Mercruiser V6 seized from Rodent Damange

[bkgoodman]

I have a Mercruiser V6 4.3LX / 262 which has been in storage for a whopping nine years.

It has received periodic maintenance, starting, fluids, even a carb and starter rebuild.

This year when "my guy" went to start it, it wouldn't budge. He pulled the engine and took the head off. A rodent had nested in one of the cylinders (which was int he "down" position). It is rusted to the point where it won't move.

The block is in good shape. The outdrive was just rebuilt and is good. The starter, carburetor - everything is in pretty good shape (as far as I can tell) except for this.

He wants to charge me a fortune for a new long block, (or really sell me an old V8 he's had laying around in his shop forever).

Right now it's in pieces. The boat is on blocks, I don't own a trailer or a vehicle that could tow it. (It's in the Nashua area).

I guess I could go get the engine from him. (Would I need a hoist to lift it in/out of my vehicle? Should I get an engine stand?)

I was planning on putting in this water this season - but that didn't work out. I'd really like to get it ready and to the lake for next season.

Any ideas what to do?!?

[NoBozo]

I'm having a hard time envisioning HOW a rodent got into one of the cylinders..and Why HE (the rodent) would want to get into a cylinder. The only way IN or OUT of the combustion chamber is through the valves. NB

[bkgoodman]

Yes, (as it was described to me) - he got in through one of the valves that was in the open position.

[NoBozo]

Originally Posted by bkgoodman

Yes, (as it was described to me) - he got in through one of the valves that was in the open position.

Since the technician has the cylinder head OFF the engine, maybe you could ask him/her to show you which valve the Renegade Rodent entered. All he/she has to do is turn the head upside down to show you the "open" valve. NB

[bkgoodman]

Originally Posted by NoBozo

Since the technician has the cylinder head OFF the engine, maybe you could ask him/her to show you which valve the Renegade Rodent entered. All he/she has to do is turn the head upside down to show you the "open" valve. NB

Excellent, excellent point!!!

If it's the exhaust, that's a long way to climb. If it's the intake, it means the air filter and throttle were open, and the cover was off.

It would be interesting to see if the plugs, and which of them were out of the head.

I specifically *DO* remember seeing that the engine cover was off the last time I saw it. I don't remember if the air filter was on or not.

But I get your point - if crankshaft is immobilized, it will be black-and-white what the valve positions were - because there is no way they could have changed from then to now!

Thanks again!

-BKG

[VitaBene]

Regarding using a v8, remember the outdrive gear ratios are different for 4, 6, and 8 cylinder engines on alpha drives.

[lawn psycho]

Too bad he tok it apart. A trick is to squirt marvel mystery oil into the cylinder and let it soak and soak and soak. It really does wonders some times. Then you vacuum it out and crank her over.

Now you need the piston to be below top dead center (tdc) but you could still try and it and use a breaker bar on the crank to turn it.

MMO was made for this kind of thing and is worth the $5 it will cost for it. Soak it for 24 hour or longer.

[bkgoodman]

Yes, that's what a lot of people are saying. The cylinder is near the bottom, so it can hold the oil, and shouldn't have too much to move before it breaks free.

I just gotta get the block back from him.

Thanks for the advise!

-BKG

[NoBozo]

I think I overlooked something. If the head is OFF an engine, with "overhead valves," the pushrods would have been removed first.. therefore ALL the valves would be closed (head OFF) because the cam is not holding certain valves open. NB

I still think the Renegade Rodent never got into a cylinder in the first place.

[MarkinNH]

Originally Posted by lawn psycho

A trick is to squirt marvel mystery oil into the cylinder and let it soak and soak and soak.

Great stuff. When I was a boy my dad had a passion for old tractors. He unseized quite a few engines using the very method you described.

[bkgoodman]

"My Guy" in the paper the other day...

Skip’s Marine in dire straits following lawsuit - "Skip’s Marine in dire straits following lawsuit"


http://feedproxy.google.com/~r/nashu...g-lawsuit.html

[Dave R]

My advice is to go get everything and bring it home. Buy a book about rebuilding Chevy V6 or small block V8 engines (the 4.3 V6 is a 350 V8 with two missing cylinders) and rebuild the short block. It's not hard to do and the parts (pistons, rings, bearings, gaskets and seals), and machine work are very inexpensive. I'd be happy to lend you an engine stand and some of the specialized tools. I don't use them very often.

[bkgoodman]

Thanks, Dave, I may have to take you up on that!

