Nerdy question about oil accumulators/Accusump

[Windsorpower]

I’ve talked myself into an accumulator for my build and I think I like the manual valve option. Hypothetically, let’s say I’ve got a 351 that just had an oil change with an 8 quart pan. A brand new accumulator is sitting in the trunk, connected to the oil gallery with a copious amount of -10 AN hose and a manual shutoff valve mounted halfway back, let’s say beside the shifter for this example. I start the engine, let it stabilize, and slowly open the valve for the first time, carefully watching the oil pressure to make sure it stays in a safe range while the accumulator fills.

Here’s the nerdy question: What happens to all the air that was in the 6+ feet of hose between the engine and the trunk-mounted accumulator? I’m guessing it burps out through the engine after several accumulator activations?

FYI, 8 feet of -10 hose holds a half quart

[Jim1855]

FYI, my choices.

I ran an 35psi electric valve with a power on/off switch on the dash. Turned it on which pressurized the engine a few seconds prior to starting the engine. The oil pressure gauge showed about 20psi prior to turning the key suppling oil to the bearings. Prior to shut down I turned the pressure valve off which saved the pressurized oil in the Asump. This sequence would be possible with a manual valve, if you don't shut off the valve prior to shutting the engine down you'll lose the pressurized oil that allows pre oiling.

You could follow this sequence with a manual valve but you need far more oil lines. With the manual valve you are swapping oil lines for electrical wires. Not my choice but it is yours.

As far as air in the oil lines I think this will work itself out but the longer lines of the manual valve installation may cause issues. I suppose you could "bleed" the lines, messy but not impossible.
This is a question I'd pose to Canton's Tech Department.

Jim

[Windsorpower]

Thanks for the response. I’m still leaning toward the manual valve, likely with the remote cable actuator. The various automatic valves increase failure chances and are, by Canton’s own FAQ’s, affected by debris and even assembly lube. Did you plumb yours into a sandwich plate?

20 psi of oil pressure on a pre start sounds like money in the bank.

[GoDadGo]

What about mounting the accumulator on the firewall and the valve just under the steering wheel if you want a manual option?

[rich grsc]

Mounting in the trunk would not be a good idea. The long length and resistance of the hose would reduce the benefit of the accumulator if you lost pressure on the track. It should be mounted as close to the engine as is practical. The idea that you need to per-oil the engine every time you start doesn't make sense. They aren't on production cars, trucks, or construction equipment. The oil never completely drains out of the bearings

[Jim1855]

Not a sandwich plate but a custom built adapter plate for AN-12.

Oil path:
Engine out to bottom of Canton filter.
Side of filter to top of Canton Thermostat.
Bottom of Thermostat return to engine.
Top half of Thermostat to Oil Cooler in.
Oil Cooler out to bottom half of Thermostat.
Asump plumbs into the bottom half of the Thermostat with the Pressure Valve on the Asump

Electrical:
Ignition switch power on to Asump Pressure Valve switch.
Pressure valve switch to Pressure Valve
This wiring shuts the Pressure Valve off when ignition is off.

Starting:
Pump carb once, a full stroke.
Pressure Valve switch on.
Ignition switch to on.
Wait for 20psi on the oil pressure gauge.
Start

Shut down:
Turn ignition off.
Reset Pressure Valve switch to off.

This system or, similar, will install in the FFR Challenge Car. Same components, same engine, different oil cooling and much shorter lines.

Jim

1855 canton fv.jpg1855 canton rv.jpg
SPF 1855 Canton oil sytem.jpg

[Windsorpower]

Mounting in the trunk would not be a good idea. The long length and resistance of the hose would reduce the benefit of the accumulator if you lost pressure on the track. It should be mounted as close to the engine as is practical.

Following quote is from Canton regarding distance between engine and accumulator:

"The system will work as intended even with that length of hose. We find that in vehicle applications the pressure and flow loss from the friction of the line is often too minimal to notice. "

[Al_C]

I'm going to take a contrarian position here. I may get lots of pushback, but what the heck!

I submit that you do not need this device, nor will it do you that much good. I wonder what your specific application might be? As indicated, you mention a 351 as a hypothetical, and while I'm certainly no expert on that particular engine, I suspect as a small block Ford it does not have exceptional oil demands. Here's my experience: I have a Gen II coyote. As long as the oil level is full - yes, right to the top mark on the dip stick - there are no issues, irrespective of how I thrash around. However, if the oil level drops, all bets are off. Down a half quart can cause a drop in oil pressure with resulting complaints from the engine.

So.... my recommendation is skip the accumulator, along with the added costs and potential failure points. As Rich indicated, the bearings never really get dry ("the oil never completely drains out of the bearings"). Just ensure that your oil level is full to the brim. Always. Shouldn't matter what pan you use; a "factory" dip stick should be calibrated to have the oil at the correct level.

