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bmc1.8 tappet clearance


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0.017" (cold) = 0.43 mm

Hope this helps, good luck.

Chop

 

That is actually only for engines with the early type camshaft though.

 

If it has the later type camshaft it should be 0.36mm (0.014").

 

I think the latter are actually more common?

 

If the engine block has external ribs on it on the lower parts just above the sump, then it is the later type, so the clearances should be 14 thou.

 

If it lacks those ribs it is the earlier type, so the clearance should be 17 thou.

 

The service handbook says it is these numbers whether the engine is hot hot or cold......

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Interesting as my MGB (1.8) manual says 0.015" cold. I wonder how critical it is. Although that was of course a petrol engine so maybe that makes a difference.

 

And whilst we are talking about BMC valve timing, the way to make sure you are measuring off the cam is to turn the engine until one valve opens, then adjust the valve that adds up to nine, i.e. valve 1 open adjust valve 8, valve 3 open adjust valve 6 etc.

Edited by dor
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  • 1 month later...

Interesting as my MGB (1.8) manual says 0.015" cold. I wonder how critical it is. Although that was of course a petrol engine so maybe that makes a difference.

 

And whilst we are talking about BMC valve timing, the way to make sure you are measuring off the cam is to turn the engine until one valve opens, then adjust the valve that adds up to nine, i.e. valve 1 open adjust valve 8, valve 3 open adjust valve 6 etc.

The "rule of 9", as I was taught many years ago.

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The issue of valve clearances is a regular topic on the MG forums. Some set the inlets a lot tighter than the exhaust and claim it works ok. 9 thou has been mentioned. I've always set to 15 thou.

Makes sense I guess, as the inlets will be much cooler. Pretty irrelevant fir a boat though I suppose.

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  • 3 years later...
29 minutes ago, Carl123 said:

Hi   Can any  on tell me the tappet setting on bmc 1.8 diesel inlet & exHAust  clearance  please 

Corrected that for you.

 

This has been answered already. 

 

Later ribbed sided blocks its 14 thou", 0.35 mm

Early cam in flat sided blocks 17 thou"  0.4 mm

 

I set mine cold but manual says the same hot or cold. Which is odd. If the rockers are worn with grooves, reface them first or use wire gauges rather than flat feeler gauges.

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On 22/11/2015 at 00:08, dor said:

Interesting as my MGB (1.8) manual says 0.015" cold. I wonder how critical it is. Although that was of course a petrol engine so maybe that makes a difference.

 

And whilst we are talking about BMC valve timing, the way to make sure you are measuring off the cam is to turn the engine until one valve opens, then adjust the valve that adds up to nine, i.e. valve 1 open adjust valve 8, valve 3 open adjust valve 6 etc.

The old and trusted Rule of 9

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