Just servicing Sonic and I want to check the tappet gaps. The engine is an Rover cooper A+ 1275 with a 1 inch & 3/4 HIF6 carby (as standard), what gaps should I set

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Respect mine and I'll respect yours.

You will need a 7/16" spanner , flat blade screwdriver and a .012" feeler guage. I just had mine adjusted to help the " Snail " run better, my brother did them, I was the one rocking the car in gear to find TDC and BOS . I,m sure there are other people here who could give you more detailed information.

( Yes I should of mentioned that this was on an 1100, of course a 1275 would be different ! )

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Kenno,,, being a 1275 it will probably have 5/16ths rocker nuts/bolts,,, therfor you`ll want a 1/2inch spanner

& the later mini engines usually are meant to be set at 15thou clearance,,, set when engine is cold

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

yep when the engine is cold
Take the spark plugs out (Helps with the rocking)
14/15/16 thou clearance
http://www.ausmini.com/forums/viewtopic.php?t=10528

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Stop Licking the Dog...I Don't Care Who Started It

How much wear is in the rocker face? If you use a feeler guage it will give bigger clearance if the face is worn. I set mine using a dial indicator and turning the eng over slowly in direction of rotation

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Research is the difference between speculation and investment. Anyone who copys some one else will always be second
www.minisprintgt.com

Yeah I've heard that's a much more accurate way of setting it all up but I don't have a dial gauge so I'll just hope their not too bad

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Respect mine and I'll respect yours.

it all depends on what cam you have

my 1275ls runs 16 inlet 18 exhaust
Fang runs 28 inlet and 32 exhaust
and the 998 on the floor runs 14 inlet and 16 exhaust

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120bhp with 450kg just fun waiting to happen

We were prob. drunk when we set it up last and thought this will be a good idea

It also depends on the rocker arm ratio as well as the cam. The higher the rocker arm ratio the more clearance you need for the same cam. The lever ratio principle applies here.
The rocker clearance is all about how much quietening ramp is built into the cam profile and to provide some clearance when hot to avoid the valve starting to open due to expansion of the engine bits when hot. The quietening ramp takes up the clearance slowly to avoid noise and sudden impact loads on the cam lobe before the lobe actually starts to open the valve. Thats why you have to use a different clearance when checking the actual valve opening and closing angles. On some BMC cams its (IIRC) 0.021" for checking valve timing, rather than the cold running clearance of 0.012" or 0.015".

RonR

For a Russell Engineering RE13 cam (probably the most common regrind round here now) the clearance is .016" with stock rockers, or .019" with 1.5s.
Same clearances apply to most Kent cams- MD266, 276 etc.

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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.

Just checking what is 15-thou in mm?

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Respect mine and I'll respect yours.

.015 inch = 0.38099999999999995 mm