

7650 is more on par with the OS GT33 which turns a 20x10.5 apc at 7400 to 7800 depending on the gasoline I use. Makes me wonder how much more I can get out of the 33 with this new carb. The DLE and the OS have the same throatdiameter as is today.

The kind of power you are getting from the engine will fly the plane with tremendous authority. Once everything is installed in the model I think the intake noise will dampen considerably; it always has in my set-ups at least, which are fully cowled...

Good to know about the choking. I've also found the 35 to be very simple 1-2 flip starts. I have a meat grinder regardless that I can use on the spinner if I need to, so it won't be a problem either way.

morecashthansense

Hi Matt,
If you see the photos earlier you will see the full length hatori pipe I think this is helping a lot as the 19 *11 is almost instantly to 7650 very very snappy response which is why I think this combo may when run in take a bigger prop, this weekend I will try my 20\8. Xoar carbon and a 20\8 falcon carbon to give me a better idea where we are at. One things for sure this motor does like to rev given the right conditions, I only have a crappy biela 21\10 which may be to much but will give it a go if the bolts line up. Must remember this is still on the first litre at 32 to 1 can't wait for 50 to 1....
Regards
Rob

MTK

Hi Rob,

One major detail I forgot for some reason is the fact that the DLE35 has yet to be run on a pipe.....only canisters which are just mufflers. They don't boost the output at all. I'd guess that I would get a couple hundred more rpm on the pipe.

I ran the PTE36R on the Mintor 38cc pipe, same props as on the DLE35 and same fuel, and got some more output but again, nothing really close to the OS GT33 equipped the same.

I'm very curious to see how the new carb changes the characteristics of all three of these powerplants.

BTW, how is the gas consumption? The way I fly my pattern planes I get 15+ minutes flight time on 330 ml of gas and have about 2 oz left in the tank.....I assume gas consumption will increase

Funny story using a Biela. A guy showed up a year ago or so with a 50cc IMAC type plane on which was a Biela 23-8 I believe. When he cranked up, it sounded like all hell broke loose. And then he took a flight.......OMGoshki......In flight, I have never seen a better power to noise converter....

Wait til you hear my latest piped and soft mounted DLE55 set-up. I hope to have video this weekend.

morecashthansense

Hi Matt,
On the test bench at least I think the consumption has gone up some it may be i am running it fairly rich though.

I have done extensive testing on a MVVS 58 on a full length MVVS pipe with lots of carbon props and I can say without doubt that the Biela prop although reasonable construction and attractive cost is the worst size for size carbon prop on the market it is so heavily loaded that you can't run same size testing so people tend to under prop their combo and can then over rev . That being said their price is so attractive I see lots around various clubs and because of our very restrictive noise legislation tend to give gas powered planes a very bad reputation for noise.
The.weather this weekend had ruled out any flying so it looks like a weekend in the garage testing and building.

morecashthansense

HI Matt,

some figures from todays testing,

Prop ,............Revs original carb .Revs New carb....DB @ 10m.
Mejzlik19*11,.....7500,...................7650 ................86Db/78Db
Xoar 20*8 Carbon..7200 ....,...,.......7370 ..........,.....86Db/85Db
Engel 18*11 3 blade ..7120,............7280 .......,........84Db/82Db

Non modified engine with canister exhaust.
Mejzlik19*11,........7220
Xoar 20*8 Carbon..6720

So it can be seen I have achieved about 400-500 increase in revs over stock but better is the response.



I missed taking my 20*8 Falcon carbon out pity as this is a lightly loaded carbon prop and should have achieved some good numbers. The front mount seems to working well as little vibration is being felt through the workmate, it may be a little to stiff as the wood may be a little to thick but this can easily be adjusted once in the airframe.

