SanitariumTour0

OK. First some history on the engine. I've had my car for about 3k miles so far. The engine has been leaking oil and burning oil pretty bad at times. I let the oil get a little too low once or twice which probably hurt the engine pretty bad. Well today I wasnt driving it hard and the oil was fine. It just all of a sudden was bucking a little and a LOUD knock from the engine. It stalled out 3 times as well. I started it up after a few tries and the engine knock is very loud and gets a little quicker with higher rpm's but it stalls quick. The power steering and brakes also seem to have gone out or are hardly there. My guess is a broken rod or lifter but Im no expert. I'd like some of your opinions as to what it might be and what I can do to fix the problem. I will be taking the valve covers off tomorrow to look and see for any problems. Let me know if you need to know anything else to diagnose it. O BTW, it is a 350 tpi and is stock.

SanitariumTour0

ttt

SanitariumTour0

so no one knows what it could be or what to look for? Im going over to my friend's house where it is in about 30 minutes so I hope someone has some input before then. Thanks

kevinc

Doesn't matter what it is, the engine's coming out:

1.) spun a bearing: engine coming out
2.) seized a piston: engine coming out

I'd whip out a compression gauge and see if you can narrow it down to one or more cylinders.

SanitariumTour0

Hmmm so it could be that bad then? If it is either of them, can I just put in a new piston, or all completely new ones? Or can I just replace the bearing that got messed up? A whole rebuild would probably be best though I would assume. While Im fixing that, I mine as well fix the oil leak and burning problem as well too. Keep the replies coming please.

90Formula-X-F

Spun bearing more than likely. I'd have to say it's done....

SanitariumTour0

you mean the engine is done as a whole and not worth rebuilding? or what do you mean? What would you suggest I do or save off the motor then? Should I just junk it and buy a new one? Problem is, I only have about 800 bucks right now so whatever I do has to revolve around that. BTW tho, my dad and I can take apart the engine and do the rebuilding sort of work ourselves so that will save the cost of getting someone else to fix it.

kevinc

If you spun a bearing, pistons won't fix it. The crank's junk, block's usually junk due to all the localized heat. Spinning a bearing is where the shell actually welds itself to the crank, spinning it within the bearing saddle and building up enormous heat.

You should be able to pick up a used short-block from the junkyard for under $500 easily, shop for a '96-97 truck 350 "Vortec" and you'll have a good bottom end. Upgrade the cam slightly, have your old heads rebuilt at the local machine shop, and you'll be back on the road better than before.

kevinc

You still don't know what's wrong, so nobody can say for sure if the engine's toast. If it's knocking it's coming out, you can diagnose what failed during teardown. If you spun a bearing it will be pretty obvious. If not, and things are just worn down, you can have the block and crank machined and rebuild it.

Again, if cost is a factor a junkyard late-model 350 shortblock and reusing your heads is the cheaper path. Most 'yards put a 30day or more warranty on their parts, so if the "new" engine knocks you can take it back.

SanitariumTour0

OK thanks for that info Kevinc. That gives me more insight as to exactly what Im going to have to do with the engine. Now with this late model "vortec" engine, will it have the L31 vortec heads or what is so special about it? Im pretty set on eventually putting together an engine that uses the Holley Stealth Ram setup, but will use my ported TPI system for the time being. Ive heard that the HSR doesnt bolt up to the vortec heads. So would my intake and all bolt up to this new block or not? Im kind of in the dark when it comes to these things. Would it also be a good idea to put a ZZ4 cam in at the same time? I've been looking at that cam for a while and I like the comments everyone has on it. If I can stay under 1200 or so for most of this rebuild/new engine, I'd hope to do that. Hopefully you can give me a few more answers to this too. Oh...I almost forgot, is this only 2 years (96-97) that Im supposed to be looking for the truck engine? IF that is the case and I cant find one, will most any late model 350 be pretty good for my budget and getting things back together close to the same way? OR will I have to buy a bunch of adapters and other junk?

