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Help!!! My engine blew and I need guidance, please!


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I have a 2004 Malibu Wakesetter VLX ... I think it's a 340 Indmar Monsoon? 

Anyway, after talking over options with my car mechanic and boat mechanic friends, it looks like I can either buy a new 5.7 Marine Long Block for about $3,000 here https://marineenginedepot.com/20012/0/Default.aspx

Or, a local vendor can provide a rebuilt for about $1,400-$1,600 depending on what he can salvage from my current engine. Only problem is that he and the car mechanic friends are telling me that the only difference would be the cam shaft. I don't understand mechanics, but my boat mechanic friends are telling me that that matters in a boat. The shop rep and car mechanic friends are saying it shouldn't. 

 

Any advice would help!

Thanks

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49 minutes ago, JLickteig said:

 depending on what he can salvage from my current engine.

 

14 minutes ago, shawndoggy said:

why can't the local vendor use a marine cam?  IIRC the issue with "marine" cams is avoiding valve overlap to discourage hydrolock.  there are lots of marine cams on amazon and at least three on summitracing.

The solution is simple, salvage to cam and lifters from the original engine.

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What is the damage?

Edit: water froze in the block?  no compression on one or two cylinders?  rod knocking?

Edited by Michigan boarder
clarification
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56 minutes ago, JLickteig said:

I have a 2004 Malibu Wakesetter VLX ... I think it's a 340 Indmar Monsoon? 

Anyway, after talking over options with my car mechanic and boat mechanic friends, it looks like I can either buy a new 5.7 Marine Long Block for about $3,000 here https://marineenginedepot.com/20012/0/Default.aspx

Or, a local vendor can provide a rebuilt for about $1,400-$1,600 depending on what he can salvage from my current engine. Only problem is that he and the car mechanic friends are telling me that the only difference would be the cam shaft. I don't understand mechanics, but my boat mechanic friends are telling me that that matters in a boat. The shop rep and car mechanic friends are saying it shouldn't. 

 

Any advice would help!

Thanks

Cam is basically a RV cam... some other minor differences... freeze plugs are brass, head gasket material... but nothing major. 

It is a GM 350 block and internals

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@JLickteig:  Your Indmar uses the GM marine short block - this will include a specific GM marine cam, along with some hardware that is marine specific such as the freeze plugs.  Indmar uses a specific to Indmar intake manifold.  If your local vendor does not know the different specific marine parts, that may not be your best route.  The existing damage would assist in making the correct decision on the path forward.

Note:  Marine parts are designed to contain spark (alternator / starter / distributor) and to have proper corrosion protection (freeze plugs / hardware) or proper power curve and hydrolock protection (camshaft).

Edited by Woodski
  • Like 3
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Just for kicks, my cam specs are:

Mfr: Straub Technologies (Pinely Flats, TN)                         

Duration at .050: 205 intake, 218 exhaust

Duration at .006: 256 intake, 273 exhaust

Lobe lift: .3260 intake, .3175 exhaust

Gross valve lift: .489 intake, .476 exhaust

Timing events at .050: Intake -5.5 open, 30.5 closed   Exhaust 45 open, -7 closed

 

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On 5/15/2018 at 5:43 PM, JLickteig said:

Only problem is that he and the car mechanic friends are telling me that the only difference would be the cam shaft. I don't understand mechanics, but my boat mechanic friends are telling me that that matters in a boat. The shop rep and car mechanic friends are saying it shouldn't. 

Now to this point. The camshaft matters in a boat SOMEWHAT because the cam can determine the operating range. 
In my old Supra I replaced the engine with one directly from a junkyard explorer. 1995. Pulled the engine put it on my stand. Took the oil pan, intake, and accessory parts off and bolted them on to the "new" engine. 
Been in the boat for 5 years. Runs fantastic. 

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19 minutes ago, Michigan boarder said:

Just for kicks, my cam specs are:

Mfr: Straub Technologies (Pinely Flats, TN)                         

Duration at .050: 205 intake, 218 exhaust

Duration at .006: 256 intake, 273 exhaust

Lobe lift: .3260 intake, .3175 exhaust

Gross valve lift: .489 intake, .476 exhaust

Timing events at .050: Intake -5.5 open, 30.5 closed   Exhaust 45 open, -7 closed

I never paid attention to the fact you have a stroker! What heads? I have a 408 SBF stroker with Trick flow heads that I'd love to put in something fast. Boat wise....it's in a mustang. 

I've seen cams crutch a low flowing head with higher exhaust duration but 13° is a lot! And I've never understood why the exhaust sometimes has less lift. Not knocking it! Obviously it works! 

Edited by Ryan1776
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18 minutes ago, Ryan1776 said:

I never paid attention to the fact you have a stroker! What heads? I have a 408 SBF stroker with Trick flow heads that I'd love to put in something fast. Boat wise....it's in a mustang. 