I am for the most part pleased with the noise as most people who was watching never even looked at the tail end of the exhaust for the noise but started looking around the engine and speculating about intake noise.
The filter I tried doesn't seem to do much at all but it does give some security that no debris will get into the carb

I have tried going back to the original walbro supplied with the engine as I hadn't tested it with the extra retard on the ignition so now as a back to back test I can observe that;

1. The wyk33 does indeed give a bit more revs on top end. And the throttle curve is linear.
2. The wyk33 is far more responsive in mid range and it helps develop more torque there as the spool up is instant on all props.
3. There is no interaction between the needles but the transition point from idle to high does have a burble as raw fuel goes through the engine, this may be reduced as more time is put on the engine and when the leaner fuel mix is tried.
4. The original Walbro works fine within certain parameters, most props spool up a lot slower and have the 3800-4200rpm burble which at the moment cant be tuned out.
5. the original throttle curve is not linear like most butterfly carbs.

So which carb to choose before fitting into the airframe, the security in knowing the original carb will work reliably is a big plus and as I have a 35 in another airframe is predictable. However as this build is about a F3A pattern plane which should live around mid throttle most of the time I think smoothness of throttle is the major consideration so The Wyk 33 wins here the extra power is a plus, planning ahead before fitting I think it is best to get the rest of the first gallon through it at 32:1 then swap to 50:1 to see if the transition between needles can be smoothed out.

I have a couple of videos which I will try and figure out this evening how to upload here.

morecashthansense

Well if this works here are a couple of video clips, the needles are still in the tweaking stage here so there are a couple of 'misses' here and there, if I recall these were shot with the mjzlik19*11.

http://youtu.be/f3g_etCkY7U
http://youtu.be/g-zU6_hIG30

MTK

Hi Rob,

Interesting videos. The sound suppression is there. Power curve seems more linear than with the standard carb. The few misses are, I believe, the result of richer running. I saw it hitting 7600 on the Mezj 19x11. That's more than enough power for anything pattern related, any class

I flew both my new Delta/DLE55 powered model and my two year old Aesthesis/OS GT33 powered model this weekend at the Pocono contest. The new Delta caused quite the stir. One of my friends took some video and we hope to post it over the next week or two.

Between the two, Delta is the better flier but is slightly noisier than all the electrics flying at the comp. I didn't fly it well tho and had tech difficulty with all things, the tail wheel.....very strange....

On the other hand, the GT33 on the ES pipe is not any noisier than most electrics flying at the comp. It seems the engine combination is getting even mellower as more run time is put on it. But I think I'm goingto retire Aesthesis....she's a little overweight and doesn't fly as well as I think I need to compete. I have a new model coming for the powerplant...

The WYK33 arrived Saturday. It comes with some type of aluminum adapter which I'm not sure it needs. Also, the throttle arm is set-up orthogonally from what is needed in an airplane application. Did you change the arm's mounting? And did you reduce the spring's tension? Did you make any changes to the idle screw? Itis supposedto be 7 turns out but mine came sealed from the factory so no adjustment is possible unless I took the thing apart. The throat diameter is 15mm so it is probably the same one you have.

I'm going to play with it on the broken in 33 and fully lean it out and see what it gets me. I'll post findings here and on the OS33 Pattern thread

morecashthansense

Hi Matt the Carb kit you got was probably set for a Zenoha so the ali block is to rotate the Carb slightly, I didn't want to drill the crankcase on mine to supply a extra pulse line so I made a new ali block with a cross hole to line up the different position of the pulse port.
The kit I got in the uk is slightly different in that the idle needle is open and after a little adjustment becomes quite loose so the recommendation is to fix with a little loctite 222 only. My needle is also around 7 turns out.
They are easy to take apart to relax the return spring a little. And yes the arm mounting will be a bit of a challenge but not to difficult mine came with a bellcrank system which is probably ideal for a zenoah in a boat.

