Accusump question
12-17-2007, 01:57 PM
#1
Racer
Thread Starter
Accusump question
I am thinking about putting an Accusump on my 2000 vette. My question is with the EPC valve. With that installed and connected to an ignition 12 volt lead, if I am sitting there with the key on lets say working on my window or rear defroster, is the accusump draining the oil back into my engine while I have the key on and the engine off??? I don't think it would be good to get 10 qts in my engine before I start it. Can this problem be solved by hooking up the lead to a 12 volt source that is only hot while the engine is running like the fuel pump lead???
Reb
Reb
12-17-2007, 03:08 PM
#3
Burning Brakes
An alternate switch is good for a few different reasons, but for two key:
a) You'll often WANT to dump the Accusump before starting the engine. The key purpose of devices like this is as a pre-oiler.
b) After a session where the sump has been used, there's no guarantee that it will be filled (depending on the EBC and your usual oil pressure). You'll often need to rev the motor to guarantee enough oil pressure to charge, then shut the sump off before shutting off the engine.
Unfortunately, neither works with a trigger in the existing system (engineer's caveat, yes . . something could be BUILT, however at significantly higher cost than a SPST switch) . . . dedicated toggle switch solves both problems.
a) You'll often WANT to dump the Accusump before starting the engine. The key purpose of devices like this is as a pre-oiler.
b) After a session where the sump has been used, there's no guarantee that it will be filled (depending on the EBC and your usual oil pressure). You'll often need to rev the motor to guarantee enough oil pressure to charge, then shut the sump off before shutting off the engine.
Unfortunately, neither works with a trigger in the existing system (engineer's caveat, yes . . something could be BUILT, however at significantly higher cost than a SPST switch) . . . dedicated toggle switch solves both problems.
12-17-2007, 04:18 PM
#4
Drifting
An alternate switch is good for a few different reasons, but for two key:
a) You'll often WANT to dump the Accusump before starting the engine. The key purpose of devices like this is as a pre-oiler.
b) After a session where the sump has been used, there's no guarantee that it will be filled (depending on the EBC and your usual oil pressure). You'll often need to rev the motor to guarantee enough oil pressure to charge, then shut the sump off before shutting off the engine.
Unfortunately, neither works with a trigger in the existing system (engineer's caveat, yes . . something could be BUILT, however at significantly higher cost than a SPST switch) . . . dedicated toggle switch solves both problems.
a) You'll often WANT to dump the Accusump before starting the engine. The key purpose of devices like this is as a pre-oiler.
b) After a session where the sump has been used, there's no guarantee that it will be filled (depending on the EBC and your usual oil pressure). You'll often need to rev the motor to guarantee enough oil pressure to charge, then shut the sump off before shutting off the engine.
Unfortunately, neither works with a trigger in the existing system (engineer's caveat, yes . . something could be BUILT, however at significantly higher cost than a SPST switch) . . . dedicated toggle switch solves both problems.
AFAIK Canton details how to do this in the installation manual, and I've installed that way (no more astray, but I don't smoke so who cares).
12-17-2007, 04:42 PM
#5
Team Owner
Member Since: Sep 2003
Location: Raleigh / Rolesville NC
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I think Eric is trying to say that you need to wire into both a switched 12v source (goes hot when the key is 'on'), and wire a switch into that lead so that you can shut off the valve when you want the key on, and the engine off.
AFAIK Canton details how to do this in the installation manual, and I've installed that way (no more astray, but I don't smoke so who cares).
AFAIK Canton details how to do this in the installation manual, and I've installed that way (no more astray, but I don't smoke so who cares).
12-17-2007, 04:58 PM
#6
Le Mans Master
The EPC is a pressurestat, a pressure-actuated switch that can be
wired to be normally closed (NC - on) or normally open (NO - off).
For use with an accumulator, the p-stat is wired to be NC - on,
then when pressure exceeds the activation set point, the switch
goes open (off).
While a SPST toggle switch is simple and cost-effective, humans
being what we are, the possibility exists that the toggle will
be off when we really need it to be on.
A possible solution for preventing unintentional discharge during
a 'key on/engine stopped' event might be to install a Digital RPM
Activated Window Switch such as the MSD #8969 or equivalent. This
digital unit can be set to activate from 200 RPM up in 100 RPM
increments. It offers more range of adjustment than the 'Pill' based
units, which cost less but whose lower range seems to start at 3000
RPM. The #8969 is priced at $110.
Note that the window switches are limited to a max draw of 1.5A.
Instructions for the Accusump include information about installing an
electric valve and the EPC on pg 5 of 11 - a 4A fuse is specified for
the circuit. Consequently, my vote is that an RPM window switch
should be wired to control a relay instead of directly controlling the EPC
solonoid. This way there is no chance of exceeding the 1.5A current
capacity of the window switch.
