TPI

Hey guys


I gotta knock.. yep, dont know why, but gotta
feelin' I didnt have any oil pressure.

So..

Im gunna hoist the block up about 4-5 inches so I can
get to the oilpan, need to replace rod bearings; not sure
how many but .. bearings only come in kits, so u do em all.
(is there an easier way to access the pan ??)

My question is: If the crankshaft isnt skored or damaged,
and I Replace all the bearing to specs, will It be the same
or better as a result?? My close friend goes to UTI here in PHX, knows too much and I trust him, says hell check out the crankshaft with a micrometer.

reason I ask is, Ive pulled blocks, put in blocks
but never had to replace bearings.

I dont have the cash to throw something new in her,
and the 350 I have Idles smooth, and strong at low RPM ..
then at 3500-4500rpm its heard, the car desont overheat,
no smokin' at startup or idle and I can reluctantly drive it with no problems. Iam not drving her, I wanna preserve the crankshaft.

ede

i wouldn't lay under the car and swap out bearings, i'd pull the engine. also if there's a knock you have more problems than bearings.

TPI

OK, Knock isnt the best description ..
only thing I can think of ..

what does a rod sound like when It has
play or a bad or spun bearing??

I have no idea.. kinda sounds like a loud tick
more so than a knock.


And then car is fine at idle threw 3500 rpm
valvetrain is good, tranny fine, cooling system
is nice (200 degrees)

I cant just junk it

does anyone feel what im sayen?

sellmanb

what's your oil pressure like during all of this? a loud tick is not a knock, so rest assured from that. You could have a blocked oil passage causing your top end to stop being oiled, thus the loud ticking. You could also have a exhaust leak.

You could also be experiencing pinging, or you could simply be in need of a good tune-up with plug wires, spark plugs, distributor cap and rotors.

I suggest taking off the valve covers and rev the car to the RPM it starts knocking and seeing how the oil flow is. After this, change the oil and filter with Mobil 1 synthetic.

If those two dont look bad but you can still hear it, then do the tune-up. If that doesnt fix it, then I'd hear around your engine, headers or exhaust manifolds and see if you've got a exhaust leak there.

Then reply to the post with results please

Stekman

All I have to say is 2 simple things:

Check the oil presure with a mechanical gauge and stick some heater hose in your ear. Simple, huh?

(you use the heater hose as a form of stethoscope)

TPI

I know what the problem is.

Not exhaust leak, no pinging..

and its not my top end. Its practically new,
no valves ticking,bad lifters,pushrods. I just put synthetic Valvoline 50 weight
and Lucas Oil stabilizer, which shut the noise up
alot, but not enuff

I know where the noise is comming from. Its bottom end.. bearings.

I know how to fix it ..

My question is, if the crankshaft is left untouched
from the bad bearing damage; will my car perform
like it did or better??

would I have to baby it? and While I do this, will the engine be able to handle a new cam??

I just put this engine in. I didnt rebuild it .. I took it from a 88 Vette about 6 months ago .. looked good and sounded great so I picked up on it. Started making it faster and it seemed to respond well to mods .. then a month ago I discover this noise and IAM NOT GOING TO PUT ANOTHER BLOCK IN IT ..

its not that i dont want to .. I dont have cash at this time

and the only reason why I said "tick" is because EDE said if its knockin its alot more than bearings.

But screw that .. the car wouldnt run like it does

sellmanb

You ought to change your main bearings while you're in there and changing bearings anyways I guess.

Since you dont want any advice, I'll just get to what you're asking then.

You wont gain any HP from bearings, it will run just like new (atleast that part of it will). Engine break-ins typically run from 500 miles, to 3000 miles, or anywhere in between. In that time I would suggest not stomping on it... I mean, do you REALLY want to take off that oil pan again? I had to take mine off twice (with the engine in the car still) in a 2 week span. First my oil pump shot, so I replaced that, found out I spun some bearings while I drove w/ the pump only putting out about 5PSI oil pressure (it's a 305, dont worry ) so I had to take it out again for the bearings.


Now I'm getting a short block 350 from a junkyard soon because it costs less and all around makes more sense.

chances are if there's wear on your bearings then you'll have matching wear on your crank journals. If your friend will micrometer them and give them a thumbs-up then go ahead and get the proper sized bearings. Otherwise you'll have to take the crank out of the car, and bring it to a machine shop and tell them to machine them back to proper spec... then ask them what size bearings you'll need.

I've been told to use Federal Mogul for bearings. Clevites have quality control issues, and costumer service issues.

I hope this answers your questions.

TPI

Im not sayin your advice isnt good, its great!

Im not looken for HP gain from bearings!! LOLOLOLOL

I just want my baby back, I miss her


I took the L98 i got from a 88 vette with 112,00 miles on it
500 bucks , its was wrecked

The engine was great, it pulled had MAJOR TORQUE
the engine was solid

So, what yuor sayen is there is no reason to junk a block just because of some bearings??

cause some people tell me u might as well throw it in the garbage because of it .. Which made me upset for weeks!!

Then I met that UTI guy . and things started looken up:lala:

sellmanb

no, you dont HAVE to junk the block because of loose bearings. Though if you have SPUN bearings then you've got metal shavings and bits running around in your oil, and you'll have to clean out the block reaaaaally hard, and probably even have to have it hot tanked, and while you're doing that you've got to change gaskets, might as well put in new piston rings, and while doing that, might as well change the weak valve springs... plus machine work, should have the block decked while it's out and being hot tanked anyways.

