Name that failure!
 

99 Baja H2X

502, Procharger, 42LB injectors, Nickerson Charger Cam. Roller rockers and springs and some port work.

Boat was running on this setup for 3 years, AFR around 11.2-11.5.

Last run of the season and this happened! I originally assumed a injector failure, but sent the injectors out to get flowed and they were all within 2% and good to go!

Now im lost, what do you think happened? Every other cylinder was PERFECT, and had no issues.

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What cylinder was it ? can you post pictures from farther away to show the cylinders next to it. Just a guess, the gasket was leaking between the cylinders, the one to the right would fire first and burn the fuel out of the one on the left causing it to run extremely lean.

Yes lean. Some type of air leak. intake gasket???????

What HP and how much boost ? do you have any pictures of the head and intake gaskets?

could have been a few diffent issues, but my guess is since your procharged your head gaskets my had started to leak from being under boost maybe the head lifted or head gaskets jus let go enough to let water in the cylinder and the water vaporized and when it does it will erode the piston above the top ring, causing detonation, or your top ring butted together causing the ring land to break and cracking the piston, but as you can see from the pictures, the piston did not only detonate it broke apart causing peices to contact the head and valves also, just my .02

need to see more of the deck,,looks like a head gasket was on its way out.definitely detonation..had the injector driver checked in the ecm,,may be a issue with it on the big end..could also be fuel delivery for that cylinder,the screen at the top of the injector could have been slightly plugged..

I dont have any more pictures as its all off at the machine shop now. It was running around 6-6.5 psi of boost. I will have the ECM checked out as well. Thanks for all the input guys! Just want to prevent future failure.

Look at the bottom right corner of that cylinder on the deck surface, no sealing witness mark and dark all the way to the water jacket. Looks like it was leaking to me.

You had to be close to running out of injector unless you're running high pressure, what fuel pump are you running ?

you may be onto something. look at the top right at also at the left where the valve releif is. it almost looks like the head gasket is for a smaller bore than the block. the witness marks for the sealing ring of the gasket almost disappears in several spots.

I had one look like that and it lost the Valve seats

assuming you are running a retuned merc ECM ? injectors seem small..don't think that caused the issue...look at block passages closely...seen some clogged and over heated certain cylinders...would be nice to have a tunable computer and be able to "see" certain data on a laptop...I am running a procharged 500HP with our own EFI system using a megasquirt computer...but running 96lb injectors...if you go to a injector sizing table you will see those way small...I am not done with the EFI change over yet...just got back working on it last week...hope to be running in a couple of weeks...

The boat has a Aeromotive A-1000 And a 2:1 FMU on it. I guess i never really seen it until you guys pointed it out. but if for sure does look like the HG may be the issue! Very good catch. There were the Felpro gaskets. Guess i should switch to cometic? or deck both surface and reuse felpro?

Detonation probably took out the gasket, mill the surfaces and use MLS gaskets, but first, find out what caused the detonation so it doesn't happen again on the next power run. You may want to install a wideband 02 to keep an eye on A/F ratios as you're running.

I'll only add this for reference, but I use a 42 lb injector on a N/A 377 cid small block.

I have widebands, refer to first post. AFR was low 11s at wot.

detonation can have many causes, could been bad gas, maybe too small of injector, maybe fuel delivery issue, with a blower anything can happen easier....

BBC don't lift heads that easy and 6-7 lbs isn't much.... The gasket sealed fine that's not a head gasket fail, you were sealed just fine to burn a piston, I would verify fuel delivery and get EGT on it so you can monitor WOT EGT's

again, that's NOT head gaslet failure.... its simple detonation

Once back together we are going to check the injector drivers in ecu! Will keep everyone updated! Would a 10-12 PSI pulley really jump up power? And I have a whole new fuel system for the boat. Twin Bosch 044 pumps. and 1000CC injectors.

Might want to check the gph on those pumps at 55psi. Might want to think about race gas at 12psi.

What's your HP goal ?

