Defective Brian Crower Valve
06-03-2013, 07:42 PM
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Defective Brian Crower Valve
Blew my head gasket and replaced my valves with Brian Crower dish faced valves.
Lasted about 85 miles before the stem of the valve broke off. Had all the work done at a very reputable shop that has done most of Hawaii's high horsepower builds. Several S2000s.
Did well during tuning. Did a 1st and 2nd gear pull from a stoplight and starting misfiring and loud tapping, we thought the titanium retainer finally let go, inspected it, valve stem was sinking and alignment was way off.
As soon as the mechanic looked at it he said it's either retainer let go or there's a low chance of a defective valve. It was the valve. Tried calling BC for support but was unable to get an answer. Anyone know how good their customer support is? What should I do?
Just one valve and retainer had damage.
Lasted about 85 miles before the stem of the valve broke off. Had all the work done at a very reputable shop that has done most of Hawaii's high horsepower builds. Several S2000s.
Did well during tuning. Did a 1st and 2nd gear pull from a stoplight and starting misfiring and loud tapping, we thought the titanium retainer finally let go, inspected it, valve stem was sinking and alignment was way off.
As soon as the mechanic looked at it he said it's either retainer let go or there's a low chance of a defective valve. It was the valve. Tried calling BC for support but was unable to get an answer. Anyone know how good their customer support is? What should I do?
Just one valve and retainer had damage.
06-03-2013, 07:50 PM
#2
If the valve stem was sinking into the retainer, it's not because the valve was defective. It means your keepers failed to keep the valve in the retainer or were installed improperly or not fully seated. Then because the valve had force exerted on it in a way it wasn't designed to, it snapped. Factory valves will do this exact same thing. They start stretching due to the keepers not being seated in the valve recess and they will eventually break. I'm afraid it sounds like complete shop error. BC puts out very reputable products and I highly doubt it was due to a flaw with one of them.
06-03-2013, 10:33 PM
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I've never heard of anything like this from BC too so I was quite confused. Strangely though only one valve and retainer was damaged. We did a full 2 and half hour dyno tune and it was fine. Hmm the shop is looking into and emailing BC.
06-04-2013, 02:01 PM
#5
Pull all the valves and get them crack tested across the collet groove. Also have a look under high magnification to see if there any any severe machining scratches across the groove. Also inspect the shape of the groove by laying a collet against it. See how they fit in a retainer.
Was your engine an F22 or F20? There are different angles on the collets/retainers of the two models and you cannot mix/match. Its very hard to feel. Some of the F22 collets have a little notch pressed into the upper edge. These cannot be used with retainers intended for AP1
One other thing to consider, if the valve clearances are set way too large the valve gets dropped onto the seat hard as its still in a high speed part of the cam profile. This can damage valves/seats. I normally see this causing valve stems to break, not the collet groove.
Was your engine an F22 or F20? There are different angles on the collets/retainers of the two models and you cannot mix/match. Its very hard to feel. Some of the F22 collets have a little notch pressed into the upper edge. These cannot be used with retainers intended for AP1
One other thing to consider, if the valve clearances are set way too large the valve gets dropped onto the seat hard as its still in a high speed part of the cam profile. This can damage valves/seats. I normally see this causing valve stems to break, not the collet groove.
06-04-2013, 05:14 PM
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Pull all the valves and get them crack tested across the collet groove. Also have a look under high magnification to see if there any any severe machining scratches across the groove. Also inspect the shape of the groove by laying a collet against it. See how they fit in a retainer.
Was your engine an F22 or F20? There are different angles on the collets/retainers of the two models and you cannot mix/match. Its very hard to feel. Some of the F22 collets have a little notch pressed into the upper edge. These cannot be used with retainers intended for AP1
One other thing to consider, if the valve clearances are set way too large the valve gets dropped onto the seat hard as its still in a high speed part of the cam profile. This can damage valves/seats. I normally see this causing valve stems to break, not the collet groove.
Was your engine an F22 or F20? There are different angles on the collets/retainers of the two models and you cannot mix/match. Its very hard to feel. Some of the F22 collets have a little notch pressed into the upper edge. These cannot be used with retainers intended for AP1
One other thing to consider, if the valve clearances are set way too large the valve gets dropped onto the seat hard as its still in a high speed part of the cam profile. This can damage valves/seats. I normally see this causing valve stems to break, not the collet groove.
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