What seal leaks first on an overfull 350?

Let's say that a hippy put 6 quarts of oil in his/her 350. Theoretically, what seal would leak said oil out- front main, rear main, pan, valve covers...what?

Not that I did this....and then replaced my oil pan gasket 3 times...and then replaced my front main 2 times....and then replaced my pan, timing cover, pan gasket, timing cover gasket, timing cover seal, and harmonic balancer...and the whole time refused to stop filling it back up with 6 quarts. I'm just posting this question for a bud.

Thanks....for helping him figure this out.
-B.

Your bud is a moron. Why would he do something so stupid.
Overfilling by one quart should not really cause anything to leak if all your, oops, I mean his gaskets are new and properly installed. What he might run into is some more oil than normal being whipped around the inside of the crankcase. This could make an poor gasket or seal show itself more readily. Tell your bud to pull his head out and take a breath.

The crank whipping the oil can help break the oil down sooner and make it foam...doesnt lube well as foam...can be hard on he assembly if there is alot of it on the crank as it can change the balance of the setup...like mud on a wheel...the faster you go the worse it is...
On a slightly related topic...
I once worked in a store where this guy came in and bought 5 quarts of oil....few minutes later he comes back and buys 4 more...then he comes back and asks me how much oil does his motor take? Well this 25-30 year old had poured all the oil into this thing already and since the oil wasnt up to the FILL CAP, he figured it wasnt full.......had no clue what a dipstick was....all he needed was a mirror and he could have seen one!!

Brianna: probably the mains. I still say your damper and seal aren't in sync. Otherwise, it wouldn't be leaking there....

My frined appreciates your help. What he did was replace all the bearings and as a precaution he filled the filter with a bottle of STP, then added the 5 quarts to the crankcase figuring that the extra 1/2 quart wouldn't matter much, but would help upon startup.
Then, after running the motor about 10 minutes and seeing that it all went fine he took it out on the highway and ran it for a mile or 2. Upon returning to his shop he noted that the rear main (that he just replaced) ws not leaking, but that there was an oil leak from the front of the motor. So he replaced the pan gasket thinking that it had been installed bad. Filled it back up with 5 quarts. Ran it and there was oil all over the front again. Figured that he installed gasket #2 wrong agian and so he redid it.
Same thing. 5 quarts back in, no need for a new filter since it hadn't ran much. Leaked from the front. Stumpy got frustrated, replaced the seal around the harmonic balancer, and the pan gasket. Same thing.
Stumpy then got a whole new pan, a new timing chain cover, and a new harmonic balancer and installed them all last saturday.

Same thing- no leak at low RPMs, but at 3K or so it starts to leak from around the harmonic balancer. Seal was oiled, harmonic balancer was oiled. Harmonic balancer is new, and the right size.
Runnig 2 PVC valves. All cylinders show good compression.
When the motor is running and the oil fill cap is off there is no noticeable positive pressure.
Chain is new....timing cover is a GM factory one with the bolt-on timing tab. Harmonic balancer is an Autozone deal..but new and all.

Anyone got any ideas? I'm sick of leaks.
-B.

"I'm sick of leaks."

Maybe the motor is sick of him abusing it and its spitting at him out of spite...sorry thats all I got for him...cept maybe ill fitting parts or irregular surfaces that need to be straightened or machined/smoothed/cleaned....

All kidding aside- The most probably theory I have heard is missalighnment with the crank snout and the hole for the seal. Is that possible? Wouldn't that make the motor eat the bearings quick? When I installed the main caps I double and tripple checked them and there wasn't one that was not seated right or anything like that. And my oil PSI is higher than it was before the bearing install.

I got a new bearing, a harmonic balancer installer (I had been using all-thread, but it kept stripping) and tongiht I'm gonna regulate and then tomorrow I plan to drive my new non-leaking motor to work.

I blame Brute for all this as his negative thoughts have tainted the project,
-B.

Brian: before spending any more of The Jeaner's grocery money, take a breath and reflect for a moment. If it's only leaking around the timing cover, what does that tell you? That something isn't sealing there. Since it's not a complicated assembly, the only deductions can be A. The timing cover isself ain't stuck on right, or B. The front main isn't sealed right, or possibly C. There is a mismatch betwixt timing cover seal and harmonic balancer shaft. (not unheard of w/parts store... parts)

Let me know what you find, SuperSleuth. No more spending until the cause is determined. Throwing money at it hasn't helped yet, has it? hheheh

Tacoma,

Your logic is good. I plan to take the harmonic balancer off again tonight and then 1) look to see if the crank snout is centered in the gasket, 2) make sure the harmonic balancer had no rough edges that possibly ate the seal, and 3) replace the seal.

I guess that I feel that A) 3 harmonic balancer seals can't be bad, B) I took off the timing chain cover 2 times now and at least one of those should have been reinstalled right, and C) that this is simple and I am a moron.

I wonder if none of my motor works work because:
1) I have limited experience assembling a motor,
2) I rush through said installation
3) I demand perfection and if there is one drop leaking I rush to replace a seal
4) I am a moron and should have been drown at birth
5) I get the parts from cheap sources (Autozone, Ebay, found behind the mall)
6) The people I get advice from secretly hate me and want me to fail for their amusement.

