In a Formula Ford I went through a similar experience several years ago. We
believe it may have been due to the oil pump foaming the oil. It's a dry
sump system with an external pump. We believe the oil line fitting where
oil from the reservoir entered input side of the pump may have been sucking
air. At one point I noticed the reservoir, AFTER it was good and warm, was
like a chocolate soufflé. When cold or in the shop, look OK, but after it
got real warm, very foamy. On track would still have pressure, but
apparently very low quality lubrication. At least that was the theory.
Replaced the pump and no more problems.
Good luck. It's a bummer changin' engines so often. But . . . you do get
good at it, huh?
Bob Alder - RMVR
-----Original Message-----
From: JOHN HAMILTON <hamilton@mail.nfdc.net>
To: vintage-race@autox.team.net <vintage-race@autox.team.net>
Date: Saturday, July 10, 1999 7:13 PM
Subject: Bearing Problems - Help!
>I'm stumped and so are all my friends. Have Volvo, B18 (1800cc) full
>race engine, Oberg filter, Accusump, baffled pan and big oil cooler,new
>high pressure pump. I'm on the third engine this year (one per race).
>Runs fine initially then eats both main and rod bearings.Engine is
>properly clearanced including endplay by a professional builder who is
>also at his wit's end. We have checked crank for straightness, line
>bored the mains, balanced and rebalanced the crank and entire
>reciprocating assembly and we still get bearing meltdown after, say an
>hour or so of racing. Assembly and reassembly are done under almost
>"clean room" conditions.Holds 80 lbs. of pressure at idle when new then
>drops when bearings start to go. Ran well at Mosport this past weekend
>and held pressure until last race when warning light went on and
>pressure was at 30 lbs. and going South. Oil temperature has been high
>at 240 - outside temperature was over 100. Oberg is full of bearing
>remains. We have also checked all passages for restrictions.There are
>approximately 7 quarts in the system. I run the engine above 7200 rpm's
>but have been doing that for twenty-five years without this kind of
>problem. Anybody have any ideas short of demonic possesion? I keep going
>back to the Oberg - cooler - Accusump circuit eventhough this setup has
>been on the car for five years without problems until this year. No
>notion is too wild. Winning idea gets team T-shirt and a percentage of
>saved psychiatric bills. Thanks in advance,
>John Hamilton
>
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