Help - Found something in my oil pan

[WIDESIDE72]

Originally Posted by snipescastle2

I'm surprised no bent valves, or really crazy backfiring.....

SBC engines are not "interference" engines like a lot of other (mostly 4 cyl import) engines. Back in the day, my brothers and I had several 70's GM cars and trucks that we would buy out of peoples back yards, pastures and driveways that were abandoned due to the polyester timing gears stripping out. We would drop the pan, clean the plastic teeth out of the oil pans and pickup, swap an aftermarket cam/ lifter (comp 268H was a favorite) and timing set in, button it back up and drive, or flip for a few bucks. Even sold one Malibu back to the seller for $500 profit!

[Norgermish]

Originally Posted by WIDESIDE72

SBC engines are not "interference" engines like a lot of other (mostly 4 cyl import) engines. Back in the day, my brothers and I had several 70's GM cars and trucks that we would buy out of peoples back yards, pastures and driveways that were abandoned due to the polyester timing gears stripping out. We would drop the pan, clean the plastic teeth out of the oil pans and pickup, swap an aftermarket cam/ lifter (comp 268H was a favorite) and timing set in, button it back up and drive, or flip for a few bucks. Even sold one Malibu back to the seller for $500 profit!

For the most part you are right about the non-interference issue on chevy SB, unless it has a big cam or 2.02, 2.08 or 2.10 intake valves. Although I have seen stock 350's with bent intake valves due to timing chain issues and/or floating valves. The lower compression engines don't have the problem but the early flat tops and factory performance engines can and do bend valves because of piston valve clearances. Don't think it is an issue with this one though.

[Norgermish]

A sloppy chain can cause broken teeth without it jumping time. Jumping on the throttle with a sloppy chain puts undue pressure on the gears and can easily break or crack a tooth. Like when the neighborhood dog ran out of chain when it tried to chase you. A cracked tooth will wear and eventually separate from the gear. Depending on when the tooth breaks off in the revolution it may or not jump time. If the tooth comes off before other teeth as it pulls the chain through, the broken teeth get lodged or bound up between the gear and chain and often break other teeth and jumps time. If the tooth breaks or comes off near the end of the travel of the chain on the gear it will fall away down into the pan...all is variable.

[enaberif]

This is what your timing gear will probably look like at least your upper ... I show this picture to everyone to show WHY you need to replace these gears..

http://i.imgur.com/qF8Guro.jpg

[mechanicalman]

Originally Posted by enaberif

This is what your timing gear will probably look like at least your upper ... I show this picture to everyone to show WHY you need to replace these gears..

http://i.imgur.com/qF8Guro.jpg

Those broken gear teeth appear to be all metal no nylon, in 68_Step picture.

[68_Step]

Originally Posted by mechanicalman

Those broken gear teeth appear to be all metal no nylon, in 68_Step picture.

Yes, all metal

[GRX]

Good call replacing the rear main seal while in there. They can easily be installed backwards so be sure the lip is installed facing front of the engine. Oil pressure exerts against the lip forcing it to seal. Also apply a thin layer of RTV between cap and block as shown in this GM service manual. Some attention to detail and you will be seep free for some time to come.

[jjzepplin]

On the rear main seal you don't want to put the seal halves flush with the block. Leave one side about an eight of an inch out of the block. Then apply the sealant and the cap. That way the break in the 2 piece seal is not right in front of the break in the main cap. Seal will be clocked just a bit. It seals better this way.

[68_Step]

The teeth look like they are from a timing gear, but luckily not this one. The current timing gears are not missing any teeth. Looks like the leftovers from a past timing gear replacement.

[jjzepplin]

Yup-that's been replaced along the way. I would still check the pickup for further debris!

[GRX]

Good to see yours are not the cause. Would this be a good time to point out
that those are actually sprockets and not gears? Maybe not.

[68_Step]

Originally Posted by GRX

Good to see yours are not the cause. Would this be a good time to point out
that those are actually sprockets and not gears? Maybe not.

But timing gear sounds soooooooo much better than timing sprocket!

[GRX]

Originally Posted by 68_Step

But timing gear sounds soooooooo much better than timing sprocket!

So true. Sprocket kind of makes you think bicycles.
Hate to admit it, I have gooped up a couple timing covers after bending over the inner lip to get it back on. People don't like to think about dropping the pan after replacing those stupid nylon tooth timing sets when they break.

[mechanicalman]

Originally Posted by GRX

Good to see yours are not the cause. Would this be a good time to point out
that those are actually sprockets and not gears? Maybe not.

Well played, sir. (with an English accent). LOL

[swamp rat]

Did you check the timing cover yet to see if they bent the lower flanges to get the cover off and on?

[68_Step]

Originally Posted by swamp rat

Did you check the timing cover yet to see if they bent the lower flanges to get the cover off and on?

Will check that this morning

Buddy: Will for chain marks too

[mechanicalman]

Originally Posted by 68_Step

Will check that this morning

Buddy: Will for chain marks too

You can get a nice, new timing cover really cheap. Cheaper at Summit but you would have to wait almost a month. You MIGHT have to stack some water pump gaskets to keep the water pump from touching, but that would not stop me. It's a good, heavy cover.

http://www.jegs.com/i/Milodon/697/65502/10002/-1

[buddy_1]

I have seen chains so loose that they wore a hole through the front cover. Since your fixing leaks and have the cover off. Check the inside of the cover for wear marks/holes from the chain rubbing on the passenger/slack side. Buddy

[slikside]

sub'd

[68_Step]

Bottom of the timing chain cover is a bit gobbered up and the inside has scratches on the right side (pass)

[mechanicalman]

Originally Posted by 68_Step

Bottom of the timing chain cover is a bit gobbered up and the inside has scratches on the right side (pass)

Not so bad, but new is so reasonable. Resist getting a chrome one, a little harder to keep sealed but not impossible, 1pc pan gasket is the key factor.

I like to put a thin smear of silicone between a chrome cover and the gasket with nothing on the engine side of the gasket, but I like to bolt it on ahead of time and tighten the bolts just enough to squeeze the silicone out of the sides then give it time to cure. You can then remove and put a thin smear of hylomar or brush on copper-coat on the engine side of the gasket (or nothing if it's a new cover) before tightening to specs.

If in a hurry, use copper-coat spray on both sides, let it dry (does not take long especially in the sun). This works best on a new cover that has never been distorted or straightened. Do not over-torque.

[leddzepp]

If you use a chrome cover, scuff the mounting surface with some fine grit sand paper. It will make all the difference in the world getting it to seal up.

[68_Step]

I have a Milodon timing cover and oil pan - my pan looks like it was on a rock cllmber.

Since the cover is new and not chrome do I use gasket sealer?

I have a one piece (thick front seal) Felpro oil pan gasket do I use gasket sealer?

[mechanicalman]

Originally Posted by 68_Step

I have a Milodon timing cover and oil pan - my pan looks like it was on a rock cllmber.

Since the cover is new and not chrome do I use gasket sealer?

I have a one piece (thick front seal) Felpro oil pan gasket do I use gasket sealer?

Not on the pan gasket, unless felpro says to and I don't think they do. I'd put a tiny dab of silicone at the bottom of the timing cover gaskets where they meet the pan gasket and maybe spray copper coat on both sides of the timing cover gasket, but new cover I'm sure you could put it on dry and no leak just don't over-torque and distort it.

I just like spray copper coat LOL. It also acts as a preservative.

[GRX]

Look for a wear groove on the balancer. If so you will need a speedi-sleeve.