the Wasp

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Jim

aspeed

Interesting to see a face and name that you are familiar with.

the Wasp

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I would really like to try some of his engines,

1) the K&B 100 Plane Engine,
2) the HP 120 Inline Twin
3) the HP 4 Stroke, with out looking, I believe it's a .49
4) RJL .61

but really, I don't need 4 more planes

Jim

dennis

My Feedback: (90)

I had the 4 of those engines
The K&B 100 was an underperformer
The HP twin was loud and was a pain to muffle and had the common fuel feed problems as the ST6000 twin. Starving the rear cylinder
The HP49 was neat to run, quiet but anemic
The RJL 61 was absolutely superb.
Others may have different viewpoints and in their case they will probably be right.

the Wasp

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dennis,, did you have the older HP 120 or the newer one made inside the USA ??

as for the K&B 100, it's muffler is rather restricted, I was wondering how it would do if the muffler was hogged out, it sure would flow better

it's nice to here the RJL ran well

thanks for the reply !!
Jim

aspeed

I have only read the K&B 100 engine test from many years ago, and have likely forgotten most of it, but the muffler was groundbreaking at the time with a zig zag channel cut in to give it a tuned pipe effect. I would not hog it out. Maybe open the outlet a bit more depending what it looks like. It may perform better than it would with an open exhaust.

dennis

My Feedback: (90)

I don't think the muffler was the culprit rather it was conservatively timed. I put a Davis diesel head on it and ran it as a diesel for a few years . It was very good with a 15/6 on it in the appropriate model.

the Wasp

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dennis,, you can see the inside of the muffler in my link below, the muffler is highly restricted and the Stinger tube has only 10 tiny holes in it to receive exhaust from the muffler, even the review in my link suggests to open up the Muffler if noise is not a problem

yet for a good point, the K&B 100 Outboard engine uses the same Case and has a Liner with higher Timing, yes, yes I know, to much bologna to just buy the engine new and then upgrade with the Outboard's liner and of course you may need a different Carb, never the less, if I had an engine that needed a rebuild it would be fun to modify one.

the K&B 100 weight is just a few grams more than my OS 61FX, both with stock mufflers

K&B Aero 100

Jim

H5606

This concerns me some - I also wonder if it is due to the (rather restrictive looking) muffler passage.

The Wasp's link didn't work for me so I thought to post pics of a K&B 100 Aero too.

The sinusoidal passage looks like it could be opened up a bit and the egress pipe (with the small holes) could be eliminated to perhaps allow more free passage of exhaust gasses.

I planned to use this engine in a Carl Goldberg Extra 300 hoping for at least the power of a decent .60 2-stroke - is this even possible?

Aside from this concern, casting and machine work look to be incredibly good for the K&B product line - similar to O.S. in quality and workmanship.

Sorry, blaming changes to the site on huge pics...

Being rear exhaust, could this engine originally have been intended for use with a header/tuned pipe?

the Wasp

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well according to Mr, Lee's write up the K&B 100 will turn a Zinger 15x6 at 9,600, a Zinger 14x6 at 10,200, and a Zinger 14x8 at 9,400 and a Zinger 13x10 at 9,300, all on only 10% Nitro, and those numbers are on par with the Saito 100 burning 20%,,, no 61 will do that,,

is it "under powered "as per asked, I don't think so, ask what it will turn those props at with a muffler like the one that came with the OS 91FX,


now as for the engine less numbers, I did buy one, and I tell you I was totally surprised, it turns unbelievably smooth, much smother than any other engine I have ever held in my hands, I will be hogging out the Muffler a bit, but not too much, and I will try to find a way to mount a different muffler, one that will flow better like the OS 91FX muffler, I'm sure a better muffler will bring up the R's more,, mine will be going on a 4 Star 60 cliped wing,


