I've got allot of K&B 4011 stuff left over from my racing days. I read on stuka that they are a good stunt engine with mods so, might be a fun project to put on a Brodak Lagg 3 Lavochkin .

I've got the early version light weight front case and the later crank case with the exhaust lugs. It was real wet nosed so I got a double sealed front bearing and left both seals on. I ran it and it sealed so good even the grease stayed in.

They say to lower the sleeve and modify the porting and head but no specs. I can take a good guess and probably come out ok but, anyone know exactly what to do?

Thanks,
MM

I run the engine with good results.  The "P" inscribed heads (on front) are from the pattern version of the K&B 40.  The P head has a hemispherical combustion chamber.  They can be found on original K&B 40 R/C pattern engines, or with luck, in the spare parts bin.  Details on my successful K&B 4011 engine (converted from R/C) are:

-The P Hemi head.
-Retrofit 0.280 venturi with a K&B or ST NVA.
-Extra head gasket (0.010").
-APC 10.5x4.5 prop.
-Fuel 5 to 10% nitro with 20-25% oil (50/50 syn/castor)
-Tongue muffler adapted to engine.

Engine will run in a "wet 2-cycle style" real nicely with a slight increase in RPM in the right places.  The APC prop really works well on this engine - recommended!  One caution from my experience...  The crankshaft on the small front end 4011 version tends to be delicate.  A hit to the ground can bend the crankshaft itself (not just the prop bolt stud).  So word to the wise, don't crash!

Cheers
DZ

 

I will need to check on the number/size of the tongue muffler holes.  It may take a couple days.

The tongue muffler wasn't anything special.  Just local made by a machinist/modeller, and supposedly for the Double Star 54.  The tongue muffler just happened to also fit my K&B 40.  A convenient match, so I bought the muffler for the K&B.  I ran it as purchased.  If you have access to either of the mufflers supplied with the old DS 54 (there were two of them I understand - a tongue and a tube style), then you could have a ready-made piece with no work on your part.

Check all this out before committing major $, of course.  I am going from memory on the mufflers for the old DS 54.  I could be wrong on the recollection.  I just know that my local purchase tongue muffler runs fine on the K&B 40.  There was no special magic with it.

The key factors with this engine, in my opinion, are the P Head and the APC 10.5x4.5 prop.  The APC prop really allowed the K&B to give an acceptable run for me.  Other sizes/brands did not perform as well, at least the ones I tried.  The APC 10.5x4.5 prop seems to also have a very good reputation among my friends for many .35 to .40 motors, and has worked for me.  That's my $0.02.  Hope it helps as a start point.  Experiment to see what works best for you.

Cheers
DZ