Hi Gary,
I would suspect that the bores are 0.030" oversize. A 2 thou error is pretty
easy to make unless you have carefully calibrated measuring instruments.
It would be unusual for a machine shop to bore the engine 0.028" oversize so
I would recommend that you get a good telescoping gauge and accurate 3 - 4"
micrometer to check again.
If it is 3.311" then you need to order "30 over" pistons.
Michael Salter
www.precisionsportscar.com
-----Original Message-----
From: owner-healeys@Autox.Team.Net [mailto:owner-healeys@Autox.Team.Net] On
Behalf Of Gary Moomau
Sent: Monday, December 20, 2004 3:22 PM
To: healeys@Autox.Team.Net
Subject: BJ8 Pistons and Rings
In 1990 I had my BJ8 engine block bored out and the machinist ordered the
matching pistons and rings to match the boring. At this point in time, I
could not work on the car and it laid in a basket condition until now.
While getting ready to restore the BJ8 now, I began inventorying all the
parts for the car and discovered that the pistons (with rings), con rods,
and a cam were stolen in a garage burglary about seven years ago. I did not
document the piston and rings sizes that the machinist matched for the new
bore. He has since retired and at the time I did not think I needed to do
this. I need some technical advice so I can get new pistons, rings, and con
rods.
I measured the bore and it is 3.309 inches. Question: How do I determine
what size pistons and rings I need to order? I have read three different
manuals on 1st bore .010 (3.28 + .010 = 3.291), 2nd (3.281 + .020 - 3.301),
3rd bore .030, etc., you get the picture. I don't know how to determine the
piston size and the ring size needed to fit the 3.309 bore. Can someone
assist me, so that I don't look like a complete idiot when I am speaking to
a parts guy when ordering?
Also, any suggestions on a parts distributor (I know Moss is out there).
Gary Moomau, '67 BJ8
Yucaipa, CA
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