BTW, Mr, Lee reported the 100 will turn the Zinger 14x8 at 10,400 with Open Exhaust, idle at 1,900 with a 15 inch prop, and 2,250 with a 14 inch prop (all on 10%),,, I bought Head Shims with mine, I will be burning 15% or 20%, not sure yet, but like I said, mine turns silkily smooooooth


K&B 100 review ,,,
K&B Aero 100
site,,
Model Engine Tests

Jim

the Wasp

My Feedback: (1)

yes, you can get it as a Duct Fan engine that turns somewhere around 22,000, or as a In Board Boat engine, or Out Board Boat engine,

Jim

H5606

Cool - thank you very much for reposting those links; they're both working and I look forward to using the resources in the future to find essential info on particular engines...

I read all of Clarence Lee's review - based on the info he provides and what you say about a smooth runner, I'm optimistic I'll be happy with the engine for the intended use.

Being a sport hack and my best interpretation in layman's terms, Mr. Lee paints a favorable picture of the Aero 100 from innovative state-of-the-art features and technology as far as glow engines go, he also acknowledges the rather restrictive muffler, so I'm looking forward to running this one and planning to open up the muffler too.

the Wasp

My Feedback: (1)

no, I said it turns smooth, when I turn the Crank by hand,, I have to say I don't understand why, but it does, note that I have not turned past TDC, I won't do that until I start it,

well it will out power a 61 for sure, as Mr, Lee reported, it should twist a Zinger 14x8 at 9.400, well if you put a Zinger 14x8 on my OS 61Fx I bet it will twist down around 6.000,,, maybe.. so Mr, Lee said, it's RPM numbers are "not outstanding, but are very good" I don't think it was truly made to be a powerhouse, more of just a "Big Lug" type of engine, with that said, now go back and read Mr, Lee's numbers, it will turn a Zinger 15x6 at 9.600 <that is Saito 100 power, and that K&B was designed before the Saito 100,

I wonder what it will turn an APC 14x8 and 15x6, they may be heavier than the Zinger's, but they are stiffer, a stiffer prop is easier to turn


Jim

aspeed

Just looking at the pic. of the opened muffler, I would be in there with an endmill and shortening the legs inside, and drilling a bigger hole on the left side of the outlet tube. I would probably go at the liner and raise the exhaust timing too. I do silly things like that though. It is a really nice looking motor, one of the better looking U.S. ones.

the Wasp

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that's just what I am going to do to my muffler, and I feel the same as you do about the Liner, but I don't think I really need to do that for a 60 size plane with a 62 inch span, it sure will pull more air with a 13x9 than my OS 61FX with a 11x8

Jim

the Wasp

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the K&B 100,
I talked to Randy, the owner of MECOA, but I have to get to that point as I tell you about my engine,

so I was going to remove the muffler from my engine to hog out the inside of the muffler on my mill/drill machine,, well when I took off the back plate to the muffler I could see that it was already modified at the factory.
I removed the muffler and back plate to spray-out the engine (as I do with all my new engines) and let me tell you the machining on this engine is beautiful, a mirror finish, I have not seen this quality of machining on any other RC engine,, Now, remember as I said before, I have never seen an engine that turned as smooth as this K&B 100 does,

so I called MECOA and Randy answered, I was asking him about shimming the head for 20% Nitro and he told me that the engine can be run on 20% in stock form.
I went on to ask Randy if he did the machining on the 100 or if K&B did the machining before he bought K&B, well Randy said that K&B forged the Case but K&B did not do the machining. Randy said that he/MECOA did the machining on the Case. at that I told Randy how impressed I was with his machining and to find just how smooth this engine turn's. and I made a comment to the fact that his CNC machining must be done at rather high tolerances for an engine to turn so smooth, to that he told me that once an Engine Case is machined for the rear bearing many companies will remove their Engine Case from the jig and re mount it in a 2nd jig to machine the front for the front bearing, Randy went on to say that his engines are machined for the front and rear without removing the Case from the jig. ether way I have not seen any engine turn as smooth as this engine does,

any way, I have now ordered an HP 61 LOL

Jim