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Siezed 57 V8 to pull or not pull it

A

ants

Member
"Hi,

Just got another proje

"Hi,

Just got another project boat (will I never learn?!), this time with a siezed 5.7 V8. Its siezed because previous owner left the bung in the boat when ashore, and it filled up to about spark plug / header level with rain water!

Anyway I have the headers off and some rusty water came out of 1 exhaust port, and on pulling the sparks plugs clean water (no rust) came out several of the cylinders. Obviously I am going to need to take both heads off, but just debating whether to do it in boat, or if really it needs to be craned out so I can also pull the sump to see if there is any corrosion in there. My gut feel is that the bottom end should be well enough coated in residue oil not to rust, and the oil level is about right so doubt its sitting on much if any water in the bottom anyway. The boat is at home so would have to get a crane / HIAB type truck in to lift it out.

Any thoughts (other than go get another engine, this one only has 250 hours on it, and is great apart from being siezed and full of water ;-) ).

The nut on the crank / balancer seems quite small (5/8 oR 9/16 from memory), so I am concerned about putting to much pressure on it to unstick engine (after soaking cylinders with oil obviously) in case it shears, would I be better to fix the (also siezed) starter motor and try that every so often instead to try to jerk it loose?

I am also confused as to how water got into cylinders, as there is no corrosion on any of the spark plug seats, or the exhaust port gasket.

Just trying to figure the best way to go about this before diving in....

Thanks,

Anthony"
 
If you are convinced that ther

If you are convinced that there is no water in the crankcase I think it would be OK to pull the heads and see what you have.
Chances are that once you oil up the cylinders and tap the pistons with a hammer handle you should be able to turn it over.
The big question then will be how much corrosion pitting the cylinder walls have.

Rod
 
"looks like I am going to have

"looks like I am going to have to pull it anyway, I tried to get the starter off and one of the bolts is siezed, and cant get any more leverage down in there, suspect it will need an impact wrench and then it will prob shear like the alternator bolt just did....

Hmmmm at least if its a right off then if its already pulled then less work to put another engine in!

Any thoughts on how water could have got into the cylinders, any experience of this?

Thanks

Anthony"
 
""and on pulling the spark

""and on pulling the sparks plugs clean water (no rust) came out several of the cylinders."

GOOD sign!

"the oil level is about right so doubt its sitting on much if any water"

Another "good sign"!

The starter should be replaced or rebuilt by a prof. shop; they have the expertise since you will be busy w/the engine.

Pump out the oil and then open the oil drain plug w/a disp. diaper under it to catch any residual oil and water. Add fresh engine oil and a new filter.

Fill the spark plug holes w/a generous shot of WD-40 and put the plugs in loose. Spray 1/2 of a can into the carb to disipate moisture inside the intake manifold. Spray a good amount into the exhaust valves.

Remove the valve covers and inspect for water and rust. If you only see condensation, spray it down w/WD-40 and reinstall covers w/new gaskets.

Try to gently rock the engine by the crank. If it moves then squirt 2-4 spoonfuls of engine oil into each spark plug hole; leave the plugs out. Try to manually turn the engine over several times. If it will turn over, another "good sign".

Take the exhaust manifolds apart and inspect for cracks, test for water leaks between the jacket; if all is good replace gaskets and reinstall them.

W/a good starter and the OD immersed in a tub of water or use muffs w/low water pressure to lube the impeller and not fill the engine w/water, try to turn the engine over for 15-30 seconds. Stop and let the starter cool down to 10 minutes.

If all worked well, install the plugs and a water supply to the OD and try to start it. WATCH the gauges. If it gets up and runs, slowly take it up to 1200 RPMs and WATCH everything. Keep it running for 30-60 minutes to drive out any residual moisture.

Change the oil and filter and run it again."
 
"Guy - thanks for the detailed

"Guy - thanks for the detailed reply :) However I think we are going to have a job to free it first.

I tried spraying oil into the cylinders and realised that they still have water in them, so I think I am going to have to remove the heads anyway to get all the water out so I can then put oil in, it has been a long time since the boat was flooded (maybe a few years) so I suspect that it would be good practise to check under the heads to see if there is any rusty debris in the cylinders, and check for stuck valves etc.

