Well.... I have a sample of the 3MM TOC 53cc that I've installed and now run in my SD models 30% Extra 260. So far, it seems to be a pretty good example of a properly-setup engine design. Haven't flown it yet, but will report when I have....

Since it's actually in my hands, I used it's weights to update my Gas Engine Weights information, posted here > http://www.rcaerobats.net/GAS_ENGINE...ENGINE_WTS.htm

Seems to be a good weight for a 3 bearing engine.

this is the first I've heard of a 3MM engine. If this has been posted before, can you point me to the thread. A forum search of "3MM" did not find anything. Suspect the search engine is not very good at mixing short strings of number/letter.

Yeah, it bites, mostly - it is very "specific", and you must be IN the forum you want to search, I think. Anyway - here's a search thread result -
http://www.rcuniverse.com/forum/sear...D&sortMethod=d

Also - engine is sold by Wild Hare RC , "rctom" is the owner, also sells aerobatic airframes and other goodies. Lots of them out there, he has a manufacturer support forum in 3D.

On the 3MM - since it's a six-bolt hub, had to re-learn how to do that. Courtesy of rctom, he suggested using the thick front prop washer from the engine, with w 10mm bolt, on a drill press. After I bought the 13/64ths drill bit (nearly exactly clearance fit for the 5mm prop bolts (uses a 4mm driver), mounted it all up, and PERFECT. Couldn't believe it. Hope everything else goes as well.

BTW - after about 30 minutes of cyclical ground run, tweaking a bit on the TBM 22 x 8, turning idle at 1500 or so, and full bore (not leaned per instructions) is hitting 6200 solid. The TBM props are a LOT of load; will be interesting to compare a NX or Xoar next.

6200 is oftly low for a 53cc engine?? Basically the prop as a NX... should be closer to 6600-6800.

The TBM is NOT - no-Way - "basically a NX". Not even very close. Thicker, and broader blade. Lots more area at the tip. I thought they were "similar", you know, like a 22" prop is like a 22" prop.... but no matter. What it is, is what it is.

Well the same company makes them to the best of my knowledge...

Either way 6200 is low... even if it had a MSC which is one of the thickest out there. with an MSC most get 6500+ on a 22x8 for a 50cc engine.

I am not knocking the product.. just saying what I have seen on other engines... even the Brillelli 50 is turning I believe a Xoar 22x8 at 6800-7000 new and that prop puts a pretty good load on an engine... infact I personally like them better than Vess myself

Personally I would say it would be better with a 21x8 so you can get the r's up to high 6s should be able to get 6800 judging by what you are reporting right now. Your old B46 is turning a 21x8 Xoar at 7000 and I just put a new carb on it that is suppose to add another 200 rpms min.

It is what it is.. an inexpensive engine. Its the same engine BCMA was selling and numbers spoken are close to the same.


So far there is only 1 inexpensive engine out there turning heads and thats the DL-50... however there is only 1 I know of that has over 15 gallons of gas thorugh it so far. I know of 1 that has a gallon and the bearings are already showing issues. These inexpensive engines are great if they last... that still remains to be seen.

Personally I would be curious to see what happens when someone who really beats up engines puts some of these new engines to the test for the summer. I want to see them with 15-25 gallons over a summer of hard flying.. that will speak volumes for them.

The 3mm TOC-53 turns a Xoar 22-8 at about 6800 rpm when new. One that I have turned a Mejzlik 23-10 at 6400 rpm after the 3rd flight when it was plenty warm. That's a big prop.

I was out with another new one today which was turning a Bolly 22-10 at 6500 rpm after about 10 minutes of running.

The TOC-53 has a hard chrome cylinder surface which takes quite a while to break in, so they get stronger over time as the rings seat.

Unless you are actually working with an engine (any engine) you should not jump to hasty conclusions. The TOC-53 is a first class piece of hardware that will haul around an 18 pound plane with plenty of power for unlimited vertical and is very easy to live with.

TF

I am not jumping to conclusions.... I am not in the market for an engine of this type, so it doesnt matter to me either way... I am just making responses to the numbers being posted.

Even at 6800 with a Xoar 22x8 it's not a total powerhouse. DA and Brillelli 50 turn that same prop at 7000+ new.

Like I said I am not knocking the product... your numbers are more inline with a 50cc engine... Bob's numbers are low.. no way around that.

I'm just starting my third gallon of gasoline in my TOC/3MM 53. I really like the MSC 22x8 props for my 50cc size engines. It's a super wide blade; they're light, put out a lot of thrust, and brake better than any I've tried. This is a wide plank that really loads. I get 6800+ rpm with this set-up. That matches and exceeds all of my other 50 cc engines.

Well those are decent numbers and probably well in-line after 3 gallons of gas.

What other engines have you tried?


LIke I said... dont get me wrong... I am a big WH supporter... owned an Edge, a Yak, and currently a Cap. More than likely shortly a 33% 260 so I am not knocking.. just sharing an opinion... which like most could be a good or bad thing haha.


I just dont see how these less expensive engines are going to compete long term with the competition. Either power or longevity is going to be compromised eventually... maybe not for the average flyer... but a 3D guy has different expectations.

