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The Kneeslider

Doers Builders and Positive People

Bad Dog 215 Cubic Inch V-Twin – Update

By Paul Crowe

Bad Dog 215 cubic inch V-Twin piston
Bad Dog 215 cubic inch V-Twin piston

Bad Dog 215 pistons on connecting rodsRemember the Bad Dog 215 cubic inch V-Twin we mentioned last year? Bill Price, the man behind the engine, hasn’t been sitting around, he’s been hard at work sourcing parts for the prototype and refining the design. I haven’t been watching very closely and Doug Staab, one of our contributors here, just sent me a note to check out the pistons. Ho boy! Now that’s what I call a piston!

These are what pistons designed to fit a 6 inch bore look like. Bill’s hands give you a reference because numbers just don’t convey what a 6 inch bore really means. Just think, 2 of these in a V-Twin displacing 3500cc or 215 cubic inches! Yikes!

Thanks Doug!

Link: Bad Dog Cycles

Bad Dog 215 cubic inch V-Twin piston
Bad Dog 215 cubic inch V-Twin piston

Posted on May 11, 2009 Filed Under: Engines, Motorcycle Builders


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Comments

  1. kim says

    May 11, 2009 at 4:03 pm

    Reminds me of the feet/metric mishap that resulted in a lost satellite near Mars.

  2. hoyt says

    May 11, 2009 at 4:58 pm

    the sound of a locomotive at idle comes to mind (or the look of a marine piston on display in Ballard, WA)

  3. JR says

    May 11, 2009 at 5:07 pm

    oh man!

    that thing is going to sound like NOTHING else!

  4. Tin Man 2 says

    May 11, 2009 at 5:33 pm

    Who says the days of bigger is better are over. This is still America, and we want it all! If this engine ever makes it to market, somebody will buy it. Pistons look as big as an old thumper John Deere, 50 yrs of farming leadership brought to a motorcycle near you!!

  5. Rich says

    May 11, 2009 at 6:53 pm

    As Oscar Wilde noted, ““Moderation is a fatal thing. Nothing succeeds like excess.”

    Cheers

  6. Mike says

    May 11, 2009 at 6:59 pm

    Tin Man 2 – Bad Dog hails from Canada

  7. Brent Meeker says

    May 12, 2009 at 12:13 am

    I’ll be impressed if he can kick start it (electric start is for wimps).

  8. JR says

    May 12, 2009 at 12:18 am

    Hell you could put this in a small muscle car and it would work quite well if you could cool it under a hood.

    Monster miata anyone?

  9. Ted says

    May 12, 2009 at 3:23 am

    I’m not impressed, O it’s big alright and it will make noise like no other but it’s going to be very limited in what it can do, how they going to get a gas mixture in that big hole and make it anywhere near combustible, 4 carbs maybe? 2 small ones for low end and to big ones or maybe a 4 barrel, how about the induction manifold that would act as a partial plenum, then what about RPM’s, that’s a lot of piston being yanked up and down and then there’s a little thing called piston feet per second, I can appreciate the work and engineering that is going into it but as far as being a functional motorcycle that will put out the power that one would expect,,forget it, just someone with too much money and a lot of time to waste, at least he’ll have a one of a kind bike.

  10. Tin Man 2 says

    May 12, 2009 at 8:22 am

    Mike, Canada, OZ, New Zeland they all seem to put out some great motorcycle stuff. Inovation and individuality seem to thrive there. Isnt Goldammer fron Canada also, probably one of the best builders of our time !!

  11. Bentzra says

    May 12, 2009 at 8:54 am

    cool idea but I do wonder how well it will actually work. That being said I love stuff like this!

  12. Bentzra says

    May 12, 2009 at 9:53 am

    Does anyone here know or have an educated guess as to what kind of HP, torque, rpm range etc this engine might have? I have no real knowledge in this area (aside from stats I read) but I would have to guess fairly low HP (for its size) lots of torque and really low RPM’s.

    Do low RPM’s = low HP regardless of torque?

    ***I am NOT trying to open up the what is better HP vs. Torque issue again, just curious***

  13. Nicolas says

    May 12, 2009 at 11:22 am

    who was talking about the bike that goes its way down the driveway while left idling … wouldn’t this thing jump like a goat across the driveway ? 😉
    I’d really like to see the finished product

  14. JC says

    May 12, 2009 at 12:43 pm

    “Do low RPM’s = low HP regardless of torque?”

    No, low rpm and big torque describes every large marine diesel on the market,a nd by large I’m talking the motors that go in tugboats and larger.

    On a HP/liter comparison, there is no way a big twin is going to compete with a multi-valve per cylinder DOHC motor, but this thing will make pretty good HP due to the fact it’s big.

    I would not be surprised that with a counterbalancing shaft it can turn decent RPM’s as well, it may not be smooth to ride even with that.

    FWIW, there is an unlimited displacement SCTA class above 3000cc, and somebody would be smart to offer a deal on a motor to run it at the Bonneville salt flats. The unlimited class can run two motors, so you could run 7 liters with two of these motors (bigger than a 426 hemi, but not by much!)

    Would be quite the beast to attempt to tame.

  15. hoyt says

    May 12, 2009 at 12:49 pm

    The web can’t get much easier than clicking on a link…check out his site for yourselves with the link the Kneeslider provided.

  16. FREEMAN says

    May 12, 2009 at 4:32 pm

    For those of you interested in the estimated HP and torque numbers, here’s a quote from their site:

    “The Bad Dog 215 is a fuel-injected, sixty-degree air-and-oil-cooled 4-valve DOHC semi-unit V-Twin, displacing 3500 cc or 215 cubic inches. We expect the motor to develop about 300 ft.lb. of torque at 5000rpm. and 300hp. at 6000rpm.”

  17. jokermtb says

    May 12, 2009 at 4:51 pm

    Kinda like the giant Stonehenge from “This is Spinal Tap”

  18. Carlo says

    May 13, 2009 at 8:41 am

    Ted is right, the speed of the piston can’t be that much given the pistons’ size,,, and by not that much I mean VERY slow imho,,, but i’d be happy to be proven wrong,,,

  19. nawitus says

    May 18, 2009 at 5:52 pm

    ‘there is no way a big twin is going to compete with a multi-valve per cylinder DOHC motor’
    My bike is a v-twin with a multi-valve per cylinder DOHC.

  20. Bob Nedoma says

    May 20, 2009 at 12:20 am

    @freeman, re: 300hp at 6000 rpm
    the motor will not survive 6000 rpm, not with those con-rods.

  21. Paul says

    May 20, 2009 at 8:00 am

    Staple that monster on the front of the ACE Cycle Car. You’d have something then. Wow!

  22. Bryan says

    June 2, 2009 at 10:50 pm

    OOooooohh! nice! Simple is the trick! True flat top promotes flame travel over that huge expanse and skirtless design reduces mass (a little). Who cares that the connecting rods won’t live past 5000 rpm. How do you use 175 lb/ft torque on a reasonably sized rear tire?

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