Sorry. I realized that this thread is veering into BS. I'll do better.

Anyone else have any advice. What I'm looking for is "This once happened to me. It was because of XXXXXX and when I realized it I did XXXXXX and felt sooo stupid. Glad I'm not the only one!"

Thanks all,
-B.

Brian: I've had a few SBC's leaking due to worn balancer snouts. Parts store.. parts can vary in quality, as can their seals. Your plan is solid, and I wish you luck this time.
1. limited experience just means you have to go slower for a while.
2. Don't rush, you get out of it what you put in. As in, I took my time and didn't have to retorque head bolts. Patience, grasshopper.
3. Perfection is a good aim but unachievable.
4. No argument here, and even your mom agrees with me. Sad. But yes, veering into BS hahah
5. Again, you get what you pay for, not always a bad thing to pay less though.
6. Sure it's amusing to think of you taking off your oil pan 3 times, but I'd like your truck to run. So I can drive it and convince my wife I can't live without a topless.... truck.

There is also the possibility that you have a mismatched pan/timing cover. Until I think '74 or so chevy used a thin front pan to cover seal . Later they changed to a thicker seal. Most gasket sets come with a diagram to show how to tell which one you need as well as both seals. anyway, if you use the thin seal on an engine that takes the thick seal it will dribble when oil starts slinging or if OVERFILLED. May not be it at all but something to check. Some gasket companys offer a one piece seal/pan gasket for pre 85engines. they are expensive but seal great.

Brian,

HAHAHA!

I know on certain engines that you are supposed to have a tool that centers on the crank snout and holds the timing cover in perfect alignment. I figured the SBC was modern enough to not need that tool. When I ran into that problem on a flatty, I put the balancer in position before snugging up a few timing cover bolts, then removed the balancer and finished the rest of the bolts.

The reason is that the holes in the timing cover allow enough play that the cover can move about a bit when you're installing it.

Why do you have 2 PCV valves? I hope you don't have one on each valve cover.

Chris

Chris that's a good point, coming from you... anyway, that's a good tip there... forgot about that one, as it's usually a done deal AFTER THE MOTOR"S INSTALLED! but this is B we're dealing with here.

On chevy there are two dowel pins in front of block that align timing cover.

That's what I figured Dave. Brian probably thought the dowels were roller bearings and put them on his rockers - voila - roller rockers!

Chris

Brian,
One more opinion for you. Once you pick the proper front pan seal size (the black rubber one) for your pan/timing cover of course is this. The paper or cork gaskets need to be glued to the block first. I use 3M weather adheasive. Then the front and rear seals get stuck on. I use silicone at each corner where the seals/gaskets meet with a little bit of 3M in the middle to hold it on.

I wrote this out because, if you are putting the rubber seals on the block and glueing the gaskets to the pan and then bolting the pan on, it will leak.

I hope your balancer sleeve work did the trick.

Have you narrowed it down to a seal or a gasket? The harmonic balcancers can get a ring worn in them and a parts store sells a very thin sleave that slips over it called a ready sleave or speedy sleave...something like that. If it's gasket, are you allowing the gasket cement (Black RTV, I hope) to set up? If not, gaskets will move. Other thing...are you PCV's in the correct way? They are one way valves in if in wrong will not let the engine vent...remember when you were pushing out intake gaskets? I think by now you should have a real good grasp on installing gaskets and I'm leaning toward crankcase ventilation being the problem. 3000RPM on stock motor parts and breather is a bunch. You're to the point where you need to either get a pair of racing valve covers with a pair of big breathers on it, or accept a leak. OH, also on the rear main you wanted to try and get just a little RTV between the ends of the seal so that oil can't get between where they butt together.

Then, there's guys like me. Having never had the facilities with which to rebuild an engine in, I've never had the oppurtunity to put one together. This is probably the reason that when it came to putting a new engine in my 67' M715, I deferred to an expert.

All En masse-

Last night I removed my new balancer, and measured the distance around the crank snout. It was centered and even, so that let me know that the timing cover was not skewed. I replaced the seal with a new one, and this time really greased it up good with assembly lube. I then put my balancer back on using my new-fangled installation tool that made the work a snap. I had greased the balancer too.
I started it up and let it idle at 1500 for about 10 minutes and it didn't leak a drop. I was wiping off the already leaked oil as the motor ran and (in a moment of stupidity) stuck my finger in the bellhouseing. A tooth on the flywheel must have snagged my middle finger and now I have a split nail.
I was pleased that the motor isn't leaking, and hope that under load and at 3K it won't leak.

Spicer,
I agree with you about the venting contributing to the leak. It seems to me that I have more problems with gaskets than I should. I have retrocatively taken your advice and today I am to recieve:
http://cgi.ebay.com/ebaymotors/ws/eB...ME:B:EOAB:MT:6

Thanks guys for all your help!
-B.

Nice covers!...a bit of nostalgia there. Expect the lower edge of the breather cover to get oil damp from blowby mist.

I want a BBC JUST so I can get a set of those covers.... a la The Yorwath Coach