I am officially on holidays having finished the last of the semester exams this evening, so I thought I would do a bit of a tune up as it's been about 3 or 4 thousand since the last.

I decided to look at the gaps after the long trip to Hay and back the other weekend, I noticed something odd with cylinder 3's exhaust valve. Its gap was massive. I took the rockers off because it didn't look or feel right to me and found the pictures below.

The stem has had the top worn down, with an angle leaning towards the front of the car with some damage to the foot of the rocker as well. I'm not sure what has caused this as the operating conditions on that valve is identical to the other exhaust valves. Clearly the head will need to come off and the valve replaced, an easy enough job, and I will replace the rocker as well.

The valves were new last year when I rebuilt a 12g940 to replace the original serviceable yet fragile AEG163 head.

Can anyone identify what has caused this?

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Those who have been looking at these engines much longer than me will probably shoot me down, but anyway,,,

Two things stick out to me in those photos - one is the post with what looks like lots of wear around the stud hole, is it an alloy type?

The other is the top of the spring around the retainer - it seems to be sticking out a lot more than I'm accustomed to. Is the valve bent??

just wild stabs...

cheers

Jacob

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'72 Clubman Van - 1022cc, 295 head, 731 cam - Daily Driver
'69 Morris 1100 S - Dinged by a bus, in shed under repair
'64 Morris 1100 - Early 1100, long term project

From the look of the bur over the valve tip it appears that it is soft. Have you tried the 'file' hardness test on it?

Is the bush and / or shaft in the rocker worn? If it is it won't let the oil go where it should.

<EDIT> on a second look it appears very much that the rocker tip has been overhanging - at some point in it's travel - the valve tip.

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Thanks, the wear around the rocker pillar stud hole is an optical illusion. It is no more than a mark. The rockers and steel pillars came as a set of forged 1.5:1 rockers. They've seen service on four cars now, I swap them from feature donk to feature donk as I go along. Its a little sad that one is damaged after so much service over so many years

The rocker shaft was new with the engine and is still in good order it appears with no wear detectable if I move the rocker sideways on the shaft.

And yes, I can quite successfully take metal off the top of the valve with a file. I can remove a reasonable amount of metal with only a few strokes of a 2nd cut file..

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

I run those same forged 1.5 rockers on my 1360, after using a VP3 then an RE13 then a RE282 cam they are still fine, I think. No funny noises yet.
I'm a bit more concerned with that valve stem wear, some valves have hardened (stellite?) tips and some are plain, some race valves are just S/S.
Can you ID what the ex valves are and where they came from?

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Arrrrr.........



I see it now. It is absolutely necessary to check these when fitting each and every time and every rocker that that don't go 'over the edge' so to speak.....

......and the valve shouldn't be that soft.

You'll be getting the rocker tip re-ground, yeah? Shouldn't be a need to replace, they usually rip ya pretty hard for 1 rocker.....

<EDIT> could also possibly benifit from a shim between the rocker and the post, but need to check where the pushrod then sits.

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I will, I have a set of rebuilt forged S rockers here as it happens (whats the chances hey ) so I will put these on the back burner and put the rebuilt set on. I'll motor around the big city tommorrow and pick up a new head gasket and valve from one of the local gurus. I wonder if Josh is at Miniimports tommorrow. He wants me to come and let him into the Cadbury factory shop...

The valve was a standard replacement, 3 of the others show a little scraping, but nothing like this one
http://www.minispares.com/Product.aspx? ... 608&title=

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Mick, you haven't used a set of forged Cooper S Rockers with Pillars for a 1.5:1 ratio set have you?

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Nah, the 1.5 rockers go with the 1.5 steel offset pillars, being bright steel I'm glad they're pretty easy to keep together.

The S rockers are kept with the correct pillars as well.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

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If you are going to run the S rockers and stock pillars with a hi-lift cam, have a good squiz at how the rocker wipes the valve stem at full lift.
Many people (including Hammill) suggest removing 1.0mm (.040") from the bottom of the pillars when you do this. I find it's essential to do with the A+ sintered rockers, otherwise they wipe right over the rocker tip.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

So I have one of three thoughts here, correct me on what would be the most likely.

1. The gap on that rocker perhaps closed up and over extended the valve

2. The valve stem is improperly hardened

3. Carnies (Circus folk. Nomads, you know. Smell like cabbage. Small hands..)

4. Other unspecified.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

items 2 and 4.

Unspecified - poor rocker geometry - thr rocker pad overhung the valve tip. Not caused by clearance closing up, just typical of the forged rocker.

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Off with its head!

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Just be sure not to re-fit with the presently available BK450.......

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