mark kibort

Here are rods in my engine, which ARE the rods mark and joe had in their engines originally, and the newest design rods that had a failure in both mark and joes engine.
they both look stout and I have 0 experience in rod design, and also ask the question, how do rods break near the bottom? if i was detonation, wouldn't we hear something on the video? wouldn't that pound out the bearings and cause a failure in the bearings? does it point to a piston failure or a wrist pin failure that would force the piston to gaul the cylinder and then stop..... causing the rod to break and sparing the crank and rod bearings?



Mark anderson and Joe Fan newest rod in failed engine


Mark Kibort stroker engine rod and mark Anderson /Joe fan rod in original engines

mark kibort

Here is the video for RACE 1 of the Porsche Club Festival of Speed at Auto Club speedway.

Greg, I added 3 spots where the rev limiter was tagged , so you could hear the frequency. match it audibly/note-wise to any car on a dyno, on the track and know if it is close to 6600rpm

I starts out with the 1st greed flag lap, with rear view cam, and then a couple of clips of the leaders in some hot cars at the end, and the final lap , with rear cam of a rev limit tag.

IcemanG17

Mark Anderson

GregBBRD

Apparently, Armchair Einstein's ear needs to be calibrated a bit.....

GregBBRD

I'm not sure I know how to read this spark plug....unlike any spark plug I've ever seen. I've seen spark plugs with melted center electrodes, caused from excessive timing....but I've never seen anything like this.

The "steel" portion of the plug is bare steel, which looks like something I just removed from my bead blaster. There's absolutely no trace of anything....just bare steel all the way to the base.

It appears like there are tiny "*****" attached to the "strap" portion of the electrode. If you blow up the picture, you can see them.

The porcelain appears to be burned on the left side (in the picture). The rest of the porcelain seems normal.

Comments?

The Forgotten On

I wanna say a valve stem seal failed causing oil to get into the cylinder, reduce the octane of the gas, and cause detonation.

Seems likely to me as it only discolored half of the spark plug. But this is just my opinion and what I saw with my 81's engine and plugs. Albeit not nearly as severe as this.

Do you have any info on how lean this engine got? It seems to have gotten really hot.

GregBBRD

Most of the plugs are very similar.....this one happens to be from cylinder #1. The cylinder that failed (#7) is different than all the others.....which I assume is from the injector spraying, while the piston was not moving. The steel portion of the plug looks like it was bead blasted and painted white. It is covered with "red *****" between the porcelain and the steel part of the plug. At first I thought this was rust, but there doesn't seem to be any sign water in what is left of the cylinder and piston....and if it is rust, it's different than any rust I've ever seen.

The hole in the engine is huge....and very wide. The wrist pin is no longer in the piston (the piston is shoved to the top of the cylinder) and the damage is so wide (on the cradle) that I'm already thinking that the pin was still in the connecting rod for quite some time.

Rob Edwards has a great photo of this....maybe he will post it. (Or maybe it is already here?)

Zero recorded data.

Catorce

Spherical ***** are ALWAYS a sign of detonation. I know, I'm pretty slow, but I did do several years of electronics engineering in college.

dr bob

GregBBRD

That will take a few days....

There's 22 928's here...plus 3 transmissions and 3 engines, without their chassis.
​​​​​

jorj7

Greg,

I had a plug like that. It was after I'd holed a piston on my Yamaha RD400, ran too lean and melted a hole in the top of the piston. The metal from the piston fused onto the plug.

__________________
George
90 S4 Grand Prix White (Murf #5 - 210 mph top speed)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com

GregBBRD

I had a client that melted about 1 million $$ worth of air cooled GT-2 engines (Long story, but never, ever let the client have access to the tuning computer at the track!), but I'm completely at a loss to explain these spark plugs. There is absolutely no color on the steel portion of the 7 plugs, which generally reflects the color of the combustion chamber. They are not just bare steel, but appear dull, like bead blasted steel.

Very strange!
​​​​
​​​​​

mark kibort

Greg, you are right on that one! However, what I was suggesting was that the RPM from the video only showed 6600rpm shifts based on audio data.. we both can be right on this one. I thought both joe and mark went back to stock ECU settings.
do you think it was over rev? what do you really think the problem was? he needed the octane of 110, and only was running around 100 and it detonated? doesn't pinging tend to pound out the rod bearings? do you think it could break a rod like this??

FredR

What size injectors are fitted? The size specified in the input data array looks suspiciously small considering they are still firing per stoke at 7560 rpm. I suspect my 30lb injectors might be struggling