I'm going to be dyno tuning a customers small block Chevy tomorrow
![](/ubbthreads/images/graemlins/violin.gif)
I fixed some problems in it including having the crankshaft machine for dual keyways , I replaced the camshaft, lifters, valve springs, rings, bearings, thicker pushrods and so on. I did have the BDS 6:71 blower gone thru and upgraded by Littlefield so it will lmake a lot more boost than before, 7 lbs max with 6 % overdrive at 6800 rpms. I could spin the blower drive pulley by hand and it would spin one or two revolutions by hand after letting it go with a good twist
![](/ubbthreads/images/graemlins/down.gif)
The block is a stock GM four main bolt production block bored to 4.030, the crankshaft is a forged steel stroker, the stroke varys from 3.745 stroke to 3.750, it is suppose to be 3.750 on all of the journals, 383 C.i.
![](/ubbthreads/images/graemlins/shruggy.gif)
I guess we Mopar racers are not the oly ones that get parts to race with that are less than perfect
![](/ubbthreads/images/graemlins/scope.gif)
The mechanical compression ratio is 8.49 to 1 and the cam is [Email]264@.050[/Email] on the intake with .715 net lift and the exhaust is 276 @.050 with .685 net lift and 113 LSA installed at 109 intake lobe center. The heads are a set of aluminum Canfield 23 degree heads, I don't have flow figures and I don't speak Chevorlet so as far as flow #
![](/ubbthreads/images/graemlins/shruggy.gif)
The blower will be ran at 5 % underdribve at first to see what boost the blower will make now and then I will try direct driving it and finally, if it last long enough
![](/ubbthreads/images/graemlins/whistling.gif)
I will reverse the upper and lower pulleys so it will be overdriven 6%. The three pulleys are two 37 tooths and one 35 tooth. the carbs are a set of 850 CFM Pro Systems blower carbs, the ignition is a MSD 7AL2 with the appropriate coil for that ignition. I will probally start with 30 degrees total timing using 111 octane race gas and go from there to see what the motor wants. So take your best guess and I will post the results as soon as I get done tweaking the motor, probally on Monday evening
![](/ubbthreads/images/graemlins/hammer.gif)
BTW, this motor ran 6:60 in the 1/8 mile (2500 ft. ltitude) at 105 mph in a 1970 Nova that is stripped out before it stripped the crankshaft keys out of it, probally wieghs around 3000 lbs with the driver ready to run
![](/ubbthreads/images/graemlins/scope.gif)
The closet guess gets to be the best guesser
![](/ubbthreads/images/graemlins/whistling.gif)
See my last post at the bottom for the update