MTK

Hi Rob,

Have you had a chance to fly the engine yet? I'm curious to know how it performs in the air with the 20x8 or 20x10 prop on it.

morecashthansense

Hi Matt, I haven't flow it yet it is still in the test rig, I have tried a 20 * 8 falcon carbon on it though as it became available after my msxr crashed. And it realy likes this prop, lightly loaded compared to other carbon props I think it was topping 7800rpm[X(]
I am in the process of finishing the fuz its all in white and waiting for the vinyl pack to arrive. A couple of weeks late now.
I have swapped back and forth between carbs to convince me to go with the barrel style as the servo mount will not be able to cope with both Carb set ups.

My Msxr was flown with the falcon 20*8 a lot and it realty suited my flying style, not the fastest to spool up but very quiet with no rip at all and that was at 7200rpm. I am looking for a replacement for the MSXR and am stuggling to find a airframe that suits the 35 Dle well. I don't fancy another Chinese scale extra\yak\sukoi etc, I have found these all look good but nowadays seem optimised for 3D ie little wing section to large control surfaces to close coupling on the tail moment. I guess once you've flown a good f3a machine everything else is a backwards step, shame the Chinese aren't building these just yet for the same price they can knock out scale jobs.
Rob

morecashthansense

Hi Matt

I've had some very interesting results this last week, after checking the tuned length of the pipe which I set at 28" and using a formula from the 'net' I realised that I was to long. Measuring the exhaust port opening at 163 degrees and assuming a sensible 8000rpm top limit it would seem for a flat disc type pipe a length of 24-25" be around the right size for a test flight. Shortening the header to give a length of 25 1\2" I now have the following results;

Mejzlik 19*11 8080rpm when cold settling to 8000 once fully warmed up
Falcon carbon 20*8 8040rpm cold settling to 7990 when warm.

It would suggest that I may be able to go shorter still for more top end revs but I will test fly first, my research also suggests that shimming the head to reduce the compression will help, don't feel to confident in doing that just yet.

Interestingly though the carbon three blade tested earlier still can't better 7200rpm!

Regards

MTK

Hi Rob,

Those are very good numbers and plenty of beans to fly any 2 meter pattern plane on the market today.

I've used an APC 19x11 on my OS GT33. I actually ran a gallon+ through the engine on that prop, around 15 flights or so, during the break-in ofthe engine. The engine was producingslightly lowerresults but on the standard 12mm carband 28" pipe length. Also, on Avgas which I know produces a couple hundred RPM lower results by itself.

Your results suggest that I might get more output by bringing the pipe in a couple inches. And when I start playing with the large bore carb WYK, there should be even more top end available. Not really necessary, but good to know it's there. The biggest thing for my evaluation will be the effect onmid range torque. The OS33 has a lot of it already so the larger carb should enhance that. I probably won't play with the new carb until the fall tho. It's been very hot here and I actually haven't done any flying in the past month or so, hibernating in the AC

Getting output from the 3 blader possibly requires the35 to have longer stroke?

morecashthansense

Hi Matt,

Just realised a mistake I have made, in order to adjust the ignition advance I actually retarded it the wrong way instead of going from 35 BTDC 2 degrees to 37 I should have gone to 33 BTDC as 37 was making it sound rather harsh due to the spark happening earlier in the compression stroke! My Bad

Reset now to 33 and there is nowhere near as much heat build up and I've has a gain in rpm to boot up to 8150rpm on the falcon carbon now(maybe due to atmospheric condition's as it was a lot cooler today). there has been a slight increase in mid range 'lumpiness' though not enough time today to sort that out yet probably low end needle can be tweaked some more.

Airframe will be finished by the end of the week and the engine can come of the test bench and start the fitting out.

I have obtained another tuned pipe for a 35cc this time the mvvs one, this will be going on my second DLE35 set with a normal carb destined for a Capiche 140 so I can do a near back to back test on the test rig and check the header length. This pipe if it performs the same is approx. $50 so it will be a really cheap combo if it works as expected.

regards
Rob T

morecashthansense

Hi Matt,

At last finished the airframe scheme, should now be able to mount the engine back in and work out the pipe mounting, then at last get some sort of meaningful sound tests.

Regards
Rob

MTK

Congratulations Rob. It's quite a looker, nice work.....

