Valve issue?

[S550Smoke]

To everyone using the s550 as a serious track car...does anyone have anyone information on the increasingly frequent valvetrain failure on the gen 2 coyote engines? I am seeing this more and more but it seems to still be off the radar as far as public concern.

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[ddozier]

One failure on a 2015 GT Performance Pack

7500 miles, but to be fair most of them were very hard track miles.
Drivers side exhaust valve failed where the stem and hat meet
No other parts of the valve-train failed or showed signs of pending failure
Car was tuned for 7800 RPM
Long Tube Headers and GT350 intake manifold

Dave

 

[EFI]

To everyone using the s550 as a serious track car...does anyone have anyone information on the increasingly frequent valvetrain failure on the gen 2 coyote engines? I am seeing this more and more but it seems to still be off the radar as far as public concern.

Hmm not really aware of this, can you share some more info on this for those of us who have not heard about it but would like to stay on top of it.

 

[Bahndvr]

One failure on a 2015 GT Performance Pack

7500 miles, but to be fair most of them were very hard track miles.
Drivers side exhaust valve failed where the stem and hat meet
No other parts of the valve-train failed or showed signs of pending failure
Car was tuned for 7800 RPM
Long Tube Headers and GT350 intake manifold

Dave

Is that the #8 cylinder?

 

[S550Smoke]

Mine was.

 

[Bahndvr]

I've heard that there is still a cooling issue with #8 but many dispell it

 

[S550Smoke]

Lots of people discredit a lot of rumors, unfortunately some hold true. MMR doesnt have the highest reputation but i personally have never had an issue with them, so i have implemented an idea of theirs (head cooling mod), along with some other things ive seen ford do with the fp350. Valve options are non existent unless you want to do head work to put over sized valves in or pay for custom valves..which i have no evidence in the bill being worth a test run for reliability. I was quoted a tad shy of 2k for std size custom ferrea valves.

 

[Bahndvr]

I had heard the rumor not from MMR but searched for the ol cooling mod and they popped up.
On my 03 Cobra I did the cooling mod. Of course I bought ported, over sized valve heads and put the cooling mod on when I replaced the heads.

Hope that price has a little polishing in it.

 

[ddozier]

Is that the #8 cylinder?

The first failure I have personally seen and did the repair was on #6 - Exhaust valve hat broke away from the stem and was ejected out the exhaust port, the piston was cracked nearly through its center and even without the exhaust valve and the piston this particular engine would run and idle and had only a misfire code in the PCM. Valve broke while engine was in decel from a 3rd gear run to 7500 rpm before I entered the next turn on track. 1/2 of the exhaust valve hat was later found in the exhaust, other 1/2 of the valve was no where to be found. Replaced the Piston, Rod, and Head on that side while the engine was in the car and put it back in service. Engine was used for the remainder of the season them replaced with a fresh short block from FORD when I had time to do a full build. Needless to say I consider myself very lucky as this could have gone real bad real fast.

The second failure (Not one of my engines) I have seen and the block was destroyed was on #2 - I did the tear down but did not spend any time on trying to figure out what happened as there was not a lot of evidence left in this particular failure, It was hard to say if it was a valve, valve spring, follower, or piston failure. There was so much damage it would have been difficult to tell. There was a part of an Intake valve embedded in what was left of the piston and the rod was bent as well. We found pieces of piston in the intake manifold, the opposite bank of pistons and oil pan. This one let go at wide open throttle at 7100 rpm. This was a Stock 2015 5.0 with GT350 Intake, Long Tubes and tuned for 8200 rpm with a little over 9K miles, more than half were track miles. Not much of the internals could be salvaged. The engine was replaced with a new Gen2 Coyote.

I have also seen a third engine that had weak compression in #2, #6, and #7. This was a stock 2016 5.0 that was tuned for 7800 rpm. After the tear down I believe this was caused by ring land failure in #7 as this piston had the most damage and the largest pieces missing. The other pistons were damaged by small bits of piston being ingested after a trip through the Intake Manifold. #2 and #6 did not have any material from the pistons missing but had signs of metal materiel bouncing around inside the combustion chamber. Motor would run and make power up to about 5K rpm then would drop off in power but would still pull to 7500 with ease. There was excessive blow by and the engine would fill both catch cans in a 20 min track session. Failure was eminent and the engine was replaced with a long block from Ford (we did not even try to have it warrantied due to the tune).

** NOTE to anyone who has a piston failure or valve failure replace your intake manifold as it will likely have pieces of piston forced back through the intake valve into the intake manifold ready to ruin the next motor you put it on.

Dave

 

[DocWalt]

I know of at least one '15 GT that dropped a valve. Way too much damage to tell what part of the valve/valvetrain failed first. Low miles, but a LOT of abuse.

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