Dry Sumping Motors
 

Dean or anybody what are the advantages of Dry Sumping Motors. I have a 36 Skater with Quad Whipple Motors Dynoed at 1025 HP at 6,200 RPM. Winter Project could be Dry Sumping and or Changing from Twin Small Whipples to one large Whipple. Trying to get a little bit more HP without running more than a 1/4 Race Fuel Mixture and still maintaining some reliability. What are the advantages and disadvantages of Dry Sumping? I know Drysump motors create more vacum so less Oil spillage but will it also pick up some HP.

Drysump should give arround 30-35 HP more. But alot of work.
Complette engine has to come apart , need to close some oiling holes in the block and sofort.

The engine does not need to come apart to change it to dry sump. First, you need to change the oil pan and remove the stock oil pump and rod. You will need to buy a dry sump pump and tank. For your engine, I would recommend a 4 stage pump. It has 3 scavange sections and 1 pressure section. Your current oil filter and oil thermostat should work fine. You will also need a mandrel on the front of the crank to drive the oil pump and a belt. It does require quite a bit more plumbing, since you have all the scavange lines going to the pump and then on to the tank.
It will increase some power by not having the crank spinning in oil. As soon as the oil hits the pan, it is sucked out. It will also help with oil temp since the oil is stored in a remote tank and not in the engine. You also don't have an issue with leaks, since there isn't any oil in the engine. You have less of a chance of the pump sucking air and less of a chance of windage from the crank digging a hole in the oil in the pan. You will get a better, more steady supply of oil.
It is a costly conversion, but well worth the money. You are on the borderline of needing it IMO. You could get away without it, but it would be a worthwhile addition.
One other thing, you should not need to run any race gas (even 25%) with 1025 hp and a Quadrotor. I regularly make 1200 hp with a 2.3L Quadrotor on pump gas with a hydraulic roller camshaft. There are other builders doing similar builds with similar results. I do a LOT of Whipples, so I'm pretty familiar with them. You may want to verify the need for the race gas with the builder to see if it is nesseccary. You may be wasting money buying that fuel. Give me a shout if you have any questions or if I can help you in any way. I can also do the conversion to a 5 liter Whipple if you are interested. Thanks, Eddie.

Eddie, sorry thats just what i heard.
But dont you need to block someting up in the motor ?????
Because when you wetsump a supercat you need to open something in the block ?!:cool:

Hi Eddie,

What are your thoughts on using a 5 stage pump,closing the valve covers and pulling 10" or more vacuum ???

Cat,
I think we have had this conversation, but I am too old to remember! My experience is a vacuum set-up in a boat is a plus as the bilge stays much cleaner. We experienced minor HP gains on the dyno at 10-15 in of vacuum with std tension oil rings.
Does your current dry sump set up produce any vacuum at idle?
Ben

We build several hundred marine dry sump pans and tanks a year at Stef's. I see your on the West Coast, REX Marine is stocking dealer for us and and DNE also is a WD for our stuff. As mentioned the retro fit is not to complicated except for mounting tanks and new plumbing along with the oil pump mount. Our offshore tanks are 2.5 gallons of oil and we have the prints for several Skater mounts. Pan wise I might suggest going to a divider pan and going 5 stages. The pan would have 4 compartments sectioning off each with its own pickup. This style of pan we have seen on engine applications promotes very good ring seal and is worth a few HP. Pans are available in steel, stainless steel, and aluminum.

You do have to block off the rear main cap, where the old oil pump was. If you don't you will not have any oil pressure.

You don't have to block off where the pump was in the rear main cap if you use your same oil adapter. You will only be putting oil into the block, and not back into the main cap. They are 2 seperate passages. They also make an oil filter adapter that only has one fitting and covers the entire area where the stock filter would go. If you use that one, you will need to block off the rear main where the stock pump goes since you are pressurizing both passages. I use a standard oil filter adapter with 2 fittings(1 in and 1 out). I just put a plug in the one labeled OUT and only use the IN. The oil leaves the tank, goes thru the pump, filter and cooler and then to the IN fitting in the adapter as if you had a stock pump in the pan.
You could use a 5 stage pump if you wish. I would close off the oval shaped holes above the camshaft and put a pickup/strainer in the lifter valley to scavenge the oil from the top end. You can then put a bulkhead fitting in the china wall at the back of the block to run the oil back to the pump. This stops any oil from running past the cam and onto the crank, thus robbing horsepower. If you did that, I highly recommend pistons oilers. You will no longer get any splash lubrication from the oil draining down from the top end.
I would then put 3 scavange lines in the pan and the 5th is the pressure section. Hope this helps, Eddie.

