Valve seat drop
09-20-2018, 04:34 PM
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Valve seat drop
Has anyone experienced or know of a valve seat failure/ drop out on a 3.2 Carrera.
After a recent rebuild and post a 1k run in process, while the car was on the dyno setting the idle and anti stall map ( no power run done as yet) car began to run rough. On examination it would appear that my valve seat on number 5 had become dislodged.
To speed up the build process a set of spare heads were sent away the be refurbed and the original seats were used. Am I just unlucky or could there have been an inherent issue with the head?
After a recent rebuild and post a 1k run in process, while the car was on the dyno setting the idle and anti stall map ( no power run done as yet) car began to run rough. On examination it would appear that my valve seat on number 5 had become dislodged.
To speed up the build process a set of spare heads were sent away the be refurbed and the original seats were used. Am I just unlucky or could there have been an inherent issue with the head?
Last edited by Beaky; 09-21-2018 at 05:43 AM.
09-21-2018, 01:08 PM
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FWIW,...I don't replace the valve seats unless they are damaged or have been machined too many times.
If a seat does come loose, its usually due to incorrect fitment; a machine shop error. I've not had this happen to me, however I have relapiur
If this happens, that steel ring makes a LOT of noise bouncing around between the cylinder head and the valve. Left unchecked, the seat will knock the valve head off its stem and thats when the real destruction occurs.
It sounds like more investigation is necessary to find out what happened.
If a seat does come loose, its usually due to incorrect fitment; a machine shop error. I've not had this happen to me, however I have relapiur
If this happens, that steel ring makes a LOT of noise bouncing around between the cylinder head and the valve. Left unchecked, the seat will knock the valve head off its stem and thats when the real destruction occurs.
It sounds like more investigation is necessary to find out what happened.
09-26-2018, 06:08 PM
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The engine has now been split and the original diagnosis of a dropped valve seat was correct - on an IB this seems to be unheard of!
To speed up the original build process a set of spare heads were sent away to be refurbed and the original seats were used. Am I just bloody unlucky or could there have been an inherent issue with those head, who knows.
Anyway my original heads have been sent away for new seats and a refurb.
The piston had a slight ding in it that should polish out I’m told, and there is no other visible damage. The piston Rod will be checked over and new shells fitted as a precautionary measure.
With any luck she’ll be back on the road shortly.
To speed up the original build process a set of spare heads were sent away to be refurbed and the original seats were used. Am I just bloody unlucky or could there have been an inherent issue with those head, who knows.
Anyway my original heads have been sent away for new seats and a refurb.
The piston had a slight ding in it that should polish out I’m told, and there is no other visible damage. The piston Rod will be checked over and new shells fitted as a precautionary measure.
With any luck she’ll be back on the road shortly.