So after a long weekend of putting in a new power booster, master cylinder, bleeding brakes, changing oil, etc it had to happen. Started up the car just like always and I hear a noise, not just any noise but a bad noise. It wasn't in one spot kinda sounded like it was bouncing around, so decided to take out the spark plugs and found two pieces of metal that looked like a clip in piston number 8. Took them out and had a friend who was a master builder on motors come by and check it out, of course it sounded fine and he even said, "sounds like a strong motor". So after that decided to change the oil in the car and take it on a test drive, well thats when everything got all screwed up. After changing the oil I started the car and Bam! Loud knocking noise started to come from the motor that when along with the RPM's! WTF!!!!! So all in all looking for suggestions on motor swaps in this thing, I'm not real familiar with 371's or even Olds for that fact. Was thinking of going with a 350/350 combo bc parts are easy and cheap, still plan to take out the motor and do a slow rebuild on it, but in the mean time still want to drive the car. So this is where I ask the all mighty HAMB people for some advise and suggestions for motor swaps or just anything at all, thanks guys!
Me? I would pull the head and see what is stuck in there. Could be a piece stuck to the head that you can't see. Worst part of the job is not breaking the exhaust manifold studs/bolts. it would be a ton less work than a swap, if it is just trash that fell in the carb. in the meanwhile, you could pull out all 8 plugs and hand turn the crank to feel if there is a piece hitting, as it goes to TDC on that cyl. You should feel a tight spot.
Keep the 371. The 371 is as good of an engine as any. Goatroper (sp?) can vouch for this and is one of the go to guys when it comes to these older Olds mils.
Also a 350/350 will not just drop in. You will need to change engine mounts, fabricate a drive shaft at the very least. So why do all that and make it harder to put the 371 back in?
If it's any consolation the Cad 500 I just put in my 71 GMC ate something that didn't agree with it with similar results. On mine I am thinking that a lock washer or other small metal object got stuck to the bottom of the carb when I had it setting on the bench and fell down the intake. I've got to bite the bullet and pull the intake and head and that is what you will need to do too. Then see how much damage has been done and go from there. I know that there is a mark on the #8 piston in my engine and that cylinder has 25 lbs compression while the others have 150 straight across. On mine I think I have something stuck under one of the valves or a bent valve to deal with and hopefully little or no damage to the piston or cylinder.
Take the head off and see what the trouble is. Could be all you need is 1 piston and maybe a valve and you are back in business. Without even taking the engine out. Of course if the cylinder is scored that is another matter. But no use borrowing trouble when you can find out the facts in a couple of hours.
I've got any part stock or speed for the 49-64 Oldsmobiles that you could possibly need...... Tony Posted using the Full Custom H.A.M.B. App!
Thanks guys! alot of good info from you all, I started to spray down the bolts with some liquid wrench so when it is time to take off the bolts they wont just break off. I am going to keep the motor and rebuild it in time. Well looks like its time to take her apart again, and damn those heads are a heavy *******!
Pull the head and see what it is. No crime to pull the pan and replace one piston, if that chunk turns out to be what's left of a ring. Did that with my '67 Caddy 'vert when it started knocking. A piston skirt was cracked, pushed it out, replaced just that one, and drove it for years until we could afford to rebuild it.
If you're worried about the manifold bolts, leave it on the head. Much easier to work on it the bench where you can reach everything!
I had a 289 Ford eat a 5/16" nut. Squashed it flat and broke the piston, bent a valve. I was in high school so I coundn't afford a rebuild.1 piston 1set of rings 1 valve a gasket set and and oil change got me going again for another 15k miles till I could afford a rebuild...... something for you to consider any way. And there isn't as much of a cool factor with a 350 imho
+1, we used to do that in the shop all the time. It's quite a lump though, so be careful. Try getting yourself a cheap borescope and have a look before you do that.
I hate doing anything twice. First I would check what a rebuild kit would cost vs a sbc, then go from there. Also keeping in mind, eventually the trans may go and finding someone to rebuild that old trans, plus the rarity of parts, a 350/350 combo may start to look pretty good. Especially if your plan to drive your car a lot and for long distances. The old "Slim Jim" in my Pontiac went south and it supposedly only had 3K miles on it. The ears on all the clutches broke off. A friend of mine said that often times, a rebuilder will just use the old clutches when rebuilding an old trans. My trans guy said the parts alone will be more than a 350th if he can even find the parts. I went with an adapter and a 350th in case it ever breaks down again.
The Jalopy Journal