[Mike.Bray]

I agree with Rich, why do you need an accumulator for a street or mild track engine? Sounds like more potential points of failure to me. If you're truly worried about your bearings get a Dart block with priority mains oiling. The bearings will have pressured oil within a few revs.

[GoDadGo]

I agree with Rich, why do you need an accumulator for a street or mild track engine? Sounds like more potential points of failure to me. If you're truly worried about your bearings get a Dart block with priority mains oiling. The bearings will have pressured oil within a few revs.

That's what I did after my engine builder destroyed by block.
I also added a double baffled pan for proper oil control.

https://youtu.be/IGYtX-3p7xk

The big question is are you road racing the car?
If not, just spend your money on a good block and oil pan.

[Avalanche325]

Just put a road race baffled oil pan on and call it a day.
I have tracked and autocrossed my 347 more times than I can count and never an oil pressure issue. I do have a combination low oil pressure / high oil temp idiot light on my dash. The only time it ever came on was a sensor failure.

I you want it for the cool factor, go ahead. Might as well put it in the engine bay where you can see it. A guy I know has one mounted up by the radiator. It has never activated in 12+ years.

[rich grsc]

Looks like a race car----I need to put race car things on it.

[Windsorpower]

Looks like a race car----I need to put race car things on it.

So which one of us emits a bigger DB stench? Me for posting my original question or you rolling in with some drivel like this? I think you win.

“I don’t always have 3000+ posts on a forum, but when I do I strive to treat others like I’m Sheldon Cooper.”

[Mike.Bray]

I thought Rich's comment was spot on. As Avalanche said, there's no need for it but if you're going for a cool factor go ahead.

[Dave 53]

I have an 818 track built car that routinely pulls 1.3 peak g's and a bit less for 7+ second at a time. No accumulator.

When researching, my basic conclusion was that an accumulator is a band-aid for a root cause issue. I didn't want an oil system that had a deficiency that the accumulator patched. I fixed the deficiency so I have a system that doesn't need an accumulator. No properly built cars that I see at the track have accumulators. But, maybe they do some good for an occasional auto-cross or extremely spirited drive. Maybe.

Prelubing a modern car engine before starting seems wholly unnecessary unless the car has been sitting a long time. As a side note, I work on ships. If a big ship engine is stopped for more than about 20 minutes, many will do a prelube routine that takes about 20 seconds before starting.

To the point of, "Looks like a race car----I need to put race car things on it"... You're all guilty of that! And that's okay! As the builder of what I consider to be a "real" race car and driver of other's, I see lots of cars dressed up to look like a race car. No disrespect, but this includes every Cobra I've ever seen. I think you guys are crazy to use 4 point harnesses (unless it's a Schroth ASM 4 point) which look cool, but are not allowed in any respectable race series because they are unsafe. A 3 point would be sooo much safer in your Cobra, but 4 points look much cooler and I get that. (Not meaning to hijack this thread with a whole new subject - it's just an example). I call such cars "tuner" or "show" cars and there ain't a dam thing wrong with them. If it brings you joy, go for it! Your joy will rub off on me and that's why I like Coffee and Cars. I respectfully chime in to present the point of view of a real race car builder. In this case, accumulators are for cars with substandard oil systems that may or may not save your engine and 4 point harnesses are unsafe. Maybe these aren't good race car examples because race cars don't have accumulators or 4 point harnesses.

You Google Schroth ASM 4 point harness and I'm gonna Google Sheldon Cooper.

[Bob Cowan]

I wouldn't track a car - any car - with a stock oiling system in it. Dry sumps and semi-dry sumps are terribly expensive. But a good road racing pan and an accumulator will suffice for most amateur racers. To hit the track with just a good pan is asking for trouble.

Also, a lot of pro builders will recommend a high volume oil pump if you have external oiling components : accumulator, cooler, heat exchanger. I don't know of anyone who recommends a high pressure pump on a Windsor.

Back to the original question. If the accumulator is mounted at a higher level than the engine port at the oil filter, there will be a dead space of air in the accumulator. A column of oil will develop behind the dead space. The oil column will pressurize the air pocket, and the gauge on the accumulator will fool you into thinking it's pressurized with oil. Depending on how you mount it, it could take a long time to work that air out of there; if it ever does.

If you use a valve to close off the line when the engine isn't running, the air pocket will likely stay there forever.

If you want it to be functional, the oil lines and bottom of the accumulator should be at or lower than the oil filter boss. That will allow all the air to self purge fairly quickly.

Initially, I used an electric valve to control it. That actually failed rather quickly. After that I just left it open, with no valve at all.

https://www.racingtheexocet.com/?page_id=265

[Avalanche325]

..... and 4 point harnesses are unsafe. Maybe these aren't good race car examples because race cars don't have accumulators or 4 point harnesses.

