[Alpines] Sudden oil pressure drop off

[jarrid_gross at earthlink.net]

Dave,

This is a basic and classic problem with these engines.

Your issue is very minor, its a stuck oil pressure relief valve.
Often you can remove it from the filter base, clean it and reassemble it, but
the problem will likely return again someday.

A better fix is to get a new relief valve, but these are very rare due to this issue.

The main problem is the design of the valve and the materials used, they gall up and
the burr will hand the piston near wide open from when the oil pressure was dumping
at higher RPMs.

Others have gotten more clever and disassembled the valve and rebuilt it with modern
unworn parts (new piston, and lined the inside of the tube section).

In any case, provided you didnt run it for long, or under load with zero oil pressure
then there is no long term damage from the problem.


HTH

Jarrid Gross

-----Original Message-----
>From: D W Spearing <kb9csw at juno.com>
>Sent: Mar 5, 2010 5:22 PM
>To: alpines at autox.team.net
>Subject: [Alpines] Sudden oil pressure drop off
>
>Hi,
>
>I have a 1967 Sunbeam Alpine Series V.  One day I drove it to work and the oil
>pressure was find; 45 psig hot cold idle or full bore and it has been that way
>since new and through two overhauls, until that day!  I got into town and
>stopped at the stop sign and the oil pressure dropped off to almost zero at
>idle!  It came up when I revved it a bit but then back down it went.  Yes, the
>first thing I did was look at the dip stick and that was ok.