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Pressurized Oil Accumulators

Low Pass

Well Known Member
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Anyone have direct experience with the Canton Accusump accumulator? If so, what size did you use?

I'm curious about using a pressurized accumulator to keep the engine lubricated with ~3-5 second negative g conditions without having to go to a full-blown inverted oil system.

Thanks!

Bryan
 
I installed the Moroso 1.5 QT. accumulator. Simple install. have not yet run it. I also have an inverted oil system with the valve mounted on the lower half of the angled firewall (less chance of it "hunting" for oil on the vertical. I also installed the solenoid valve to be able to use it as a preoiler for the next start.
 
Thanks for the quick replies! This the one y'all are using?

23901_part.jpg


http://www.moroso.com/catalog/categorydisplay.asp?catcode=13600
 
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Yes, that is the one. Be sure to order the mounting brackets, and if you want to use it as a pre-oiler, the electric valve too. The mount is very sturdy... Moroso has a great product.
 
Accumulator install

My ride is set up with a 3qt Accusump tapped into the Lycoming filter housing // link: http://www.accusump.com I like it a lot. Tip on install on what I did and didn?t.
1. Have a remote pressure gauge on your panel
2. Remote pressure valve to charge // easy location to access. You will end up adding charge pressure to charge the accumulator before start up to help push the oil into the engine faster on those cooler days or you will be there for quite awhile waiting for the complete discharge. After oil pressure goes to ?0? then re-set the empty charge pressure.
3. Electric on / off solenoid.
4. 5/8? hard line 3003 aluminum tube to fire wall, then Aeroquip flex line to engine tap location.
5. Didn?t do: Oil drain @ accumulator valve. I would have like to have thought of this during install, it is on my to do list. The accumulator is behind the pilot seat and is lower that the engine when static (tail dragger). When servicing engine oil, I?m not able to remove the left over oil in the hard line run.
 
Are you guys installing a check valve just upstream of where the accumulator in plumbed in as recommended in the automotive applications? If I understand the system correctly, the oil is always flowing the same direction through the cooler so a check valve downstream of the cooler but upstream of the accumulator would make the accumulator much more effective.
 
23905 was the valve I used (sorry about delay in response, I just saw your post). I have no check valve. I just teed it in like Moroso recommended.
 
I would prob have taken you up on that a few days ago but have since ordered the 1.5 qt 23903.

How many seconds are you guys seeing out of the 1.5 qt units with no check valve? I also have an inverted system with my valve mounted as stated above but, for a non-aerobatic prop, there is too much of a delay in the transition from normal to inverted operation and during zero G of more than 3-4 seconds.
 
I would prob have taken you up on that a few days ago but have since ordered the 1.5 qt 23903.

How many seconds are you guys seeing out of the 1.5 qt units with no check valve? I also have an inverted system with my valve mounted as stated above but, for a non-aerobatic prop, there is too much of a delay in the transition from normal to inverted operation and during zero G of more than 3-4 seconds.

I get about 6 or 7 seconds of pressure with a 1.5 quart accumulator.
 
Pressurized Oil Accumulators - where to install

Hello,

I bought the Moroso 1.5 QT. accumulator for my RV7A project.
Where do you recommend to install this unit?
My first idea was to install it on the firewall on the side of engine.

Witold
 
Hello,

I bought the Moroso 1.5 QT. accumulator for my RV7A project.
Where do you recommend to install this unit?
My first idea was to install it on the firewall on the side of engine.

Witold

You can put it anywhere you want. Many aerobatic planes have it in the tail if they need weight back there. Of course the hose would be expensive, but the length of hose is not an issue otherwise.
 
Pressurized Oil Accumulators - how to install

Hello,

Moroso 1.5 QT. accumulator in RV7A - which oil line the accumulator should be connected to?
Moroso recommends to install T-piece on oil line from oil cooler to engine - is it correct installation on Lycoming IO360?

