Sucked a Valve!
#11
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Re: Sucked a Valve!
My guess is that your cam has to much overlap for the silent choice exhaust. The SC exhaust dumps the water into the exhaust very close to the engine to accomodate the "Y" diverter. If your cam has much more overlap than the stock engine, your choices will be to either eliminate the silent choice with straight pipes to dump the water further downstream into the exhaust or change the cam to one closer to stock with very little overlap. The water that's getting into your engine is probaly not coming from outside the boat but from inside the engine as your cooling water dumps into your exhaust stream.
Your choice is probably going to be between a louder boat that doesn't have silent choice or a boat with slightly less performance by swapping out the cam for something abit tamer. I would be concerned that you might fix the engine only to pull water back (potentially breaking another valve or worse) into the engine because of the silent choice/cam combo you're running. Just my $.02.
Your choice is probably going to be between a louder boat that doesn't have silent choice or a boat with slightly less performance by swapping out the cam for something abit tamer. I would be concerned that you might fix the engine only to pull water back (potentially breaking another valve or worse) into the engine because of the silent choice/cam combo you're running. Just my $.02.
#12
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Re: Sucked a Valve!
The water is probably from a split cyl wall of damage to the head from the valve pieces.
I have repaired the same engines for the same problem for other people.
I have repaired the same engines for the same problem for other people.
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Re: Sucked a Valve!
Well, pulled the engine today, removed heads and oil pan, what a mess. Valve head went through the head rupturing water jacket which is why the engine filled with water. Apparently it ran long enough to pump water to all cylinder and hydro-locked bending piston rods. Parts of head from #7 cylinder found in cylinders 1 & 6. steel shavings found in pan, believed to be from pistons. All from an intake failure (appears to be fatigue failure) in a matter of seconds. The shop will finish their assessment tomorrow, looks like it's back to the drawing board.
They were running so good and only 35 hours, oh well. You can bet we're going back with serious quality valves this time! Shop is recommending stainless, any thoughts?
Al
They were running so good and only 35 hours, oh well. You can bet we're going back with serious quality valves this time! Shop is recommending stainless, any thoughts?
Al
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Re: Sucked a Valve!
You are lucky that you are not sleeving the block. Not cost wise but durability wise.
Severe duty intake valves and Inconel exhaust valves.
Good quality springs like Isky 8205 Plus.
Severe duty intake valves and Inconel exhaust valves.
Good quality springs like Isky 8205 Plus.
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Re: Sucked a Valve!
Originally Posted by Infomaniac
You are lucky that you are not sleeving the block. Not cost wise but durability wise.
Severe duty intake valves and Inconel exhaust valves.
Good quality springs like Isky 8205 Plus.
Severe duty intake valves and Inconel exhaust valves.
Good quality springs like Isky 8205 Plus.
2 - rods
2 - TRW pistons (.030 over)
Set - Rod bearing
1 - 990 GM head
2 - new valve (told them no way all new serve or extreme duty SS valves)
Sleeve #7 cylinder
Of course the usual stuff that goes with taking one down and putting back together, i.e. cleaning, mag-flux for cracks, gaskets, etc.
I removed all accessory leaving a couple of motor mount bolts hand tight, took the boat to their shop, they lifted out of the boat. They will drop it back in the boat and I strap on all accessories.
Does that sound like a nice round $3,000.00 job to them? Maybe it is I simply don't know. What do you guys thing?
Al