On the plus side the exhausts all look like new(ish), and from looking in the rocker cover thru the oil caps that also looks immaculate. So its really a question of 1) unsiezing it 2) how much damage to the cylinders/pistons

I tried turning the crank via the harmonic balancer wheel centre bolt but its solid (I had a vague hope that as there was water in the cyinders it may have just been water locked), but it such a small bolt head I think it will sheer with any decent load so the question remains how best to unsieze it; via starter motor (seems very small, I have a bigger one on my old 3.0L 4cyl mercruiser!), or blocks of wood on the piston heads and tap them. Seems I could either burn out a new starter motor, sheer the crank bolt, or break a piston head, or all three! hmmmm....

I did finally get the starter motor off, but am still in two minds whether to start pulling the heads off in the boat or pull to work on it, so I can drain the sump properley etc, and if I can unsieze it then prepare and paint the rusting parts of the engine before it goes back in.

Anthony"
 
""time since the boat was

""time since the boat was flooded (maybe a few years)"

I missed that info. With the heads off you can check for a cracked block by filling the water jacket and watch for the level to drop if cracked internally. If it checks OK then I would go ahead and try to free the pistons with heavy doses of PB Blaster and turn the crank to get a look at the cylinder walls. Do you have room to drop the oil pan to remove the pistons & check the crank? If the cylinder walls are not pitted you may get by w/a good honing and re-ring.

If no room, time to pull the engine and do a reman. Cylinders may need to be resized due to pitting since the pistons are siezed.

If you are able, get two bottles of cheap toilet bowl cleaner that is about 28% acid. Remove the water circ. pump and and close the block drains. Pour the cleaner into the water jacket of the block until it is about 1-2" deep and let it soak 2-3 hours. This solution is strong enough to loosen and dissolve the sludge on the bottom of the water jacket but not hurt the block.

To drain the block tilt it w/the front down at 45 deg. and flush the crud out w/a strong stream of fresh water from a hose. Buy a garden hose style pressure wand that uses water pressure w/o compressed air to poke the wand into the jacket to improve flushing. All of the crud should come out of the circ. pump openings. Mix a solution of 1 quart of water and a cup of baking soda and pour it into the water jacket to neutralize the acid. Flush it out as before.

Keep us posted on your findings and progress. Use this same thread. Best of luck."
 
Interesting suggestion Guy. I

Interesting suggestion Guy. I have a few crustys in my hoses from previous exposure to salt water. I was planning on removing them to clean but was concerned about residual "crud" left in the block. Any reason I couldn't fill the block with toilet bowl cleaner then rinse with water from muffs? I realize it would take a number of gallons but oh well! (4.3L) Or would I be better off with something like diluted muriatic acid?
 
"Anthony;
I suspect the water

"Anthony;
I suspect the water got in through the carb and intake system, based on what you said about it sitting in the rain and filling up.
How it got in there is really immaterial; the fact its been there quite a while means that cylinder wall pitting is very likely.

Based on this and the starter problem I would be pulling the entire engine if I was you. Pulling a marine engine is not difficult if you can get clear access to the front and sides, and you have a hoist with long reach.

Disconnecting the plumbing and electrical is pretty easy. Pulling the drive is easy. Then it only 2 bolts on the rear bellhousing eyes and the two front mount studs.

Rod"
 
sledderdoc:

Diluted muriati

sledderdoc:

Diluted muriatic acid will work. It's just too dangerous as a concentrate to recommend using it. If your engine is FWC then just use an HD radiator cleaner and flush and fill. Dip the exh. mans. and risers in muriatic acid.
 
"I also agree with MR. STEWART

"I also agree with MR. STEWART on the way water entered your motor. Usually on the 350 GM motors, they have a 9/16 headed ,3/8 dia.bolt in the sides of the block ,a couple of inches back of the motor mount bosses[ this is in automotive applications, I'm not sure if the marine block would be different or not]. these two drains being about an inch or so up from the oil pan rail will not allow all of the water to drain ,but about 90%. you can also reverse flush through these holes to break up some of the garbage in the bottom of the water jackets. Hope this helps"
 
"Hi guys,

Just thought I wo

"Hi guys,

Just thought I would come back and update you now that I have pulled the engine and got the heads off. I think the alloy cylinder liners have saved the day, as although there is obvious rusting, its not the actual cylinder walls that have corroded, I think debris from the head has come down into the cylinder.

