Why do they make more stock power? what's different than a standard zen? how popular are they at the races? do they make more modded power? Is a sikk 27cc really a 26.4? are they heavier or taller? ???

The biggest difference I found on an older Sikk was its head clearance was quite a lot less than a stock Zenoah.

Lohring Miller

Anthony,

The Sikk "marine" engine make more STOCK horse power for quite a few reasons ....

#1 They use a Full circle type crank ... ( better case stuffing )
#2 Pistons skirt, under wrist pin is more open ... ( breaths better )
#3 Exhaust port width and height is more than a stock Zenoah ... ( better top end )
#4 piston to head clearance is a LOT tighter ... ( better torque & fuel burning )

:-\ So stock for stock the Sikk makes more power everywhere in the power band,
But uses a 2 bolt cylinder that is a MAJOR weakness.

** Do a tad bit of tweaking on a Zenoah you get to the Sikk power level really easy, take either engine to "FULL MOD" status the Zenoah will run GREAT, the Sikk will fail a lot quicker and be NO where near as reliable ... IMHO.

can you make em 4 bolt?

Nope

A little off topic, but we tested the same hybrid cylinder on both a standard PUM crankcase and an RC car crankcase that had been modified to use a standard PUM ignition. Though the RC car crankcase had a full circle crank, there was no difference in power. I know this doesn't seem logical, and Midwest Engines built a similar engine that was very fast, but that is what we found.

Lohring Miller

what the hell is a fullcircle crank and it's benefits?

The standard Zenoah crankshaft has an offset counterweight like most automotive crankshafts while the RC car crankshaft has two crank disks with a thicker section as the counterweight. This should fill the crankcase more and raise the crankcase compression. I have not actually measured the crankcase volume with a full circle crank, so that could be the explanation for our results.

Lohring Miller

I,m seeing the new M&D 26cc at 7.0hp still in testing I think it gonna be the way to go or a qd25ht

Unless your going to race, don't waste your money on an exotic engine :-\

A modified zenoah set up correctly is more that potent enough IMO