I am running a "Bunny" 23-8 prop from Wildhare on my 53 with 2 gallons through it at a steady 6500. (I believe it is nearly the same as a xoar prop) And I can say that the power seems to be on par with my DA 50, and my ZDZ 50.

So far mine has been very reliable and easy starting, it only has to pass the test of time now and that will only come with more stick time but for now I am very impressed.

I appreciate the rpm information from those who are running this engine. Good to get comparitive info out there.

Jake - your opinions noted. Thanks.

I ran one of these engines as a lookee -and on the MSC22x8 - close to 7000 using muffler provided . It revs right along with Mezjlic 22x8 -sorta
If you judge prop load by appearance , wider- thicker etc., you will not get result you may assume - one of the biggest load props I have for a 50 is a very narrow thin prop from ZM
engine was nice n smooth easy to operate
sizewise larger than DA/ZDZ --more like 3W.

Dick - regardless of how it "performed", that ZM prop is pretty cool looking! Shame that appearance doesn't equal performance.
Sounds like your sample ran pretty well. That was stock single-tube can?

yeh -the single tube muffler -worked very well and I got no increase running open stack -surprise.
the ZM prop (22.25" x12") does perform on 50/40 ZDZ with very long full tuned pipes - very quiet -the right plane for the combo tho -as you might guess is a 1000 sq in pattern type setup.
totally different ballgame . almost like an electric-

Like other people have posted here, in my side-by-side testing the 3mm TOC-53 is virtually identical in power to a DA-50. All of my testing shows this, and customer reports back this up. It is easier to mount and hook up, and the standard muffler fits more cowls. Weight is 8 oz. more as Bob's table shows clearly.

FYI I have had a couple canister headers made for this engine, as soon as I can test them, assuming they work out OK that will be another option, along with a custom Bisson wraparound that I had made.

I am working hard to increase the engine's versatility.

I tend to agree that Bob's numbers are low, I'll be working with him to find out why.

TF

Well, different day, differnt prop. But everything else the same. Same gas, same needles, same humidity/temps... this time just changed the prop to my new NX 22 x 8. Different beast altogether. Turned SOLID 6670, fully warmed up. Bouncing a bit, as rings are working in, I'm sure, and it's not 'lean' on the top, but what I would fly with.

So.

TBM = 6220
NX = 6670
Both 22 x 8, both new.

Have a feeling this is gonna be just fine....

Acording to Gene at TBM, the TBM prop is the same prop as the NX. Might check the prop for balance or drilled on center. Something is throwing your rpm's off. Might be mis-labeled.

Yeah, I know....
That's why I'm even more surprised. They are drilled properly, very carefully balanced, and both are 22". Can't check the pitch, but looking edge-on held together, they "look" the same.

I'll fly them both, but it's good to know the stuff is "in there".

Someone else wrote me that his well-broken in DA only does 6600 with the same prop (NX 22 x 8), so if accurate, this is doing "okay", and I won't gripe.

Very solid and smooth transition, too. Very low vibration; of course the 'resonant' point is still there.
Idle is 1500-1480.

Boy, that ZM prop that Dick has in the photo looks like the spittin' image of a small Fuchs. Going to have to try one of those. It's got to be a fast power transfer 3D prop.

I have to disagree with the TBM being the same as an NX, regardless of who siad so. I have about all the props you can get in the 22-8 size and the TBM is much closer to a Menz, almost identical, and a little narrower than an MSC. With an MSC I would expect a lower rpm number than other props but better thrust and response. The TBM would be in line with a Menz, which I place right behind the MSC, with the Menz providing a higher rpm count, but with a slower thrust response. The NX will have fairly high rpm numbers but be more of a screamer than a puller.

The numbers here with Aerobob's engine lead me to think it still needs a little needle tweaking. Don't be afraid to set the engine up for the best performance, even when new. The "fat" break in's don't provide any benefit, and may be detrimental due to a lack of reliability because it's too rich. A rich mixture break in does not help the engine's thermal cycling as well. It keeps the engine too cold for everything to come together properly. I hate a dead stick with a new plane or engine. Makes the flying day much too tense.

Ya know...

I bought a TBM prop also for my new DA 100 and I'm down on revs as to what i'm supposed to be getting. I'm turning around 5700, granted it's a new engine.. but I should be over 6k! I ordered the TBM thinking it was the same as the NX... I've got a Xoar on order now to replace it next week. Seems to me from what I'm reading here all the TBM props are down on Revs... Mine was also WAY out of balance, more than I've ever had to balance a wood prop before. I would send it back on their "satisfaction guarantee" but I've had it over 30 days, so I don't know if they would take it although I haven't asked either.

The only thing that I am positive about is that *my* TBM prop of the same size as the NX was 500 rpm difference. Folks may not agree, or speculate that something else is going on, and I would probably question it myself. Except that I was running the radio and the tach.

I don't mind that they are different, and my past experience with TBM wood props on other airframes has been that they "work" very well.

Part of the reason that the tach doesn't always tell the tale, as they say

I agree, I'm just happy to find out others are having the same results with the TBM props, I was worried it was the engine. I'll find out next week for sure, I'll tach it with the TBM and then put on the Xoar and get my answers.