View single post by Ron Earp
 Posted: 04-30-2006 12:07 pm
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Ron Earp



Joined: 03-12-2005
Location: Cary, North Carolina USA
Posts: 339
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The hp figures are healthy and if on the mark would be really strong, but the torque suprises me even more, at around 84 ft/lb per liter! 

Getting more than around 80 ft/lb per liter is extremely difficult to do with a motor.  Even very modern 4 valve designs using variable camshaft timing and/or variable valve lift, such as the E46 M4 3.2L 4 valve six is at 81 ft/lbs per liter and Honda's S2000 2L 4 banger Wondermotor is at 81 ft/lb per leter too. 

Most 4 valve engines, like say an arguably less technically advanced 4 pot like the Yamaha designed  2ZZ-GE built by Toyota and used in the Toyota Celica as well as the Lotus Elise/Exige puts out around 122 ft lbs with 2L, or about 60 ft/lb per liter.  Nice write up on those motors here and the reason I mentioned it is I've been looking at it since my racing buddy Jeff has ordered a new Lotus Exige, lucky dog. http://www.sandsmuseum.com/cars/elise/thecar/engine/toyota.html

Are your dyno plots from a engine stand type dynometer? And what sort of SAE procedure were the numbers taken under, it can make a big difference.  I don't supposed we'd be lucky enough to have rear wheel hp/toque figures for the combination? If the little Lotus 907 will produce torque at levels of 60 ft/lbs per liter I'd be pretty happy, but really excited if it'd produce more and I'd need to duplicate some of your combination pronto (might be a little cheating there!).  I imagine my output will pale to yours, but without a common procedure between the methods,  comparison and conclusions will be difficult to make.

Last edited on 04-30-2006 12:23 pm by Ron Earp