In Bill Hoddinott's Burkland interview in the most recent issue of
Bonneville Racing News they said they have Vibratec Fluidampers with 4 keys
on each engines and a custom coupler made from "old Lenco parts" between the
crankshafts .
John
> Sparky and others --
> My thought on this is that more torsional dampening in the form of a
> better harmonic balancer might be what is called for. Of course that is
> aside from the issues of misalignment between the two engines and Dave's
> suggestion to put in a 45 degree separation between the two engines to
> smooth out the torque peaks. But be careful with this. Such a proposal
> can double the forcing frequency and put it closer to one of the new
> vibration mode frequencies than you want.
> I do think that I'd want someone else's experience with the coupling of
> two engines as an example to follow or a benchmark. Lacking that I'd
> spend some time relearning the methodology of torsional vibration analysis
> I learned in my mechanical vibrations course some 50 years ago and
> promptly forgot. At the time the hot setup was a tabular calculation
> protocol known as Holzer's method. http://www.sdrl.uc.edu/book/Chap-5.pdf
> Den Hartog, pg 197
> The right contact in the world of engine, turbine or other heavy rotating
> machinery engineering could provide access to modern computerized methods
> for torsional vibration analysis. If you were to get into this your shop
> capabilities would likely make it possible to determine actual spring
> constants and moments of inertia that an engineer with the right software
> would need to begin the calculations.
> Ed Weldon
>
>
> ----- Original Message -----
> From: "John Burk" <joyseydevil@comcast.net>
> To: "LandSpeed List" <Land-speed@autox.team.net>
> Sent: Tuesday, March 23, 2010 5:41 PM
> Subject: Re: [Land-speed] Multiple Engines
>
>
>>I think crankshafts are stout to raise the harmonic frequency and resist
>>bending . For torque capacity think how small the transmission input shaft
>>is .
>> John
>>
>>
>>
>>> List,
>>>
>>> When connecting two engines together at the crankshafts, what is the
>>> best offset to use? My thought is that harmonics should be arranged such
>>> that the rear crankshaft gets as little abuse as possible. Ideas?
>>>
>>> Thanks,
>>> Skip
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