rickj1

As background on this question...I am in Afghanistan and getting my info second hand.

I have a 28' Nordic with a single 500HP.

My son was brining the boat back in and had a knock in the engine. Took it over to the marina. No compression on 2 cylinders, I think 6 & 8. They took the heads off and told me, and I quote "there is a piece of metal broke off between two cylinders (I think 6 & 8)". I was told that I probably got the engine tooo hot a few times as the cause of the problem. My other friend builds race car engines and said he would look at it to possibly put a sleeve in it to fix the problem. The marine mechanic says it cant be done.

Can you or does anyone recommend puting a sleeve in the engine?

I am assuming since I have not been told otherwise that the upper end and the remainder of the parts are good. If so, what are my options for a shortblock? Any suggestions where to look for that?

My friend that builds race car engines may be able to build me a new short block. I was also consideroing buying the block, maybe a Dart, and the rotating parts and have my friend build it. I dont know which way would be cheaper since I dont have a lot of extra money sitting around.

Chris Sunkin

Sleeving is typically done when a block is not able to be bored oversize. It can also be done when a liner is cracked. If the engine blew the head gasket between two cylinders, I personally wouldn't look at sleeving to repair it. If it's not too bad, ecking the block may take care of it. You can get Cometic marine head gaskets in diferent thicknesses and possibly make up for what you have to deck off. The GM blocks are tall of deck spec anyway. You need to get the engine to a compepent marine engine builder. There are dramatic differences between automotive & marine engines.

Cobra Power has a deal on cosmetic blemish Dart blocks, if you need to go that way.

The comment "got hot a few times" concerns me. Engines don't just "get hot". Something has failed. The first order of business would be to figure out what happened- or you may be doing all of this twice.

Griff

Sounds like the head gasket went between the cyilinders, then the heat burned/melted the block. I don't think it can be fixed with sleeving. Maybe it can be saved with decking the block and thicker gaskets as Chris said.

rickj1

Not being there makes this difficult.

Another guy in my power boat club said there was a amrine shop that worked on his block with a similar problem and added material to the block. Is that the "ecking" that you mentioned?

I just found out that there is "some material" missing from the head also. The marine shop said they could fix the head and true it up so it would work.

I am probably at 2K worth of work at the marine repair shop currently. that is why I thought about a new block and maybe some new internal parts as an option to welding in some added material to the block. I will check out the Dart blem's you mentioned. I guess it helps if I can use the same heads and all the other existing parts to save me some money

As far as over heating...The only example I can think of is when I hhad my boat on the rack at the marina and the yard guy accidentially shut off the water hose to my muffs on the out drive and I didnt notice it right away. Burnt out my impeller. I didnt check the heat at the time when I shut the engine down.

Rick

Vinny P

Chris made a typo.. by typing "ecking", he means decking. Decking the block is when a competant machine shop sets the block up on a milling machine and takes off a bit of material from the deck ( or top of the block, where the head bolts to) to flatten out the surface. You can only go so far before the deck becomes too thin. By taking some material off, you would need to use a thicker head gasket to make up the space between the piston and head, or the compression would be too high. Can you post a picture of the damage?

Pete280

I've seen the damage, it basically is a 1/16"-1/8" channel between two cylinders on the block and the head.

btw, it's a 500efi if that matters

Chris Sunkin

Yes, decking, not ecking. Sometimes I type like I'm an ickhead.

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Rick, IMHO get the motor out and take it to a reputable machine shop. They are the experts on those GRAY area's if the block is salavageable let the "MAN" tell you.. I gone though a similare situation w/ my motor w/ a sleeve being next to another sleeve. Hope all goes well.

Rookie

"1/16"-1/8" channel between two cylinders"

I did this between 2 cylinders on a head before (blew a head gasket), I took it to my engine machine shop they welded and decked the head and no problem.

I just saw this on another persons block last month and I'm pretty sure it was welded up at the same shop bored and decked similar to my head.