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

[scoflaw]

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

How's sloshing crank oil making its way into the timing cover. Oil in the timing cover drains down into the pan. Oil level in his pan won't be high while cruising, alot of it will be up top and on its way down. I say get in there and start looking

 

[joewithaboat]

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

How's sloshing crank oil making its way into the timing cover. Oil in the timing cover drains down into the pan. Oil level in his pan won't be high while cruising, alot of it will be up top and on its way down. I say get in there and start looking

Take a half full bucket of water with you next time you go out on your boat and see if it doesn't slosh around. Oil is doing the same thing.
He could have a pin hole/crack some place in the front of the pan or timing cover. This could be slung around by balancer once oil is on the outside???. Just guessin here.

 

[Pete104]

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

Hey Rob, Where are you getting the replacement seals from?

 

[RobOp]

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

Hey Rob, Where are you getting the replacement seals from?

I've been getting them from NAPA. I've checked the specs on the seal and measured the harmonic balancer sealing surface shaft size (1.766 in) and what I'm getting is the correct seal.

 

[RobOp]

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?

I've been told that under load the engine will develop much more crankcase pressure which may promote the seal to leak.

 

[scoflaw]

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

Your engine has no crankcase pressure if vented properly, breather tubes or a PCV system. I think if you want to resolve your problem, call in one of your more mechanically inclined buddys, to take a look. Sometimes a fresh set of eyes can help.

 

[RogersJetboat454]

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

Here's something that just came to mind, and I'm not sure if it's applicable to the V6 but...

On small block V8's there is a threaded hole in the front of the engine near the fuel pump boss that I believe hearkens back to the days when the SBC had engine mounts on the front rather than the sides. Some assume that this hole is blind, but it actually intersects with the push rod bore for the mechanical fuel pump. The push rod is oiled by engine oil basically finding it's way off the cam and traveling down the rod into the bore for the push rod. I would imagine more oil would be present here as engine RPM's increase, and oil pressure goes up. I would think that oil may just drip from this open hole, but it could be plausible that if this hole is leaking, it may be traveling down the side of the block to the balancer where it is getting slung all over the place (stranger things have happened).

May be worth a quick peek to see if there is any threaded holes on the front of your engine near where the fuel pump boss is. If you find them, look in the hole to see if you can see the push rod. Most people will seal off this hole with just a regular bolt with it's threads coated with liquid teflon, or a bolt with a copper washer behind it's head.

It's a long shot I know, especially where it looks like your previous crank seal got damaged by a mechanical problem. Just throwing idea's out there.

 

[joewithaboat]

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

Here's something that just came to mind, and I'm not sure if it's applicable to the V6 but...

On small block V8's there is a threaded hole in the front of the engine near the fuel pump boss that I believe hearkens back to the days when the SBC had engine mounts on the front rather than the sides. Some assume that this hole is blind, but it actually intersects with the push rod bore for the mechanical fuel pump. The push rod is oiled by engine oil basically finding it's way off the cam and traveling down the rod into the bore for the push rod. I would imagine more oil would be present here as engine RPM's increase, and oil pressure goes up. I would think that oil may just drip from this open hole, but it could be plausible that if this hole is leaking, it may be traveling down the side of the block to the balancer where it is getting slung all over the place (stranger things have happened).

May be worth a quick peek to see if there is any threaded holes on the front of your engine near where the fuel pump boss is. If you find them, look in the hole to see if you can see the push rod. Most people will seal off this hole with just a regular bolt with it's threads coated with liquid teflon, or a bolt with a copper washer behind it's head.

It's a long shot I know, especially where it looks like your previous crank seal got damaged by a mechanical problem. Just throwing idea's out there.

That's a good guess!!

 

[RobOp]

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

Here's something that just came to mind, and I'm not sure if it's applicable to the V6 but...

