Cam chain tensioners

Randy Grein randygrein at
Sun May 17 14:26:43 PDT 2009

Um, I think you're forgetting that KC HAS done a lot of the testing  
out there, especially if conjoined with that done by Factory. I'd be  
interested in seeing charts too, but this isn't the first parasitic  
loss analysis I've heard from reputable builders. Dan Zlock showed me  
his electric waterpump. Testing on the Zlock Dyno showed a 1/2 HP gain  
just from switching from stock to electric; there's no free lunch but  
it would seem that the stock unit is sized to pump the right amount of  
water at normal speeds which is way more than needed for racing with  
the average RPM being doubled. .5 HP isn't much in a superbike motor,  
but the little improvements add up. Add in any windage and oil splash  
improvements, etc and you can get a fair bit of power without reducing  

Randy Grein, WMRRA #41

On May 17, 2009, at 12:55 PM, Beth wrote:

> On Sun, May 17, 2009 at 12:35 PM, KC Gager <kc at> wrote:
>> The testing we have done and Marc @ Factory showed more like 3 but  
>> I like to
>> not over state....i think u all would be amazed at what drag cost  
>> you on a
>> motor. Rings cam chains grears water pumps grears oil valve trains  
>> and the
>> list goes on...and it all adds up.
> KC,
> My educational background is in math and physics. While I am not an
> engineer by formal education or licensing, I have enough understanding
> of frictional losses to question that a whole 2 HP is lost to the
> tension the automatic cam chain tensioner put on the chain alone. That
> is not to say it my hypothesis is incorrect, and I'll happily accept
> empirical data collected using proper methodology. Since there is, as
> you understand, a myriad of things causing losses in an engine, one
> needs to isolate cam chain tensioner as much as possible via very
> controlled testing conditions.
> I'll see what's published out there already on teh intarwebs. :) The
> SV engine is well documented and a known quantity.
> -Beth

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