I have had mud plug up the water hose going to just one header tube thus that header tube runs much hotter than all of the others. Hotter means better scavenging. Lean condition on just that cylinder.

That piston melted due to a lean condition. I never said that the bearings were damaged. I said IF it was detonation that destroyed that piston I felt the bearings would have been hammered.
The top ring came off WHEN the top of the piston melted off. I have melted pistons many times and they were NOT caused by detonation. That piston melted and coated the cylinder with it. That one cylinder ran lean for a lot longer than 10 seconds. If the head lifted off of the block it would have melted the head gasket also. I run EGT gauges on my engines for a reason.

Yes High Impedance, and they will be controlled by a tuned flash in the ECU. We now have 2200CC HIGH Z injectors that can idle stoich at IPW of 1.10-1.20 MS Amazing how technology has progressed!

Number 6 Sir. 3rd Back on left side of engine.

Its an MEFI4, still fire the same though.

Thanks, I was just curious where that piston was when number 4 fired.

maybe you should stick to correcting spelling&grammar,or be a spelling b captian,you are better at that than you are understanding what is going on inside a cylinder.now flame away tough guy.

Always an A S S. Keep it up MIKE. - You don't know a thing about me but YOU know everything. If you are so smart - You tell me why car headers are so much better than boat headers when everything is the same. DUH
How many engines have you built? How many pistons have you seen melted?

:lolhit:arent you going to correct my spelling,i will keep it up,what are you going to do about it tough guy?i know by what you say that you dont know ****,just think you do,you are just a big mouth -no brain -PUNK.now go back to the spelling b.:lolhit:

and yes i am an ass AMERICAN SUPER STAR.

HEY STUPID - You must have me confused with someone that cares about your spelling. I don't care. - It just proves how stupid you are.
You didn't answer my question... MR LOUD MOUTH KNOW IT ALL

:lolhit::thankyouthankyou:MAYBE IT,S TIME FOR YOU TO TINKER WITH YOUR DINKER!

I can attest that mike has probably built 15 engines in the last 2 years alone. Used to build and race blown alcohol, worked as an assembler at a machine shop, has a pair of blown 540 950hp engines in his cat he built that runs a buck and a quarter, and 1200hp whippled 598's he runs in his fountain at the moment. And he has seen his share of smoked pistons . Not trying to defend him, just stating facts. He isn't new to this stuff. You walk in his shop and you'll find every engine tool you can think of, big blowers , rods, heads, cranks, and all kinds of cool stuff to play with sitting on shelves. He's built everything from a 389 Pontiac resto engine, to a basic 502 build, to huge power blown alky stuff. He's just a hobbyist like the rest of us with a love of horsepower . Just sayin.

+1,, i have been their as well and all above is true..also i will be the first to admit that i have blown up a ton of stuff with the help of nos..that was before we had the data logger and all the egt's and o2 sensors in each tube of the header and i will still crush or peel a ring land off a piston even with a 7k data logger..

Yes - He may be but HE doesn't need to be an A S S HOLE. He doesn't have a clue what MY capabilities are. He just likes to name call. I don't know why he has a thing about spelling - I don't care - I never have and have never called him out on it.

read my and your posts and then tell me who did the name calling,you are pathetic!

So YOU have a problem with reading too.

Maybe YOU should reread post #46 - that is where YOU started calling ME names. I don't give a dam about your inability to spell.

what name did i call you in post 46

So, any news on the motor ? any pictures of the head gasket ?

Read it again - after post #46 you just started calling me names. I don't know what your problem is with me - You don't know me or what I am capable of doing.

i know that you are confused about many facets of engine operation,and that you have an attitude,but i dont give a chit about you.im not going to waste any more of my time attempting to teach you anything because it,s evident that you know everything.truth is you dont recognise detonation when it is as clear as a bell.im done with this,and you.carry on with your rant if you feel the need.

so i did no name calling in post 46,but it,s ok for you to call me ASS ******* STUPID,dude,maybe that,s how you roll,like i said,you are pathetic.and i certianlly hope that you saying that i dont know what you are capable of is not a threat to me,if it is let me know.

You have a problem - GET OVER IT. I don't give a dam about YOU - But when You come on here and start calling me names I am going to defend myself.
I would think that if that engine was running with low enough octane or too much advance to do that much damage to one piston it at least would have done some damage to other pistons. Did any eyebrows on other pistons get deformed? What caused just that one piston to melt or detonate like you say? Sounds like the injectors have been checked and it sounds like the ignition was not the problem. did the spark plug come loose. the only one offering an idea that could cause just one cylinder to melt down was my suggestion to look at the header.
If you are such an expert than tell us what caused the meltdown on just that ONE cylinder.

mtuned,after you repair the engine damage i suggest replacing the cap and plug wires,it is posible that the cap has an internal crack or carbon tracking causing that cylinder to fire at the wrong time causing the detonation,it is also posible that the energy from a plug wire is jumping into another wire,i know this sounds crazy but i have seen it hapen with msd wires that are 3 or more years old in a marine envirement.

