Unleaded cylinder head identification

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DonSoutar
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Unleaded cylinder head identification

Postby DonSoutar » Thu Apr 05, 2018 11:06 pm

I am restoring a 1965 2 door and have just split engine. Cylinder head has casting number 12G202 SM on it, is this a modification. Also there seems to be inserts on the exhaust valves does this mean its unleaded. Unable to post pic as took it with my phone and when I try to attach it site says file is too large.

philthehill
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Re: Unleaded cylinder head identification

Postby philthehill » Fri Apr 06, 2018 8:51 am

The 12G202 cylinder head is the standard cylinder head for the 1098cc Morris 1000 engine and was made for use with leaded fuel.
If the exhaust valve seats have been replaced with inserts the cylinder head in all probability has been converted to use unleaded fuel..


DonSoutar
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Re: Unleaded cylinder head identification

Postby DonSoutar » Sun Apr 08, 2018 5:18 pm

Many thanks for the info. It also looks like it has been rebored as pistons are marked 0.508 which I believe is equivalent to 20 thou.
As a matter of course given engine is dismantled should I replace the piston rings.

philthehill
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Re: Unleaded cylinder head identification

Postby philthehill » Sun Apr 08, 2018 5:22 pm

Before doing anything check the piston ring clearances and go from there.
Piston ring clearances are given in the BMC wksp manual.


DonSoutar
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Re: Unleaded cylinder head identification

Postby DonSoutar » Wed May 09, 2018 3:18 pm

I am about to fit a new ring gear to flywheel and never noted which way round it goes on. Am I correct in saying teeth with tapered fronts faces the direction of the gearbox.

philthehill
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Re: Unleaded cylinder head identification

Postby philthehill » Wed May 09, 2018 5:36 pm

You are correct in that the lead in for the starter Bendix on the ring gear faces the gearbox.



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