Thursday, February 5, 2009

More details on home-built Enfield V-twin

Aniket Vardhan built his won Royal Enfield 700cc V-twin motor from two 350 motors. The Columbus, Ohio man's accomplishment, seen on YouTube, won admiration from around the world. More than one commenter has yearned for such a motor from Royal Enfield. Vardhan has been peppered with questions about the motor, and has answered some of them on the Bulletech Yahoo message board.

Members asked him about the shape of the crankcase, why both exhausts face forward and whether the motor will fit in a Bullet frame. His responses include:

"I tried hard to make the crankcase look 'Enfield' -- the more rounded profile in the front, which hints at the big, heavy flywheel spinning around inside.

"The distributor casting is the stock one and it's probably going to stay there until the motor is tested thoroughly, then I will machine up a more elegant one that doesn't stick out so much!

"The layout was simply dictated by the fact that I had to use the given Enfield head -- as you know, the size of the intake and exhaust ports and valves is different, so they couldn't be switched. Personally, the 'both exhausts forward' layout has advantages -- both cylinders have the hottest portion (the exhaust port area) pointing forward at the cool breeze. And, of course, not to forget, the mighty Vincent was the same way!

"I made it to fit the frame, but the top tube does have to be cut and lengthened -- that is the only major mod. Also, the engine mounting plates are custom, both front and back, but that is basically some flat steel with holes in slightly different places. I have mocked it up in the test bike, and actually, the longer wheelbase looks rather good, more proportionate with the bigger motor. I will be going for the classic Brit V-twin looks of the beautiful Matchless Model X, BSA Y13, AJS 1000 etc.

"Right now, the oil pumps are the classic piston ones but the castings are such that if needed, the gear ones may be used as well. The entire oil feed system is removable to allow cleaning and blowing with compressed air without dismantling or removing the timing cover -- that copper oil pipe assembly is removable entirely after unscrewing the mounting Allen screws. I really love the look of the old engines with the copper oil pipes.

"I really would have liked the simplicity of one carb, but here's the main problem: if the rear cylinder were reversed (with the exhaust port facing backwards and the inlet forwards), then we have to deal with the fact that the rear cylinder now must have the cams, push rods etc. on the LEFT side of the engine, while the front one has them on the RIGHT. You see, this would make things really complicated in terms of using the existing primary case, cam drive, oil system and greatly compromise overall simplicity.

"I guess the one thing I can claim to have kept as my principal goal in the layout of this engine is to keep things as simple as possible for the owner-mechanic to have as trouble free an experience as possible. This engine is really no more complicated (or less simple) than the single-cylinder engine. I am confident that any owner or mechanic who has worked on the single will find this twin just as tinker-friendly."


  1. Best wishes for Aniket, there's surely plenty of low mileage Enfields out
    there that could be retrofitted with his engine! He'll need somebody
    like Hitchcock's behind him though..

  2. i was impressed when i saw the video on you tube. i ride an enfield myself, and that twin ran a tickle down my spine. wish i could build one for myself. best luck. i will be keeping a track to see the bike.

  3. AWWWWW so long is the wait! You bloody home enginers keep comeing up with variations of these v-twins! Are you TRYING to make me cry? Do you want me to kidnap you and force you to make one out of old tin cans and wood? Excellent STUFF!

  4. so are amazing

  5. Anonymous6/03/2011

    really Aniketh your r a genious


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