Hallo to everybody !
About a year ago I did an engine swap ( a rebuilt 350 for a 305 / TPI / the rebuild made by a professional engine-builder ). Some weeks ago, the engine started to knock a little bit, oil pressure wasn´t as high as suspected, and now the knock is really loud and makes me very, very nervous.
Today I pulled the oilpan and checked the main bearings ( only one, because it already gets dark outside ). I never saw a new bearing, therefore I´ve no comparison, but I don´t think this looks okay ( see attached picture ).
What should I do now, do I have to pull the engine or can I pull the crank with the engine still in place ? What could be the reason for this ?
Thanks for your help,
Uwe

 

Hmm, where is my picture ??? - Shouldn´t drink too much ...

 

time for a rebuild bro, your bearing has grooves and pits. the crank is probably also grooved. a rebuild is probably the way to save a lot of work later on a half rebuilt motor... looks like bearings on a motor lacking oil changes frequently

i just went thru all this on mine and now mine is knocking but its coming from the torque converter or flywheel area.. surely not the rear main bearing.. hasnt gotten worse and hasnt gotten better but i had to drive it home 65 miles with no loss of pressure or power.. just knocking like athe dickens.. well see

 

Hi Conrab,
as I mentioned, this is a rebuild engine, about 4000 miles since, first oil-change after 500 miles, then after 2000 miles. Oilpump is new, too. What exactly do you mean with the term "spun bearing".
Thanks for yout quick reply,
Uwe

 

That bearing is DESTROYED. But it probably isn't the one that was knocking.

It is a victim of metal shavings in the oil.

Something in that motor has disintegrated, probably one of the rod bearings. The pieces of metal in the oil cut all those grooves in that one.

 

TTT
Nobody answered my second question : Is it possible to pull the crank with the engine still in the car ? - If not, is it possible to pull the crank without removing the pistons ( and the heads ) ?
Thanks,
Uwe

 

a crank can be removed with the engine in a vehicle, been part of that surgery in the past, but I can't say it will be easy in a thirdgen. it was a bitch in a full size lifted truck. by the time you remove everything to get the crank out, and lift up the engine, disconnect/slide the tranny back, might as well just pull the motor out. and you can remove the crank with the heads and rods in, it just requires care and time...done that chore, too.

 

Thanks a lot, Phil. Then i´m going to pull my engine tomorrow. I´m happy to hear that i don´t need to touch my heads.
Uwe

 

Thanks a lot, Phil. Then i´m going to pull my engine tomorrow. I´m happy to hear that i don´t need to touch my heads.
Uwe

 

Hallo , there I am again, with some more questions : I have the crank out ( don´t know how to get it in again with all the pistons and rods still inside ??? ), all the main bearings are destroyed, main-1 worst, main-5 least. The rod bearings don´t look that bad (see picture ). The crank journals have the same scratches as the bearings. I have no spun bearing. What could be the reason for that happen ? By the way ... I tried to turn the cam by hand ( crank removed ), but no chance, even with the sprocket as a handle. Is this normal, are the valvesprings so strong or are my cambearings destroyed, too ? .
Any suggestions for my further actions ???
Thanks,
Uwe

 

That bearing looks fine.

They start their life with a very dull finish of some kind of soft grey metal. Wear makes them shiny.

Scratches in the bearings = metal shavings in the oil. There is no other explanation. This is a bad thing.

The oil passages in that engine go from the oil pump, around various places at the back of the motor, up across the back to the rear cam bearing journal, around the outside of the cam bearing through a groove cut in the block, and from the rear to the front of the engine in a passage that is just above the cam. If you look at the front of the block behind the cam gear, and at the back of the block around the rear cam bearing behind the flywheel, you will see 3 plugs; the one above the cam is the end of this passage. (The other 2 feed the lifters on each bank.) There is a vertical hole drilled from underneath, through the cam journal hole, and up into that passage, to feed each main bearing; and a similar groove behind each cam bearing, to connect the 2 halves of the vertical passage. The rod bearings get their oil through holes in the crank that align with the ones in the block as it rotates. If you have metal in the oil, then it is hiding behind the cam bearings, in all those grooves; and it will immediately destroy a new crank, just like the one you have now. I'm afraid you have to take the whole thing apart and have it cleaned thoroughly, to get all those metal shavings out of it.