I just looked and actually I can't find any data on that.  The build was done in 2013-2014, we had one set of heads but sent them back and bought something different.  I need to figure that out.

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On 5/15/2018 at 5:43 PM, JLickteig said:

I have a 2004 Malibu Wakesetter VLX ... I think it's a 340 Indmar Monsoon? 

Anyway, after talking over options with my car mechanic and boat mechanic friends, it looks like I can either buy a new 5.7 Marine Long Block for about $3,000 here https://marineenginedepot.com/20012/0/Default.aspx

Or, a local vendor can provide a rebuilt for about $1,400-$1,600 depending on what he can salvage from my current engine. Only problem is that he and the car mechanic friends are telling me that the only difference would be the cam shaft. I don't understand mechanics, but my boat mechanic friends are telling me that that matters in a boat. The shop rep and car mechanic friends are saying it shouldn't. 

 

Any advice would help!

Thanks

@JLickteigOk man, what actually happened? Inquiring minds what to know. 

Edited by Ryan1776
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Just to add to the thread, one method commonly used to prevent hydrolock when a more aggressive cam is used, extending the water mixing point of the exhaust system  via a longer riser.  That moves the mix point farther down and lower relative to the bend.  Hydrolock can occur as an engine cools and the cooling creates a draw on the exhaust side which sucks water in the exhaust system up in to the combustion chamber, how this relates to the camshaft is the fact of a more aggressive cam profile will leave the valves open via greater duration or overlap thus creating a bigger vacuum signal.  

FYI - I am running the GM Fast Burn aluminum cylinder head and a ZZ4 camshaft, coupled to a 4" exhaust system, great combo for slalom and barefoot applications. 

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6 minutes ago, Woodski said:

Just to add to the thread, one method commonly used to prevent hydrolock when a more aggressive cam is used, extending the water mixing point of the exhaust system  via a longer riser.  That moves the mix point farther down and lower relative to the bend.  Hydrolock can occur as an engine cools and the cooling creates a draw on the exhaust side which sucks water in the exhaust system up in to the combustion chamber, how this relates to the camshaft is the fact of a more aggressive cam profile will leave the valves open via greater duration or overlap thus creating a bigger vacuum signal.  

FYI - I am running the GM Fast Burn aluminum cylinder head and a ZZ4 camshaft, coupled to a 4" exhaust system, great combo for slalom and barefoot applications. 

These kind of things are used to control the water flow at idle when you get aggressive with the cam.

http://www.cpperformance.com/c-389-jet-header-water-control.aspx

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13 minutes ago, Woodski said:

 how this relates to the camshaft is the fact of a more aggressive cam profile will leave the valves open via greater duration or overlap thus creating a bigger vacuum signal.  

Actually the more overlap the less vacuum there is. Because the the exhaust valve is open at the same time as the intake during the initial portion of the intake stroke. So when one piston is moving down on the intake stroke another piston is "sitting" at TDC with both valves open. 
 

Edited by Ryan1776
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@Ryan1776:  The vacuum is from the mass cooling so throttle plate closed the mass of the intake manifold can act as the heat sink source.  Chances of two exhaust valves being open is greater with a more aggressive camshaft.  For a cam that works well on a watersports boat, the cam is not the issue, it becomes the height difference between the exhaust port and the resting water level.

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@Woodski

 you're kinda all over the map here and contradicting and negating your previous comments. 

At first I thought we were talking about running vacuum with the phrase "vacuum signal", that is my fault as I missed interpreted what you were meaning. 

But you equated the water being "sucked" up the exhaust manifold directly due to the cam overlap. "how this relates to the camshaft is the fact of a more aggressive cam profile will leave the valves open via greater duration or overlap thus creating a bigger vacuum signal.  "

Then you move on to, "The vacuum is from the mass cooling so throttle plate closed the mass of the intake manifold can act as the heat sink source.  Chances of two exhaust valves being open is greater with a more aggressive camshaft." And in the same thought negate that effect by stating, " For a cam that works well on a watersports boat, the cam is not the issue..."

Overlap has nothing to do with how many exhaust valves are open in the engine as system. It has to do with to exhaust and intake valves in a shared cylinder. Duration is what matters. You cannot conflate duration and overlap. The current theory is to pick cam events individually and let the overlap fall where it lies. But that is a hot topic of debate in and of itself. 

So if I were to argue that the cam overlap is the issue...