I forgot the cheeks this model has. These should fit a small twin nicely. Here in the states Valley View RC has a small 40cc twin. Supposed to put out about 4 3/4 HP, more on pipes

morecashthansense

Hi Matt,
I haven't come across any small twins yet but am considering changing out a Mvvs 58 in a Comp artf 2.3m. Extra for the new dle twin. I think the power would be down on the mvvs as it is on a full pipe but ithe dle would probably have better power in the mid range can't see it throwing a 24*10 at the same revs (7650) but it may make it a better flying machine.

Regards

morecashthansense

Hi,
Well the capiche has flew today, whilst not the dle 35 with the 'new' carb it is the standard carb with a MVVS tuned pipe, below are the flight logs for your perusal.

This combo was flown on a Falcon 20*8 carbon prop and I think from the data it can take a bigger prop there is no lag at all just a mid range burble which needs to be tuned out otherwise the throttle is a switch from tick-over to full as quick as you dare open the stick.
Also it is not at all noisy, with some sound deadening around the inside of the cowl it had less impact than a 40 size glow motor the worst thing was some airframe resonance as this combo is on solid mounts, this looks very promising for the combo with soft mounts and a different carb.

marrinersgarage

Hi,

just wondering if there is any update on this? particularly interested in how the carb worked out etc as I'm currently running at DLE35 in my Integral.

cheers,

Dave

morecashthansense

Hi |Dave,

Due to a recent job change I have not got out flying much, however I have flown the Majestic about a dozen times since this thread was started which has given me a little insight into this set up,

basically the engine mounted from the front with the rubber style anti vibe mount works very well, combining that with a full length Hatori pipe and the carb mod has made a very powerful and thankfully very reliable set up. It still has a slight burble at just over tick over in the transition range but I believe this can be tuned out when I have put about 2 gallon through it. It is a little annoying though as this seems to be the throttle position which equates to my usual cruising speed..

It is very easy to start needing no choke and one warmed up hand starts are a lot easier than before with the standard carb. The Walbro barrel carb is very easy to set as the two needles do not interact like the standard carb, one for tick over one for high range and transition.
I am running a large air filter in the cavernous fuz just in case but that and the long pipe means it cant be overheard at the flying strip over a OS40 glow for instance.
Prop choice I think will be key in the future and the Falcon 20*8 has now given way to the Mezjlik 19 * 11. This combo is still far to powerful for what is needed in this airframe to perform any manoeuvre you can think of.
I think possibly a DLE20RA could fly this plane well however the DLE35RA and pipe has balanced with no weight added anywhere, the weight of the engine combo with fuel etc is very comparable to the YS170 dingo set up which this plane was probably designed around, I have yet to use anywhere near a full tank of fuel as this combo seems very efficient I think I have about a 20Oz tank and could easily have fitted half that as flight up to 1/2hr are possible!


I think if I were to attempt this again to a not quite new good F3A airframe I would probably now opt for one of the cheap 38cc four strokes that are around, I do much prefer the low torque of a four stroke.

If you want any picture of the present install just let me know and Ill try to post them up.

morecashthansense

Hi Managed to get two more flights today, the motor definitely doesn't need the Hatori pipe it gives monster power but possibly a bit to peaky on a 19*11 mezjlik, Ground clearance and a to flexi undercarriage means broken props. I have a three blade Im trying to put on but not till I am confident enough to grease every landing.


The carb mod is working very well it doesn't throttle cleanly when cold (meaning mixture is very close) and needs a minute to clear its throat and warm up a bit, then clean throttle all the way up the range. Over revving with a 19*11 or 20*8 so prop choice is going to be a bit of a minefield. Very very powerful combo though catches most people off guard whenI ask them to hold onto it to blip the throttle..

marrinersgarage

Thanks for the info, will probably experiment with both the mount and carb in the future.

I understand the appeal of a 4 stroke but I do like the simplicity and power to weight of a good 2 stroke!