I have a 350cu in a 69 Nova.  The motor used to be hooked up to a th350. On a drive back to college from winter break it started doing some weird things.  The oil pressure dropped and eventually went to 0 according to the gauge, the water temp rose to around 195, and heard some weird noises from the enigine bay.  When I was able to stop and let the motor cool, the only problem I could notice was a rythmic screaching sound from the rear of the motor.  I was told that it sounds like a water pump going out, but the sound wasn't coming from the water pump.  
I took the tranny out because we thought it was the torque converter.  After draining the tranny pan, I found a lot of finite metal shavings in the pan.  I replaced the tranny with a 700r4 to allow for better cruising rpm.  After getting it completely installed.  I got it started back up and it ran fine for a little while and then the sound started again after running the motor for almost 5 minutes.  I checked the oil dipstick and it was almost black.  I'm think either the rings blew on one of the back cylinders or a main bearing has gone.
If anyone has any ideas about what this could be or if it has happened to you, please let me know.  

You can drive a motor hot(195 isnt hot...its about right) but you cant drive a motor without oil pressure and not do un wanted surgery on the bottom end.
Guages dont really lie like we may believe...I never thought that my temp. gauge worked till i threw my fan belt and it hit 255.

Id definitely check out the bottom end before I did anything else. The gradually dropping oil pressure indicates to me that youve probably turned a rod journal and carved up a bearing....maybe not spun all the way if it wasnt knockin though.

The screeching was probably the converter...i dont have a whole lot of experience with trannys..but Ive ruined enough engines to be able to trouble shoot em. My brother has a 350  that squeeks and we think its the distributer...havent figured it out yet.

Just to be safe pull the pan and look for copper dust and then start pullin rod caps....i would. Good luck.

-Shred

I concur with shred. If your oil pressure dropped slowly to 0, and your engine temp rose to (I assume)a relatively high temp of 195, then I'm not sure why you swapped out the transmission. It sounds like you have engine troubles... Definitely pull the oil pan and inspect all the bearings, both rods and mains. Check the oil pump pick-up to make sure it's not clogged. Replace the oil pump and pick-up while you're in there, it's cheap insurance. Hopefully a new set of bearings and a new oil pump will get you going again (assuming that you haven't damaged your crank).

Good luck.

Hey, the problem your having is definitely a main bearing. i had the same problem about 2 years ago. i was on the highway when the temperature rose and my oil pressure dropped to zero. a knock was present in mine. i had spun the no.1 rod bearing. a screaching noise is what a main would sound like. my best advice would be to drop the pan and inspect your main caps. if any are bued or otherwise,you'll know. i hope this was some help.   

thanks a lot for the help everyone.  Yeah, my next intentions were to remove the oil pan and inspect the bottom end.  I'll just have to go into the motor to find which bearings are messed up, main or rod.  

The noise is most familar to me from a few past engines . I had always found it to be a rod bearing. It has spun in the cap or is close to dooing so. For some reason you have too much clearence. This is causing the low oil preasure or the low preasure caused it. Take the pan off and look for a rod cap that is darker in color. This is caused by heat build up. You will need a reground crank ,bearings and a rod on the cheapest way out. I am sure if it sounds like I think the groves in the journal are pretty bad.  

thanks a lo for the help guys.  I finaly was able to pull the motor and sure enough there was metal grindings in the pan.  It ended up being the #1 cylinder rod bearing, it was smashed and ground down.  

I found a replacement motor, but is basically a stock rebuild.  The motor is a 350 with stock punched cylinders(0.020 over)that has stock replacement pistons (flat top with the d-dish) and I was planning on putting my cam, heads, and intake on it.  I have a Comp Cams Magnum 280, Edelbrock Performer RPM Air-Gap, and stock '76 heads off a pickup with 1.94/1.60 valves and are most likely 76cc.  All these parts were on a 350 that was punched .060 over.  What effects would this cause going from a .060 over to a .020 over?  I am running a set of Comp Cams Magnum 1.52 roller rockers, but also have a set of Erson 1.60 roller rockers.  If I installed the Erson's would I have to put screw in studs on the heads and would they affect my performance (the springs are matched for the cam)?  Could I use both for a 1.5/1.6 combo or just use one or the other?  

I was also thinking about putting a 400 crank in the .060 over block, but am worried about the cylinders being no good since there is some wear.  Is it not worthwhile to do to the .060 block since I think it would need to be bored and would call for custom/race pistons and make the cylinder walls too thin since the car is used as a daily driver?  If I was to stroke the .020 block, what is there all to be done to it?  Different pistons, rods, machining  on the block?

I've also heard about putting a 327 crank in a 350 for a wicked combination.  Has anyone had experience with this and what would need to be done to accomplish this?

Ryan

Edited 4/3/2005 3:55 pm by 69novarodr

Go back and carefully inspect the damper. Failures of the number 1 rod can sometimes be linked to a damper that no longer is doing its job. This allows unresolved vibrations to cause the crank end to whip as it rotates. This pounds out the number 1 main, not much, but enough that oil pressure is lost to excessive leakage back to the pan. This oil starves the highly loaded rod bearings of number 1 cylinder with fatal result to the bearing and journal.