hobbsy
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| posted on 14/7/06 at 06:43 PM |
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Accusump - how is yours "activated"?
I've got a Fisher Fury Blackbird with an approx 3 litre Accusump. Its got an electric valve rather than a manual one and its activated by a
switch on the dash.
However I've spoke to another 'bird engined car owner who also had an Accusump (or a similar Quaife badged item) who said he was "on
all the time".
The previous owner of my car said that it wasn't needed for ROAD use and hence the switch. However he forgot to turn it on during one track day
and killed a big end on a tight corner.
The Accusump website refers to wiring it to your ignition switch (see http://www.accusump.com/acc_products/acc_valves.html) but aren't there
some catches here as if you sit with the ignition on but the engine not running won't it empty itself completely into the engine (hydrolock ARGH
etc)? The website refers to building oil pressure from the Accusump before starting to reduce engine wear but when would it stop pumping oil in,
surely without the oil pump running it could pump in more than you want before it hit the pressure limit where it stops?
Or if you stall it and don't knock the ignition off fast enough?
Basically I'm going to be running quite sticky road tyres (R888's) and probably even stickier track tyres (ACB10's) I'd like
to have it wired up so its on all the time (better safe than sorry).
What would be the best way to achieve this?
I guess the "only on while engine running" could be achieved by a relay energised off the generator? Or am I being a fool and missing a
far more elegant way of tackling the problem?
[Edited on 15/7/06 by hobbsy]
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DIY Si
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| posted on 14/7/06 at 07:56 PM |
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One possable option is to run it via a timed switch. Ie, the ignition comes on and then say 30 secs later the accusump is switched on. Not sure how
difficult this would be to acheive though.
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kb58
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| posted on 14/7/06 at 08:29 PM |
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Yeah I went round and round with this issue, and Accusump themselves. I sent a list of questions to Accusump and received rather vague answers.
If you use the electric valve, Accusump says it's suitable only for street driving. For hard core racing they recommend a manual ball-valve,
for simplicity and reliability, but also to ensure it supplies oil fast enough. Turns out the electric valve has a rather small orifice, great for
not letting it charge too quickly, starving the engine, but not so good when you suck air in a corner and need oil Right Now.
They go on to say they sell a kit that "converts" the electric valve into something suitable for racing, and here's my issue... they
don't change the electric valve, all they do is change when it's open! So my question was, "how can this possibly supply oil to the
engine any faster than before?" The answer was, "I don't know, it just does." And there you have it.
I think the product is good to have - I have one because I couldn't afford a dry-sump system. However, short of having a "smart
valve", their system should only be activated with a manual ball valve. Open it when you head out on course, then close it when coming into the
pits. The trick is remembering to do so...
[Edited on 7/14/06 by kb58]
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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INDY BIRD
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| posted on 14/7/06 at 09:32 PM |
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i have a 4 pint accusump on a blackbird
opperarting on a manual valve for the reasons explained above.
i then made a attachment to the valve that goes under the dash for ease of turning of and on.
when priming the engine the psi moves to around -20-30 and then i start the engine.
works fine.
if you stall the engne just restart seems not to be a problem.
i would reccomend the manual valve over the electric just get into the routine of turning off and on then no probs.
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hobbsy
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| posted on 15/7/06 at 09:32 AM |
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I'm going to check which electric valve I have, I read about the two types on the website and I'm hoping its the higher flow version.
Although I am worried by your comments that its not really any different!
If I'm going to stick with the electric valve I'm still keen to come up with an automatic solution as its a real pain having to remember
to switch it on and off. And the cost of not switching it on during track use is high!
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andkilde
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| posted on 16/7/06 at 03:33 AM |
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quote:
Originally posted by kb58
Yeah I went round and round with this issue, and Accusump themselves. I sent a list of questions to Accusump and received rather vague answers.
If you use the electric valve, Accusump says it's suitable only for street driving. For hard core racing they recommend a manual ball-valve,
for simplicity and reliability, but also to ensure it supplies oil fast enough. Turns out the electric valve has a rather small orifice, great for
not letting it charge too quickly, starving the engine, but not so good when you suck air in a corner and need oil Right Now.
They go on to say they sell a kit that "converts" the electric valve into something suitable for racing, and here's my issue... they
don't change the electric valve, all they do is change when it's open! So my question was, "how can this possibly supply oil to the
engine any faster than before?" The answer was, "I don't know, it just does." And there you have it.
Hmmn, dunno about the small orifice explanation, the explanation I got from, presumably, a different Accusump guy was the electric valve takes a few
moments to open which is long enough to allow starvation before the valve is fully open -- thus explaining how wiring it to the ignition might
mitigate this.
As for "hydro-locking", the Accusump energizes the pressure side of the oil system so with the engine not running it should simply send
oil into the main oil gallery at ~25psi (or whatever pressure you pump the air side ot the accumulator to) which will only trickle past the bearings
-- it's prevented from rushing back to the sump by the check valve you install when you plumb it. Also, if it did manage to empty itself, it
would likely just puke a bit on the ground or fill your catch can (which argues for fitting a large catch-can if you're worried) -- there is no
direct connection between the oil system and intake/exhaust.
Cheers, Ted
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andkilde
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| posted on 16/7/06 at 03:38 AM |
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quote:
Originally posted by hobbsy
its a real pain having to remember to switch it on and off. And the cost of not switching it on during track use is high!
You could use the manual ball valve hooked to a dash mounted "Morse" (push-pull) or Mini heater cable -- if you're worried about
forgetting to engage it just put your ignition cut "key" on a lanyard wrapped around the Accusump cable.
Cheers, Ted
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kb58
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| posted on 16/7/06 at 05:01 PM |
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quote:
Originally posted by andkilde
...the electric valve takes a few moments to open which is long enough to allow starvation before the valve is fully open -- thus explaining how
wiring it to the ignition might mitigate this.
As for "hydro-locking", the Accusump energizes the pressure side of the oil system so with the engine not running it should simply send
oil into the main oil gallery at ~25psi (or whatever pressure you pump the air side ot the accumulator to) which will only trickle past the bearings
-- it's prevented from rushing back to the sump by the check valve you install when you plumb it. Ted
About the electric valve taking a moment to open; if so, their upgrade kit that converts it for racing does nothing to fix that, in fact it makes it
worse if what you say is true. They add a pressure switch in series with the solenoid, so as the oil pressure goes up and down with rpm,
they're openning and closing the solenoid. If it takes a while to open that's probably bad news.
They don't supply a check-valve with their kits so most people won't have one. About the Accusump overfilling the engine, I agree
it's not much of a problem with the engine off, but it will be sitting at a light with the engine running.
It was tough getting information out of them, they either didn't know how the race version of their electric system worked, or were evading my
questions. As said before, I still think an Accusump is good to have, but it's important to understand it's just a simple "balloon
full of oil being controlled by a small valve."
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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Jon Ison
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| posted on 16/7/06 at 06:04 PM |
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I had a ball valve on mine, mounted in sidepod on drivers side, I often forgot too switch it off, never caused a problem just meant no pre oiling.
why not put a big sticker on dash "accusump"
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