Blew up my Boss motor on a track day - Why???

[Bill Pemberton]

For those at the Mustang Roundup the Pump and Pantry Gas Station a 1/2 mile down the highway has 100 Octane Race Fuel in a pump over on the far West Side ( essentially where the Truck Diesel Pumps are ). I believe it is VP Racing fuel and one of the participants at the event , Charlie Bosselman , put in the tank per racer requests last year. He and his family own Bosselman Truck Stops and the Pump and Pantry convenience stores , and he is a track rat ( has a AC Cobra replica and a FP500S ) so he jumped in to help fellow racers.

You can drive over, use like a regular pump and then go over and fill up the 91 Octane at another. His 91 is regular ( no ethanol ) if I remember correctly. Pass this around as many may not be on the Forum this weekend.

 

[BKBoss302]

BKBoss:

My first thought is run a custom tune that requires you to Data log, or a Dyno tune so your Tuner can set up the proper fuel & timing tables to avoid a possible lean run condition and/or detonation (knock).

Looking back you ran the OEM TracKey with LTH’s & Cat deletes & no other intake mods except a drop in high flow air filter in the OEM air box. (Assuming same intake tube & 80mm TB). My question here is how did you account for the O2 sensor pcm data? Did you have any dash warning lights?

Just sorry to see you had such a catastrophic failure.

My thought was if I deleted the cats the track key tune would account for and make up anything it needed to balance things out. I have never had any dash warning lights after each mod that was installed. My only thought was to eliminate restrictive exhaust through the cats and eliminate a source of extra heat right under my feet. Just for clarity I am still using the stock headers/manifolds with a Lethal Performance X pipe. No LTH's on this one. Question is do I put the cats back in?
I am planning on installing a AEM CD-7 with data logging and maybe a tune but I haven't decided on which tune yet or if at all.

 

[BKBoss302]

Same thing happened to my 2012 Boss. I usually mixed 91 and 100 octane at the track. It’s cheap insurance. Yep mine still blew. My hole in the side of the crankcase on #8 looked very similar to yours. The back of my oil pan was blown out. Fortunately mine was covered under warranty. I also had a small fire but was quickly extinguished. Make sure everyone is carrying a fire extinguisher. Good luck with your rebuild.

Thanks Voodoo Boss. I have a Sparco under hood fire suppression system with 5 nozzles around the perimeter of the motor but luckily I didn't have any fire. Also have a hand held fire extinguisher in the car.

 

[TymeSlayer]

Always mix race fuel with my 91 octane which is the highest normally available here in Colorado. Luckily I did find a small motorcycle/kart track about three miles from the house and he fills my jerry cans with 100 octane for me. I usually will run the car till about two thirds full and dump in 100.

Very sorry to hear about the engine grenading but happy to see you kept the car safe.

 

[Fabman]

This is what I love about e85. 108 octane @ 3 bucks a gallon.
Did that motor have Billet oil pump gears? That's taken out an awful lot of motors.

I have one that looks very similar as well....we could make bookends.

 

[Dave_W]

After the cat delete, are your downstream O2 sensors still installed? I believe the TracKey is CARB-compliant, so shouldn't it still be looking at cat efficiency comparing upstream & downstream O2 readings, and throw a MIL when it doesn't see a difference?

 

[BKBoss302]

This is what I love about e85. 108 octane @ 3 bucks a gallon.
Did that motor have Billet oil pump gears? That's taken out an awful lot of motors.

I have one that looks very similar as well....we could make bookends.

View attachment 58642

I do not think the motor has billet oil pump gears but I am the second owner and wont know until later this week or next when we get the motor out. In some ways I hope it was the pump gears as I still don't have a definitive reason why this one let go and/or what to do with the next motor. My plan is to make sure I use higher octane fuel and ensure the tune doesn't create a lean condition. Sorry to hear about your motor failure. That's a tough way to making bookends.

 

[BKBoss302]

After the cat delete, are your downstream O2 sensors still installed? I believe the TracKey is CARB-compliant, so shouldn't it still be looking at cat efficiency comparing upstream & downstream O2 readings, and throw a MIL when it doesn't see a difference?

Hey Dave W,
My x pipe does have all the O2 sensors still installed in both upstream and downstream locations. Never threw out any codes after the change. I am thinking about putting the cats back in for the next motor until I figure something out.

 

[Mad Hatter]

As mentioned before by several posters.... taking out the Cats, and not updating the tune, WILL leave the car lean. The safest thing is to get a tune specific to what you have done on the motor.

Years ago I ran my car with Cats and LTHs on a stock tune for while, Got scolded by Shaun at AED.

 

[Dave Bowman]

Well I blew up my motor on my 4th track day this year. Does anyone have some insight as to why?
Here are the details:
Stock motor with 11,000 miles, no cats, X-pipe into Borla mufflers, washable air filter in stock airbox, Sebra 72 row oil cooler, fresh oil, Ford Track Key, 91 octane non-oxygenated gas
Number 8 piston is exploded and the rod with no cap on it is wedged in the area between the heads
Number 4 piston is still in the cylinder and 1/2 the rod is still connected to the crankshaft
Two big holes in the block on either side
Motor is still in the car until next week.
Bigger question - how do I prevent it from happening again?

View attachment 58601

you should be using 93 octane. Possible detonating issue.

 

[302 Hi Pro]

BKB:

Let’s look forward now. What engine replacements are you considering?

Gen3 Coyote 5.0l or perhaps the 5.2l from Ford Performance?

