----- Original Message -----
From: "David Councill" <dcouncil@imt.net>
To: "John Di Fede" <difejo@optonline.net>; "MG Mail List"
<mgs@autox.team.net>
Sent: Monday, April 26, 2004 6:07 PM
Subject: Re: Fw: Cam Recommendation for MGB
David
I replaced my cam about two years ago. I installed the cam that Moss sells
here in the US. It is a cam manufactured by Crane. I am looking for a
replacement because I had a problem with sticking valves, which trashed a
couple of tappets (lifters) and the corresponding cam lobes.
I must stress to anyone out there rebuilding a cylinder head, that you
insist your machinist use the proper valve to stem clearance as listed in
the MG shop manual. Failure to do so will result in sticking valves and
possible other valvetrain damage. I've had this problem twice with two
different machinists.
I agree that cam selection is confusing, and I think the best way to decide
on a cam is to solicit the advice of others with experience using a
particular cam.
Regarding compression ratio, you have to measure the volume of the swept
cylinder and the combustion chamber when the engine is apart. I also have
the slighlty dished h/c pistons which have a dish volume of about 6.5- 7
cc., and if you are bored over .060 your cylinder volume is 1868cc /4 =
467cc, but unless your head is removed you will not be able to measure your
combustion chamber. Combustion chamber volume will vary depending on
manufacturing tolerances, or if the head has been skimmed or if the chambers
have been polished or altered. I recall that the chamber volume as listed
in my shop manual is from 42.5 to 43.5 cc. You can find the chamber volume
by pouring a measured amount of liquid into each chamber. You'll need a
graduated cylinder measured in mililiters.
I stay away from rice rockets, and realize that I'll never run with them.
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