Photos of existing installation would be very helpful for me :)


Thanks,
Witold


You can put it anywhere you want. Many aerobatic planes have it in the tail if they need weight back there. Of course the hose would be expensive, but the length of hose is not an issue otherwise.
 
Hello,

Moroso 1.5 QT. accumulator in RV7A - which oil line the accumulator should be connected to?
Moroso recommends to install T-piece on oil line from oil cooler to engine - is it correct installation on Lycoming IO360?

Photos of existing installation would be very helpful for me :)


Thanks,
Witold

You connect at any point. I put a T-fitting at the oil cooler exit.
 
Thanks Ron,

In my application would be easier to connect T-piece on the oil line from engine to cooler (this one which is located lower on Lycoming 360 engine). But I'm afraid if this option will work correctly due to the fact that this line is very close to oil sump - it means if oil pressure in engine drop, the oil from accumulator can go to sump instead of to engine. ??? But I'm not sure if it works in this way.

Witold
 
Thanks Ron,

In my application would be easier to connect T-piece on the oil line from engine to cooler (this one which is located lower on Lycoming 360 engine). But I'm afraid if this option will work correctly due to the fact that this line is very close to oil sump - it means if oil pressure in engine drop, the oil from accumulator can go to sump instead of to engine. ??? But I'm not sure if it works in this way.

Witold

That's a pressurized line too. It will work.
 
Check Valve

I don't understand why a check valve would be necessary as long as you tap in on the pressure side of the oil pump. It seems to me that, as long as the motors turning over, the pump itself would act as a check valve to prevent reverse oil flow. I'd like to avoid putting more than the necessary number of connection / potential failure points in the oil system. Does that logic make sense?

I'm thinking of using the Electric Pressure Control valve. In addition to the basic on / off function of the less expensive solenoid, the EPC valve only opens when the pressure in the system hits the trigger point for discharge / charge. I'm thinking of using the valve that has a discharge trigger of 35 PSI and a charge trigger of 40 PSI.

Finding a good mounting location will be a challenge in my -4. I'd like to be able to see the gauge and reach the charge port without opening any panels / covers. Alternatively, I guess I can add a remote air line with a charge port and gauge. Hmm . . .
 
Pressure switch closes with ignition and holds pressurized oil in the accumulator. When you activate the ign switch for next start you get a blast of pressurized oil in the engine before it makes 1 revolution. Really cool feature as you never start or turn a motor over after initial install or during oil changes without pressure.

I have one on a race car/street car and it works great and has saved me after having motor trouble twice prior to the install.

Even though I am building a 9 and don't plan aerobatics obviously I am tempted to install a small one.
 
Pressure switch closes with ignition and holds pressurized oil in the accumulator. When you activate the ign switch for next start you get a blast of pressurized oil in the engine before it makes 1 revolution. Really cool feature as you never start or turn a motor over after initial install or during oil changes without pressure.

I have one on a race car/street car and it works great and has saved me after having motor trouble twice prior to the install.

Even though I am building a 9 and don't plan aerobatics obviously I am tempted to install a small one.

I didn't install a solenoid on my accumulator but the benefit of having one is important if you don't fly regularly. When a Lycoming sits for a long time (like two weeks +) there is very little oil on the camshaft and premature camshaft failure can be attributed to cam wear before oil pressure is sufficient to bath the cam during startup. To a lesser extent cylinders suffer the same type of damage. I fly quite often so I didn't see the need for a solenoid valve on my accumulator. In my case, the accumulator is not charged until the engine oil pressure fills the accumulator and it empties following shutdown. A solenoid activated (opened) when ignition is turned on will pre-oil the engine and will close at engine shutdown to retain the oil under pressure until the next start. (Note: The solenoid must close before oil pressure is lost at engine shutdown. If you have it wired to the ignition switch and shutdown by moving the mixture control to idle cut-off you may lose pressure before you switch off the ignition. Many install a dedicated switch for the accumulator solenoid.) In either case the accumulator will provide a few seconds of oil pressure when the sump pickup is uncovered due to aerobatic maneuvering. Of course if sustained negative G flight is anticipated a full inverted oil system is appropriate. It's your decision.

