----- Original Message -----
From: "Bill Babcock" <BillB@bnj.com>
To: "'Rocky Entriken'" <rocky@tri.net>; <VANDECARR@aol.com>;
<fot@autox.team.net>
Sent: Tuesday, October 01, 2002 5:35 PM
Subject: RE: Accusump
> Absolutely right Rocky, though the issue of the sun heat is not
> eliminated. If the accusump was full and the valve was closed when the oil
> was cool, the pressure would rise from the sun's heat. But the only way it
> would be likely to blow the sump would be when the bladder has failed and
> the system is completely full of oil.
About the only way I can fill the Accusump with cool oil is when I have
emptied it for some reason (like taking it out of the car) and had to
pre-load it upon reinstallation. Then the first time I start the engine, I
then heat the oil, and the oil that is in the Accusump when I shut off is
heated. I've never seen that as a problem meriting any concern.
> For that matter, my accusump has a relief valve on it. I thought they were
> standard. It's never lifted, but I always thought it would sure be messy
> if it did. I think it's on the air side though.
Mine doesn't, but then it's a pretty old one. From this thread, I'm thinking
still the superior design. The end caps screw in (with real fine threads so
it is several rotations), not held in with a circlip.
> I've never been completely sure how much oil to put in my car with an
> accusump installed. In theory you could run the sump quite a bit lower
> since the accusump will deal with any loss of pressure due to the pump
> inlet getting uncovered. In practice I like the idea of having plenty of
> oil, so I rev the engine to fill the accusump with about 80 pounds of
> accumulator pressure, close the valve and let the oil get to about 180
> (the water temp usually reaches 210 about the same time), shut the engine
> down and let it drain to the oil pan and then set the level at the bottom
> mark of the dispstick. I figure that's pretty conservative. If you run the
> engine at about 2K revs and get the oil pressure to about 30-40 pounds,
> let it heat up, close the valve, shut off the engine and measure the oil
> level it will be right about the high mark or even a bit above.
I seem to be right at 7.5 quarts. Sometimes I am working from empty without
it being charged. Typically, this is an oil change where I want to change
out the Accusump oil too. So I warm it up first, shut off the engine without
shutting off the Accusump valve, then drain it. Enough will still be in
there in the bearings when I re-fire it that it will endure the "dry"
start". Then typically I will put in 5 quarts, fire it up again, recharge
the Accusump, then measure what's left. (My dipstick is not in the engine;
the hole is plugged, so I carry the dipstick in the toolbox.) Usually needs
2.5 more -- the .5 is what the filter, oil cooler and lines hold.
Hmmm, I guess that would be filling it with cool oil too, if I only run the
engine enough to recharge the Accusump.
But of course my real point is that what is in there after a track session
or an autocross run ain't cool.
> When I'm racing I don't spend any time at that low an RPM (2K), so I
> suspect the oil pan level is down around the bottom mark, but I don't ever
> see oil pressure higher than what I can get with cool oil and a bit of
> revs, so I'm reasonably sure I'm keeping everything where it should be.
Heh, me neither. I warm it up at 3 grand. My experience duplicates yours. I
also have an adjustable oil pressure relief valve on the engine so I can
"tune" that pressure to what I want.
> The valve on an accusump should be open for as long as the engine is
> running (unless you're trapping the volume to pre-oil), otherwise it's not
> doing you any good. I hate it when I forget to turn off the valve and I
> don't have pressure to pre-oil the engine. Not only am I dredging the
Done that too! Hate it too!
> crank through oil, but it feels bad to crank over unlubed bearings, once
> you have the option.
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