Custom built motor from MMR?

Lots of choices out there to consider before you think about Tunes, Cats or Cat-less?

 

[xr7]

I vote for the 5.2L Aluminator, 580 Naturally Aspirated Horse Power, Yes.

 

[LS587]

I have a 2014 Boss 302S race car that I bought new in September 2014. It's never been raced, just used for NASA TT and Shelby Club events. During about its 4th or 5th event, in July 2015, it blew its engine just like yours did. My car was new enough and I provided video like you have and data acquisition data to Ford Performance and I got a new stock Boss engine from them. In my failure analysis, I think either the #4 or #8 rod bearing siezed. The car companies use all-aluminum rod and crank bearings these days, and they don't have any forgiveness in them, like the old tri-metal bearings did. Car companies won't use tri-metal bearings anymore, because the babbit of the tri-metal contains lead. I told them that they advertised the 302S as a race and track day capable car, but they said that serious racers, which I am not, pull the engines and prep them with high durability parts, including tri-metal bearings. Before I installed the new engine, I installed tri-metal rod bearings with the special coating that the Nascar engine builders use for quick break-in. I think I bought the bearings from Roush, but they may be a standard option with Federal Mogul. I've run the car in many track events since then, and never had a problem. I've always run 98 octane race gas in the car, including when it blew up.
Incidentally, I had run my 2102 Laguna Seca Boss in track events from 2012 through most of 2014, or 3 years, and never had a problem with it. On the chassis dyno for NASA TT classing, the 302S put out about 50 Hp more than the street Boss, because the 302S runs a Ford Performance tune. I never modified either original engine in any way.
So a question for others who may have a lot more experience with these modular engines, if I am right on rod bearing siezure being the immediate cause of failure, why does every modular engine seem to blow on the back 2 cylinders? Because detonation causes higher rod bearing load? And would I have been having detonation with 98 octane gas?

 

[captdistraction]

The rear rods see the most stresses due to heat, as the coyote naturally runs most hot in cylinder 8 and then cylinder 4 (then 7, 3, etc) due to the head and coolant designs. So when you start seeing detonation, you'll see it in cylinder 8 first followed by the others - thus putting more wear/force on the rod bearings for those cylinders.

In non-boss engines, its a big reason why #8 ringlands would break in the GT cars (they had a weak ringland design), but #8 is where that would manifest itself the most. Flipside: if you starve the engine for oil, #5 seems to be the usual first rod to die.

 

[Tonymustang302]

Im only running 100 at the track and changing oil every 2 track days.

 

[Mad Hatter]

My thought was if I deleted the cats the track key tune would account for and make up anything it needed to balance things out. I have never had any dash warning lights after each mod that was installed. My only thought was to eliminate restrictive exhaust through the cats and eliminate a source of extra heat right under my feet. Just for clarity I am still using the stock headers/manifolds with a Lethal Performance X pipe. No LTH's on this one. Question is do I put the cats back in?
I am planning on installing a AEM CD-7 with data logging and maybe a tune but I haven't decided on which tune yet or if at all.

Safe thing to do is log your car and get a tune for ANY significant changes... Get your self a SCT x8 or such and be safe.

Does the AEM log lambda and knock etc??

 

[BKBoss302]

BKB:

Let’s look forward now. What engine replacements are you considering?

Gen3 Coyote 5.0l or perhaps the 5.2l from Ford Performance?

Custom built motor from MMR?

Lots of choices out there to consider before you think about Tunes, Cats or Cat-less?

I just wanted to review my mistakes and move forward with more knowledge.
Here is what I have learned:
1. Used the wrong octane fuel. Need more octane for track use. Will use race fuel in the future.
2. Should have given more thought and action to a properly tuned motor.
As for engine replacements I am going to be limited primarily by budget. I would love a 5.2L Aluminator but that is about 2X my budget. My current plan is to install a Boss long block at this point.

 

[BKBoss302]

Safe thing to do is log your car and get a tune for ANY significant changes... Get your self a SCT x8 or such and be safe.

Does the AEM log lambda and knock etc??

Good question. I have to contact AEM for some direct information or maybe somebody here knows that answer already. I need a more informative dash in any case. With winter right around the corner I have about 6 months to figure it all out.

 

[Mad Hatter]

I just wanted to review my mistakes and move forward with more knowledge.
Here is what I have learned:
1. Used the wrong octane fuel. Need more octane for track use. Will use race fuel in the future.
2. Should have given more thought and action to a properly tuned motor.
As for engine replacements I am going to be limited primarily by budget. I would love a 5.2L Aluminator but that is about 2X my budget. My current plan is to install a Boss long block at this point.

I saw that Shaun at AED is selling shortblocks that are nicely setup. Maybe he does long blocks as well?. Boss heads will be expensive and hard to find.

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After seeing the insides of two of my engines.... I would not buy a factory short block any more... Some pretty hidious oil passages etc in the blocks.. and tons of casting sand ready to come loose and kill the engine.

 

[67GTA]

Avoid additives, they don't work and likely cause more damage.

Historically I have felt this way as well about octane boosters, however this Torco fuel accelerator is a different animal. This has worked extremely well to boost the crappy 91 octane here in CA. I’ve tried blending 100 octane race gas at the the track with pump gas, only to fight random misfire codes. Hard to tell how fresh the fuel at the track is, and at least with the Torco I know what I have no matter which track I’m running at.

https://torcoracefuel.net/products/torco-accelerator