I have a 1.5 quart accumulator and it fits nicely at the top of the firewall on my RV-8. You can install it anywhere you have room. Many aerobatic aircraft have accumulators installed in the tail section when weight is needed back there due to center of gravity concerns. The only downside of that is the cost of the long supply hose.

You may wonder why I have both an accumulator and a inverted oil system? During zero G or knife edge flight the shuttle ball of the oil valve does not seat in either the inverted or upright position and cavitation may occur. During these short periods the accumulator kicks in to maintain pressure. The 1.5 quart accumulator is good for about 5-7 seconds of pressure. That's plenty.

 
Canton Racing Tech Support

I had a great conversation today with Bob at Canton Racing Products. I'd read everything I could find and wanted to answer some of my remaining questions before I placed an order. When it was all said and done, I decided to go with:

Accusump:
- 2 quart accumulator - 24-026 ($207)
- Pro Electric Pressure Control Valve - 24-275X
(x = new and improved version) ($222)
- Mounting Clamps - 24-200 ($17)

On Bob's advice, I ordered everything from Summit Racing. Their prices were much lower than the retail prices on the Canton Racing Website. Saved me over $100 dollars and I got free shipping.

I'm planning on mounting the accumulator in the baggage compartment, running hard aluminum tube to the firewall and then using flex hose to connect to a T in the pressure line after my oil cooler. The EPC valve will be mounted near the firewall on the cabin side to make wiring easier. I am not using a check valve.

Some interesting points that Bob made during our discussion:
- The check valve is unnecessary and may actually reduce the performance of the system. It restricts flow / pressure to some degree. He also felt is is good to have the accumulator maintain pressure on the output side of the oil pump - keeping the pump "primed" and thus allowing pressure to be restored more quickly when the pump comes back online.
- I asked him about draining the line between the accumulator and pressure line tap point at an oil change. He said putting a T fitting or some other type of drain valve at the accumulator would be fine. No 90 degree turns for the flow path though - might create some pressure fluctuations for the sensor.
- I asked about environmental constraints regarding mounting the accumulator forward of the firewall. He simply warned me against exposing the accumulator to excessive heat. They've seen the oil ring seals fail due to high temps. The other risk is that if you lose air pressure and the electric valve is closed the retained oil in the cylinder will try and expand if it heats too much. That could cause an overpressure situation which would cause the the relief valve (175 psi) to open. I like the fact that the Accusump has a relief valve. I don't believe the Moroso unit does.
- It's important to mount the system such that you can easily check the air pre-charge and add air as necessary. This is one of the reasons I decided on a firewall aft installation.

We'll see how it goes. I hope to have this installed in January.
Thanks to everyone for all the great advice and war stories. It should be an interesting experiment!
Randy
 
Randy,
I mounted my Moroso 1.5qt accumulator vertically on the center of the firewall. I can easily see the pressure gauge on preflight and have had no issues with the unit in 75 hours of operation. I really appreciate the prelube benefits, and on a X country flight, I close the valve to keep the oil as a back up should I develop an oil problem, I figure I will get the low oil pressure warning and then open the valve while finding a suitable landing site. It might make enough difference to save the engine.

The RV-4 tends to be tail heavy, mounting the weight of the accumulator and the oil in the baggage compartment is going to be a large penalty when you start loading up towards max weight. Just a thought. Merry Christmas
 
Mounting Location

Thanks Mike,
I was just puzzling through the CG issues last night. You're right, the baggage compartment may be a bad location. I'm also concerned about leaks / servicing at that location. I like your idea of vertically mounting center firewall. I'm reconsidering the firewall forward option.