SanitariumTour0

One more question. Sorry. I have been toying with the idea of a 400 engine for a little bit now. Would it be wise to build up a very mild 400 engine for now? By next week, I'll have about 1200 or so to spend on an engine so maybe it wouldnt be a bad idea? Or would I just run into too much cost and hassle?

SinthetikIroc

iTrader: (1)

save up a lil more and get a 383 short block from gm

SanitariumTour0

well dude i would but guess what? I work at Pizza Hut. Money doesnt come easily. Plus this is my daily driver. Im using one of my parent's cars right now but I would also like to get it on the road ASAP instead of it sitting waiting for money to SLOWLY pile up. Anyone else?

kevinc

Short block = no heads. Just the block w/ the crank, rods, pistons, cam, and timing setup. You'd be reusing your current heads, which a Stealth Ram will bolt up to. If you go long block (short block + heads) you'll have the Vortec heads which won't bolt up to either your current intake or the Stealth Ram.

What's special about is that it's a late model block with relatively low mileage potentially, and has provisions for a roller cam. Easier upgrading later on.

kevinc

For $1200 starting out, you won't have anything left over for decent heads upgrading to a 400ci engine. You'll chew up pretty much all of that just on a used 400 block and crank, plus the machinework and new parts to rebuild it. There's no such thing as a late-model 400 waiting in the junkyard that could be pulled and used.

As for the 350, pretty much all of them from '88 up have the basic roller cam provisions and 1-piece rear main seal but may need minor machinework to drill and tap the three holes to hold the lifter retainer in place...nothing serious.

SanitariumTour0

Hey thanks again Kevin. I will definately be taking your advice. So you think I should get the 96-97 truck vortec engine or just any late model engine because of having less miles and wear and tear on it? Usually however I think most junkyards kind of sell their engines pretty much complete. So if I get one like that, I can take the vortec heads off and sell them right? Or are they not the same thing I hear everyone talking about on the message boards? We should be towing the car home tonight I think so maybe tomorrow I'll be able to find out what is wrong with it.

SanitariumTour0

ttt

kevinc

I already answered most of this above. The heads are real Vortecs and can be sold as such for a few bucks.

With truck engines you stand a better (but not certain) chance of getting 4-bolt mains and roller cam with reuseable lifters.

RB83L69

Whatever you do, DO NOT get a truck engine that's not a Vortec, even if the junkyard guy tells you it's "almost as good". It's not.

Avoid saying the word "Vortec" when talking to the junkyard. They will instantly recognize you as a hot-rodder and will charge you more because they think they'll be able to get it. Just say you need an engine for a 97 truck, and you won't accept anything but the right motor for it.

Yes you could sell the heads; or you could kep then and use them.

SanitariumTour0

OK well the engine is torn apart. Something happened to one of the pistons. The side of it is missing pieces and on top a little bit. There were small pieces of it on top of all the pistons on the one side. And then there was some coming up the one runner. Now that I found out exactly what it is, now what should I do??? Does that mean I can just get away with new pistons? OR do I need more than just that? I need to know what I need quick because if that is the case, I can spend money on actually making it a performance engine instead of just a rebuild. It looks as though the engine might have been rebuilt sometime before I bought it because everything looks relatively nice inside. My dad said it looks like it had a hone job on the cylinder walls too. Well guys let me know what is next so I can start rebuilding. Thanks!
Almost forgot something...before all this happened, I ran the car pretty hard before I got to work cuz I was trying to show off at a corvette show. I noticed that the overflow tank for the antifreeze was overflowing and leaking out everywhere. So what exactly happened?