Ben,We know you are at that young tender age where memory doesn't fail ! Yes, I also recall you and I talking about our 5 stage,sealed system pulling vacuum. However,it seemed interesting to hear Eddies comments. Also,I'm curious why more is not said about closing the valve covers and pulling vacuum.

We are pulling 11" at 5,000 and above...the vacuum decreases as rpm decreases,until positive pressure occurs at approximately 1,500 rpm and increases as rpm continues to decrease. However,the flapper valves open as positive pressure starts to occur,thus protecting the seals. The flapper valves would also open in the event of a piston burning.

We also find a fringe benefit at idle. In summary,the system idles well.

Incidently,the pan,tank and pumps come from Stef...good stuff.(The tank is square--4 gal.) The pulley ratio should be sized for volume of oil consumed. For example,we have piston sprayers,lifter sprayers,valve spring sprayers,honed push rods, HP6 filters and dash 12 lines w/nascar screens.

Dry Sump
 

Thanks Eddie for all the Info. GT Performance out here does my work . The reason i run 1/4 Rac Fuel is the Lakes I go to out here don't have anything more than 89 Octane. So i use soem race fuel to raise the Octane. I have a 100 Gal. tank on my Freightliner and I just add a bit to keep from having low octane.

That makes sense on the fuel. Gary at GT is a great guy. You are in good hands with him. If you have any more questions, I would be happy to answer them.
Here are a few pics of a dry sump 598 ci I'm building with a 5L EfI Whipple. I also included a pic of the oil filter adapter that I use. Notice the plug in the "OUT" hole. This passage leads straight to the rear main cap where the stock oil pump goes. That is why you don't need to block off the main cap. They also make an adapter that has only 1 large port in it and the oil can go into either hole in the block. In that case, you must block off the rear main or you would not have any oil pressure, since all the oil would go right back into the pan.
Eddie

A few more.

what horsepower does drysumping start to make sense? 800? 900?

Is it only good on blower motors?

In a pleasure boat, I don't do it until about 1100 hp. It is more rpm dependent than hp dependent. At real high rpm's, the crank counterweight and the rods will start to "dig a hole" in the oil from windage. It can become so bad that it will uncover the oil pump pickup.
It is not just for SC engines. Higher rpm NA will benefit from it also. You typically see it on larger SC engines because of the stroke and power. The larger the stroke, the heavier and longer the crank is and the farther it sticks down in the pan. In that case, it is more likely to create a ton of windage.
One other thing. For me, the larger the engine (hp), the more oil I want in it. All of that power creates heat. The less amount of oil you have, the faster it will heat up. You may not be able to keep the heat managable. When you get a pan much over 14 qts. it becomes hard to control all of that oil. No matter how many baffles and trap doors you have, the oil starts to slosh around and leaks occur. The oil will inundate the rear main and the rear pan seal and it will eventually start to leak. Those seals are not made to be submersed in oil.
With a dry sump tank, I run 5 gal. of oil with no worries of leaking.
Hope that answered your questions, Eddie.

Thanks Eddie, very informative!

My pleasure.

I'm trying to understand the "dry sump" methodology. I don't want to sound ignorant, can you expalin the oiling system, like a diagram or explanation of how the oil flows?

it is just what the name implies. on a " wet sump" the oil is stored in the oil pan and sucked up and into the motor thru the oil pump pickup which is ALSO in the oil pan. the oil circulates thru the motor and " drips" back into the pan thru gravity. the downsides are that the crank splashes in the oil which aereates it and causes drag and the oil itself is subject to g forces and can be forced away afrom the pickup and thus starve the motor with catastrophic results.

on a dry sump, the oil is stored in a carefully designed tank away from the motor. therre is a seperate EXTERNAL pump that is actually several individual pumps bolted together driven by a toothed belt drive off the crank. one of the " stages is " pressure" . this sucks the oil from the tank and delivers it under pressure to the motor , usually into the filter housing. the oil circulates and collects in a very shallow and carefully designed pan which is being sucked dry by the other " scavenge" stages of the pump. they deliver the oil back to the tank. you will hear talk of " over scavenging" ie, the pump actually sucking hard enough to pull a vacuum in the bottom end. sometimes this is effective... sometimes not. but the bottom line is that the system is a much more effective and reliable oil system for any motor that sees sustained hi revs or significant g loads. the power benefits are minimal but real. no one does a dry sump to make power because the pump and drive losses will often offset the windage gains... but there are some gains anyway. It is done because in hi reving hi g load environments, its the best way to keep the motors alive.