I don't think you will be able to do this with what you have, because of the metal in the oil; but it's actually not hard to put a crank back in with the rods already in the cylinders. All you do, is put rubber or plastic tubing on the rod bolts, and guide them over the crank journals.

 

Incidentally, you need to find where the metal in the oil came from; if it didn't come from one of the bearings, then it came from a cam lobe. If so, you need a new cam too, and then find out why the motor ate the cam. Usually it's because the heads were assembled incorrectly, in particular the valve springs weren't set to the correct installed height, or they were the wrong valve springs.

 

Thanks, RB. No good news. Don´t know if it´s worth it. Here in Germany it´s hard to get the right parts for exotic cars. Perhaps I should look for a new engine. ( Or for a new car )
Uwe

 

It shouldn't be that tough getting parts.... no doubt some of the mail-order places will ship internationally? Speaking strictly for what it's like over here, parts for German cars are sometimes expensive or only available from a few sources, but they're not rare or impossible to obtain.

I would not recommend selling the car in that state, with a blown-up engine, as it will be almost worthless. That would be economic suicide.

It's really not that hard to rebuild the engine. All of the machine shop procedures and that sort of thing are largely the same for American engines as they are for European or Japanese ones. You can get any info you need from right here: specifications, tricks of the trade, etc. Don't give up on it.

How much metal is in the oil? Is it large enough pieces to be able to see it? Is there a damaged cam lobe?

 

Don't give up, man! It's not that hard to order all needed parts at once; you just need to know what to buy - you won't unless you disassemble the engine and find the reason source of shavings. Then start examining all potential damages (crankshaft, cam/lifters, oil pump are the first things that came to mind).

Single parts are less expensive in Germany (overseas shipping is $$$), but combined orders are lot cheaper when ordered in the U.S, just don't bother with crank - if you're not going to buy aftermarket one, then better find a good core locally or at ebay.de. 45 lbs package costs a lot!

Make notes of all things you're not sure of, ask here - lot of knowledgable and helpful members will advice you. Then you can make a wishlist

Make sure you've included new bearings (yeh, the ones for camshaft too), gaskets and rod bolts if they're still stock. How do your motor mounts look?

While waiting for new parts to arrive - clean and prepare block for assembly, take a look into engine bay - it's easy to fix problems with rust, wire harnesses etc.

 

RB,
thank you for encouraging me. My rebuild engine doesn´t even have 5k miles on it. During that time I did an oil-change 3 times. The oil looked a little foamy, discoloured ( hard to describe, a mixture between red, brown and gold ). I didn´t see any (!!!) metall pieces in it, but it was very thin. - The engine is a 1987-block, my TPI-stuff was from a 1985-block. I had to modify the intake. At first I thought coolant was mixed eith the oil, but my coolant-level remains constant. My cam lobes are looking fine. ( Is it normal that you can´t turn the cam by hand without the crank ??? )
Uwe

 

Just an idea... some aftermarket timing kits with double row chain require grinding in the front area of the block - they're wider than factory setup. The metal shavings might come from chain or sprocket rubbing the block.

