dead cylinder!-gctid352561

[Guest]

Had a bad feeling I was running short of 8, did a compression check and sure enough I have a bad one.

Planning on pulling the valve cover and seeing if I can locate a stuck valve or bent rod etc.....anything else to check before pulling heads? The boat is in the slip, no trailer-- Has anyone pulled their heads while on the water?

I'm tempted to start tearing it down, but if I run into frozen bolts or other surprises it would get messy!

[Guest]

your on the right track, thats what I would do...

first pour a bit of oil into cyl do a comp test see if it makes a difference, that will eliminate rings, but if you are at 0psi prob a valve issue...

pull valve cover and look for broken valve spring , stuck/bent valve, bent push rod ...ect

as for pulling the head off in the slip, I cant see why not as long as you are prepared to get towed somewhere for haul out if it becomes neccessary...as you said it could become messy...personally I would rather do it on the hard

Good luck!

[Guest]

Thanks Matt--yeh,tried to get a little oil in there, no change. I'm hoping against hope for a quick fix, so I can run it while I start saving up for a proper (closed cooling!!) repower in the future. If I have to pull the heads, I'll probably just go with my local mechanic as he's very resonable about haulout and labor charges. Fingers crossed!

[Guest]

I hear ya on not wanting to put to much money into an engine you plan on replacing soon anyway...Ill keep my fingers crossed for you too ...at least you have a decent mechanic you trust, thats half the battle

[Guest]

Which cylinder?

Some of the big blocks from that era ended up having a manifold issue that allowed condensate to pour into the 2 rear cylinders. Just wondering if you have a bad hole on #7 or #8.

[Guest]

Check the waterline in relation to the elevation of the rubber coupling hose you will need to disconnect to remove the exhaust manifold to ensure the waterline is below the level of this hose where you are disconnecting it.

[Guest]

myflies wrote:
Check the waterline in relation to the elevation of the rubber coupling hose you will need to disconnect to remove the exhaust manifold to ensure the waterline is below the level of this hose where you are disconnecting it.

There is no water up that far. Just take the intake and exhaust manifolds off.

You can see a lot then. I had to change my cam so I had to pull the engine, but getting the head off is only a couple of hours at most.

You can see the exhaust in the back of my pic well above the water line.

Attached files http://baylinerownersclub.org/media/... off.jpg[/img]

[Guest]

check737 wrote:
There is no water up that far. Just take the intake and exhaust manifolds off.

The waterline varies with boat model. My 1998 2052 Trophy with 4.3L V6 has a riser block between the exhaust manifold and the elbow to raise the elbow above the waterline. Unless I had some really high volume pumps on my boat that were guaranteed to not stop pumping, I wouldn't remove the exhaust manifolds on my boat while the boat was in the water.

[Guest]

My money is on a burnt or bent valve due to high timing and ethanol fuel. I had this problem with my boat last year. Pulled the intake and head in just a couple hours cleaning gaskets and preping for reinstallation is another story... I had about 8 hrs total when it was all said and done and 260 bucks in the valve job/replacement and gaskets.

[Chief_Alen]

zero compression in one hole is valves or a hole in the piston.

Pull the valve cover off and see the valves first.

I too would like to work on the boat on land.

[Guest]

Thanks for all the input, hoping to get some time to go down and pull valve cover this weekend--

It is indeed the rear #7 cylinder that is 0.

I've changed the exhaust manifolds in the slip, so waterline is not an issue. Never had intake manifold or heads off though, so I'm a little cautious about tearing down in the water. Into the unknown once again!

[Chief_Alen]

Keep us posted

[2850Bounty]

MikeMag wrote:
Thanks Matt--yeh,tried to get a little oil in there, no change. I'm hoping against hope for a quick fix, so I can run it while I start saving up for a proper (closed cooling!!) repower in the future. If I have to pull the heads, I'll probably just go with my local mechanic as he's very resonable about haulout and labor charges. Fingers crossed!

Mike, if there was extensive piston damage, it would raise it's ugly head in a different way.

Here's a thought for you:

A future repower is in the works, correct?

This would be a like engine, correct?

Pull both heads and check them out.

Also check out the bores and piston decks.

If all checks out, over-haul these existing cylinder heads!

Re-install onto your existing engine, and run out the remaining life from it.

When the time comes, pull these cylinder heads, check them again, clean the mating surfaces, and install onto a new "like" short block.

I see no issues if the new block needs to play catch up with cylinder heads that may have 50-100 hours on them by the time this would occur.

Replacing cylinder heads on a good working, but used XXX hour lower end, is nothing new.

With the new short block down the road...., you'd just be doing the reverse of this.

Cost would be whatever the cylinder head work would be (work required anyway), several shop hours, new gaskets, etc.

The cylinder head work will have been done, and it would get you on the water.

Talk to your mechanic for his advice on the matter.

.

[Guest]

myflies wrote:
The waterline varies with boat model. My 1998 2052 Trophy with 4.3L V6 has a riser block between the exhaust manifold and the elbow to raise the elbow above the waterline. Unless I had some really high volume pumps on my boat that were guaranteed to not stop pumping, I wouldn't remove the exhaust manifolds on my boat while the boat was in the water.

'00 Maxum 2800 SCR 7.4 BIII

Not a 4.3

That is why knowing what installation is so important.

[Guest]

MikeMag wrote:
Thanks for all the input, hoping to get some time to go down and pull valve cover this weekend--

It is indeed the rear #7 cylinder that is 0.

I've changed the exhaust manifolds in the slip, so waterline is not an issue. Never had intake manifold or heads off though, so I'm a little cautious about tearing down in the water. Into the unknown once again!

How were the rest of your cylinders compression numbers?

If good, I'm going to guess a very crusty exhaust valve due to water reversion or condensation. Post pics of the #7 exhuast port in both the head and the manifold.