Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

[RobOp]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

OK.. sounds like you have crankcase ventilation covered.
By the sounds of the reman tag, the crank installed was either pristine, or new.

Is there a possibility that the timing cover is not holding the seal square to the crank? In other words, either the cover was stamped incorrectly, or is pushed in, and the seal is biased in one direction. Do you happen to notice 1 part of the seal getting chewed up in peticular (top, bottom, left, right) or is it pretty much the entire seal getting chewed up equally?

When I slip the seal installation/alignment tool over the crank and on the seal it seems to slip right over the seal and fits perfectly flush and centered.

The last time I pullled the balancer the seal was not damaged, although it was still leaking profusely. How can I test for excessive crankcase pressure?

Again it only seems to leak when the engine is under load at cruise speed, would that indicate a crankcase pressure problem?

 

[RobOp]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Might be a dumb question... are you using a coat of oil on the seal to lube it up? Sounds like they are going on dry, if they only last a few minutes.

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The seal and balancer are dripping with motor oil when I put the balancer on.

 

[90stingray]

The seal and balancer are dripping with motor oil when I put the balancer on.

Well... I had to ask.

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[RobOp]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Are you sure it's leaking at the seal and not a pin hole rusted through the timing cover?

I'm not sure of anything, but the engine is a Mercruiser reman dated May 10th 2010, it looks new! It was installed in September 2010 and I bought it in November, just after the warranty ran out. I'm not sure but I think the engine only has 10 to 15 hours on it.

 

[90stingray]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Get a different timing cover and give her a try. I would also attempt the runout check with your dial gauge. That magnetic base can surely stick to the engine block...

 

[Pete104]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

$.02 more. Are you sealing the balancer? They have a full key slot.

 

[RobOp]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

$.02 more. Are you sealing the balancer? They have a full key slot.

I don't understand what you mean by sealing the balancer. Is there something I'm not doing?

 

[joewithaboat]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

I don't understand what you mean by sealing the balancer. Is there something I'm not doing?

Oil can work its way out the wood-ruff key slot then out from under the bolt... sometimes

Can you post a pic of the chewed up seals?

As far as something cheap and easy... you might clean the engine well and add a bit of uv die to the oil. Get a black light and check to see if oil is possibly coming out some other near by place.

UV die at parts store, cheap black light bulb from Walmart or kraft store.

 

[RobOp]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Here are a couple pictures, one is the last seal that got chewed up, the other picture shows white paper towels under the front of the engine and what the resultant leaking spray is doing. That is from about 30 minutes of run time. Keep in mind it will not leak in neutral, even at 2500 to 3000 rpm, it just leaks under load.

You can see it is being slung and sprayed by the balancer. I've thought about the uv die but as you can see when it leaks, it goes everywhere! I'm not 100% sure but I'm thinking it is either leaking from the seal or running down to the balancer shaft. The belts and pulleys stay reasonably clean, the spray seems to stay behind the balancer. There is no oil coming out from the front of the balancer.

 

[Thalasso]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Here are a couple pictures, one is the last seal that got chewed up, the other picture shows white paper towels under the front of the engine and what the resultant leaking spray is doing. That is from about 30 minutes of run time. Keep in mind it will not leak in neutral, even at 2500 to 3000 rpm, it just leaks under load.

You can see it is being slung and sprayed by the balancer. I've thought about the uv die but as you can see when it leaks, it goes everywhere! I'm not 100% sure but I'm thinking it is either leaking from the seal or running down to the balancer shaft. The belts and pulleys stay reasonably clean, the spray seems to stay behind the balancer. There is no oil coming out from the front of the balancer.

View attachment 127335

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The cover dosen't appear to be on straight. It looks like it is to far to the right.

 

[RobOp]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

The cover dosen't appear to be on straight. It looks like it is to far to the right.

That is an illusion, when I put the seal insertion/alignment tool on the crank snout it seems perfectly centered to the seal.

 

[RogersJetboat454]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

The last time I pullled the balancer the seal was not damaged, although it was still leaking profusely. How can I test for excessive crankcase pressure?

Again it only seems to leak when the engine is under load at cruise speed, would that indicate a crankcase pressure problem?

As long as the hoses and elbows from the valve cover to the flame arrestors are clear, that should be adequate enough ventilation for the crankcase. You also said you pulled the elbows off, and were able to listen. That tells me the rubber grommets in the covers are open (some grommets come from the factory closed off, and you need to cut them open when using them for a breather or PCV valve). I suppose if you really want to eliminate the thought of crank case pressure you can pull the oil cap off while someone else is driving the boat and see if the leak stops. This may make a mess, and should be done under full supervision of you while the cap is off.