Lets assume we have a closed intake and an open exhaust valve which could cause the condition of cooling of the cylinder to pull water up by creating this vacuum. At the point were water could rise up though the riser and back into the engine,  we have all 4 exhaust ports mixed, meaning water cannot intrude the engine right at the head or at the top of the riser where each exhaust runner is still separated, it is somewhere down the line at a common mixing point. Meaning it can equally pull from say cylinder 3 as well as 5 or 1 or 7, depending on which valve is open. And that being the case, you will have a situation where one of those other 3 cylinders will have an intake and exhaust valve open together, and air will take the path of least resistance and pull from the open intake valve and equalize the pressure. In that cylinder were both valves are open, but the throttle closed, there is plenty of "leak" there to allow air flow though the cylinder and neutralize the pressures.  Keep in mind there is still enough air flow to allow that engine to run and displace enough air to allow a 350ci engine to idle at 800rpm, Or whatever the idle rpm is.

Now if you want to talk about reversion. This is in running situation. Not sitting. Just covering all my bases here. 

The reversion most people talk about is the exhaust reversion into the intake during overlap.   This doesn’t mean the exhaust is coming from the lake, it’s coming from the exhaust pressure that’s still in the cylinder!

Think about it… pressure differential causes gas flow.   The exhaust stroke upwards creates pressure which pushes it out the exhaust port.   The ONLY time that there could possibly be a negative pressure, is when the piston goes past TDC and starts to pull down.  Even if you had a cam with [email protected]” on a 108LSA and ICL, with a 350” (5.7” rod, and 3.48” stroke), the piston is only pulling down 0.051” by the time the exhaust valve closes!   Which is 0.64 in^3.   There is no way that volume /vacuum would be enough to fill up the entire exhaust system and pull water into it!!! (that’s 2 teaspoons of volume by the way to put it into perspective).

Now if I were to argue about the exhaust port location vs water line, I would say the exhaust port is also irrelevant, but more the floor of the riser and the water level. 

 

Edited by Ryan1776
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45 minutes ago, Ryan1776 said:

The reversion most people talk about is the exhaust reversion into the intake during overlap.   This doesn’t mean the exhaust is coming from the lake, it’s coming from the exhaust pressure that’s still in the cylinder!

Think about it… pressure differential causes gas flow.   The exhaust stroke upwards creates pressure which pushes it out the exhaust port.   The ONLY time that there could possibly be a negative pressure, is when the piston goes past TDC and starts to pull down.  Even if you had a cam with [email protected]” on a 108LSA and ICL, with a 350” (5.7” rod, and 3.48” stroke), the piston is only pulling down 0.051” by the time the exhaust valve closes!   Which is 0.64 in^3.   There is no way that volume /vacuum would be enough to fill up the entire exhaust system and pull water into it!!! (that’s 2 teaspoons of volume by the way to put it into perspective).

Now if I were to argue about the exhaust port location vs water line, I would say the exhaust port is also irrelevant, but more the floor of the riser and the water level. 

 

True, reversion isn't caused by piston moment (the piston's not moving very fast at TDC anyway), it's caused by overlap.  When the intake valve first opens, the pressure in the combustion chamber is greater than that in the intake manifold, so exhaust briefly flows into the intake manifold.  Because of this, the pressure drops in the combustion chamber and is now less than the pressure in the exhaust manifold.  Since the exhaust valve is still open, the exhaust briefly flows back into the combustion chamber, along with any water present. 

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@MadMan "When the intake valve first opens, the pressure in the combustion chamber is greater than that in the intake manifold, so exhaust briefly flows into the intake manifold."
Correct, but for the pressure to be greater, the piston still needs to be moving upward. And therefore the exhaust gas that reverts into the intake port is not from exhaust already spent though the runner but what is still in the cylinder. Because there is still positive pressure expelling the spent charge out the exhaust as well. 

"Since the exhaust valve is still open, the exhaust briefly flows back into the combustion chamber, along with any water present. "

No way. Not enough time NOR strength. As I pointed out by the numbers, with a fairly aggressive cam, not what we have, the piston is only down in the cylinder 0.051" when the EV closes. And that VERY little volume of air/vacuum that exists before that E valve closes wouldn't be able to pull back water from THAT far down stream in the system. This is also not taking into account the fact there are other cylinders sending their burnt charge down the same pipe at the point of communion which will have significantly higher effect in forcing the water out than the extremely short amount of time the EV is open with the IV. 

 

The other thing is, we’re talking about VERY low RPM causing this issue (if it were high RPM, we know the overlap doesn’t cause reversion). At low RPM the throttle is choking off 90%  of the air flow.   Meaning… the cylinder isn’t even CLOSE to being full of air.  (it’s the basic principal of how a throttle works right?) So if the exhaust can flow well enough to empty the chamber at 5000RPM, it can certainly EASILY empty the chamber only 10% full at idle.

Edited by Ryan1776
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1 minute ago, Michigan boarder said:

So what happened to the engine?

One post on Tuesday and gone.... 

Total thread hijack, but at least he's getting notifications. 

Edited by Ryan1776
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