Plus, you'll want to put in a new oil pump while you're doing this, it's about 50 dollars. M-55 Oil Pump, M-55A Oil Pump Pickup, SA-55 Driveshaft (I think that's the code atleast), and Mr. Gasket #26 pressure spring is the perfect combo.

You'll espescially want a new oil pump if yours was running with little metal shavings in it.... see why some people think it's just easier to toss a new, or junkyard block in there? heh. But if the bearings arent SPUN, just loose then you shouldnt have metal in the oil and you can just change the bearings.

Bearings ~ 80-90 (rod and mains)
lubes, oils& filters, such ~ 90
one-piece oil pan gasket - 40

That's about what you're looking at, assuming you have all the tools on hand. And you CAN do this with the engine in the car, I was going to, but a new block was more viable for me.

TPI

Your a Saint man.

Im praying on Loose bearings (Engine had low miles)

Since I put an 1988 Vette L98, it didnt exactly match up to the 89 T/A shell .. I couldnt figured out where the sender unit is for
the oil pressure gauge, imma gunna pick up a mech. gauge.


If it turns out I had nice oil pressure, why else would the
bearings mess up?? anyother cuases I should watch out for??

I have a hoist and most of the tools, the UTI guys says
he can do the main bearings and rod bearings (all)
in a weekend.

Turns out he has the same problem with his 4.3L S-10!!!


A guy has been tellin' me that he doesnt think its a good idea to just throw some main bearings in there, but he doesnt tink around with V8s either.

This is my best option, If I had it anyother way id
already have an Ls1 or somethin LOL

sellmanb

if your oil pressure is fine then there's no problem with oil flow at all lol.

Seriously, before you go pulling the pan, atleast do a spark plug (gap them), plug wire, dizzy cap, and rotor tune-up... I have a hunch you arent experiencing rod knock, it's probably SPARK KNOCK... can be confused with knock if you've never heard rod knock before (it's nasty sounding, believe me )... but if oil pressure turns out crappy, just reference to the above post for help.

Stekman

Does it sound like a dull metal on metal thunk that resounds from the bottom center area of the engine?

TPI

Its commin from the bottom ..

Not really a thunk .. but its sound like metal on metal
and repitious

thats why I dont think its Ignition knock.

I can tell there is loss of power when I starts to knock
and hesistantly pulls .. but it does pull (surprisingly)

Stekman

Does a marble bouncing around in a coffee can describe the sound to a better degree?

TPI

hehehe .. I know what your gettin at

forget about it, Its lower end ..

its just doesnt sound like a thunk tho.

Its repitious as hell as gets even faster when the engines
spools up .. "like its moving with the engine"

its metal on metal for sure


its like a tapping noise,

doesnt sound like anything hitting anything hard in there .. but a subtle tapping thats heard easily

Stekman

After all your mind changing, you're still describing detonation moreso than knock.

Plug in your oil sender and check the gauge.

TPI

Not that easy,

I plugged in the sender unit and it jus pinned 60 .. all the way past 60. So, its not reading correctly


It cant be detonation it just cant. IF it is, Id hit myself in the
head with a crowbar, thats how deadset iam on this.


I can feel the vibration when I drive the car
and its comming from the front of the car.

U can hear the ticking even with the hood closed and give it
gas and becomes louder .. but its not thunking.

Stekman

Then pick up a crow bar and get ready. Until you prove me otherwise by replacing your sender with one that a.) works or b.) fits the engine, i am still led to believe detonation.

Hit me up on a messenger and we can talk.

RB83L69

If you have good oil pressure, you probably don't have bearing problems.

It could easily be a dented oil pan being hit by the crank, a cracked flex plate, failed harmonic balancer, etc. etc. etc.

I would not recommend trying to change out bearings while laying under the car. Too hard to keep clean, get the pan to seal, and otherwise do a premium job. You'll spend more time fighting all that, than it takes to pull the motor and turn it upside down and do it right.

But even before jumping to the conclusion that you need to change the bearings, I'd suggest a little more investigation. In particular, check your oil pressure with a real oil pressure gauge (not the trim pacakage in the dash, no matter what sender you hook it up to), and then if it's good, dismiss the bearings from consideration. Then use a heater hose to locate the actual source of the noise. Or, if it turns out that the oil pressure really is low, pull the motor and do it right.

Brett H. - 89GTA

Replacing bearings without align-honing the block and turning the crank sounds like trouble to me. The factory uses select-fit bearings to get the clearances to fall within spec. A set of standard bearings are probably going to give you clearances that are either way too tight or way too loose.

TPI

Depending on how the crankshaft looks.

IF the bearing journals are damaged .. cant I get them machined to a certain size bearing?

If it turns out I got good oil pressure and the crankshaft looks
good .. then the block is good right??!!

The guy thats going to do this with me in my garage didnt seem to concerned with clearance and such. He wants to just jacked the block up to get a nice look at the condition of the crank. IF he likes what he sees and says we can do it, well pulll
it and set it on a stand.

He heard the knock and said it just sound like maybe 1 or
2 bearings

Im getting that mechanical oil pressure guage today .. ill let ya know what it reads and what step were taken next

If it turns out we need to pull the crankshaft out..
Then ill go ahead and do piston rings.

anything else to recommend while the crank is out??

Thanks guys