i am new at convertions to engines but i have managed to tweak out my talon 32 cc whipper snipper motor. N E ways i want to know if its possible to join two full crank whipper snipper motors together so u end up with an inline 2 cylinider motor. i want to no this for a project i wish to remain secret.i have complete machining capabilitys and n e work is possible for me. n e help would be greatly appericated

Secret project eh?, well I could tell you how, but then I'd have to ..............
Seriously, I dont know of anyone that has done this, but looking at the engine, there is not much of the original you would use, (only the top ends)
you would need to fabricate a new crank, new cranckcase,new induction manifold..etc if you want a compact aero engine, but as its a secret I dont really know what you are aiming at
maybe you just want to bolt two together for a laugh, who can tell?

you mean like this?.....
this is two 88cc huskies set for an alternate firing.....it sound like a very upset swrm of hornets it powers a cut down Nosen mustang pylon racer. it will spin a 24 x24 prop at 9000 on the ground. the coupling is a steel affair with new keyways cut in both shafts and coupler

I built a Kawasaki 25cc inline twin. Blade and slot drive between the two.

thanks all ne ways its for a car that i just cant get enuf power for

Crusty knows how to get double the power out of those engines.

Anyway I think you would save yourself a lot of trouble if you used a chainsaw engine, they have much better power to weight ratios than the 25cc homelites, and 31cc ryobis, a 45cc homelite chainsaw would be a good choice.

gluck.

i was goin 2 use a couple of small full crank motors and run them at alternate fireing

do you have n e diagrams as to how u joined the two?

Might be easier with cantilever cranks, this is from just engines site. It's the moki 360

Oh, I see you actually have the engines. My bad, I guess if i where going to do that i would make a sleeve that would fit over the back of one of the cranks and onto the front of the other cut as sort as pratically possible. I would lock the sleeve on the the shaft with high tensile bolts going through the center of the shaft, you would obviously need the holes setup so the engines are 180o apart in there respective cycles. Then I would make up some sort of support to hold the two together, maybe a nicely machined item made from ally barstock. You would also need to syncronize the carbs.

This is the front 25cc Kawasaki that I just took out of a plane using it as a single. The rear view shows the blade slot that the rear motor blade fits into.

My late friend Bill VanLeeuwen built a 250cc inline twin for racing...The hardest part is making a coupling strong enough...He got the coupling strong enough after many attempts, but the engine was not competetive with the opposed twins...
There are a few inline 3 cylinder engines around, made a few years ago..One is currently being used is a scale warbird...The engines are coupled together by grinding a hex on the end of the crank and using a form of hex socket to plug into...It stays together for about 3 flights before having to be re done...I have some crank parts here to check for straightness and put back together....
I had an inline twin G62 a few years ago, built by a customer in Colorado...Worked pretty good, but the coupling got looser every time it ran...Finally took it apart and sold it as 2 separate G62s....
The best inline twins were/are made by Challenge Tool, called Husky Challengers...I think the one in the Fastrat porting paragraph above is one of these...NO problems with coupling, don't know what it looks like, but the rest of the engine is museum quality.....

I have always been led to believe that the large single cylinder 2 strokes made more power than twins.

Something about larger ports are possible on larger cylinders.

I know they vibrate more but... if you spent the time balancing or counter balancing them they should have more potential.

A company in Canada makes an inline called a Merlin...Made from 2 Q52s..It's long and heavy, runs pretty smooth, no more power than a good 100cc single..Costs about $2500...