Incidently, I've written before about adding a throttle switch for the
purpose of bypassing the EPC in the event of oil pressure problems at
high RPM. Beyond a desired %throttle, the switch could apply power
directly to the valve solonoid instead of through the EPC switch.
.
wired to be normally closed (NC - on) or normally open (NO - off).
For use with an accumulator, the p-stat is wired to be NC - on,
then when pressure exceeds the activation set point, the switch
goes open (off).
While a SPST toggle switch is simple and cost-effective, humans
being what we are, the possibility exists that the toggle will
be off when we really need it to be on.
A possible solution for preventing unintentional discharge during
a 'key on/engine stopped' event might be to install a Digital RPM
Activated Window Switch such as the MSD #8969 or equivalent. This
digital unit can be set to activate from 200 RPM up in 100 RPM
increments. It offers more range of adjustment than the 'Pill' based
units, which cost less but whose lower range seems to start at 3000
RPM. The #8969 is priced at $110.
Note that the window switches are limited to a max draw of 1.5A.
Instructions for the Accusump include information about installing an
electric valve and the EPC on pg 5 of 11 - a 4A fuse is specified for
the circuit. Consequently, my vote is that an RPM window switch
should be wired to control a relay instead of directly controlling the EPC
solonoid. This way there is no chance of exceeding the 1.5A current
capacity of the window switch.
Incidently, I've written before about adding a throttle switch for the
purpose of bypassing the EPC in the event of oil pressure problems at
high RPM. Beyond a desired %throttle, the switch could apply power
directly to the valve solonoid instead of through the EPC switch.
.
12-17-2007, 05:08 PM
#7
Pro
Here's something you might want to consider. If you wire it into the iginition, it will be active all the time the engine is running. That is, it will be active while running on the street. My concern would be that if you come to a stop light where the car is idling, will the system begin discharging oil (depending on the activation oil pressure)? You wouldn't want the oil pan to become too full.
I have mine hooked up to a switch. I use it to prelube the engine before starting, then shut it off while on the street. Of course, it is on while on track. I think that if one is concerned about oil starvation on the street, then one is driving in a way that isn't appropriate (assuming the engine's oil level is in spec).
I have mine hooked up to a switch. I use it to prelube the engine before starting, then shut it off while on the street. Of course, it is on while on track. I think that if one is concerned about oil starvation on the street, then one is driving in a way that isn't appropriate (assuming the engine's oil level is in spec).
12-17-2007, 06:14 PM
#8
Racer
Thread Starter
I was thinking the fule pump would be good for this. When you turn the key on, the pump only runs for 2 seconds and then shuts off. It turns back on when the engine actually starts. I was also thinging of shiming the oil pump so that at idle hot, the pressure is still higher than the which ever valve I decide to use. ( ie 25 psi ) I don't beleive that a slightly high oil pressure when running is going to hurt anything is it?????
Reb
Reb
12-17-2007, 06:38 PM
#9
Le Mans Master
that has a higher spring rate will not affect the pressure at idle.
Generally speaking, pressure at idle is a function of the displacement
of the pump relative to the amount of volume that 'leaks' out at the
various bearing surfaces and other discharge points. As RPM rises,
eventually pump displacement exceeds the volume that can discharge
and pressure rises.
When pressure begins to exceed the value required to unseat the
by-pass valve, surplus oil volume is routed to the inlet side of the pump
(on Gen I-Gen III pumps, at least). Pumping generates heat. Excessive
by-passing leads to rising oil temperature because it is recirculating and
gaining heat with each pass through the pump.
For more pressure at idle, it is necessary to tighten clearances or
increase pump displacement.
.
12-17-2007, 07:19 PM
#10
Le Mans Master
12-17-2007, 07:59 PM
#11
Racer
Thread Starter
I got out the service manual and read up on the fuel pump. It seems that the PCM controls the fuel pump and will only keep it on for about 2 seconds after it no longer receives pulses from the ignition. That means it is only on while the engine is running.
By adjusting the pressure down a little and hooking it up to the fuel pump line I think I might have all that I need.
Thanks
Reb
12-17-2007, 09:03 PM
#12
Melting Slicks
12-17-2007, 10:53 PM
#13
"AlohaC5" Senior Member
An alternate switch is good for a few different reasons, but for two key:
a) You'll often WANT to dump the Accusump before starting the engine. The key purpose of devices like this is as a pre-oiler.
b) After a session where the sump has been used, there's no guarantee that it will be filled (depending on the EBC and your usual oil pressure). You'll often need to rev the motor to guarantee enough oil pressure to charge, then shut the sump off before shutting off the engine.
Unfortunately, neither works with a trigger in the existing system (engineer's caveat, yes . . something could be BUILT, however at significantly higher cost than a SPST switch) . . . dedicated toggle switch solves both problems.
a) You'll often WANT to dump the Accusump before starting the engine. The key purpose of devices like this is as a pre-oiler.
b) After a session where the sump has been used, there's no guarantee that it will be filled (depending on the EBC and your usual oil pressure). You'll often need to rev the motor to guarantee enough oil pressure to charge, then shut the sump off before shutting off the engine.