Also, how do you preflight the gauge / service the accumulator with your location. From underneath?

Thanks,
Randy
 
Thanks Mike,
I was just puzzling through the CG issues last night. You're right, the baggage compartment may be a bad location. I'm also concerned about leaks / servicing at that location. I like your idea of vertically mounting center firewall. I'm reconsidering the firewall forward option.

Also, how do you preflight the gauge / service the accumulator with your location. From underneath?

Thanks,
Randy

Randy,

I would not be too concerned about checking the accumulator pressure on preflight. I check mine when I open the cowl for oil changes. I have had the accumulator for about seven years and have never had to recharge it.
 
Randy,
I can see the gauge through the oil filler door on the cowl. The accumulator can be rotated in the mount to make pressure gauge viewable
 
Preflight

Ah ha! I guess I'm making too big a deal of the air pressure. Thanks for the info guys!
 
Accusump Oil Accumulator RV-4 Install

I finished my Accusump installation today. My initial plan was to put the accumulator in the baggage compartment but as I looked into that idea further, I decided against. I wanted to minimize the rigid tubing work and keep the system as simple as possible. When I opened the avionics compartment, I realized I probably had room between the instrument panel and the firewall for the fairly large, two quart accumulator. So, that's where it went!

I built a mount for the accumulator that runs the width of the fuselage just behind the firewall. I ran rigid 5/8 aluminum pipe to the firewall, then used 601 hose to a T fitting at my oil cooler. I used the new electric valve with pressure sensor - the 57 psi version. I installed a switch on the panel and an LED to indicate when the valve is open and thus indicating when the accumulator is supplying oil or being recharged. I ground tested it today but haven't flown it yet.

This was a really fun project and I learned a lot about aircraft plumbing! I'm excited about the new accumulator and 1/2 Raven system I've installed and look forward to seeing it all come together. I'll give another update after flight testing!

Here are some photos of the install:

IMG_0075_zpssshval4i.jpg


IMG_0084_zps2gvpurzj.jpg


IMG_0082_zpslmupwq2o.jpg


IMG_0077_zpsgjfdv5b4.jpg
 
Flight Test

I flight tested my Accusump accumulator three times over the last couple of days. It works exceptionally well! Before Accusump, anytime I pushed a little zero to negative G, I immediately got a low oil pressure alert / indication. Now, I can SUSTAIN 1.5 negative for six to eight seconds before losing oil pressure. That's pretty amazing considering I don't have an inverted oil system!

Between the new Accusump and the new 1/2 Raven Air/Oil Separator, I'm very happy with the aerobatic capabilities of my carbureted 0-360 equipped airplane. I especially like the fact that my Hartzell CS prop stays supplied with oil pressure and I maintain control of that bad boy when the engine sags / quits during inverted flight.

My airplane comes back from aggressive aerobatic flying with a clean belly and I have a clean conscience knowing my engine didn't suffer!

The indicator light I installed is VERY helpful in monitoring the actions of the Accumulator and I'd highly recommend one for anybody that installs an accumulator with an electric pressure valve.

Canton Racing puts out a quality product and it is working VERY well for me!
 
Interesting. What about checking oil level?

Hey guys,
Interesting topic. I watched that video of Moroso and have a question. If we charge the system with oil at shutdown in order to lube the engine with oil before next start.

Wouldn't that mean that I now can't accurately check the amount of oil in the systems with the dip stick because there is over qt in the accumulator. Any thoughts? or am I misunderstanding this. Sorry if this is a silly question.
 
Checking Oil Level with Accumulator

During normal operations, I always shut down with the valve closed so that the accumulator is charged. Before start, I pre-oil the engine by throwing the switch to open the valve. The only time I shut down with the valve open is if I'm going to service the oil system.