It's not much different than a standard wet sump system. Obviously there is more plumbing involved since the pump in on the outside of the engine.
If you reference the pics that I put above, I used a 4 stage pump. It has 3 scavange sections and 1 pressure section. One side of the pump has the inlets and the other has the outlets. On my pump, the 3 scavange lines go to the inlet side of the pump but there is only 1 #16 line going back to the tank. The pump has internal passages that connect the 3 sections together internally. This just simplifies plumbing since I only have to run 1 large line back to the tank instead of 3. The 3 scavange lines all hook to the oil pan. As soon as oil drains into the pan it is sucked up by the pump by these lines and goes through the pump and back to the tank. That is why it's called a dry sump.....there is no oil that stays in the sump of the oil pan. All of the oil is stored in the tank, which in my case is 5 gallons.
There is a line at the bottom of the tank that the pump pulls from. There is a lot going on inside of that tank. It is not just a wide open tank. There are several baffles, etc to help remove the air from the oil. When the oil is returned to the tank, it is aerated and bubbly. It needs time to get the air out so you are not pumping air filled oil to the engine. A correctly built tank is very effective at removing the air.
After the oil goes through the pump, it is then just like a wet sump system. It goes to the oil stat,the filter, the cooler, and then into the engine. After it goes through the bearings and the valvetrain, it drains back to the pan where the scavange lines pick it up. It then starts all over. Hope this answers your questions.
Eddie

Steve, I guess we were typing at the same time.:drink:

But now ? Isnt it because of the Vacc in the lower that you have to plug some of the oiler bores in the block ??????

Thats what if been told and doesent it make sence ,,,,,because otherwise the Vacc will suck the uper and you will actually not have enuff oil in the motor wile running?

And therefor you need to take the engine appart ?:rolleyes:

Because if you have a supercat drysump motor and wet-sump it like i did you need to open those holes up,,,,,,,so why wouldent you close them when you dry sump a wet sump motor ????????????????:party-smiley-004:

the short answer is no . the oil system is an open loop. on the wet sump version, pressurized oil is delivered to the filter IN thru a dedicated passage. it is then delivered TO the motor thru the center port of the filter housing.

now

if all you do is deliver oil to the CENTER port of the filter housing
from an external pump and then scavange the pan, all you are doing making the wet sump oil INLET in the block redundant ... it will see no flow. there a dozen ways to do deal with this all simple and easy and a lot of them bolt on. but there should be no passages that need to be blocked. and the vacuum will have no effect on oiling ( assuming i understand your question) because there is no differential pressure inside to cause any issue. the whole vacuum idea started a long time ago in winston cup when people discovered that running extremely light ring tensions would make big power but would also make huge blowby and LOSE power... sealed crankcases with vacuum allowed very light tension with no combustion chamber contamination...

it works. there is no question about that. but it isn't simple to get right and is not a case of " more is better" and in the vast majority of cases where ultra light ring tensions are impractical because no one wants to be rebuilding their motors all the time, the whole vacuum deal is more a freebie by product rather some reason to spend 5 grand on an oil system.

There are no holes to be plugged!!!
If you have any sort of breather in the valve cover, you will not pull vacuum until very high rpm. You definitely don't want the pump to pull vacuum if you don't have piston oilers. It will suck the wrist pins dry.
There is no way a dry sump pump can suck the oil from the top end of the engine if you have any sort of breather in the valve cover.

Great thread!! How about maintenance on dry sump system? How long between pump rebuilds and how much? Same with the pump belt? A broken or thrown belt would be catastrophic!!! Does that happen often?! Do you replace ever yr or 2? How much are they?

Great Thread, and thanks Eddie for all the info. I am looking to build some 800+ hp NA motors for a future project and I am leaving no stone unturned in the search for maximum reliable power. I have been looking into a vacuum pump, but it sounds like this is a much better way to go. Can you give us a ball park price on a 5 stage dry sump system as I am still interested in those advantages.

Bringing this back to the top...

With a dry sump system is it possible for the oil to drain into the engine if sitting for a day? If so what would be the best way to eliminate this issue? I don't want to put valves on the tanks...have heard horror stories about that. I suspect that the oil is syphoned out of the reservoir until it is the same height within the engine as in the tank. Is it best to rig the dry sump tanks so that the resting oil level would be only a couple of inches of oil in the bottom of the pan if sitting for a while? As soon as the engine is turned over the scavenge pumps would drain the pan...

Another concern is the vent out of the dry sump tanks going to a puke tank, drain valves to remove moisture/settled oil vapour. I have heard guys running the vent lines back to the intake so the engine will inhale the fumes. I have 4.5 l whipples and am not crazy about running a line to the hat...but when you shut down after a run you can definitely smell the oil vapours...makes me want to pop the hatch all the time to make sure everything is alright...
Does anyone run a air/oil separator and drain the oil from it back to the reservoir or is it best to catch it and drain every so often?

Any insight to these 2 issues?