Siezed 454 OMC King Cobra

[sam60]

Re: Siezed 454 OMC King Cobra

I pulled the spark plugs the 1st weekend and water came out of #6. I pulled the exhaust manifolds today and the water manifold portion was clogged with crap. I ran 1/2" all thread rod through them and pushed out lots of crud. They will be in the steam box with the block tomorrow afternoon. The engine needs gone through and my cost is wholesale parts only.

 

[bruceb58]

Re: Siezed 454 OMC King Cobra

You are going to want new manifolds/risers. Before doing much more, make sure you find a place to purchase them.

 

[HT32BSX115]

Re: Siezed 454 OMC King Cobra

You are going to want new manifolds/risers. Before doing much more, make sure you find a place to purchase them.

Dittos!


Can you post a picture of the "CRUDDY" manifolds/risers??




I think they're certainly available...... buy them first though!!

Not cheep though.....
http://marineengineparts.com/shopsite_sc/store/html/page542.html

http://www.boats.net/parts/detail/omc/O-0914044.html

If you can get them "wholesale" may the force be with you!!

Good luck!


Rick

 

[sam60]

Re: Siezed 454 OMC King Cobra

I don't need new exhaust manifolds, they will be fine after they are in the cabinet washer. The engine is out. Pics here.

http://s246.photobucket.com/albums/gg114/poofdirt/Engine out/

I am wooped. Going back to buddies tomorrow only to put it on the engine stand and get the boat out of his shop. I took me 5 hours of trying to contort by body to get to everything I had to unhook. The only help was my buddy running the forklift.

 

[HT32BSX115]

Re: Siezed 454 OMC King Cobra

I don't need new exhaust manifolds, they will be fine after they are in the cabinet washer. The engine is out. Pics here.

http://s246.photobucket.com/albums/gg114/poofdirt/Engine out/

I am wooped. Going back to buddies tomorrow only to put it on the engine stand and get the boat out of his shop. I took me 5 hours of trying to contort by body to get to everything I had to unhook. The only help was my buddy running the forklift.

Hmm.....I don't always like to be the guy with the bad news, but I think you may have a cracked block! (between and above the the two rear core plugs....)

 

[sam60]

Re: Siezed 454 OMC King Cobra

No problem, Next door neighbor has a fresh long block for 200 bucks. There is no bad news, it's all easily solved. I am aware of the difference between marine and street engines.

 

[HT32BSX115]

Re: Siezed 454 OMC King Cobra

No problem, Next door neighbor has a fresh long block for 200 bucks. There is no bad news, it's all easily solved.

You are one lucky dude! Just make sure that that it's a truck engine, use your current camshaft or plan on obtaining the right camshaft for it.

With all that water in the exhaust ports and a cracked block, I would expect the manifolds to be cracked too. I would not trust them if they're really rusty. They should last a good long time if they were only ran in Mead, but I know you get pretty cold temps there............ Your risers/elbows might be ok ....the surfaces might need cleaning up though.....

 

[sam60]

Re: Siezed 454 OMC King Cobra

Not as lucky as I thought. The block he has is a mark IV. The search is on for a 91-95 Gen V block.

Casting #10114182.

 

[sam60]

Re: Siezed 454 OMC King Cobra

73 de Rick:

I think I may have found an identical block nearby and out of a 1994 GMC truck. It will be Saturday before I can get to it and confirm the casting numbers. From what I have read, I will need a Marine Gasket set and not much else is different. I will do the bearings, rings and have my heads checked..(maybe should have my head checked). Also new hoses filters and such. What else should I think about? Are the truck blocks drilled and tapped for the block drain plugs? I'll let you know what I find.

Thanks

Addendum 1-

I also used the hose from a compression tester and put 150 PSI to each cylinder while it was still in the big 'ol fat girl and the valve seals held tight other than one that must have been an intake valve as MMO mist was coming out of the flame arrestor.