 

Z,
good idea, i have to check that tomorrow. But at the moment I have no chain installed ... and can´t turn the cam manually.
Uwe

 

IF the heads are still intact, then you cant turn the cam because the weight of all the valvesprings are pushing against the pushrods, which are putting pressure on the lifters, which sit on the cam. In order to turn the cam, you have to compress the springs,etc. Not necessarily easy to do with good springs and by hand

 

man that sounds weird hearing a chevrolet called an exotic car ..lol..doesnt it ..but over here the german cars are the same way i guess just never thought of it ..lol..we take for granted what we have over here in plenty ....we all need to be thankfull that 305/350 chevy parts are so cheap around our areas guys..

lol

 

i wouldnt mess with doing any thing half-assed if you have a motor full of metal shavings. anything less than a full rebuild would not last. that doesnt mean you wont be able to salvage alot of parts. pull the whole thing apart, hot tank the block and and start inspecting for wear and measuring clearances. find what caused the problem in the first place and remedy it and replace everything that doesnt meet spec. everything will have to be cleaned meticulously. there are some good books that explain the whole process like chilton's rebuilding small block chevy book. follow it to the letter and you should be ok.

 

Damn, and I tought Italy, Germany, Etc. made exotics... never new we made any here... If I were you I'd turn my attention to what part actually failed.. if the metal shavings arn't from a failed component I would then turn my attention/violent rage toward the builder/machine shop that did the work...

 

Okay, intake and cam are out. The cam lobes and bearings don´t show any signs of wear. Question : My Chilton´s manual says that the cam bearing holes have to be at certain positions. If thats true, then mine aren´t installed the right way.
Some other things I found ( which I don´t know if it´s normal ): 1.) The screws from the cam sprocket (double) are scratching the inner side of the timingchain cover. ( By the way, how is the cam secured not to travel to the front ?? )
2.) The opening in the heads, where the pushrods are moving, are ... hmm, how to describe ... "eggshaped" . All of my pushrods are not aligned to the middle but are grinding at the heads. ( I compared that with my old 305 laying in my garage, and there the pushrods are right in the middle of the openings )
3.) This was my own fault : I stripped a thread in the head when boltiing my oldstyle intake on, and the threads probably fell into the engine .
Sorry for the long text ( and the bad english ), but with your help I´m sure to get my great car running again.
Thanks,
Uwe

 

1. The cam gear bolts should not be rubbing the cover. If this is a roller cam, there should be a retainer plate holding it in place; if it's a flat tappet cam, tehn the lobes are ground at a slight angle, and the lifters are pushing it rearward. Plus, the distributor ger (loaded by the oil pump) is trying to pull it into the block.

2. Older heads used slots in the heads which fit tightly to the push rods, to guide the rockers. Newer ones use little "rails" on the tip of the rockers, and the push rod is free to wander around in the head to wherever the rocker takes it. Both alignment systems work well. You can only have one of them in effect at any one time, however: either you have to use the new-style "self-aligning" rockers and have large holes in the heads, or you must use old-style rockers and the narrow holes. ONE AND ONLY ONE. There is also the guide plate method of aligning them.

3. Probably not an issue.

Look to see if you have rockers with either completely flat tips where they meet the valve stem, or little "rails" to hold the rocker centered on the valve. I'm guessing you have the "rail" type rockers. If so, the metal in the oil may have come from either the push rods being forced against the heads, or the rocker tips.

 

RB,
thank you for confusing me - Some data of my engine may help perhaps : block casting=10054727 / heads casting=14101081 / crank casting=14088535 / cam casting=??? ( the only numbers I see are 14 and 838 ). My rockers haver roller tips with 1.6 ratio.
Are these the right rockers for the heads ?
Uwe

 

RB,
thank you for confusing me - Some data of my engine may help perhaps : block casting=10054727 / heads casting=14101081 / crank casting=14088535 / cam casting=??? ( the only numbers I see are 14 and 838 ). My rockers haver roller tips with 1.6 ratio.
Are these the right rockers for the heads ?
Uwe

 

It sounds to me like the "pro" who rebuilt your engine isn't too familiar with chevys.
The source of the metal shavings might be the cam bolts hitting the timing chain cover, but the filter should remove that. Unless it's plugged up, then it will bypass dirty oil into the system.
Something to watch out for too is all the places where particles can "hide" after a block is machined.
Once I took a block in to be decked after the cam bearings were put in. I'm glad I decided to replace them, cause there was some grit in the grooves under the cam bearings.
That's just one example of where shavings can become lodged.
If you have any machining done, the block should be completely disassembled and cleaned afterward.
Take your used oil filter and cut it open to check for metal particles.

