Oil accumulators

[turbohunter]

Have'nt used one.
Seems like a good idea.
Obviously not necessary, but is it a good idea for drag racing? Does it solve a non existent problem?
Have seen all the sales vids etc. but would like real world experience from you guys.

[jayb]

You are flying through the traps at 140 or so, and then you hit the brakes.  The oil runs away from your pickup and your oil pressure gauge goes to zero.  You either A) Add more oil to try to cover the problem, B) Change to a dry sump, or C) Add an accumulator.  The accumulator solves the problem instantly, and also allows you to give the engine oil pressure while cranking.  I like them 

[turbohunter]

I hope I'm flying through at 140

[Autoholic]

I recently went "flying" at 140 through a "trap". Life is so much more tasty at speed and Mustangs handle it very well.

I now know how I will enter the Gates of Heaven, at 200 MPH and everyone will hear me coming from a mile away. I'll say I was dying to get in.

[fekbmax]

Cheap insurance. Well worth the have. Especially here in the southeast where lots of tracks have a short shutdown.

[cammerfe]

I had a Mecca accumulator on my '63 F-100 ICB for years. I used it mostly as a pre-oiler and it contributed greatly to engine longevity in the mildly-modded 390. I strongly suggest that you put the electric valve on it for ease of use.

KS

[turbohunter]

Thank you gentlemen.

[Qikbbstang]

Devils Advocate I have my doubts about accumulators here's where I get my doubts. I always wondered how well an accumulator could work as advertised.  When you think about the mechanicals involved particularly pressures in the precharge and engines max oil pressures..  If we have for example a 2-quart model, note it's called a "2-qt Capacity". First I have to wonder how much oil can actually be available for lubrication of an engine that's lost oil pressure from the pump. A 12.00" x 4.25" accumulation cylinder is rated at 2quarts.. A factor that supposedly adjusts the capability of how much oil can be injected into the motor is by what they call Precharge Pressure ranging from 4-60psi. .... Spend some time thinking about how much oil can be held and available for discharge in a  12.00" x 4.25" cylinder with an air bladder that is pre-pressurized (Precharge Pressure). How much oil can actually accumulate as the engine is run and the cylinder's volume is compressed by the engines oil pressure against an internal bladder to accumulate said volume of oil.
     Point blank you are not filling a cylinder with 2qts of oil and then putting a gas blanket on top of the oil so that when a valve is actuated it can fully discharge all the oil from within the cylinder* - this method could in fact discharge the entire cylinder of oil. . Instead you have the engines oil pressure compressing the oil in a 2quart space against a precharge pressure. I believe precharging does not make much difference in how much oil is available to make up pressurize into an engine that lost oil pump pressure.  If you start against a low prechage pressure you only have that much less volume you can compress into the accumulator under a given engine oil pressure.
      Further unless I missed it there is not a restrictor/bleeding check valve that permits oil to be discharged at full rate into the motor and then recharged at a slow rate as oil pressure from the pump returns - in effect as oil pressure returns from the pump the oil is essentially re-filling both the accumulator AND oiling the motor, a 50/50 deal vs 100% of pump oil going into the motor. From what I see they only sell a one way check valve that simply prevents reverse-flow into the oil filter - something we all know is a disaster from a recent topic.  Finally keep in mind all the ability of an accumulator to discharge its guts into an engines lube passages is on a wicked curve as the accumulator discharges oil it's available pressure to send out that oil drops like a rock.
    Last I get the feeling the pre-charge pressure is kind of smoke & mirrors. IF you have 60lbs of precharge pressure in the bladder is it all that different if it starts at 5lbs precharge pressure vs 60lbs pressure?.......... there can not be all that significant an effect on oil volume going in/out of the accumulator when the bladder starts at 5psi vs 60psi precharge (think piston making pressure in engines cylinder) If you start at 60 psi a max oil pressure of 90psi is not going to offer that much volume under compression.   All this under FoMoCo Muscle Parts stating the hi-perf FE pumps flow in excess of twenty repeat (20) gallons of oil per minute at 4,000rpm 70-80psi. How good is a quart or two?


