Advice-bought a 83 supra closed bow- engine issues

[Yama1]

Just bought an 83 supra closed bow with supposedly remaned 454 from ??? and a new velvet drive from 2010 with all new gauges that weren't wired correctly. I admittedly didn't chk the motor all that well, my mistake. Like compression, plugs, rotate crank, carb, etc. I did chk the lag bolts for the motor mounts to the stringers and that's all good. Interior was not too bad after a little cleaning.
My big issue is the engine. I have found out that it was last used in brackish water and apparently not flushed well. The wiring kept it out of the water last year for the last owner and now I have discovered it's locked up and the carbs are a bit corroded. So it's decision time so I don't get any more screwed cost wise and end up with a bigger project than I need right now. After all it's about summer.
Looking at what might be the best option here.
Opt 1 - I pulled the plugs, soaking with mystery oil right now and hoping this chance may be recoverable, but.........

Opt 2 - find a used engine and replace and then fix the wiring, not a major concern with the rats nest.

Opt 3 - sell as is for another ones project.

Hopefully I didn't give too much although I had to put new tires on the trailer to get it home.

Any thoughts

[michael hunter]

I would start with #1 . How is the engine oil?

[DAFF]

Let the engine soak as long as possible. Keep adding more oil / diesel to the cylinders and keep them topped up. Get a long 1/2" Johnson bar and put a socket on the main crank pully bolt. Try working the engine back and forth at first little by little then more and more. Dont try to force the engine all in one direction you can destroy whats left of the rings and cylinder walls.

While waiting go through the boat and make an extensive list or what is good and what needs to be repaired. Drain the fuel tank change filters and don't worry too much about the engine. I have seen many siezed engines which turn out just fine.

Most of all don't rush the engine anti sieze project. Let the oil work.....

Oh ya .... Pics please and welcome to the forum...

[Yama1]

Will post some pics tomorrow. I went ahead and pulled the carb and sprayed some stabil fogging penetrate in the intake and also the valve covers.

Put some more MMO and sprayed some stabil fogger in the cylinders again and put the plugs back. Crank still won't budge so far. I will make a block to connect to the crank pulley that will allow for some more torque for rocking until broke loose. I think I could shear the crank bolt no problem.

I will let it sit until the weekend and then take the manifolds/risers off, then the intake and maybe heads if I have too.:p

Only the rear 2 plugs had signs of crystallized rust and salt. That could be from the condensation being in the coast humidity. Maybe, hopefully not any previous leaks and such.

Keep you posted

[cadunkle]

With teh stirngers being solid and if the boat is in otherwise good condition I would just pull that engine and plan on at least a freshening up. If it was done a couple years back it should mostly be alright. Plan on doing rings, bearings, hone the cyls, clean the pistons, and lapping the valves. If the pistons and seized you can count on scoring up the skirts and walls if you get it free and fired. Also the valve faces will be rusted and crusty.

Cheap and easy, and then you know it's in good condition and not going to leave to drifting. If you're ambitious and that's all it needs you could have it done in a weekend. Do it right and you won't regret it.

[Yama1]

Here are some misc pics. Have to put the speedos in

[Yama1]

another pic

[DAFF]

I see the spray can tune up didn't work too well.... After seeing the picks I pull the drive line too. The carb looks like it was cleaned in a fire pit!!! I would spend some time and research how all the wiring is supposed to be run and follow suit. All in all it looks to be a solid boat and with some work it will be well worth it.

Take your time and give the old boat some love. It will repay you on the lake.

[beast 496]

Over all the boat looks great, but I think Bubba was working on the engine. I advise pulling out, and rebuild or replace with a new Vortec 454 gen V block and heads. Great find Al

[Yama1]

That's what I'm thinking needs to happen too. A nice fresh up and or replacement. Supra still has a few of the original engine harnesses that I can get. I will rewire the rest of the boat. Let the fun begin. Cool thing is it has a new alternator, risers, ex manifold, starter, velvet drive, gauges, Mallory distributor in box, etc. So that's a good thing

Bubba must have been lazy and just broke out the spray can......I guess that's one to get er done. Crazy

[wotan2525]

My engine sat for 3 years and I sheared the crank bolt trying to get it unstuck. I thought I was in trouble but a mechanic friend took some kind of fitting and hooked up compressed air to one of the plug holes. Turned it right over. Just a thought.

[Yama1]

Pulled one bank of heads and came up with this. I was getting excited seeing all the remanned parts and how clean the crank/cam and lifters were looking. Well that changed when the heads came off.
Sure enough 1 of the cylinders walls was rusted and a bit pitted. So I am debating to pull the block and see if it can be salvaged and use over size rings and or get new pistons. This think has less than 100 hrs on it.

Is that worth doing or just get another remanufactured motor, the new long blocks are very pricey?

[DAFF]

Pull the other head off, get the engine to turn freely and put it back together. The most you will be out is a gasket set and some time. The engine doesn't look all that bad to me.

You more than likely will get lucky !!! You can also do a compression test after you had it running for a while. This way you can tell the extent of the damage from sitting. Its going to smoke for some time from all the oils in the exhaust. So make sure you park it outside on the initial start up.

[Yama1]

Pulled the other head and cleaned them all up. Only 1 cylinder needed some work. Got it to break loose and kept cleaning/lubricating for each little bit of movement. The pics show a little of yesterdays activity. The bad cylinder cleaned up pretty well, feels ok, but running and a compression check will tell the true tale. The other cyls look fine as you can see. I cleaned the heads and intake by stripping and painting. A little pain, but worth it if the engine is saved by only good ole cleaning and new gaskets. The motor will look much better than the neglected before appearance.

[Yama1]

here are 2 more pics

[cadunkle]

If that rusty cylinder cleans up nice and you can't feel the pitting with your finger then I'd run it. If you can feel the pitting and it won't clean up easy I'd pull the short block and hone it.

You're already .040" over... I will qualify this by saying I don't know much about rebuilding big block Chevys... But I would be leery about boring that block again, given it's already .040" over, will be in marine use, and the block has been run regularly in salt so who knows how rusty/thin the other side of those cylinders are. Either way, my goals would be to run it without an overbore. I would still be more comfortable pulling it and checking/replacing the rings, but that's your call. It doesn't look terribly bad though aside form that one cyl.

[Yama1]

I agree with you cadunkle. Yes there is no telling without a complete short block teardown and run through, especially given it's history and 0.040 over bore.
I would hate to pull the motor and find that the block is scrap anyway, but I will definitely try to clean that bore up more maybe by bead honing what I can with piston at the bottom. You can feel some in the bore which the rings probably won't compensate for. As an engineer, I know that's not the correct way, but I have nothing to loose right now but some time and gaskets. Currently, I am taking this approach because I don't have any way of removing the engine easily.

At minimum, at least new rings would be a good start, but if I go that far, I am sure I will sink alot more time and money into making it right.

If I get any low compression or blowby, I will get another short block and spec it.

Let you know

[Yama1]

Well I spent this weekend getting the motor back together. Not so much fun without taking out of the boat. The engine looks much better than when I started. Hopefully all the extra work will be worth the effort if all goes well on startup.

I need to complete the wiring, get a coil and get my carb back(it was trashed). Here are some pics of the before and after. If all goes well, I will pull the motor for a proper winter makeover.

Have a question, anyone ever pulled the tranny and bell houssing with engine still in position? The flywheel cover was off and looks a bit rough although the velvet drive is new. I thought I would wait until after I get it running or after summer.

Still have to rewire the boat from engine harness(new) to gauges.

Thanks