 

These heads (081) are designed for use with SA rockers - the rockers should be guided at the valve tip. I'll try to include a picture of SA rocker tip.

edit: the one on the right side is SA rocker arm, if your heads aren't equipped with guideplates then these arms are required...

 

do you have flat-tappet lifters or roller ones? Roller setup needs a retaining plate under cam sprocket (or cam button) to prevent camshaft from moving forward and rubbing timing cover.

 

Z,
i have flat tappet lifters, no roller cam !!!
Uwe

 

in fact:

14088843 - FT, 202/206 @.050, 115 lsa, .403/.415"; 1983-86 305HO

I've been thinking about those cam bolts rubbing; if the crank sprocket isn't seated properly (pushed deep enough onto crank snout), then it "pulls" camshaft forward trough timing chain.
This could happen also when crank sprocket is put wrong side - it fits only one way, at least mine does.

 

Z,
thank you for the mail, I got the picture. My rockers look like the one on the attached picture. The other drawing shows what I mean with the pushrod-openings in the heads. The left one is the actual situation ( pushrod not in the middle of the slot ), the right one shows the situation on the other engine which appears better to me.
By the way, where did you get the casting number #14088843 from ? If that´s true, I have a 350-block with 305-heads and 305-cam ??? - You could be right with the assumption that the "professional engine rebuilder" wasn´t very familiar with chevrolets.
Uwe

 

Your rocker arms do not have the rails; so they are the correct type for the heads you have, with the slots.

If the rockers are 1.6 ratio, then the push rod will tend to be at the end of the slot closer to the rocker stud, because in order to create the higher ratio (stock is 1.5) the push rod end of th erocker is shortened compared to stock. The slots are often not long enough to accomodate this. There is a little tool that you can use with an electric drill to elongate the slots. Look very closely at the push rod seat in all the rocker arms, and at the slot in the heads; if you see any unusual wear at either of those places, the slots need to be elongated. In my experience, about half of all heads will need this.

Using those particular 305 heads on a 350 is not necessarily a bad thing. Sometimes people do that intentionally to increase the compression.

There's no real "difference" between a 305 cam and a 350 cam, other than the factory's choice of which motors they put them in. They fit the same. I don't see where you're likely to have the 843 cam, but if you do, it's not too bad of a choice for a TPI 350. There are far better ones of course, but again, it's not "bad". It's certainly not the cause of your problems.

The cam bolts will sometimes rub the timing cover just from hard braking, or an accident. They will also tend to rub if the builder used washers under the bolts (not stock), or used a lock plate (also not stock). Either of those things usually requires an aftermarket timing cover.

Post any numbers or letters you can find on the end of the cam. As long as you have the engine apart, it would be smart to choose a cam that will work the best with the rest of the parts you have. There is a HUGE variety of them available, from a large number of manufacturers. Cams are quite cheap and can make a big difference to how the engine runs.

 

Okay, there I am again,
I stripped my motor almost completly down. ( Exception : Cambearings, because I have no clue how to get them out, and more important how to get the new set in. The right tool costs over 400 Euros here in Germany ). Pistons, heads, pistonbores ... everything looks fine. I don´t know, where the metal in my oil came from. The main bearings and the crankjournals are destroyed, the rodbearings and cambearings look fine. What causes the loud knock ??? - Should I remove the cambearings to look into the hidden grooves although the bearings look okay ?
RB => All numbers and letters I found onto my cam : 14 - 838 + GM D1 ( or DI ) CWC ( or GWC ). Can you tell me, what cam I have ???
Thanks for your help, guys
Uwe

 