 

[bruceb58]

Re: Siezed 454 OMC King Cobra

Brass casting plugs and transfer over your starter and water pump.

 

[sam60]

Re: Siezed 454 OMC King Cobra

I agree on the brass freeze plugs, the painted in freeze plugs didn't do their job. I will asume that they are steel for now.

 

[bruceb58]

Re: Siezed 454 OMC King Cobra

I agree on the brass freeze plugs, the painted in freeze plugs didn't do their job.

They didn't do their job because that is not their job.

 

[HT32BSX115]

Re: Siezed 454 OMC King Cobra

I agree on the brass freeze plugs, the painted in freeze plugs didn't do their job. I will asume that they are steel for now.

You want brass in a raw water cooled engine so they don't rust out. That is the only job they do........people only call them "freeze" plugs..... (in error)

 

[Joshua Nichols]

Re: Siezed 454 OMC King Cobra

Bet the ones in that block are brass.. Looks factory...

None of it likely was a big deal to begin with.. Still.. The fella you bought it from didn't care much about it once it gave him some trouble.. Didn't drain the block a long with the original problem.. Now the whole thing is toast..

Saw a super charged 496? Looked cool for 12k..

You got that boat for cheap... About 3 or 4k you should get it up and running easy...

Thats a new long block and new manifolds..

 

[sam60]

Re: Siezed 454 OMC King Cobra

OK, either way as my friend Joshua has said, I need some parts. A 496 is not in my budget. I am going to look at a 10114182 block tomorrow that is out of a 1994 Suburban that had a flat cam. The quest continues as I plan to have this thing running good and looking great when the temps get below 100 degrees.

http://s246.photobucket.com/home/poofdirt/index#!cpZZ3QQtppZZ20

 

[Joshua Nichols]

Re: Siezed 454 OMC King Cobra

hunt down some manifolds... A GM 454.. Those are easy to find..

freeze plugs didn't do their job

If they didn't leak.. They did their job.. They are not a fail safe for not winterizing a boat engine..

Core plugs, sometimes wrongly called freeze plugs or frost plugs, are plugs that fill the core holes found on water cooled internal combustion engines.
http://en.wikipedia.org/wiki/Freeze_plug
The sand casting cores are used to form the internal cavities in the engine block or cylinder head(s), usually forming the coolant passages. The traditional plug is a thin, domed, disc of ferrous metal which is pressed into a machined hole in the casting. Alternatively a non-ferrous metal such as brass offers improved corrosion prevention. In some high-performance engines the core plugs are large diameter pipe plugs.[1]

Core plugs can often be a source of troublesome leaks as a result of internal cooling system corrosion. Ease of replacement depends on accessibility. In many cases the plug area will be difficult to reach and using a mallet to perform maintenance or replacement will be nearly impossible without special facilities. Expanding rubber plugs are available as replacements when access is a problem.

 

[sam60]

Re: Siezed 454 OMC King Cobra

Got it Rick and Josh. Core plugs, not freeze plugs, Thanks. Still in search of a 10114182 block. Took this weekend off.

 

[HT32BSX115]

Re: Siezed 454 OMC King Cobra

Got it Rick and Josh. Core plugs, not freeze plugs, Thanks. Still in search of a 10114182 block. Took this weekend off.

Sorry to belabor the point, but for everybody else viewing this thread, this is a common misconception. that REALLY needs to be squelched so most of us keep reiterating it!!

I was looking at you a few days ago as I flew over Pahrump! You don't have much lake to run your boat in around there......how long does it take for you to get to Mead from there??

 

[sam60]

Re: Siezed 454 OMC King Cobra

Yeah, pretty dry around here. When it rains alot we get a couple of inches in the dry lake bed.

It's about an hour and 20 minutes to the Lake.

Are you a pilot? In the military?

 

[HT32BSX115]

Re: Siezed 454 OMC King Cobra

I retired from the USAF in 2004 flying that thing in my avatar picture.....Now it's all "straight and level"!!