DURANGOKID59

A few weekends ago, I somehow sucked water up in to a few cylinders and the motor obviously quit. I got it back to the dock and pulled the plugs and water came out of the holes. I did a compression and leakdown test, and the #7 cylinder has no compression and showed a leak going through one of the valves. I tore the exhaust manifolds off, and the rocker cover off to find that the intake valve was bent and had broken the keepers and rounded the edges of the the rocker itself. I havnt torn the head off yet, but is this damage possibly the result of sucking water in to that cylinder, or am I chasing 2 different problems? Its a 1992 454 carbed out of a 92 Outlaw if that helps any. Thanks in advance.

GOODT

more then likely its from the water I have 3 500 efis all withe the same problem all three had cmis that where leaking

DURANGOKID59

So from you experience the cylinder possibly filled with water and caused a bent valve and all the other little broken pieces Im finding in it? Sorry to ask dumb questions, Im just not mechanically familiar with how the internals work. The next step is to pull the head and see how much damage I did to the piston if any now correct? Thanks for the quick reply by the way

jmherbert

Yes, I'd bet what you have seen is due to the water. Likely quenched and broke a valve or a valve seat.

Your bottom end MIGHT be O.K., if the valve/seat did not break or severely damage the piston. The right thing to do would be to tear down and rebuild the motor. A piston hitting a valve cand bend or break a connecting rod. It may look OK and run for a while, then go boom.

Either way, you need to find out how that water got in. Chances are strong that your manifolds/risers are shot. I don't trust the stock units at all, their design will fail sooner or later.

DURANGOKID59

So it is feasable the water caused all this, and still have to find the source of the water. It does have the stock manifilds on it. What causes them to go bad? Is it cracking or warping or something of that nature? I suppose there is no true way to find out if I bent a rod other than pulling the motor out? Thanks for the help guys.

jmherbert

The "right" way to do it is pull motor if there is any sign of piston/valve collison, and at least replace that piston and rod.

However, with the time of year it is, if there is no or only slight collison marks, I would be very tempted to chuck a new head on it and finish the season out. Beware that a broken connecting rod can really ruin your day (destroy the short block beyond repair)

Those stock exhausts can crack, warp, gaskets can fail. I hate them. I had problems earlier this year with them. Kept leaking into my brand new motor, but would not leak a drop when pressure tested. I replaced them with Revolutions, because they do not have the wet joint, the manifolds give the risers water thru a hose instead of a gasketed flange., makes it impossible for them to leak there. The stock style exhaust I had was only a few years old, and looked brand new.

I personally will not ever put that style exhaust on any future boats I own.

Almost forgot, check your flappers to make sure they are still there.

DURANGOKID59

Thanks for all the help Jm, and GoodT. Im just trying to diagnos it the best I can with limited knowledge I guess Ill have to see what the piston looks like when the head comes off, and go from there. Again thanks for the help.

pkspx

I had cyl #7 blow in my 454 3 years ago, heres pics of my damage

No one knows exactly what happened but as far as we know Cyl 7 cracked, water came on and on the exhaust stroke while the valve was open the piston came up and tried to compress the water (thats a nono lol) anway so it ended up costing a complete rebuild new block new heads new pistons everything else was good.

Cyl #7 Cracked from top to bottom


cyl #7 Exhaust valve gone....


Cyl #7 pistons hehehe

DURANGOKID59

Wow, I hope thats not what I find when I pull the head off. That would not make my day.

offthefront

iTrader: (1)

I would 'bet" its the exhaust manifolds ...the stock manifolds are going to leak ...just depends "when" ...if I bought a BBC with stock exhaust they would be first on the list to be eliminated .....m