I did just buy and engine stand today, and I believe there are some auto repair shops that lend our hoists. I think moving the engine around is going to be the hard part.

I don't know what kind of "specialized" tools I may need - I rebuilt an engine on my Cressida once, and I had to borrow some whacky thing to lift the valves once from some stranger on the 'net!

I dug out the service manual - which I bought many years ago when I rebuilt the carburetor. I think I am going to take your approach. I'm going to borrow a hoist and a pickup and get the engine this week. I'll let is sit with MMO or PB blaster for a couple weeks while I'm on vacation, and see how it does when I come back.

Also - I talk to my "mechanic" - yesterday, who said something about me buying his V8 - and him putting my V6 in someone elses boat. (Wait, I thought you said it was unsalvageable!?) He was obviously willing to give me nothing back for my engine - even though he was going to put it in someone else's boat.

He did also mention a good machine shop down the road - and I have been reading on some options with respect to honing or reboring the cylinder.

I'm starting to believe this thing is not-so-unusable after all...

Thanks for the help!

-BKG

[lawn psycho]

Well is looks you have already have some motor savvy. Given you still have a stuck piston (or frozen crank) you have a block of unknown condition.

Before going into the whole rebuild route I would exhaust every root possible to get the crank to turn. If you bust something you haven't lost anything at this point. Get a breaker bar on the crank pulley bolt and turn it like a Mo-Fo. If you soak it long enough you might get somewhere. Another thought is to overfill the crank case with some marvel mystery oil to soal the crank and bearings in case that is you issue.

I am not one to discourage DIY but a motor swap is a whole lot easier than a rebuild. Most likely cheaper too. Getting the heads right with proper valve geometry is not forgiving for engine longevity if you get it wrong I've rebuilt motors before but I had an engine guy set the valves, rockers, etc.

I'd be much more inclinded to buy a motor already rebuilt and plunk it in. Since you don't need the boat in a hurry it seems, then it could make for a fun project.

Sounds like it's time for you to start reading on the Mercruiser Forums for the nuances you will run up against. Call Marine Parts Express as they may have a rebuilt "kit" to help reduce parts chasing. Good luck.

[Dave R]

Originally Posted by bkgoodman

Thanks, Dave, I may have to take you up on that!

I did just buy and engine stand today, and I believe there are some auto repair shops that lend our hoists. I think moving the engine around is going to be the hard part.

I don't know what kind of "specialized" tools I may need - I rebuilt an engine on my Cressida once, and I had to borrow some whacky thing to lift the valves once from some stranger on the 'net!

I dug out the service manual - which I bought many years ago when I rebuilt the carburetor. I think I am going to take your approach. I'm going to borrow a hoist and a pickup and get the engine this week. I'll let is sit with MMO or PB blaster for a couple weeks while I'm on vacation, and see how it does when I come back.

Also - I talk to my "mechanic" - yesterday, who said something about me buying his V8 - and him putting my V6 in someone elses boat. (Wait, I thought you said it was unsalvageable!?) He was obviously willing to give me nothing back for my engine - even though he was going to put it in someone else's boat.

He did also mention a good machine shop down the road - and I have been reading on some options with respect to honing or reboring the cylinder.

I'm starting to believe this thing is not-so-unusable after all...

Thanks for the help!

-BKG

I have a valve spring compressor, piston ring tools, cylinder hone and stuff like that. Lemme know if you need it. You may just need a hone and new rings, that would be ideal. With luck, the valves will be in good shape and you can just lap them and install some new seals. That'll save some machine shop cost. Setting valve lash is really easy, no need to worry about stuff like that.

[bkgoodman]

Originally Posted by Dave R

I have a valve spring compressor, piston ring tools, cylinder hone and stuff like that. Lemme know if you need it. You may just need a hone and new rings, that would be ideal. With luck, the valves will be in good shape and you can just lap them and install some new seals. That'll save some machine shop cost. Setting valve lash is really easy, no need to worry about stuff like that.

Thanks a ton! Sounds like exactly the stuff I need. I figured a good honing may do the trick - but as long as I have everything in a billion pieces, it probably would hurt to do a good valve and ring job on this nearly 20 year old engine!

It was actually a valve spring compressor that someone once lent me working on my old car engine.

I'm in Nashua, don't know where you are - it will probably be at least a month or so before I've returned from vacation, broken the stuck piston free, and am ready to get into that level of detail. We should hook up via. Private Message.

Thanks again!

-BKG

P.S. Love your boat name!

