Seized, then Unseized 350 Chevy

[gussie]

I am a newbie to this great forum, and very grateful for any assistance.

My son bought a 22' whaler with a Mercruiser 350 which was seized. Boat sat for 3 yrs. Owner said he replaced with new, not rebuilt, long block in 03 and use boat for 2 seasons. We used WD and light oil thru plug holes, left overnight. Still seized. Pulled RT engine head, cylinders clean. More WD and oil, left overnight. Still seized.

Pulled other head, now can turn with socket and bar. Cannot see any rust in the cylinders, only sign of any rust is in the inside of valve covers, a patch here and there. Almost no ridge in cylinder walls, apparently very few hours on engine.

Question is, do we pull the engine and completely go over the engine, or do we accept that, even though no visible rust or corrosion, it was the stuck rings and it is fine. I don't understand that we had to pull both heads before the engine would turn.

 

[KJSmitty]

Re: Seized, then Unseized 350 Chevy

Did you look at both heads to ensure the valves weren't stuck/seized?

If the engine wouldn't turn with the heads on, yet did once the second head was removed, I would check to ensure the valvetrain is free for rotation/operation.

- Nothing was in one of the cylinders corresponding with the second head was it?

 

[krisnowicki]

Re: Seized, then Unseized 350 Chevy

Where there any trickle stains from water any where? Like where water would trickle down into the bottom of the engine? Did the engine have oil or any fluid in it when you got it? If so what did it look like?

 

[gussie]

Re: Seized, then Unseized 350 Chevy

Thank you for your replies.

The valves are fine, no rust, corrosion, or anything else. The lifters move up and down, no sticking, the push rods appear fine. One can see each piston move ever so slightly, when pushed, so that none of the rings are stuck in the pistons. All the rocker arms move well.

I think I will take the heads to the local machine shop and have them checked, since I do not have the tools and instruments.

As mentioned earlier, the only sign of rust anywhere, is on the inside of the valve covers and a little on the head under the covers.. I presume this was condensation. The dip stick has just oil, not too dark, and it is up to proper level.

I must say, I remain a little perplexed that the engine didn't turn until the second head was removed. This engine fits very tight in the Whalers small bilge, so perhaps we didn't have the room to get the WD 40 all around the piston until the head was removed.

Pulling this engine will be a PITA. Maybe we don't need to. What do you think?

 

[KJSmitty]

Re: Seized, then Unseized 350 Chevy

Me personally would not at this point.
When you rotate and look in the cylinders where the pistons sat/stuck, is their any pitting, edges or rough spots etc. from the rings or piston skirt contact area etc.? If not, I would have the heads checked "well" then put her back together. (Smear oil in/on the cylinder walls prior to head install for initial turn/start lube).
If you removed the lifters and got them out of order it would be best just to replace them - and the pushrods etc. Change the oil and filter and prime the oil pump with an adapter on a drill. I'd perform this until oil actually came out the pushrods/rockers etc.. Final assembly then use a set of muffs and run water through the drive/engine and start her up.

Let us know as you progress.

Best of luck

 

[wca_tim]

Re: Seized, then Unseized 350 Chevy

I would do what he said, cept maybe put something like marvels or fogging oil in the cylinders so it'll burn easy when you start up rather than fouling the plugs... just a thought, definately on prime the you know what out of it, maybe turn over a little while priming without plugs in just to let bearings turn and distribute oil everywhere...

Me personally would not at this point.
When you rotate and look in the cylinders where the pistons sat/stuck, is their any pitting, edges or rough spots etc. from the rings or piston skirt contact area etc.? If not, I would have the heads checked "well" then put her back together. (Smear oil in/on the cylinder walls prior to head install for initial turn/start lube).
If you removed the lifters and got them out of order it would be best just to replace them - and the pushrods etc. Change the oil and filter and prime the oil pump with an adapter on a drill. I'd perform this until oil actually came out the pushrods/rockers etc.. Final assembly then use a set of muffs and run water through the drive/engine and start her up.

Let us know as you progress.

Best of luck

 

[gussie]

Re: Seized, then Unseized 350 Chevy

I stopped at the local machine shop and talked to the machinist. What they will offer is, to basically do a valve job. They also reccomended to magna flux the heads.

I can see that, as my son starts adding up all the items and what it will cost, he really needs to closely examine what he wants to do.

Is this the right engine for this boat? The motor just bearly fits, and access is very poor. The total weight of the engine and outdrive is almost 1100 #. The Whaler 1982 22' Revenge originally had a Mercruiser 4 cylinder. I don't know the weight. The dry weight of boat w/o engine is about 2400 lb. Fuel is 77 gal.

Does anyone have a comparable boat with the Mercruiser 5.7. How does it perform?

 

[captmello]

Re: Seized, then Unseized 350 Chevy

I'd get the valve job done and put the thing together shouldn't be more than $350. I've got a 20' bowrider with a 5.7 vp, it's nice to have the extra power if you want it.

 

[wca_tim]

Re: Seized, then Unseized 350 Chevy

I know it's ver dependant on hulls and preference... but I'm guessing my 18 foot boat weighs around 1400 pounds without the engine... and i love having a v-8 in it...

 

[Fishermark]

Re: Seized, then Unseized 350 Chevy

What outdrive do you have? Have you pulled the outdrive off and then tried turning the eninge to see if there is any difference? Maybe it is the outdrive that is stuck and not the engine. Just a thought.

 

[gussie]

Re: Seized, then Unseized 350 Chevy

Thanks for your input and suggestions. The V8 power will be nice, I guess.

Once we get rid of all this rain, in the NE, we can get back to the boat engine.

First thing, we still are scratching our heads about having to pull that last head to get the engine to turn. Also, we are reluctant to accept all of the things said to us by the seller ( he fibbed about the trailer ). It does appear that there are very low hours on the engine. Just to be sure that the there isn't something funky about the heads, especially the last one we removed, we are going to reinstall with the old gaskets, and see if the engine will still turn. If it does, we will pull the valve springs, check the valves, guides, install new seals, and put everything back together and run it.

There is one last thing, though. I have never looked at marine exhaust manifolds and risers, so we still have to evaluate that issue. Might take a little time to get someone to look at them, or just order new ones.
Thanks again all.