Dr. Destructo blows a rocker apart

[Element Tuning]

So just one more thing we'll have to address when building these FA20 motors.



Somehow it appears the rocker roller pin walked out and punched it's way out the valve cover today on the way to the dyno. How convenient No question about it I've been running our Pro Comp engine, Hydra EMS, and 60 Trim turbocharger very hard to 9k rpm and at 22-23 psi on E85. I've also been running a mix spark and fuel cut traction control strategy which when using the spark but tends to have a ton of "popping" but is not an uncommon strategy for racing traction control.

I'm not going to say this is a normal failure but we'll clearly be addressing this in our motor builds as we need this roller pins to stay in place under extreme conditions!!

Trying to get this racing program off the ground!



Has anyone seen this specifically yet? I've heard some chat of dropped valves and then the rocker spitting but this is different, just the roller failed.

Thanks,
Phil Grabow

[ML]

9k rpm?! never seen this one.

[Element Tuning]

Originally Posted by ML

9k rpm?! never seen this one.

Now you have.

http://instagram.com/p/r5sBnItvc5/?modal=true

[ML]

Originally Posted by Element Tuning

Now you have.

http://instagram.com/p/r5sBnItvc5/?modal=true

Still making power ?

[post_break]

So how do you keep oil pressure happy?

[Element Tuning]

Originally Posted by ML

Still making power ?

What you can't tell? The heads are not stock, we have +1mm Ferrea intake and exhaust valves, multi-angle valve job, bowls ported, and valve springs. It's an amazing improvement compared to the stock stuff which I agree chokes pretty hard after 7500 RPM.

[Element Tuning]

Originally Posted by post_break

So how do you keep oil pressure happy?

Oh that's a saga that I don't want to cover all over again. We've documented it here but some of it we do keep a secret as part of our engine build. It's was a long process of testing and trying different things but we eventually were able to hold adequate oil pressure to 9k RPM.

http://www.ft86club.com/forums/showthread.php?t=63723

[gramicci101]

Was there any damage to the valves or surrounding pieces beyond the valve cover?

Also, since you're already experimenting with spark cut for traction control, what about working in anti-lag during shifts? Any benefit there? The popping is probably late fuel detonation in the exhaust pipe, so why not harness that to keep the turbo spinning?

[Calum]

Phil, was there any sign of the other pins walking? Could this have been an isolated incident?

Thanks for sharing this with the community!

[Element Tuning]

This happened today and all we had time to do was pull the valve cover and peak inside. Honestly besides the hole in the valve cover all we see so far is a very small impression in one cam lobe. There were no signs of overheating due to a lack of oil so the pin just wasn't pressed in tight enough for this application.

I did also cut apart my oil filter and there is no debris in it as I was worried since the hole dumped oil very fast. We still need to pull out the motor and perform a leak down to see if we got away with murder.

[Element Tuning]

Originally Posted by gramicci101

Also, since you're already experimenting with spark cut for traction control, what about working in anti-lag during shifts? Any benefit there? The popping is probably late fuel detonation in the exhaust pipe, so why not harness that to keep the turbo spinning?

The turbocharger doesn't lose spool with the Hydra traction control because it doesn't close the throttle plate. Now you do have an option to lower boost as one of the strategies but fuel cut has always been the smoothest. I was playing with using a combo of fuel and ignition cut cycles as I was loosing traction in 4th gear. There's two schools of thought in regards to traction control strategies on race cars and one is cut spark so you don't get a lean condition and the other is cutting fuel (random cylinders) doesn't cause a lean condition because of the sudden injector stop. I'm pretty convinced over the years random fuel cut cycles not only works better but is safer.

The Hydra does have anti-lag strategies for launch and flat-foot shifting. For drag cars we do use the anti-lag to target specific boost levels for launch and then it cycles off. For flat-foot shifting its not needed as the throttle stays open so we don't loose boost.

[gramicci101]

Thank you for the detailed response; I appreciate it.

[xwd]

I wish I could find evidence from more than just my memory but I vaguely remember hearing about this happening on a couple cars, even a stock one. Or maybe that was the rocker itself breaking, can't remember.

[SportInjected]

Element tuning, exposing fa20 weaknesses one failure at a time!

Trying new things and going beyond the limit, I respect that!