Here: http://www.anthonybradley.plus.com/merc/Port%20bank.JPG is the ghastly sight when I first pulled the head. Here: http://www.anthonybradley.plus.com/merc/port%20bank%20after%20some%20cleaning.JP G is after some cleaning with rust penetrating oil and a plastic blade to chip / scrape the rust from the cylinder walls.

At the moment I am thinking of pushing the questionable pistons out the top (maybe easier said than done!) after I have cleaned the walls, and then lightly honing the walls with one of those centrifugal home honing tools (anyone used one before?) to get rid of any remaining highspots. Obviously new piston rings and clean the pistons up. In an ideal world I would have stripped the block totally and sent it to be perfectly machined to be 100% sure, but I dont have unlimited time or budget, and this isnt a race boat, just looking for a reasonable repair esp as there doesnt seem to be any pitting of the walls. I guess the compression check once its back together will determine if that is the right route after all...

Oh BTW the other bank wasnt as bad, 2 cylinders had surface rust but that easilty removed by wiping it down with rust removing oil and a cloth.

Have rust penetrating oil soaking in the port bank for the next few days to get down past the pistons and hopefully unsieze them.

Oh and the water def didnt come in thru the carb, so must have got in past the plugs or a gasket (I think it was left partly immersed in rain water for a few months).

Look forward to your comments as always.

Thanks,

Anthony"
 
"Think again, the cylinder wal

"Think again, the cylinder walls are "cast iron" the pistons are alum. alloy. the rust you see is the cylinder walls."
 
"Hi, I originally thought that

"Hi, I originally thought that the cylinders were cast iron too, but I (incorrectly?) concluded that they were lined as there is a definate layer between the rust and the wall, when its cleaned off the wall is left with no pitting or rust marks that I can see, its smooth to the touch and look; I have never been able to clean up rust like that before.

Maybe its the glaze on the walls that forms a light barrier that rust stuck to but didnt go thru?

Well I am confused....

Anthony"
 
"Anthony;
No 1 and no 5 look

"Anthony;
No 1 and no 5 look really bad to me.

You are going to pull the pistons and deglaze the cylinders, right? I have no idea why you are wasting time and effort cleaning the cyinders with the pistons still in them.

When you have the psitons out and the cylinders all clean, check the inner surfaces very closely with a magnifying glass and a bright light. If you find pitting you need to rebore and go oversize pistons and rings.

Rod"
 
"At first I was like--NO WAY.

"At first I was like--NO WAY. But, I remembered that I did the same thing years ago to an old VOLVO motor. I got the boat for free, because the boat/engine got swamped. I did just what you are going to do. I honed the crap out of it. I probably bored it out a few thousands over tolerance. New rings and gaskets was all I spent money on. RAN GREAT, except for alttle piston slap at idle!! Good luck-keep us posted
Chris"
 
"Thanks for the encouraging wo

"Thanks for the encouraging words Chris, the engine only has 280 hours on it from new (I have known it since new) before I got it as a project, so the rest of the engine has very little wear on it, so fingers crossed its not to bad after honing. I'll hone it till clean then measure it, if the worst cylinders are not recoverable as are I figure that the engine is worth boring a few cylinders and a few over sized pistons to bring it all good again, just trying to not go that route if I dont have to.

Will keep you all updated, thanks!

Anthony"
 
"Anthony, be advised, machine

"Anthony, be advised, machine shops will not bore just a few cylinders. Its pretty much an all or nothing deal. Also, they will want to tank the block to clean it. Which means new cam bearings. Also, they inspect for cracks before any boreing begins. So you see, once the machine shop gets involved, it gets costly. I should know, I just finished rebuilding a 260, 350ci. Mecruiser. But, first things first. Tear it down and mic it up!! Like Rod says, Give it the big V-(visual inspection). Let us know
Chris"
 
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