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View Full Version : S/c 2011 gt 5.0 engine blew up analysis



69gt4speed
03-09-2011, 04:46 PM
Well it blew up a while ago.. Beefcakes 2011 gt vortech s/c 5.0 engine blew up... So he had it rebuilt went to put it all together.... Here's what he's saying, sounds good anyways.

Why My Engine Blew....
I know all have had lost of speculation, too much power, bad gas, bad tune, etc..

From everything we've come to investigate about the engine. Our best guest the cause of the problem was the Caspers Electronics o2 extension harness.

After putting the new engine back in the car, we had issues right out of the gate with random o2 codes on bank 2. SCT Data logger was randomly not picking up a/f out of bank 2. 95% of the time, getting no reading.

I bought 2 new o2's thinking the old ones possibly got oiled from when the motor let go.

Put them in, and immediately had the same codes and no a/f. One time it would be o2 sensor code, then heater circuit code. etc.. All random codes related to the o2 sensor on bank 2.

We pulled the new o2's back out of both sides and got to looking at them closely. What we found was a little interesting. The passenger side, which had no harness extension, when you look at the holes the o2 plugs into. There is gold (connector) right at the tips of the holes.

On the Caspers harness. The gold (connector) is recessed inside the hole nearly half an inch. On top of that, the clip was busted on the connector. My guy at the shop said, hmmm, makes sense now. I asked what he was referring to. Originally the engine builder sent me a pic of one piston. I thought only one was gone. Turns out that all 4 bank 2 pistons were ate up. 5,6,7, and 8. The guys at my shop said that there was my problem.

More than likely, there was very little connection in the harness. When the clip broke, not enough connection to hold. We played around with the stock harness for a bit and was able to move it around and plug the factory harness in to the o2 without the connector.

Jump into the car, fire it up, and voila! No o2 codes and a/f was reading fine.

At Bradenton this past week, I was talking with my tuner and started talking to him about the harness. As soon as I mentioned header harness, he got a faint grin, not laughing, but like knowing what I was going to say.

He told me the American Racing shop car had tuning issues for a few weeks. He was remote tuning the car, and told them there was no issues with the car, it had to be somewhere else. They discovered the same thing, the harness was the issue with the car.

There was also another car that showed up at the NMRA race that was having similar code issues. Turns out he has headers with the same harness. (everyone uses these harness').

Also talked to Justin from VMP, told him my findings, he told me that he had recently went to order some of the harness' from Caspers and they told them they were "redesigning" the harness because of the clips breaking.

I talked to them myself today, moroso about the connector vs the clip. He said they use oem connectors. I assured him the connectors look nothing like oem. Then he told me they are "bosch" oem connectors.

Again, best guess is the clip had broken at some point and lost connection, more than likely under wot. John Lund explained to me that these cars when they don't pick up a reading, default to a 14 to 1 a/f. More than enough to detonate a s/c'd Coyote at WOT.

Bank 1 was completely untouched in the engine as well.

So, there ya have it.

Obviously Rob dog needs to build some good harnesses and sell them to lt hdr guys. It is kinda weird factory connector, I had to swap mine for cat pipe to x/or pipe.

snickerlicker
03-09-2011, 06:11 PM
Good news, and all the more reason to put a s/c on your car Rob!!

69gt4speed
03-10-2011, 01:38 AM
Yea vmp's car is running 11 to 12# boost. Stock compression. They noted the stock converter flashes to 3k on launch. Stock n/a stall is like 1.9k so that extra tq does the job for stall speed. Prob why they will be quicker whp to whp over nitrous as you can't launch w nitrous on w/o a boom or some huge pop. Yes I know that 100%,, even on my 03 stick is tricky. Had to set it at least 3.4k w 30% duty cycle on solenoids. You would not dare use nitrous on stock converter when launching off the line till 3.5k or so. Same w vortech etc. w/o a 3k stalled converter it will be slower if traction is good. So street wise a pd s/c looks to be street and track good for less $ overall.

I'm paying the 2011 off tommorrow.... :)

Beefcakes new engine
http://www.streetfire.net/video/2011-built-shortblock-coyote-first-startup_2205659.htm

Nick
04-13-2011, 01:47 AM
Do you know beefcake or were you just posting this as general info? Just wondered, because I'm probably buying a car from him.

JustinS
04-13-2011, 05:46 AM
Rob has passed away since this post, you won't get an answer.

AutoMods
04-13-2011, 12:20 PM
yea our buddy rob is gone. see the death notice thread for more info