Unfortunately, neither works with a trigger in the existing system (engineer's caveat, yes . . something could be BUILT, however at significantly higher cost than a SPST switch) . . . dedicated toggle switch solves both problems.
12-18-2007, 12:14 AM
#14
Le Mans Master
Originally Posted by Slalom4me (2007.10.09)
The key components in the optional E.P.C. consist of a brass tee fitting
(1/2" Male x 1/4" Female x 1/2" Female) like those made by Weatherhead
and an adjustable pressurestat manufactured by CEME.
The pressurestat is a switch that can be configured to be normally
closed (NC - on) or normally open (NO - off). For use with an
accumulator, the p-stat is wired to be NC - on, then when pressure
exceeds the activation set point, the switch goes open (off).
The CEME pressurestat supplied in the past for the E.P.C. has an
adjustment screw under a circular red cap and the actuation point is
adjustable within a range of 0.2 - 6.0 bar. Using a factor of 1 bar
= 14.504 psi inch, this is equivalent to a range of 2.9 - 87 psi.
My vote is that the only difference between the three E.P.C. choices
offered by the vendor is that these have been calibrated to different
actuation values. If an owner of an E.P.C. is not satisfied with the
set point he has chosen, he is able to adjust it instead of needing to
buy a different pressurestat.
High Performance Pontiac published an article by Jim Dietzler about
installation of an accumulator with the electric valve and optional E.P.C.
Despite what the article says, aside from blue anodizing and a Canton sticker
instead of a Mecca sticker, the accumulator hasn't changed much in 20 yrs.
This image from the article shows the CEME pressurestat and the red
cap covering the adjustment screw, as well as the 'anti-tamper' daub
of green paint. It also illustrates how the pressurestat is wired
into the +12VDC circuit feeding the electric valve.
Low or no pressure results in 12VDC to the valve solonoid and oil feeds
from the accumulator to the engine. Pressure above the set point
results in no power to the valve solonoid and no oil from the accumulator.
.
(1/2" Male x 1/4" Female x 1/2" Female) like those made by Weatherhead
and an adjustable pressurestat manufactured by CEME.
The pressurestat is a switch that can be configured to be normally
closed (NC - on) or normally open (NO - off). For use with an
accumulator, the p-stat is wired to be NC - on, then when pressure
exceeds the activation set point, the switch goes open (off).
The CEME pressurestat supplied in the past for the E.P.C. has an
adjustment screw under a circular red cap and the actuation point is
adjustable within a range of 0.2 - 6.0 bar. Using a factor of 1 bar
= 14.504 psi inch, this is equivalent to a range of 2.9 - 87 psi.
My vote is that the only difference between the three E.P.C. choices
offered by the vendor is that these have been calibrated to different
actuation values. If an owner of an E.P.C. is not satisfied with the
set point he has chosen, he is able to adjust it instead of needing to
buy a different pressurestat.
High Performance Pontiac published an article by Jim Dietzler about
installation of an accumulator with the electric valve and optional E.P.C.
Despite what the article says, aside from blue anodizing and a Canton sticker
instead of a Mecca sticker, the accumulator hasn't changed much in 20 yrs.
This image from the article shows the CEME pressurestat and the red
cap covering the adjustment screw, as well as the 'anti-tamper' daub
of green paint. It also illustrates how the pressurestat is wired
into the +12VDC circuit feeding the electric valve.
Low or no pressure results in 12VDC to the valve solonoid and oil feeds
from the accumulator to the engine. Pressure above the set point
results in no power to the valve solonoid and no oil from the accumulator.
.
different value on the bench or on a trial & error basis in the car. Maybe
Canton will even custom calibrate to order for customers who buy
directly from them. I've never asked whether this service is offered
but I can think of no technical reason why Canton could not do this
for customers
.
12-18-2007, 07:34 PM
#15
Melting Slicks
Thanks for the information.
I purchased a ~20 psi valve some time ago (haven't installed it or the accumulator yet), but I think it propably needs to be set higher. I normally run 40 psi at idle and 80+ psi under throttle. At the last HPDE event, the instructor was saying my oil pressure was dropping in the corners slightly below 20 psi
. Guess its time to get that accumulator mounted.
I purchased a ~20 psi valve some time ago (haven't installed it or the accumulator yet), but I think it propably needs to be set higher. I normally run 40 psi at idle and 80+ psi under throttle. At the last HPDE event, the instructor was saying my oil pressure was dropping in the corners slightly below 20 psi
. Guess its time to get that accumulator mounted.
12-20-2007, 12:34 AM
#16
Instructor
Member Since: Jun 2000
Location: Livermore CA
Posts: 154
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Some people really like Accusumps and some don't. I like mine for pre-oiling the engine. And after logging the EPC valve in my DL-90 data logger I really like the Accusump. PM me and I can send you a link to the graph.