Boat was at about 5400 RPMS on a 4 Blade 30P. I will be flashing it to rev to 6k, and looking for enough power to get me to 5800-5900 rpms

That doesn't look like detonation to me - That piston melted badly. Are You running headers? Did the header lose water for that cylinder? If it did that cylinder would have run lean.

um yes that IS detonation from being LEAN

If detonation did all of that damage I would expect to see bearing damage from being hammered to death. Yes I know that detonation is caused by a lean condition. But usually detonation bad enough to cause that much melting would crack the piston. For some reason that cylinder went lean. I would think if the head gasket went bad or the head lifted you would have a burn mark on the head or the block. That damage didn't happen in ten seconds. ten seconds running lean melts eyebrows - ask me how I know.

Yes. Seen pistons that got lean and burnt up in one pass, torches a hole in it. Rest of piston top looked nice minus the hole.

it peeled the ring land,,seen it on many nos engines and has done it in less than 7 seconds....its detonation..

which procharger did you have?? they have a max rpm limit and when you over drive them they self distruct..check the chart on prochargers website to see what you can spin it to,also if you up the pounds of boost you will need a bigger cooler which you can get from frozenboost.com

Bearings don't always get damaged like that, besides I don't see a pic of the bearing to see that anyway, that is detonation period, ask me how I know.....lol and yes a 10 second WOT pass can and WILL do that.....

that is detonation,it appears the octane might have been to low,maybe got some bad fuel.we must keep in mind that the afr reading is an average of the cylinders on that bank and on all big block chevrolet,s some cylinders will be leaner than others.it seems strange that you ran this combination for 3 years without problems before the failure.if you did not make any changes i would suspect either a bad injector or a driver problem in the ecm.the failure was not caused by a head gasget problem.generally a failure like this one is caused from to much ignition timing or a fuel with to low of an octane rating.as far as the bearing being hammered,if you measure the upper half of the rod bearing from this cylinder i guarentee you it is hammered.

this statement is 100 percent correct!

detonation is not always due to a lean condition,in this case it appears to be from to much ignition timing or to low of octane fuel,when you burn an eyebrow,that is almost always from being to lean.and this failure could have happened in less than 10 seconds.my spelling&grammar might not be correct,but i am well versed on supercharged engines and diagnosis of failures.

Finally... Someone who see it same as I do.... So may opinions are so off sometimes!!

please explain how 1 tube could be dry but the others flowing water and how this can make a cylinder go lean.

Rod bearings are flawless. (I AM NOT) But could reuse them without any issues. Not even a scuff on the surface.

Injectors have been tested and flowed at FIC and were SPOT on.

Leaning towards possible injector driver.

I would NEVER ever put a frozen boost intercooler on my boat, as those cores are junk and offer horrible cooling. The new core i'm using for this build is the 1000 hp Garret core. Seen here. Garrett Air to Liquid Intercooler Core 1000HP : atpturbo.com

I build race Jetskis, and have tested all the ebay / frozen boost cores vs precision core, and garret core. Trust me the difference was insane, all testing was done with Motec standalone datalogging software.

I'm going to snatch a photo today of all the pistons so we can see the burn patern across the cylinders. Really appreciate everyone's input on this.



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you say the rod bearing looks perfect but did you measure it with a bearing micrometer,it can look like new and still be junk.

I didin't myself, That's all off at the machine shop now. How ever bearing shell was still tight in the rod, which is a good sign.

Time will tell, I just want to figure it out so I have this figured out for the new long block! Only thing worse then blowing up a engine.. Is doing it twice!

"Injectors have been tested and flowed at FIC and were SPOT on.

Leaning towards possible injector driver."
I am going to assume that because you are running 42 lb injectors that you are also running a factory merc /delphi mefi3 ecu. If so your probably NOT going to find a problem with the injector driver because- Mefi's are BATCH fire, your ECU is firing a batch of FOUR injectors everytime it fires, if there was a problem with one of the 2 injector drivers, you would have problemss with four injectors, Smitty

As far as your injector "size" being too small, it is common for fuel press to be bumped up on these procharged applications, a 42lb injector becomes a 53lb injector when press is raised from 43.5 to 70 psi which will very easily support 600 hp at .55 bsfc, ideal, no but has been used on LOTS of stuff.I don't believe your injectors suddenly became "too small" with no other changes in past 3 years. IF you were reusing tjose injectprs (which your not) I would STILL throw away the one that was on the cyl that melted down even IF it tested good juct in case it is a intermittent problem. Are your new 1000 cc (96lb) injectors also high impedance, I just started seeing some high impedance injectors that big in past year or so but still hard to find, Smitty

What cylinder did that piston come out of ?