03 Procraft 200 EFI Merc (blown)

[fishinwrench]

13 hours ago, luckycraft said:

Is that canoe in the background for sale?

Everything is for sale.  Make me an offer 😅

[aarchdale@coresleep.com]

I have a 2004 192 Super Pro.  Its been a good boat, very wide and stable. Mine isnt fast by any means, Mine just has a 150 Xr6 and it runs about 54 loaded down pretty good, I would love to have that 200 on it

[aarchdale@coresleep.com]

Out of curiosity what caused the thing to melt down?

[fishinwrench]

1 hour ago, aarchdale@coresleep.com said:

Out of curiosity what caused the thing to melt down?

I haven't torn it down and inspected it.....and don't plan to.   But judging by the way the piston melted down, the white-hot deposits on ALL of the spark plugs, and the fact that the fuel in the vapor separator tested over 18% alcohol content, my guess (for now) is typical detonation from low quality fuel..  

This happens when a glowing hot spot inside the combustion chamber begins to ignite the fuel mixture as the piston is still moving up the cylinder on the compression stroke.  Also known as "pre-ignition" or "dieseling".   Sometimes, as in this case, it blows the edge of the piston off so that the excess pressure escapes out the exhaust port.   In other (worse case) scenarios it blows a hole completely out the side of the block.  

This motor actually has detonation sensors that are designed to retard ignition timing if pre-ignition is detected.....but when you have a glowing hot spot inside the combustion chamber it doesn't need a spark from the spark plugs to ignite the fuel mixture....so detonation sensors can't save it.   

Bottom line......Poor quality fuel, and a driver that wants to haulass.  😏

[MrGiggles]

Wrench, why you gotta tempt me...

[aarchdale@coresleep.com]

How can we be sure to get quality fuel.  Why dont cars "detonate" and burn a piston like an outboard?

 

Stupid questions i know, but its got me wondering. 

[oldfella]

still available? What is the main side color? hard to tell in the pictures.

[MrGiggles]

1 hour ago, aarchdale@coresleep.com said:

How can we be sure to get quality fuel.  Why dont cars "detonate" and burn a piston like an outboard?

 

Stupid questions i know, but its got me wondering. 

Automotive EFI systems are smart enough to detect the lean condition and correct for it, outboards may not be. Cars also don't typically sit for months at a time with the same fuel.

In the event of a big failure, car engines will burn a piston from pinging, but it's rare. With knock sensors and all of the redundant engine management, it's very hard to do, unless it's turbocharged, those are way more prone to it. Low speed preignition is a big problem on turbo direct injected engines, I still don't think they have figured out a way to stop it, they say the right kind of oil helps. Ford went back to port fuel injectors in addition to GDI, which also helps with intake valve coking, and may lessen pinging.

Ethanol is very resistant to pinging (E85 is like 108 octane), but it has less potential energy, requires more of it to do the same amount of work. Flex fuel vehicles have ethanol sensors that constantly check ethanol content and adjust fueling as necessary. If you ran it in a typical car engine, the worst that would happen would be crappy running, and a lean code would set from the PCM dumping fuel while trying to correct the lean condition. The knock sensors should dial back timing way before engine damage can occur.

It's also worth noting that marine engines run at 100% load 90% of the time, that would be like a car going up a steep grade running as fast as it can without losing speed, engine damage is way more likely to occur in those conditions.

[fishinwrench]

58 minutes ago, aarchdale@coresleep.com said:

How can we be sure to get quality fuel.  Why dont cars "detonate" and burn a piston like an outboard?

 

Stupid questions i know, but its got me wondering. 

Not a stupid question.   

Shift your car/truck into 1st gear, mash the throttle and hold it at 6000 RPM for awhile.   You'll be calling for a tow truck shortly.  😄

[fishinwrench]

1 hour ago, oldfella said:

still available? What is the main side color? hard to tell in the pictures.

Yep, it's money green/gold/white.