[Dave R]

I got your PM and sent you an email. My advice is to inspect thoroughly and fix only what is necessary. Valves don't expire, so don't assume it'll need a valve job because it's 20 years old, they could be in perfect shape.


That said, there are some parts that just make sense to change while the engine is apart: Rubber bits, like valve seals, do dry out over time and they are very cheap and easy to change, so those should be done. Rings should be changed any time the pistons are removed. Bearings can be inspected and re-used, but they are usually really cheap, so I recommend putting in new ones during re-assembly. Crank seals should never be re-used.

You may want to investigate replacing your heads with Vortec heads and installing a roller cam. I think they are both bolt-on improvements that Mercruiser used in newer 4.3s that will give a nice HP and torque boost.

[Dave R]

Originally Posted by bkgoodman

P.S. Love your boat name!

Thanks


My wife and kids are big time Harry Potter fans (I'm not a big fan). They came up with it and I think it's a unique and interesting boat name regardless of its origin, so I am fine with it.

[VitaBene]

Originally Posted by bkgoodman

Thanks a ton! Sounds like exactly the stuff I need. I figured a good honing may do the trick - but as long as I have everything in a billion pieces, it probably would hurt to do a good valve and ring job on this nearly 20 year old engine!

It was actually a valve spring compressor that someone once lent me working on my old car engine.

I'm in Nashua, don't know where you are - it will probably be at least a month or so before I've returned from vacation, broken the stuck piston free, and am ready to get into that level of detail. We should hook up via. Private Message.

Thanks again!

-BKG

P.S. Love your boat name!

Fill those cylinders with marvel Mystery Oil before you go on vacation.

[robmac]

bkgoodman,I am in Nashua and have an engine crain if you need one. I agree with all the advice you've gotten,free up the frozen cylinder then inspect each cylinder for scoring and ridges. I have built alot of engines along with freeing up siezed ones (which I then drove ) and as stated prior if it's apart make sure you get a master engine set and replace all seals and gaskets timing chain and gears etc.. PS,not a fan of Skips or his former location.

[bkgoodman]

Robmac: Thanks!

I did buy a hoist last night, so I'm borrowing a friend's truck, and I should have the engine back to my place within a few days.

I knew I needed the gasket set - I didn't know/think about the timing chain and gears. I am going to do a ring job too (never did one - don't know what it entails).

Assuming I can get the engine to budge loose, I don't know if I should take it to a machine shop? Hone it? Have them do it? Have them lap the valve seats or whatever while it's apart? Do that myself?

I can't really judge the condition it's in. Maybe if you're in the area you could take a peek

-BKG

[ApS]

Originally Posted by Dave R

My advice is to go get everything and bring it home. Buy a book about rebuilding Chevy V6 or small block V8 engines (the 4.3 V6 is a 350 V8 with two missing cylinders) and rebuild the short block.

If the engine was disassembled in the boat, and the chances of getting it to turn over are good, why go to additional lengths like removing the engine?

We've gone from a simple solution—to a rebuild—which may be completely unnecessary.

[TOAD]

Were the spark plugs left out? That might be a point of entry. Other than that there is no easy direct route to get into one of the cylinders.

[donnamatrix]

Wow... reading this post, y'all should open up a marine mechanic shop. I can barely understand this conversation, except there was (perhaps) a rodent!

[bkgoodman]

I think I overlooked something. If the head is OFF an engine, with "overhead valves," the pushrods would have been removed first.. therefore ALL the valves would be closed (head OFF) because the cam is not holding certain valves open. NB

Ah...correct, but we could probably devise what the valve positions must have been based on the current crankshaft position - which couldn't have moved - because it is seized.

There may have been pieces of acorns in there too - I can't remember if I saw them or heard about them - or if they were large enough to have gotten in through the spark plug hole..

[NoBozo]

Originally Posted by donnamatrix

Wow... reading this post, y'all should open up a marine mechanic shop. I can barely understand this conversation, except there was (perhaps) a rodent!

Thanks DM: We are probably not as smart as you give us credit for. We probably know more than the person in the street...BUT when we go to our friendly repair facility ..Auto or Marine......We usually CAVE. It's the easy way .

As long as you are not willing to pick up the tools and do it yourself..We are at the mercy of the SHOP...they know this: We don't feel like, or don't have the tools, time, knowledge, or incentive to do the job ourselves. SO: We say OK...Do it.....and we justify it by telling ourselves......at least it will be done ...

When it comes to repairin something....THIS is Absolute:.."It's in the Knowin...not the Doin." Almost anyone can do the work...but you have to know HOW. NB