RB is right about the rockers, there have been some 1.6 rockers that have caused the pushrods to hit the guide slots if the heads or block have been machined. When you reinstall everything turn the engine over twice (intake and exhaust strokes) to check EACH pushrod clearance. Take a good close look at the main and rod bearing surfaces in the block (or rod), where the bearing mates against it. There should be no shiny or scratch marks there to indicate the bearing moved around. You REALLY, REALLY need to find out where those metal chips have come from, otherwise you're gonna have the same problem. I would recomend that you just toss the oil pump, it has to be junk by this point.
I have seem some guys install the cam bearings and then machine them to fit the cam, the old guy who taught me to build engines (this was in 1974) told me that if you install them correctly, that shouldn't have to happen. The reason I mentioned that, is because that may be where the metal came from.
When you put the engine back together, use a product called plastigauge to check all of the bearing clearances, this is a simple way to make sure the machining is done correctly, and does take some of the guesswork out of it. (it is not super accurate, but it will help you spot potential problems). DO Not, spin the engine over with the plastigauge in it. The other item is that whenever you install anything, spin the motor over to make sure that it's not binding. For instance, you install the crank bearings, plastigauge them, take them apart to check the 'gauge, clean them and reinstall them. As you torque each main the final time, crank the engine over by hand. That way, if there's a problem, you only have to address what you did last. Same way with each piston/rod assembly. The biggest problem I've seen with cam installations is guys over-tightening the lifter adjustment and wiping out cam lobes. Assuming that you're using a relatively mild cam, special break in springs are really not needed. But, you do need to crank the engine over by hand while priming the oil pump until you see oil running out of all the rockers, and use an oil pressure gauge as well. It's better to find a problem this way, than with the motor in the car. I used to use Crane cam lube, which is a moly based grey crud, I later discoverred that this was hard on the bearings, (great for the cam lobes however) lately, I use Melling cam lube which is red in color, seems to stay put and is more oil-soluable. Coat the cam with that, then put white lithium on the bottom of the lifters, put it all together and pour STP over the whole cam lifter assembly. I know there is a million other ways to do it, but this has worked flawlessly for me, and will buy you a little insurance if the engine doesn't start immediately. One other thing, clean everything twice, and use a pressure washer to blow out all of the oil passages, blow both with and aginst the normal oil flow, use a washing detergent (such as Tide over here) and hot soapy water to clean everything, then do it again. You may have to block different bearing holes and what not to direct the oil flow while you're doing this. Coat everyting with a rust inhibitor (WD40) when you're done, but, clean it off of the bloc/rod bearing (mating)surfaces with lacquer thinner before installing any bearings. Clean off the back of the bearings as well. Just wipe the bearing face clean, don't put chemicals on it, put some oil on the face of it (remember, you already checked it for clearanc eby this point) and torque it, twice. I hope that helps, It's not hard to build an engine, it just takes patience and time to do the job right.

 

Blacksheep,
thanks for you answer. What do you recommend : Cambearings remove or not ? - And what do you mean with "STP" ??
I still have no idea, where the heavy knock came from. My bearings did definately not spin. Perhaps the engine-rebuilder was the culprit of the whole problem, not having the engine properly cleaned.
Uwe

 

You will have to remove them I'm afraid, they're very hard to clean behind. Let me ask you this, what does the bearing surface look like?, if their is any "brass, or copper" color showing? If so, they should come out. You also need to know if they're indexed properly with the oil grooves/slots behind them. They don't have to be perfect, (this is hard to explain, there are several different types of cam bearings out there) a competent engine prep guy should be able to figure it out. Usually, over here, the engines are sent out, cleaned/machined and we get the block, engine bearings, rings, crank, etc already machined. Then it's up to the builder to reclean and to recheck clearances, and then assemble it properly. Normally, at this point the cam bearings are installed in the block, and rod/pistons are already together, but not in the block. Make very sure, on disassembly, that you mark the direction and the spot where all of the mains and rod caps, etc. go. STP is similar to "Wynns" or "Lucas" these are very thick oil supplements. I don't normally use them, except for reasons stated.