Engine swap in '92 Ultra???

I am having a continuous "knocking" in my 92 Ultra with the SC 3.8. It is not a rod. The noise only appears after warm-up. Different "experts" say it is a rod, some say a wrist pin and others don't know. The car runs great! The noise has been getting louder the last few days. It increases/decreases with the rpm's. Any ideas? So, I am getting ready for an engine swap. I have access to a low mileage regular 3.8 (non SC) from a 1993 Bonneville. What problems am I going to have by replacing the Supercharged 3.8 with a regular 3.8? Thank you in advance......

well first of all, the ECU should not be compatible with the non SC engine...so wiring loom might be diffrent as well..but GM makes things alot the same between models so not sur about that.

the other stuff should fit right in.. the tranny and engine mounts should be placed the same. as for the exaust...

but your gonna lose ALOt of power... if i was you, i'd checked for another SC engine...like a 94 maybe.. still a series 1 but with a bigger supercharger ( eaton M62 vs. M90) with about 20 HP more.. instead of a non SC engine with 170 hp..

im affraid you might have to buy another ECU and fit it if you put that bonnie engine in.

as for your knocking, its hard so say but if its appears after warm up , it cant be good.. so an engine swap/ rebuilt is needed..

dont try to fit the SC on the bonnie engine.. its not built to take it and its not built the same inside.. neither is compression the same coze its not a normally aspirated engine the compression is lowered on purpose to enable boost without detonation.. long story... heheh

deadring

The Engine blocks are the same except for the internals. The SC engine has a lower compression ratio than the non SC motor. So, you would be better off getting a rebiuld jasper motor or whoever is there locally. what is the oil pressure at the motor when warm? I would have someone pop the valve cover off and re-torque all the the rockers.. could be a bad lifter or bent pushrod. let us know...

Not for nothing, But also a bad headgasket would also cause a knock if its firing accross from cylinder to cylinder. If its burned in between cylinders, it will ignite the adjacent cylinder and cause it to knock.. Had that happen on a fresh rebuilt 350 twice.