Piper 285 cams & T28 turbo question

What is the ideal rev limit for the above combo? I'm shifting at 6k bit there is more to go.

Also I assume due to the profile of the cams, ticking is normal?

Cheers peeps.

People do say 285's are "tappy" mine wasn't and still isn't all that bad.

I rev mine to 7k and occasionally beyond, if the fuel is there and it wants to make more power then keep going, 6k gives you a small power band with a T28.

The c1j with a 285 will take 7k easily. :agree:

I remember reading something about how the cup cars were recommended to change valve collets if the engine was consistently using high revs. Can't remember the intervals exactly. On the road the road I'm guessing it won't be all that consistent just the occasional burst.

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Originally Posted by GTphil

People do say 285's are "tappy" mine wasn't and still isn't all that bad.

I rev mine to 7k and occasionally beyond, if the fuel is there and it wants to make more power then keep going, 6k gives you a small power band with a T28.

The c1j with a 285 will take 7k easily. :agree:

I remember reading something about how the cup cars were recommended to change valve collets if the engine was consistently using high revs. Can't remember the intervals exactly. On the road the road I'm guessing it won't be all that consistent just the occasional burst.

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Thanks for the reply.

AFRs are betweeb 11-12 @ 6000 rpm so will check beyond later.....

Tapping is worse when cold, when warm its only slight so will tolerate that for now.

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Originally Posted by GTphil

I remember reading something about how the cup cars were recommended to change valve collets if the engine was consistently using high revs. Can't remember the intervals exactly. On the road the road I'm guessing it won't be all that consistent just the occasional burst.

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Yeah if they regularly exceed 6500RPM.

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Originally Posted by Alex

Yeah if they regularly exceed 6500RPM.

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:laugh: mine needed changing ages ago then:wasntme:

Also I'm guessing with standard valve springs also for the 6500 revs bit.

maybe different with a different spring rate and less valve bounce.

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Originally Posted by fastevo1

Tapping is worse when cold, when warm its only slight so will tolerate that for now.

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I would reset the tappets. :agree:

I think Piper settings are slightly bigger gap to standard hence the extra tapping sound, but kinda defeats the point of high lift cam widening the gap, but that said, it's all todo with heat transfer/expanding. I set my old one to standard setting without any trouble, but I wouldn't recommend you do the same.