*  I sold Halon fire suppresion systems where a cylinder was filled with Halon (same low vapor/boiling point characteristics as Freon) and then a 360psi nitrogen charge (blanket) was added to the filled cylinder to be able to shove the low pressure Halon in liquid form up the syphon tube out of the vessel and on through the piping system to the fire.  That's how you shove fluid into a critical situation.

[jayb]

They actually don't have a bladder, BB, they are a free floating piston with an O-ring seal.  The air behind the piston is pressurized to around 5 psi with the accumulator empty, and then the oil pump fills the accumulator with oil at the oil system pressure. 

You know that the gpm rating of an oil pump is free flow, right?  Not into an orifice?  No way the engine will use anywhere near 22 gpm under any circumstances.  I'd guess that a 2 quart accumulator would keep the engine oiled for at least 15-20 seconds, which is all anybody should ever need.

They just work.  Trust me ( )

[machoneman]

Almost all the serious SCCA types and most open wheel racers do use a form of in-car accumulator. In IndyCar and F-1, due to weight, they have a neat canister on a rolling cart that has those fancy quick disconnect fittings. Before start-up, the line is snapped into an oil passage on the engine and a valve is opened. Once running, the valve is close and the fitting taken off.

Hey, if it's good enough for all these forms of racing engines......

[turbohunter]

Found this vid pretty helpful in understanding the way they work and how they are constructed.

https://www.youtube.com/watch?v=vyaGoj60A6s

[Qikbbstang]

Absolutely know they have the floating piston (accu-sump site shows high prelube pressures) and understand Muscle Parts FORD GPM rating  must be a design spec though a gerotor pump is positive displacement so there is virtually no reduction of flow from loading as with centrifugal pumps. As mentioned I've long pondered the 20+ GPM number and just come to believe it has to be recirculating internally within the pump big time- but why in the world would they "by the book" design a pump/lube system with so many friggen GPM???.... .Bypass/recirculating a FE oil pump internally likely does not use excessive power,,, maybe?    Perhaps for quick recovery?...but I have no idea. The thought of a std auto filter even flowing 5GPM and trying to filter scares the hell out of me. It's got to be bypassing internally. Hard to comprehend many gallons flowing through an engines lube system. My engine builder mentioned watching a see into cut-away motor run where you could watch bearings and he was surprised at how much. Likewise I purposely scheduled my trip to the Circle Track Trade Show to witness Smokey run his Smoketron with strobes in the window pan that showed the blobs of oil slamming around the crankcase. 
I got to chuckle at saying they use pre-lubers in all out race cars that obviously are dry sumps - hardly transferable to a wet sump.
BTW Jay the Fram HP1 is a race filter and has a much different filter rating then a std or Mobil 1 Filter.

[machoneman]

One must have a solid understanding about engines, let alone pre-lubing, dry or wet sump, to recognize what Jay is saying. I chuckle at.....those who don't!

Any engine benefits by using said device to avoid dry starts, especially racers that aren't fired up regularly. Many wet sump (Trans-Am clones, Euro cars, etc.) vehicles in SCCA competition are wet-sumped and cannot, by rule, have many modifications on their respective oiling systems. Yet the one mod that is allowed in all classes is an accumulator, both for starting and heavy G-force cornering.

One who had at least a rudimentary knowledge of racing in general would know these facts. Like Jay said....trust me! 

[FordEver]

I have the 3 qt accu-sump on my NSS 67 Fairlane, got it mainly to pre-oil as car sets between races. My road race friend saw it said good move, he said one lap without the accu-sump and engine is gone. In drags, front or rear pickup pan, pickup may get uncovered during run or on decell.
BB, sometimes one can overcomplicate things, just get one put it on and go racing!
These FE,s are too expensive to take the chance.

[Qikbbstang]

You guys are doing a good job selling me on them, yet IF the FEs pumping capability is anything near the 24 gpm @ 4,000 rpm figure from FoMoCo a quart or two of pressure feed oil is gone through in a second or two at best right? ..............Jay you are far on the opposite side of the equation in your belief about "I'd guess that a 2 quart accumulator would keep the engine oiled for at least 15-20 seconds, which is all anybody should ever need."

Can anyone tell us how long it takes their specific sized accumulator to blow-down on just a hot engine/hot oil with a non-running motor?............