454 Magnum water Ingestion, Valve Kiss, Ok to use Piston?

[JC766]

Hello,

I have a 1999 454 Magnum Engine that I'm tearing apart to try and fix. The motor only has 35 hours on it believe it or not.

I removed the heads and found cylinder 2 had a bent exhaust valve and a crushed pushrod. The piston also had a nice ding it from where it hit the valve.

I dont have the tools or capability to pull the motor out of the boat so I'm asking if the piston is still safe to use. I know the internals are forged being a MAGNUM engine so can I safely get away with not trying to replace that piston?

The cylinder walls are good.

Heads look good besides that one valve and some scattered rust corrosion all throughout. The engine was damage and then sat for about 4 months. I just bought the boat. Owner was not really sure when or how it was damaged.

It appears water leaked from the exhaust elbow into the engine. Although I'm surprised that is the cause for the bent valve because it seemed like a small slow leak.

 

[Bt Doctur]

If I`m seeing rusted pushrods water was getting into the motor from someplace. most likely it was a stuck valve from water ingestion and the piston is most likely fine.
Doubtful you could have bent the conrod.Pull all the valves and check for a crack in the exaust seat area.

 

[alldodge]

Agree with Bt and will add, grind off the edge of the piece so it doesn't come loos when running

 

[wrench 3]

My thinking would be that the water rusted the valve stem and caused the valve to hang up, stay open and get bent. It wouldn't take much.
I agree with AllDodge to file the thin edge of off the indent but because it would heat up from the combustion and cause ignition ping.
Check the push rod. The rest should be good, except for the valve.

 

[JC766]

That is good news. I was reading some responses about valve kiss on a Chevy Chevele forum and it was a mixed bag. 50% said it was ok and 50% said replace. But they seemed to be talking about aluminum pistons. I was hoping the extra strength of a steel forged piston would keep me safe especially since I never plan to go past an OEM setup. With regard to the rust I didnt think it was much of a problem either as long as I clean it up. The guy I bought the boat from didnt know anything about working on an engine and didnt want to deal with it so he just let it sit 4-6 months broke with the water still in it. I'm fairly knowlegeable so I picked it up. Didnt know the extent of the damage until i started pulling it apart.


I plan to replace the pushrod and the valve obviously, do I need to replace the lifter and the rocker portion as well? Is it possible since the valve and the pushrod were destroyed that it bent the rocker as well or warped the lifter?


In a slightly related topic, why are the holes for the water passage through the block really large but the head gasket only has small pin holes at top and 1/2 holes at the bottom. It seems like its purposely restrciting the water flow. My guess is because it would push to much water to the exhaust and that the large holes are only for closed cooling systems.

Thanks

 

[Bondo]

That is good news. I was reading some responses about valve kiss on a Chevy Chevele forum and it was a mixed bag. 50% said it was ok and 50% said replace. But they seemed to be talking about aluminum pistons. I was hoping the extra strength of a steel forged piston would keep me safe especially since I never plan to go past an OEM setup. With regard to the rust I didnt think it was much of a problem either as long as I clean it up. The guy I bought the boat from didnt know anything about working on an engine and didnt want to deal with it so he just let it sit 4-6 months broke with the water still in it. I'm fairly knowlegeable so I picked it up. Didnt know the extent of the damage until i started pulling it apart.


I plan to replace the pushrod and the valve obviously, do I need to replace the lifter and the rocker portion as well? Is it possible since the valve and the pushrod were destroyed that it bent the rocker as well or warped the lifter?


In a slightly related topic, why are the holes for the water passage through the block really large but the head gasket only has small pin holes at top and 1/2 holes at the bottom. It seems like its purposely restrciting the water flow. My guess is because it would push to much water to the exhaust and that the large holes are only for closed cooling systems.

Thanks

Ayuh,.... Welcome Aboard,..... Yer pistons are Aluminum, just like every other piston in every other motor,....

Forged, yes, but still aluminum,....

Odds are the valve rusted into the valve guide,... No reason to change the lifter, nor the rocker,....

 

[JC766]

THank you Bondo,

I know you guys always say stick with Mercruiser parts (which I intend to get all the gaskets by) but can I fudge on the valve and pushrods? Cheapest I can find one valve (part # 816962) is $100 and push rods $20 a piece. Most performance stores sell sets of valves for 1-$200. In my research I have not seen a difference in the valves for BBC marine versus auto motors. Is it possible to go to NAPA and just get them there? Still trying to find a cross reference application.

Thanks

 

[Bt Doctur]

BB valves ARE NOT $100 apiece. keep checking