Like Joe said, to be 100% sure on the seal leaking, I would hose it down good with brake clean, pour in some engine oil compatible UV dye, and watch to see where it dribbles out with a black light.

As far as checking runout on the crank, I would pull the balancer and timing cover. Reinstall the balancer, and see if you can sneak a dial caliper behind the balancer to it will ride on the surface that the seal normally does. Harbor Freight sells a dial caliper that clamps on with a vice grip (no messing with a magnet). I was able to get mine for $28 with a 20% off coupon.

Dial caliper;
http://www.harborfreight.com/clamping-dial-indicator-93051.html

Coupon;
http://www.bestfreestuffguide.com/File:Harbor.PNG

 

[RobOp]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

As long as the hoses and elbows from the valve cover to the flame arrestors are clear, that should be adequate enough ventilation for the crankcase. You also said you pulled the elbows off, and were able to listen. That tells me the rubber grommets in the covers are open (some grommets come from the factory closed off, and you need to cut them open when using them for a breather or PCV valve). I suppose if you really want to eliminate the thought of crank case pressure you can pull the oil cap off while someone else is driving the boat and see if the leak stops. This may make a mess, and should be done under full supervision of you while the cap is off.

Like Joe said, to be 100% sure on the seal leaking, I would hose it down good with brake clean, pour in some engine oil compatible UV dye, and watch to see where it dribbles out with a black light.

As far as checking runout on the crank, I would pull the balancer and timing cover. Reinstall the balancer, and see if you can sneak a dial caliper behind the balancer to it will ride on the surface that the seal normally does. Harbor Freight sells a dial caliper that clamps on with a vice grip (no messing with a magnet). I was able to get mine for $28 with a 20% off coupon.

Dial caliper;
http://www.harborfreight.com/clamping-dial-indicator-93051.html

Coupon;
http://www.bestfreestuffguide.com/File:Harbor.PNG

I wish it just dribbled out, it does not seem to leak when in neutral, even at higher rpms, then when I get out and cruising it sprays all over the place.

I will procure that Harbor Freight dial indicator setup and check run-out. How much run-out is tolerable?

On the same subject, I just had a friend mention something; this engine may have only had a couple few hours on it when I bought it, the rings may not have seated yet. The first thing I did when I got the boat was to put Mobil 1 synthetic in it. I'm now told this was probably not a good idea, I may have excessive crankcase pressure because the rings are not seated yet and the synthetic oil may be delaying the ring seating process.

Does this sound possible?

 

[RogersJetboat454]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

I will procure that Harbor Freight dial indicator setup and check run-out. How much run-out is tolerable?

I wouldn't think anything more than a couple thousandths is tolerable.

On the same subject, I just had a friend mention something; this engine may have only had a couple few hours on it when I bought it, the rings may not have seated yet. The first thing I did when I got the boat was to put Mobil 1 synthetic in it. I'm now told this was probably not a good idea, I may have excessive crankcase pressure because the rings are not seated yet and the synthetic oil may be delaying the ring seating process.

If you are that worried about using synthetic, then switch back to conventional. With a couple hrs on it, the rings should have started to seat. Is the engine huffing any oil out the back? Do the plugs look oily? Like I said before, with basically wide open breathers (as opposed to a fairly tight PCV system), the crankcase should have ample ventilation. Try pulling the oil cap off while your underway if you don't think it's enough, and see if the leak stops.

 

[joewithaboat]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Have you ever had the timing cover off ? I think i would try a new cover or drill the dowel pin holes out on that one and use the seal tool to center it while tightening the bolts down. Check the crank as well while you are in there. I would think you could spin it over with the starter to check it. I'm on board with only a couple thousandths as Rodger said.

 

[scoflaw]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Just like a water leak, you've got to get your face in there, up close, and witness the actual event. Lose the belts so you don't get hurt.

 

[RogersJetboat454]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Lose the belts so you don't get hurt.

OP's got a leak while cruising. I wouldn't run this engine underway with out the circulatory pump doing it's job.

 

[joewithaboat]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

The more i think about it, I'm betting on a pin hole some place nearby!! I think Don S. already guessed this.

 

[scoflaw]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

So what's different about cruising that you can't duplicate at the dock?

 

[joewithaboat]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

So what's different about cruising that you can't duplicate at the dock?

Oil level sloshing around and getting spun up by the crank?