I service and check my oil level with the accumulator charged. I service the oil to five quarts. With a maximum oil level of eight quarts, that leaves me with plenty of excessive sump capacity to handle the oil that is discharged from the accumulator. I've also found that is the level that minimizes oil loss due to inverted operations. Even with my excellent Raven Oil Separator, if I service the oil above six quarts, I'll lose some of it overboard during aggressive zero to negative g maneuvering. The only time I'll service it higher is if I'm going on an extended cross-country flight. In that case, I'll service it to six quarts to compensate for oil burn during the flight(s).

Your dipstick is still accurate. You just need to remember to service the oil with the system in a specific configuration. If you choose to service it with the valve open (accumulator discharged), just pick a higher number to accommodate the quantity of oil in your accumulator. With my two quart unit, I'd probably target seven quarts. Again though, I normally service to five quarts and service with the accumulator charged.
 
Good question - WWRD?

Hey guys,
Interesting topic. I watched that video of Moroso and have a question. If we charge the system with oil at shutdown in order to lube the engine with oil before next start.

Wouldn't that mean that I now can't accurately check the amount of oil in the systems with the dip stick because there is over qt in the accumulator. Any thoughts? or am I misunderstanding this. Sorry if this is a silly question.

Good point - I just ordered the parts for the accumulator - had not thought of this, but it would be right, the static level would read 1 qt higher than the running level due to the storage qt. On the other hand, if the pressure was dropping due to low oil level, the oil would be returned to the flow until the pressure was zero (if it was an inflight oil discharge) so the quart would still be "usable" in the extreme event, even if it was a creeping event.

Just when I thought I knew all the possibilities of this half-raven. Always something to learn.

WWRD? What would Ron Do?

Edit - I see Randy posted above. Good Advice, Thanks.
 
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Thanks for the explenation

Thanks!
I had never heard of this before but it seems like a great thing to have if during the winter weather prevents you from flying every week. Keeping everything lubed. Wouldn't it be perfect if this thing also had a build in heater so the oil pre lubing the engine would be nice and warm?
 
Structural Question

So lots of discussion about the performance and use of the accumulator but not much on mounting. My 7 only seems to have room on the left firewall just above the brake line pass throughs on the firewall. Mounting horizontally, the right side mount can tie into the vertical angle on the left side of the hot air box. The left side will not attach to anything stiff. The sketch below is my thinking for a stiffener to carry the weight and moment of the mount. The accumulator weighs 4.68# holding one qt of oil. The center is 2.25 in from the firewall. With 1/2 of the load on each mount, 6g?s and 20% overload, this comes to 38 in-lbs bending moment on the firewall. I am proposing a 3/4x3/4x.063 angle attached at the bottom of the firewall and to an angle stiffener at the top. Rather than make a line of rivets spaced ~2? apart along the length, I would plan to mount it on top of the lower angle (.125? thick), then allow it to be spaced 1/8 from the firewall up to the cross brace. A 1/8" spacer would be installed where the fasteners penetrate the firewall for the accumulator mount. Rivets would be used for the upper and lower points of the vertical stiffener.

The upper and lower attachments could use gussets for more rivets to share the loads.

I am very sure that the strength of this arrangement is sound for the load, but there are two possible issues. 1. The new stiffener might begin to share loads on the FW and fail at the ends. 2. The lack of direct attachment to the firewall, and sharing a line of rivets are not technically acceptable (?).

So, what do you think?
Firewall%2BMod%2BAccumulator.jpg
 
Indicator light

The indicator light tells you when an open signal is being sent to the valve. I find it very helpful in evaluating the performance of the system.
 
Needing help please.

I am still needing input on how others mounted the accumulator. Post 3 above. Vans officially declined to comment, but did make some unofficially. The ends should be gusseted with additional rivets.

How did you do your firewall mount on a 7?
 
Bill,
I used .063 3/4x3/4 angle on the cockpit side of firewall where the accumulator mounts go. I made the about 8" long. Very sturdy. My accumulator is mounted vertically on the engine side of the firewall.
 
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