I'm going to be dyno tuning a customers small block Chevy tomorrow 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 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. I guess we Mopar racers are not the oly ones that get parts to race with that are less than perfect 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 # 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 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 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 The closet guess gets to be the best guesser See my last post at the bottom for the update

630hp and 600ft/lbs....

667HP, and run 6.44 back at the track with a gain of 4 mph

if you can get it on one of those go dyno machines it should "show" over 700 HP real easy with 7 lbs of boost. realistically will probably make around 640 hp and 590 ft lbs.
it sounds like you fixed a lot of problems.

One suggestion----the engine really needs a methanol injector---manually actuated---it helps to keep the engine "happy" in traffic and also produces a little more HP.

The engine specs is very close to my son's GMC truck engine---a few more inches and a little less boost. His blown 355" produced 720HP on the Superflow, his 5000 lb. truck ran 7.0/101MPH with mufflers and street slicks at the local track---and then he drove it home!

ole Cab's getting to be a regular GM guy

a lot can be said for good heads so here is something.

What will it make?






Not enough.

I got the motor onto the dyno and was not able to make any pulls do to the owner not supplying all of the linkage to operate the carbs. I had ask him for it several times before Christmas and once after that. Other things have been happening that had distracted my attention away from that project so I didn't realize it was missing until we treid to hook up the throttle cable today I was able to manually operate the throittle to get the motor started and set the timing and check the boost at 4500 rpm, it made 12 lbs I need a smaller pulley to keep the boost below 12 lbs for bracket racing, I would like to see him have around 8 to 10 lbs. max at 7000 rpm to keep the motor safe and easy to tune on the local race gas, 111 octane supposidly I'll post a "What it made" post when I get the parts needed so we can attempt to make some actual pulls and results and then tune it. I finally got to make some pulls on the SBC blower motor, it made 727 HP at 6900 RPM with 11.1 lbs of boost, it made peak torque at 5200 RPm with 652 ft lbs peak. The blower is under driven 5.6% and it did not get hot even with several back to back pulls, the blower case never exceeded 130F Over all I'm pleased with the results, sorry for taking so long to get them posted

any intake temps takin?
for them to not bring the linkage is stupid!