Re: Low Oil Pressure
herbeam (herbeam(at)cari.net)
Mon, 2 Dec 1991 09:42:02 -0800
Accordng to Rootes....50 lbs oil pressure is acceptable at over 2500
rpm...as long as you have 35-40 lbs oil pressure at cruise it is very
acceptable.. A performance book I have says that more than 50 psi of oil
pressure on an engine that doesn't exceed 6000 rpm is not necessary and a hi
volume pump on near stock engines only drags the hp down.
The oil filter mount you have is acceptable....check the oil pressure relief
valve for proper operation (hex head cover facing the right fender
well....(pull it out when the engine is warm and see if its sticks or binds
in the open position...also check your oil filter pressure relief spring and
valve which is in the same block (hex head cover facing the front of the
engine).
If your pressure dwindles to 25psi and the relief valve is operating
properly...you have an internal problems such as a worn pump or too loose
bearing clearances somewhere....The other things that could be wrong are
improper assembly of the timing chain oiler assembly (or lack of)..has ball
and spring and the end of the tube should be pinched off. I would check the
pump first...especially the clearance between the bottom of the gears and
the bottom cover....alot of times the gears wear into the pumps housing and
cover plate, and can be corrected by removing metal from the bottom of the
housing and the cover plate. New series 1-3 pumps are hard to come by but a
1725 pump can be adopted to the engine either by using a series V cam or
exchanging the dist drive gear. Good luck
-----Original Message-----
From: MR JEROME T PEREIRA <CJWR71F(at)prodigy.com>
To: alpines(at)autox.team.net <alpines(at)autox.team.net>
Date: Tuesday, December 01, 1998 10:57 PM
Subject: Low Oil Pressure
>Im new to the mailing list, and just now getting back to finishing
>restoration of a Series 1 Alpine I started ~15 years ago.
>
>I started by running 10-30 oil (leaked too much and resulted in low
>oil pressure) I changed to 20 50, and get approx 50 psi on startup.
>Once engine is hot (15 minutes on the highway) oil pressure slowly
>drops off to approx 25 psi. I dont want to run the engine until this
>is resolved. Suggestion Ive gotten so far was to check the oil
>pressure relief valve. The engine has an non-original oil filter
>base for a modern oil filter (fram ph16 currently installed) and
>therefore the base is not the same as original (although I have 2
>original bases with cartridge type filters). Adapter plate has
>"Crysler" stamped on it ...I assume this is from later days when
>Crysler was involved with Sunbeam. Alternate suggestion was to pull
>the oil pump and check the clearances.
>
>Questions: Can anyone confirm this adapter base is acceptable? (it
>looks like a good fit and doesnt leak) Do I need a special pressure
>relief valve for this base or did it come with only one spring value?
>(stock valves are larger diameter and dont fit...also stock unit felt
>a little stiffer when I pressed on it with a screwdriver) ......If
>the pressure relief valve checks out OK, does anyone have any
>suggestion prior to pulling the oil pump?
>