On small block V8's there is a threaded hole in the front of the engine near the fuel pump boss that I believe hearkens back to the days when the SBC had engine mounts on the front rather than the sides. Some assume that this hole is blind, but it actually intersects with the push rod bore for the mechanical fuel pump. The push rod is oiled by engine oil basically finding it's way off the cam and traveling down the rod into the bore for the push rod. I would imagine more oil would be present here as engine RPM's increase, and oil pressure goes up. I would think that oil may just drip from this open hole, but it could be plausible that if this hole is leaking, it may be traveling down the side of the block to the balancer where it is getting slung all over the place (stranger things have happened).

May be worth a quick peek to see if there is any threaded holes on the front of your engine near where the fuel pump boss is. If you find them, look in the hole to see if you can see the push rod. Most people will seal off this hole with just a regular bolt with it's threads coated with liquid teflon, or a bolt with a copper washer behind it's head.

It's a long shot I know, especially where it looks like your previous crank seal got damaged by a mechanical problem. Just throwing idea's out there.

Originally the hole was open, I've put a 3/8-16 x 1/2 bolt with teflon tape in the hole to plug it up, it made no difference.

 

[RobOp]

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

Weekend oil leak troubleshooting update:

I changed the oil and put fresh 10W-40 non-synthetic in.
I wrapped the fuel pump in absorbent pads.
Wrapped the power steering pump in absorbent pads.
Shoved absorbent pads behind the water pump in front of the intake manifold and top of timing chain cover.
Removed the oil fill cap and put absorbent pads over the opening to make absolutely sure the crankcase is thoroughly vented.

Then went out for a test run.. No change, the engine is clearly spraying oil from behind the harmonic balancer.

I am quite sure at this point it is leaking from the harmonic balancer seal. I don't believe a pinhole could leak this profusely.

Phase II:
I put a speedy (repair) sleeve on the original harmonic balancer.
Removed the new harmonic balancer from the engine.
Installed a new seal using the seal installation and alignment tool. The seal surface on the timing cover is clean and smooth.
Installed the original harmonic balancer with speedy sleeve.

Went out for another test run.. There was a difference, the leak rate is only about half of what it was before. I attribute this to the fact that the speedy sleeve slightly increases the diameter of the sealing surface on the harmonic balancer making the seal tighter.

To me, this seems to confirm that the leak (oil spray) is indeed coming from that seal.

To summarize my dilemma:
Oil is leaking and spraying out from behind the harmonic balancer.
Harmonic balancer seems to spin true, no wobble at idle.
The seal appears to be centered and flush with the installation/alignment tool.
It only leaks under load while out cruising. Will not leak in neutral in the slip, no matter the rpm.
The engine runs well and I cannot detect any unusual vibration when comparing port and starboard engines.
The engine holds oil pressure at all power settings.

Although I have not measured the crankshaft run out at the snout, my engine guru friend tells me he believes it is ok based on it spinning true at idle and the fact that it will not leak in neutral.

The predominant theory at this point is that the crankshaft is somehow defective and vibrates under load causing that seal to leak.

Any more comments or suggestions before I come to the conclusion that I have to pull the engine?

Thanks.

 

[joewithaboat]

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

Although i have owned a couple 4.3's and rebuilt two, i have never combined parts from multiple engines to assemble a complete one. Apparently there are some distinct manufacturing differences through out the years in regards to the cranks. Having worked in a machine shop, a long time ago, I know that reman builders don't balance individual rotating assembles, it takes too much time. They work from known weight combination's. It is possible that because these engines already have an inherent imbalance issue that the wrong weight crank, rods and pistons combination could have made it that much worse and the crank is whipping around. You could also have a broken crank which i have seen more than once. And yes both times the engine's was running OK. I distinctly remember the rear main kept leaking on one.

Did you ever read this link in the crankshaft, piston section?

http://hotsixes.com/index.php?option=com_content&view=article&id=14&Itemid=12

 

[RobOp]

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

Joe,

Thanks for the reply! I've looked at the hotsixes link and now my head is really spinning, sounds like there are alot of ways for things to go wrong here. I have no idea what is inside. I was condsidering pulling the engine, repairing whatever looked broke and putting it back in. Now I'm wondering if that is a good idea... I don't want to spend all year screwing around with this engine, maybe I should bite the bullet and just put another long block in.

