Cam bucket wear

[mjheathcote]

I've managed to find the time to measure my valves clearances, which in general are not far out (couple of thou) from when I last set them on the bench 10,000 miles ago. As I want to tighten them up slightly I have removed the camshafts and measured the shims that I fitted.

Surprisingly in 10,000 miles from new, all the cam buckets have to a larger or lesser extent worn in the middle body and very bottom. This was the case when I last rebuilt the heads too, but at that stage I did not know the mileage they had done. Also the right hand head buckets (UK off side) have more wear than the left hand head ones, the right hand head always runs hotter than the left by 5 to 10 degrees C...

Anyway, the worst case bucket has a major diameter of 1.312 inches (assume same as a new unworn one) and a minor diameter of 1.307 inches at the max wear points. Therefore 2.5 thou wear.
Is this acceptable and normal is the question?

All cam bearing surfaces/cam lobes etc are all lovely and clean, no scores etc.

Thanks,
Mike.

[GDPR]

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Someone needed to answer..... so it'll have to be me I suppose.....

I think you'll be fine on that amount of wear Mike, especially as you say it's even so that means the bucket is spinning in the correct manner when in operation...

Russ:dude:

[tonyh]

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[mjheathcote]

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Thanks for the replies.

Yes you can see daylight with a straight edge held up to the light, some are worst than others, the worst have 2.5 thou wear at the worst point.

I think I may have a new spare bucket, should you be able to rock, ever so slightly mind, a bucket when in the head?I'll have to investigate tonight. Difficult to see if the heads are worn without diving in and removing a head.

Yes I do have chrome cam covers, so maybe they where sand blasted I don't know, however when I rebuild the engine 10,000 miles agoI did not and I had the same wear pattern on the oldbuckets that I scrapped.

There isn't by chance any quality issues with cam buckets? just a thought that maybe they are not hardened correctly maybe?

Thanks,

Mike.

[mjheathcote]

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These are interesting:

http://www.arrowprecision.co.uk/details.php?id=66702

They are expensive because they are Nitride Hardened, so they don't wear like mine have..... apparently, but four times more expensive....

[Coppo]

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Hi Mike.

I had the same thing happen to my right hand head after a rebuild after about 300- 400 miles the buckets were getting noisey. After changing them they got noisey again, third time I checked the springs and found four of them were knackered...my own fault I used the old ones.

I bought all new springs and buckets.....Bingo the engine is running spot on and is not using so much oil.

Have you used new springs ?

Paul.

[GDPR]

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Coppo wrote:

Hi Mike.

I had the same thing happen to my right hand head after a rebuild after about 300- 400 miles the buckets were getting noisey. After changing them they got noisey again, third time I checked the springs and found four of them were knackered...my own fault I used the old ones.

I bought all new springs and buckets.....Bingo the engine is running spot on and is not using so much oil.

Have you used new springs ?

Paul.

You've called your engine Bingo??

[Coppo]

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kryten wrote:

Coppo wrote:

Hi Mike.

I had the same thing happen to my right hand head after a rebuild after about 300- 400 miles the buckets were getting noisey. After changing them they got noisey again, third time I checked the springs and found four of them were knackered...my own fault I used the old ones.

I bought all new springs and buckets.....Bingo the engine is running spot on and is not using so much oil.

Have you used new springs ?

Paul.

You've called your engine Bingo??

Great name don't you think.......

[mjheathcote]

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Coppo wrote:

Have you used new springs ?

Yes I have.

I have another theory now. I have measured a brand new bucket and it measures the same as the unworn area of the ones fitted. Why at the time I purchased 17 I don't know!

Anyhow they measure 33.34 mm (1.312 inch)....but looking at the web site for the super dupper nitride hardened ones they state the outside diameter as 33.38 mm (1.314 inch). Now is it possible I have a set of under sizedbuckets? ...this would certainly cause accelerated wear I would imagine.

I find that I can wobble slightly the new bucket in the head, just like the worn ones.

So should you be able to wobble the bucket in the head, or should they be a slideing fit with no wobble at all?

Does anyone have a new bucket they could measure to try and determine whether I have undersized buckets?

:?

[Andrew S]

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Hi Mike

This was information that I obtained when comparing my LH head buckets to measure variances. Not sure that it will help, but an indication of what I was up against. I think I am correct also that not all the bores for the buckets are the same and possibly the rear 2 or 3 are larger buta smidgen and possibly has something to do with allowing more oil to pass to improve flow. Not sure andmay be wrong

Cheers

Andrew

[mjheathcote]

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Thats interesting Andrew.

Looking at the figures, it appears yours have worn the same degree as mine, although into a barrel shape, but mine are a hour glass shape?

What did you do as a result of these figures?

[Andrew S]

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I replaced them all and it made no difference at all. The new ones that I got from Paddocks measured the same. I have since rebuilt my engine as I had two loose valve guides, so all this is history, but I have kept it, as you do. I really need to get out more.

I am under the impression that all the buckets that are sold come from the same source, so as they are being used in new engines, they appears not to be a problem with them.

I presume that you have a good oil flow over the top of the buckets do you? I ran mine quickly with cam cover off so that Icould prove the point. Have large rag to hand.If they are covered inoil, they should not wear andif the shims have worn, you could turn them upside down and that way you wont haveto adjust the gaps and play around

Just thinking aloud

Cheers

Andrew

[mjheathcote]

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Oh these are new bucket readings then? Thats not good, on paper anyway.

Can you remember if you had any wobble?

Plenty of oil around the place so I am not worried there, also nice clean cam bearing surfaces etc.

[StagnJag]

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Andrew S wrote:

I replaced them all and it made no difference at all. The new ones that I got from Paddocks measured the same. I have since rebuilt my engine as I had two loose valve guides, so all this is history, but I have kept it, as you do. I really need to get out more.

I am under the impression that all the buckets that are sold come from the same source, so as they are being used in new engines, they appears not to be a problem with them.

I presume that you have a good oil flow over the top of the buckets do you? I ran mine quickly with cam cover off so that Icould prove the point. Have large rag to hand.If they are covered inoil, they should not wear andif the shims have worn, you could turn them upside down and that way you wont haveto adjust the gaps and play around

Just thinking aloud

Cheers

Andrew

I have no personal experience but I seem to remember reading that the shims are chamfered on one side and can pop out if they are put in the wrong way around.

Just a thought and I could be wrong :P

Regards


Dave

[Bob Heritage]

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I have no personal experience but I seem to remember reading that the shims are chamfered on one side and can pop out if they are put in the wrong way around.

Just a thought and I could be wrong :P

In the Words of Murray Walker 'Unless I'm very much mistaken'