[6pack] Bearing clearances and Plastiguage

Vance Navarrette v.navarrette at comcast.net
Sun Aug 8 19:03:27 MDT 2010


	Jerry:

	Oil pressure is sensitive to lots of things, including oil
viscosity and the spring pressure of the relief valve.

	What type of oil are you running?

	Plastigauge is accurate enough to get the job done, although
there are more accurate ways of getting things measured plastiguage is
cheap and easy. For the occasional driveway mechanic, it is definitely
the way to go. I have built several engines, and in every case,
plastigauge indicated that the crank journals were spot on. Could be
dumb luck, but it seems to work for me. 

	Vance 



-----Original Message-----
From: 6pack-bounces at autox.team.net [mailto:6pack-bounces at autox.team.net]
On Behalf Of Jerry C Shaw
Sent: Sunday, August 08, 2010 6:05 AM
To: 6pack at autox.team.net
Subject: [6pack] Bearing clearances and Plastiguage


Have lower oil pressure for a rebuilt engine than I would like.

What main and connecting rod bearing clearances are normal?

Used micrometer on all reground crank surfaces giving  0.010 undersize
with
mains @  2.303" and crankpins @ 1.865" . Stupidly didn't check
clearances
during installation assuming shells were 0.010  undersized as stated on
the
box.

Also, one of the car mags says Plastigage is not accurate. See
http://www.carcraft.com/techfaq/116_0701_plastigage_vs_micrometer/index.
html
Jerry
'74 TR6


More information about the 6pack mailing list