Mercruiser/Quicksilver is supposed to be such a quality reman, now I'm not so sure, if they can make this kind of mistake. If I go with a new longblock, where should I get it?

Another question, do have any feel for how complicated and what changes would need to be made to install 350s (or 305s) in place of these V6s? It sounds like the 350 have never had these vibration / balance problems.

Thanks

PS - How can an engine run ok with a broken crank? and short of tearing the engine apart how can you tell?

 

[Alwhite00]

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

Did you contact the place you got the engine from? Did they respond?

LK

 

[SuperNova]

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

You ARE pre-lubing those seals before you install them aren't you? Dry is not good.

 

[Jamie 10017]

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

I would also check the end play of the crank and make sure it is within specs, if the thrust bearing is bad the crank will walk and do all kinds of weird things, and thats is what is eatn up the seals. Just sayn, look for the cause before you just put another seal in. Jamie

 

[RobOp]

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

Did you contact the place you got the engine from? Did they respond?

LK

I bought the boat in November, the engine was installed in Sep 2010 but only had a handful of hours on it when I bought it.

The engine is a Mercruiser/Quicksilver factory reman, the engine is out of the 12 month warranty period but I will be contacting them if I have to pull the engine.

 

[RobOp]

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

You ARE pre-lubing those seals before you install them aren't you? Dry is not good.

Both the seal and harmonic balancer sealing surface are dripping in motor oil when I put the balancer on.

 

[RobOp]

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

I would also check the end play of the crank and make sure it is within specs, if the thrust bearing is bad the crank will walk and do all kinds of weird things, and thats is what is eatn up the seals. Just sayn, look for the cause before you just put another seal in. Jamie

The original seal and the first one I installed were chewed up. The second seal I installed was not damaged but still leaked. I installed a third seal when I put the original harmonic balancer with speedy sleeve back on. It is now only leaking at about half the rate it has in the past.

How do you check the crank for end play with the engine in the boat. I have pulled up and down and sideways on the crank and can't get it to budge.

 

[91rr]

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

I've been getting them from NAPA. I've checked the specs on the seal and measured the harmonic balancer sealing surface shaft size (1.766 in) and what I'm getting is the correct seal.

Hey Rob, Have you tried a different brand seal to make sure.

 

[joewithaboat]

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

Joe,

Thanks for the reply! I've looked at the hotsixes link and now my head is really spinning, sounds like there are alot of ways for things to go wrong here. I have no idea what is inside. I was condsidering pulling the engine, repairing whatever looked broke and putting it back in. Now I'm wondering if that is a good idea... I don't want to spend all year screwing around with this engine, maybe I should bite the bullet and just put another long block in.

Mercruiser/Quicksilver is supposed to be such a quality reman, now I'm not so sure, if they can make this kind of mistake. If I go with a new longblock, where should I get it?

Another question, do have any feel for how complicated and what changes would need to be made to install 350s (or 305s) in place of these V6s? It sounds like the 350 have never had these vibration / balance problems.

Thanks

PS - How can an engine run ok with a broken crank? and short of tearing the engine apart how can you tell?

I really don't know anything about mercrusier/quicksilver remans but if i had to take a wild guess i would say that it is probably sub- contracted out... and everyone knows how that goes, low bidder.

There are several threads here discussing the 4.3 to 5.7 swap its not too bad. Ill see if i can find one. Ive never done it myself but may in the near future. Some things... starter, distributor, alternator, power steering, fuel pump, possibly carb all can be reused.

Accurately measuring the thrust clearance is probably not going to work unless its upside down with the pan off.

Here is a small video i found that shows how a crank can be broken and the engine still run. Ive seen it 2 times once on a 302 ford once on a 350 chevy.

http://www.youtube.com/watch?v=eCCwFo23s9o&feature=results_main&playnext=1&list=PL0B616572C6F6B92A

Id say at this point its time to pull it and tear into it.