Dropped a Valve-gctid391180

[itsabowtime2]

OK gear heads. What caused this?

Back story. Looking at a boat. During transport from sellers property to the dealer one egine drops a valve. Engine is being replaced with a 'new' motor. Sales person is finding out if new is indeed new, reman etc. Engines have about 600 hours on them (2002 SBC, 5.7L Volvo 260hp)

So what caused this? And more importantly could it happen to the other engine? (I know that yes it could) Is this a maintenance issue? The engines have been run hard issue? Or a fluke/once in a million chance happening.

The good news (for me) is that it has happened on the sellers watch.

[Guest]

When you say it dropped a valve are you talking about the valve dropped down thru the piston and out the side of the block, or did it just tulip and start skipping????? Advanced timing and the cheap government fuel/ethanol usually cause these kinds of problems.....

[Guest]

Abigayle III wrote:
When you say it dropped a valve are you talking about the valve dropped down thru the piston and out the side of the block, or did it just tulip and start skipping????? Advanced timing and the cheap government fuel/ethanol usually cause these kinds of problems.....

Along with the above reply, if they put a "cheap" valve in it as a re manufactured block, they are not that great in standing up to the above conditions. So may just be an isolated incident or they will all go. Ya need a crystal ball at this point

At a minimum I would really check the other engine with a fine tooth comb - compression (both dry and wet), timing, maintenance records, manufacturer and see what info they have, etc.

May work out - at least you will get 1 new engine if you buy

[itsabowtime2]

Abigayle III wrote:
When you say it dropped a valve are you talking about the valve dropped down thru the piston and out the side of the block, or did it just tulip and start skipping????? Advanced timing and the cheap government fuel/ethanol usually cause these kinds of problems.....

Good question.

When I speak with them again I will ask.

[2850Bounty]

I too would like to know their definition of "dropped valve"!

Did a valve spring retainer keepers come loose and out?

Did a vavle tulip under extreme heat?

Did a valve spring break or collapse?

If a valve actually dropped, did it contact the piston and cause damage?

Correct terminology, or the lack there of, is often an issue.

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[Guest]

It can be all kinds of things, I like to link it to over-revving and the resulting valve float that can let the keepers come out.

Maybe it kicked out of gear under load?

[Guest]

In my experience actually dropping a valve,i.e. having the valve drop down and bang on, or break off on top of the piston is a mechanical issue, mot often caused by weak valve springs or over revving and floating a valve,

There are other conditions caused by heat and detonation, but it usually doesnt invole actually jamming a valve into a piston.

I have pulled motorcycle engines down with as little as 50 lbs spring pressure and those are just a failure waiting to happen.

[itsabowtime2]

Tony, Rick, Ryan.

Thank you. Now I have a much better understanding of what can cause this. Once the repairs are complete I am going to call their service department directly and see what they determined as the cause.

There is no way of checking to see if the other engine could suffer the same fate is there. Even on the bad motor, is there a way to determine if it was over-revving vs. heat.

Rick, on the '02 FI engines, are they not computer controlled / RMP limited? and the timing as well? (knock sensors and all that wonderful :right technology)

[2850Bounty]

itsabowtime2 wrote:


Rick, on the '02 FI engines, are they not computer controlled / RMP limited? and the timing as well? (knock sensors and all that wonderful :right technology)

Phil, which model engines?

RPM may be limited, the timing will definitely be EST, and these will very likely use the knock senors.... but again, need to know which engine models.

http://"http://www.marinepartseurope...el number.</b>

I've got one for us........

If a radial cylinder aircraft engine suffers similar valve damage (at one of the lower cylinders), do we say that we "dropped a valve", or that we "raised a valve" ????



Then what do we call it if we loose a valve at either the 9:00 O'clock position, or at the 3:00 O'clock position cylinder????? "We slipped a valve sideways???"

I think that well seasoned mechanics should be more creative, and use more descriptive terminology.

,

[itsabowtime2]

Rick, they are 2002 5.7L 280hp FI engines mated to the Duo Prop drives (not composite) Gi is the model.

[2850Bounty]

Phil, have you been able to learn the dealer's interpretation of "Dropped a Valve" yet? Just curious.

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