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-   Engine, Exhaust, Transmission (https://www.ft86club.com/forums/forumdisplay.php?f=8)
-   -   Dr. Destructo blows a rocker apart (https://www.ft86club.com/forums/showthread.php?t=73858)

phobos512 09-09-2014 07:39 PM

http://cdn.meme.li/instances/500x/54193820.jpg

White64Goat 09-09-2014 08:05 PM

Shit must be getting serious now...........Formula 1 Tyres...............:D

mike the snake 09-09-2014 08:06 PM

One of the main reasons I went with the Element Tuning Hydra Standalone and Hydramist meth injection was that Phil took the time to answer my questions thoroughly and was very knowledgeable on everything FA20.

I'm a very happy customer. I think more people should consider running the Hydra Standalone.

Element Tuning 09-09-2014 09:02 PM

Quote:

Originally Posted by dwx (Post 1939717)
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.

I know my dealer has seen broken valve springs and then broken valves which can spit the rocker out. I can see a case if using a factory valvetrain that you could float a vakve at 9k rpm and spit the rocker.

In my case the pin the roller rides on physically walked out. Our spring seat pressure really isn't very high in terms of a high performance engine so this isn't a case of too much of a good thing. Oiling was also good and no signs of galling or excessive heat.

Purely a case of a factory part fail in a high performance application. We'll address this on any new builds from here on regardless of this possibly being an isolated insident.

Thanks,
Phil Grabow

Element Tuning 09-09-2014 09:05 PM

Quote:

Originally Posted by phobos512 (Post 1939810)

I straight up can't help myself running the gears as this motor is downright nasty at 9k! :) We will make it reliable as it's just too good to resist.

AZFA20 09-09-2014 09:48 PM

I haven't seen the pins walk out yet on the FA20 rockers but I have seen plenty of the FA20 rockers being shot out of their homes.

jdcorbitt3 09-09-2014 10:17 PM

I have heard of rotor bearings creeping, particularly in the 13,000rpm range on rotaries. this is due to hitting the resonant frequency of the rotor assembly. the fix was to drill and tap the bearing and rotor and run an allan screw in it.
i suspect you might be hitting harmonic resonance of a part in the rocker arm, like maybe the roller pin.
It is amazing to see all the component movement in a high pressure engine like yours. some aircraft engines like the BR710 have a regime where extended time in that regime will cause damage and ultimate failure.

john

Calum 09-09-2014 11:08 PM

Quote:

Originally Posted by AZFA20 (Post 1940025)
I haven't seen the pins walk out yet on the FA20 rockers but I have seen plenty of the FA20 rockers being shot out of their homes.

With this type of valve train valve tip height is exceptionally important when you increase the redline. That said, as long as the valves are ground to the correct height when installed after cutting the seats and lapping, it shouldn't be an issue.

SmsAlSuwaidi 09-09-2014 11:15 PM

1 Attachment(s)
Its a pretty common issue with these motors.

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spitfire481 09-09-2014 11:18 PM

I've seen them blow through the valve cover at high revs/power with stock springs, but never with upgraded springs

Dipstik-sportech 09-09-2014 11:19 PM

Did you find out if it damaged any internals yet?

humfrz 09-09-2014 11:49 PM

If the others stayed in place ...... maybe this one just wasn't pressed in correctly ... ??


humfrz

Dezoris 09-10-2014 12:24 AM

Are those rollers swedged on both sides or just one? How much more valve spring pressure is on tbose stock rockers? At the level you are at could be a rocker issue with the higher rpm or just the rollers not pressed properly. ID want to see the other rollers as well.

Good luck regardless.

SmsAlSuwaidi 09-10-2014 12:26 AM

Dr. Destructo blows a rocker apart
 
Quote:

Originally Posted by Dezoris (Post 1940234)
Are those rollers swedged on both sides or just one? How much more valve spring pressure is on tbose stock rockers? At the level you are at could be a rocker issue with the higher rpm or just the rollers not pressed properly. ID want to see the other rollers as well.

Good luck regardless.


Stock spring pressure is very very soft, to the point that opening them is easily done with a finger


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