Date:         Wed, 13 Sep 2000 08:19:27 -0700
Reply-To:     Stuart MacMillan <macmillan@HOME.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Stuart MacMillan <macmillan@HOME.COM>
Subject:      Re: Air cooled oil pressure question
Comments: To: Puzerewski <Puzerewski@EMAIL.MSN.COM>
Content-Type: text/plain; charset=us-ascii

That is perfect for any VW engine flat four engine, air or watercooled.
Figure 10 psi per 1000 rpm for an engine with acceptable bearing
tolerances.

And yes, this is low compared to other engine designs where bearing
tolerances are tighter.  In the VW alloy split case engines expansion
upon heating up prevents the bearings from being as tight, hence lower
oil pressure than you might be used to seeing.  My new professionally
rebuilt WBX has 75 psi at idle when cold (relief valve limit) but drops
rapidly as it warms up to 10 psi at idle, and around 45 psi at 75 mph.

So, you can see the need for heavier oil, 20w-50, or even better in the
air cooleds  use single weight oil and change it with the seasons, use
up to 40w for very hot climates or trips in hot areas, and my engine
rebuilder even recommends 40w in the WBX for hot climes/trips as well.
Single weight oils are physically thicker than the multi grades.  Change
oil and filter every 5000 miles/six months or seasonally with the single
weights.

Looks like you have a very good engine!
--
Stuart MacMillan
Seattle

'84 Vanagon Westfalia w/2.1
'65 MGB (Driven since 1969)
'74 MGB GT (Restoring)

Assisting on Restoration:
'72 MGB GT (Daughter's)
'64 MGB (Son's)

Parts cars:
'68 & '73 MGB, '67 MGB GT