We don't have 4 point harnesses. We have 5 point harnesses.

That being said, some people use that as 4 point, or even 2 point (lap belt only) which is very dangerous.

[Windsorpower]

Thanks for your reply, Bob. I’ve run across your name on various forums during my accumulator research and I was hoping you’d chime in. I could care less about “cool factor”’and am honestly just trying to protect one of my bigger investments. My parents first house cost less than half of what I paid for this powertrain. I’ve got another 500 hp car that I built 15 years ago that I pre-oil with a scavenge pump and it’s nice to see 50 psi before start. That pressure gauge is at the split for the turbos, so no dry starts ever, even after a long winter. Cheers.

Not sure how or why “cool factor” ever entered into this discussion but it sucks that someone made that leap.

[Bob Cowan]

Not sure how or why “cool factor” ever entered into this discussion but it sucks that someone made that leap.

That was my fault. I was thinking of Rich's comment when I wrote that. I apologize.

[Avalanche325]

That was my fault. I was thinking of Rich's comment when I wrote that. I apologize.

I have to take blame for that too. I said "cool factor" as in, if you just want it, put one on. I didn't think saying build your car your way would be offensive. Lot's of things are done on these cars simply for the "cool factor", so it is valid to ask. I have drilled and slotted rotors. Arguably, just slotted is better. I did drilled because they look cool.

Look at how many times people come in here asking about putting an oil cooler on and have no idea that it is a bad idea on a street car unless you put a thermostat on it. They just ask which one to buy. They didn't ask about a thermostat but found out that there was such a thing when people voiced their opinions. Then for pure cool factor, about half of the coolers on peoples cars aren't even plumbed up.

[Mike.Bray]

Worrying about pre-oiling a relatively mild street engine reminds me of a car in the Dakar Rally one year that broke the rear end during the race. Caused by the extra weight of the spare rear end he was carrying. I think we all overthink things on these cars sometimes.

[rich grsc]

He just needed another jack or two and a few more tools and he could have finished.
Mike that is the epitome of needing to pre-oil a functioning engine before starting it.

[Railroad]

I can see pre oiling being necessary for some engines?, but how many Millions of hot rods, daily drivers, race cars have spent and survived their entire life without it?

I do have a rebuilt flathead v8 that has never been started, that has plans for pre oiling for break in.
I have a modified fire extinguisher bottle, I can pressurize with a few qts of oil. I might live long enough to get it done.

[Avalanche325]

I can see pre oiling being necessary for some engines?, but how many Millions of hot rods, daily drivers, race cars have spent and survived their entire life without it?

Over a B B B Billion. Picking on pre-lubers? Are there no boundaries?
Disclaimer - The preceding statement is the authors likely lame attempt at humor and in no way represents the opinion of forum users, Factory Five Racing, AKA FFR, the Ford Motor Company, Shelby American, or AC Cars England Ltd.

I do have a rebuilt flathead v8 that has never been started, that has plans for pre oiling for break in.
I have a modified fire extinguisher bottle, I can pressurize with a few qts of oil. I might live long enough to get it done.

Of course it is considered prudent to pre-lube a newly built engine. That is mainly just to get the oil pump, lifters and passages filled. With assembly lube, we are probably fooling ourselves on that one too.

[Dave Tabor]

I added an Accusump to my Gen III Coupe after adding a rear wing/aero nose - the car will pull 1.2 lateral G on the track.

With the wing and Toyo R888R tires, I could buzz/light the low oil pressure warning indicator on my dash at will at various points on a couple of tracks, especially if off-camber.

The motor is a FRPP Boss 302 crate with a CP302LT-RR 7"/7 quart pan.

The Accusump has a manual valve that is only used during oil changes/adding new oil.

I hated to add the Accusump due to the thought of extra points of failure but it's all AN connections.

Dave
Gen III #17
22,500+ miles

[Ford & Jeep Fan]

I’ve talked myself into an accumulator for my build and I think I like the manual valve option. Hypothetically, let’s say I’ve got a 351 that just had an oil change with an 8 quart pan. A brand new accumulator is sitting in the trunk, connected to the oil gallery with a copious amount of -10 AN hose and a manual shutoff valve mounted halfway back, let’s say beside the shifter for this example. I start the engine, let it stabilize, and slowly open the valve for the first time, carefully watching the oil pressure to make sure it stays in a safe range while the accumulator fills.

Here’s the nerdy question: What happens to all the air that was in the 6+ feet of hose between the engine and the trunk-mounted accumulator? I’m guessing it burps out through the engine after several accumulator activations?

FYI, 8 feet of -10 hose holds a half quart

The air get pushed back and up into the accumulator as i see it.
isn't the (compressed) air what pushes the oil back to the engine?? isn't the accumulator just a vertical tank with only a bottom inlet/outlet??