Ok guys after looking at the op pics, It looks like the damage started around the intake/eyebrow area and burned around the top of the piston toward the exhaust valve side, so why would it start there near the cooler side of the incoming air charge? I don't have the answer just bringing up an observation. Could it have a small crack in the cyl head? Steam jet cutting into the piston and once it penetrates to ring it self destructs? don't know what are your thoughts?

Might want to look at the head gasket between the cylinders.

What do you guys think about this for fuel setup.
3L Surge Tank Twin Fuel Pump Bracket Genuine 2 x Bosch 044 Fuel Pumps | eBay

And a single Walbro 255 feeding that?

Mtuned... clean your PM inbox... its full :)

Cleaned ! Teamsynergy

Why not just run a single aeromotive or Weldon pump and eliminate all that poppycock?

Because that's the thinnest part of the piston and that's where it starts to melt.....

You can melt down just one cylinder at a time, it happens all the time, some run leaner then others.... My buddy has 800+ hp procharged engines in his Formula, over last 7 years melted twice.... each time it was ONE piston.... its carbed also, no no per cylinder injectors.... it just happens that way...

Worried about the stock fuel line being able to supply the correct amount of volume to two bosch044 pumps. Surge tank will elimnate this issue.

Yes, I know what a surge tank is. I can see you're a car guy. A surge tank can help, but its not designed for continuous Full throttle, like a boat does. It can work in a drag race application because theres normally enough fuel stored in the surge tank to complete a pass. Theres no way around it, if you're fuel line is too small, at some point the engine can starve for fuel in a boat..

Theres a hundred thousand guys on here, who've done what you're doing, with probably 2, or 3 times the power your making. Replace the stock fuel line and pickup with larger lines, run a Aeromotive pump, or other marine style electric pump, call it a day. Unless of course this melted piston thing is up your alley, forget the car stuff for boats.

Agree!!!

Thunder is completely right, that surge tank deal is sure cool looking but will do nothing after about 12-15 seconds of WOT, could even make your fuel pumps suck air as tank level gets too low, it will only support as much hp as the pump supplying the tank can put out after sustained wot, I'm not sure how you drive your boat but I have ran my flatout (with over 1000 hp) for 5plus minutes before, when it only had 700-750 hp ran it at wot for 20plus minutes, think more like endurance or Nascar than drag race when you pick your parts, Smitty

We use surge tanks in alot of road race applications. Not sure of you guys are aware that the RETURN line from the fuel system is also plummed back into a surge tank to function properly. So any excess fuel the regulator bleeds off will also fill back the surge tank, once the surge tank if full it bleeds back into the fuel cell...

Either way, i am certain you guys are correct that i can work around the stock feed line just fine. Its just the factory line on my boat and fittings were very small.

Thanks for the advise, I guess i will just go with a single weldon fuel pump and call it a day. I am trying to plan the fuel system to be able to support large demand, as I will be tuning it on E85 at some point with much larger injectors.

Full force - Yes I know that some cylinders run hotter than others. That is why I have my EGT probes in the header for #6. BUT I have run a little too lean and done damage to one or two pistons - BUT - To completely destroy one piston I would think there would be SOME damage to another. If there was a bad injector or blocked fuel line I could see it. But that was ruled out and the electronics I believe was ruled out.
If it was timing then again I would expect damage on another cylinder. I would have thought there would have been at least one eyebrow deformed. Is it possible that that cylinder had more compression than the others? Less Quench? Loose spark plug?

I don't want to dwell on the surge tank since you are going to a weldon single anyways but do you understand what I am saying, no matter how much extra the bosch pumps dump back to the tank , after a certain period of sustained wot the max flow from the 255 dumping into the tank would be the max fuel you could get to the motor as it would be the only supply to the surge tank unless I am missing something? Its a cool looking set-up and I could see it working good on something where you were in and out of the throttle. In my case whenI went from 600 to 700 hp a aeromotive a1000 could not keep up under boost and I went to a Essex. When I went from 700hp to 950 hp a while back, I couldn't get enough fuel from that and I went to a aeromotive eliminator. When I went from 950 hp to the 1050-1100 I currently am running the eliminator wouldn't keep up so I added a voltage booster that sends voltage up to about 16 volts after 4-5 psi of boost. A big weldon would be a better set-up for me BUT I didn't want to overload the return regulator and lines and have to replumb everything again to handle the extra return when not into the throttle, I see since then they have a tick toc voltage reducer for that now. What are your hp goals in the future, these blower motors are fun and some is good, more is BETTER, Smitty

I totally get that, just saying I have seen just ONE do that a few times before, many small things could cause it to be more lean then others... crazy things happen real fast under boost...

I would be interested in seeing the spark plug from that Cyl. It should be able to tell us something,