Soulrev

Umm, when you say "torn apart" do you mean the motor's sittin on your garage floor with the crankshaft sitting next to it, all the pistons taken out, etc? Or do you mean the motor is sitting in the car, with the intake and heads removed? Cuz if it's sitting in the car with the intake and heads removed, it sounds to me like you threw a rod. I'm willing to bet if you pull that motor out there's probably a chunk of cast iron missing from the side of it. Although you mentioned the sides of some of the pistons so I'm just going to assume you have the motor out and totally torn down. As for the coolant, that's from overheating. It was overflowing because it was boiling, which if you had a 50/50 mixture of water and antifreeze, that means that motor got WAY too hot.

As for saving the block, 99% of the time when a motor blows up like that, yeah, you might be able to save the block, but it's not worth it. By the time you got it magnafluxed and machined and dropped all kinds of money into it for a new rotating assembly, etc. you're gunna end up paying more for used junk than you would to just go out and buy another. I know you said you've only got about 800 to work with but if you can scrounge up more your best bet would be to buy a new shortblock and reuse the heads (after you get the heads checked for cracks). When it comes to junkyard motors, personally I don't believe in spending a dime on one.. Yeah sometimes you can find a good deal but you really know nothing about it. Especially if your car is your daily driver, you're going to want something you KNOW is dependable.
Also I've yet to run into a junkyard that puts 30 day guarantees on anything. I dunno, I'm sure there's some out there like that, but the 6 junkyards in my general area don't work that way. Usually it's "as is" and no returns accepted.

And finally, the power steering and brakes not working is just because the motor isn't running.. Don't worry about em.

SanitariumTour0

Hey thanks for the reply. Everything is out and on my garage floor. I definately blew a piston ring which is what happened. That was also what was causing my blowby. The only thing damaged is the one piston though and it looks as though the engine was rebuilt not too long ago. When I talked to my dad some more, he said that the deck was already bored .030 over and had a comp cams 262H cam in it. So I have more in my engine than I new about. Whoever did the rebuild did a crappy job on it. There are 3 different kinds of pistons in it and some of the rods are stamped different numbers than what they used to be. I think it failed because of a REALLY poor rebuild before I got the car. So you still think I cant get away with keeping the bottom end? To be on the safe side and if I had a bunch of money, I'd say I should but money just doesnt allow for it. I need this car back on the road. I know most of you will think Im stupid for doing it that way but I almost have to do it right now.

kevinc

If you dad thinks a deck can be bored, I'd say go get a junkyard longblock rather than trying to rebuild it w/ his help.

Decks are flat surfaces and get milled. Bores are cylindrical and get bored.

SanitariumTour0

sorry that was my fault...im just getting into engines...so he knows what he is talking about.

ChevTech84

SHORTBLOCK......... OIL STARVATION MAY HAVE ALSO WORN THE
VALVE GUIDES PRETTY BADLY SO I WOULD HAVE THEM CHECKED AS WELL. ITS LIKELY THAT THE CRANK/ROD BEARING ARE WIPED
THROUGHOUT THE REST OF THE MOTOR, SO REPLACING THE ONE THAT SPUN MAY JUST BE A BAND AID. ALSO THE CRANK JOURNAL
MAY BE DISTORTED IF YOU CONTINUED TO DRIVE IT AFTER NOTICING THE NOISE.

SanitariumTour0

OK I'll check that stuff. And Im not sure if you read the rest of the post, but it was a piston ring that went and then subsequently it looks like part of the piston was gradually being destroyed. So I guess unless that hurts the crank/rod bearing too then that shouldnt be a problem. After noticing the noise, I ran it for no more than about a mile to get to my friend's place. I then started it up about 2 or 3 times to check where the noise was coming from, so I hope that didnt mess up anything too bad.

ChevTech84

Does the bore the piston that had the damage came out of have any scuffing? Do the bearings have a copperish color or cracks in them? I beleive I read somewhere that you also over heated the engine badly in that case warpage and cracks could occur in the
block and heads. Do not reassemble the engine without checking
this stuff out, unless you want the practice of taking it all back apart again (I say this from countless experiences). I still am heavily favoring a short block and head check. The time and money you will spend on rebuilding your engine will do nothing for your situation but make it more confusing.