i swapped in my 357 and it has no power it is slower than my old worn out 305 i can hear a slight knock in the bottom end towards the front of the motor the engine runs pretty smoothe and it revs up quickly. my check engine light is not on. it runs great but when i drive it it has no power. i think a geo metro would beat me in a race right now. my question is can the slight knock in the botom end cause the knock sensor to trip without throwing a code? i know when the knock sensor trips the computer takes out timing to try to remove the knock. i think that is where all of my power is at but i am not sure. i am going to check my oil pressure on sunday.(my gauge does not work right now) any ideas?

 

Did you do anything for ECM tuning for the increased displacement?

 

no i did not think that the .040 bore would hurt anything the major difference is the compression. would i have to tune for that?

 

It's not the .040" overbore, but the change from 305 to 350.

 

i replace the the ecu with one from a 350 with the 350 prom so thats not the problem.

 

Make sure nothing it banging up against the bock or the car maybe.
At the shop in my school we had a work van come in and it was running horrible when it was droven but was fine when it was parked. Turned out the latters on the top of the van would shake the hold car and the knock sensor would trip and retarted the motor.

And if its not that you might have spun a bearing i think im not the best of diagnostics but im just going with past events that have happen to ppl i kno.

 

Just wanted to eliminate the obvious.

I'd say get a scan of the knock counts. If you have an audible knock, it could be causing problems.

 

will the knock sensor throw a code? i have no codes showing up.

 

That i kno of no it will not throw a code unless the it has gone bad

 

ok thank you all for the replies i am removing my motor tomorrow. i will replace the rod bearings and check everything else hopefully it will run better when im done. does anyone have the torque specs for everything? i need the rod caps, timing chain, cam retainer bolts, torque converter and any others you might have.

 

These are all in FT POUNDS these come strait from a General motors Computer program that my shop class uses to rebuild engines there for 305 and 350s with vin code L

Cylinder head-65
Intake manifold-30
main bearings caps-70
connection rod caps-70
Exhaust manifold-20
Flywheel bolts-60
camshaft sprocket-20
torional damper bolts-
waterpump-60
oil pump-65
clutch pressure plate-35
water oulet-30
oil pan-12