If you took a 350 SB with
Comp Magnum 292H cam
Edel Victor Jr intake
600cfm Holley carb
WP Sportsman II 72cc 2.02/1.60 200cc heads
mechanical fuel pump

And then you hooked up a NOS Super Powershot kit with the 100hp jets installed and went out and ran about 6 bottles of NOS through it with the timing set at 48deg???

I would expect a spun bearing at least with that kind of timing, NOS or not. Whats your compression?

Even without the spray-48 degrees of timing should have rattled with detonation without good fuel. Normally a 100 shot will not do too much harm--if the engine tune up was ok. Did you burn any sparkplugs? You should have noticed a problem with the engine running after the first 2 bottles. If the thing still runs after 6 bottles you still need to look at things to see what is hurt. Figure most of the damage will be pistons and rod bearings. If nothing has happened let me know, I need a tuneup that runs at 48 degrees with no broken parts!

Compression- guessing about 9.1 but we don't know what pistons are in it.The carb is a factory replacement Holley w/ 62.2 main jets in it.The idle screw was almost all the way tuned in and the pump lever was almost all the way locked down.But the weird (or weirder I should say)thing is that when we pulled the plugs out, they were pig rich...And one of the last times he ran the bottle out of Nos and hit it again with just air in the lines, the motor ran better than than normal w/out NOS....

No broken/burnt up plugs, he said it never knocked,and his MSD Pro Billet was set with the largest bushings (28 deg) of mech and his initial was 20-22deg :eek:

I'm dumbfounded cause the reason he wanted my help was to help him get the stumble out of his carb off-idle, other than that he said it was "perfect!!" graemlins/thumbsup.gif

MSD Pro Billet was set with the largest bushings (28 deg) of mech and his initial was 20-22deg


The largest bushing will have 18 deg mech IIRC.

Top of his rod bearings might be fried. They'd look blue almost. Then there are the top rings to dwell on. :eek: Hopefully his balancer marks are way off, or he's run against the odds and won. For now.

I'd say if he really did that with pump gas that things wouldn't be too happy in the bottom end.

Maybe the MSD isn't a Pro Billet then cause the instruction sheet he has says that 18 is the lowest bushings and 28 was the highest...

speaking of dwelling on the rings...
Last night we decided to use the air compressor to air up the cylinders to see if they would leak any.Not only could we hear the air coming out of the cylinders,when we first shot the air in the motor it actually spun the motor a 1/4 turn or so.. :eek: graemlins/thumbsup.gif

has it ever burnt the electrode off??

Originally posted by 1968 hot rod:
has it ever burnt the electrode off?? Not that I know of, he says they were just black...

Lowest # bushing should equal the largest bushing. I'm not going to go and dig up my instructions. That's just how distributors work. If you restrict the motion of the adv plate, you lower the mech advance.
If your running the largest physically bushing, or 18*, then you will have about 38* total. Which could explain why the motor still works.