asymmetric 2 cilinder VW conversions/plans?

[swampthing]

Hello,

A newbie question: I got a 1500cc, 83mm cyl, single-port heads engine. I know that for balanced, and optimized weight, symmetric conversions with two opposite cylinders are best, and I have studied the plans for the "better half" type.

Are there plans or experiences using an asymmetric (one side, cyls 1 and 2 or 3 and 4) conversions, that would retain the whole crankshaft, and whole length case? I have heard they exist or existed, but cannot find anything.

I am thinking of using it on an airboat / air-sled, so cost savings are more important to me than weight savings and reliability.

Thank you very much!

[GTS225]

I would think, from an engineering standpoint, one could build the 1/2 VW, utilizing the entire case(s), crank, and cam, while reducing it to just 2 cylinders.  The stumbling block(s) would be balancing the rotating assembly, and providing oil galley plugs where needed as you'd be missing the other two rods.  I think it'd be simpler to build the opposed twin rather than an inline twin just for the balancing issues.

Just my opine.....Roger

[Dan_]

Are you just trying to save on fuel?  If you are not looking to save weight put the whole 4 banger on it...

[swampthing]

Are you just trying to save on fuel?  If you are not looking to save weight put the whole 4 banger on it...

Removing the head and set of jugs does reduce weight somewhat, and having fewer cylinders hopefully makes for easier cooling. (on the source engine, it is the cylinder 3 that has signs of overheard, locked piston rings).

[Dan_]

Minus 2 jugs and 2 heads will save some, but you will still have all that crankshaft slapping in all that oil creating drag and you will surely have to bolt weights equivalent to the pistons and rods that will be missing...  

A V-Twin is a ready made solution.