28 replies to this topic

[Spaceframe7]

I am re-building a 711M Crossflow engine to F.F. specs and fitting a dry sump system. The dry sump parts are all brand new and consist of a Pace 5 port side mounted pump, an older model Crossle dry sump tank (1/2" BSP inlet and outlet, but tank is not able to be taken apart for cleaning), remote oil filter and Mocal HD oil cooler. I have read in a couple of articles (including Burton catalogue plus an old Cosworth technical bulletin showing both 4 and 5 port side mounted pump installations on the Ford engine) that a gauze filter should be fitted on the oil tank outlet that connects directly to the pressure pump. This of course is to prevent any detritus from damaging the gears of the pump. I cannot seem to find any such filter that would be suitable, and wonder how it could be fitted inside the 1/2" to 5/8" BSP fittings (no way to fit it inside the tank without cutting it open), or is there a non-bulky manufactured filter that could be fitted in the hose between the tank and the pump? There is a mesh filter already fitted in the sump pan, but this type would not work in the tank as the gauze filter is open ended and I'm not sure how I could modify it to fit inside the tank or oil line. Advice please from anyone who has completed this modification. Thanks.

[McGuire]

Moroso and others make inline filters that will go in your line between the tank and pump but to my knowledge the smallest have 10AN fittings (5/8 inch) so you will need to buy or make adapters to your British Pipe Threads -- or simply install AN barb fittings in your (braided?) line. The problem with an in-fitting gauze screen is very little surface area -- doesn't take much foreign material to stop oil flow altogether. A 1/2-inch fitting, especially so. That's pretty small.

Meanwhile, a gauze screen between the tank and pump introduces a philosophical question: The screen will block solid material from reaching the pump, but once it is plugged it also effectively stops oil from reaching the pump. Are we trying to protect the oil pump or the engine? Your call but in my personal opinion, if you want protection here you want at least a high-capacity inline filter such as the above -- in addition to 1) the main oil filter between the pump and engine oil feed and 2) the inline filters in each scavenge stage between the engine oil returns and the scavenge pump. The scavenge filters will catch the bad stuff closest to where it occurs, while the main filter stops the bad stuff before it can get back into the engine.

[Spaceframe7]

reply to McGuire: Many thanks for your suggestions. I have searched all my old 70s U.K. car magazines that fully detailed fitting dry sump systems (mainly to Ford 'Kent' engines), and perhaps strangely not one of them provided any information on fitting filters between tank and pump. I do not know how Cosworth fitted this device to their various recommended oil tanks (no listing of oil tanks in their old price lists that I still have), but as noted, their service bulletin diagrams definitely suggested installing such a filter. I have an inquiry into Burtons U.K. to see how they manage it, but to date have not received a reply. All the current ads for dry sump tanks picture inlet/outlet connections on the tanks almost identical to mine. I fully take your point though that it is cheaper to repair/replace the pump than the engine. I guess every good idea i.e. fitting a dry sump system to avoid bearing starvation on heavy cornering or acceleration, has its minor (but expensive?) downsides. Best regards. SS

[Bloggsworth]

I don't recall there being a filter between the tank and the pump on my FF Merlin, unless there was one inside the tank of which I was unaware. Shouldn't be too difficult to make one, it is on the suction side after all, just a question of what gauze/mesh size to use, and the ideal surface area. Design it to unscrew so that the filter is easily checked and cleaned.

Mind you, there should be a filter between the return, pressure, side and the tank so, in theory, there should be no detritus in the tank anyway!

Edited by Bloggsworth, 15 August 2010 - 07:09.

[Lee Nicolle]

Personally I think any inline screens are bad news. Far too much resistance. What I have used is a screen over the collection area in the pan. I use a coarse mesh and over about a 2 1/2 " square area. The small stuff will go through the screens without any appreciable resistance to the pick up capacity.Really it is only big stuff you need to keep out of the pump, the stuff that can sieze the pump. Which ofcourse when those bits are in the pan you have not got an engine anyway

[Tony Matthews]

I may be being dense here, but don't dry-sumped engines retain the standard engine oil filter? That surely takes care of the small stuff.

[mariner]

If you cannot clean the tank I think a filter on the line INTO the tank is a wise idea and probably more useful than one on the exit as you will never be able to be sure the tank is completely clean of junk if you can't clean it.

[Spaceframe7]

If you cannot clean the tank I think a filter on the line INTO the tank is a wise idea and probably more useful than one on the exit as you will never be able to be sure the tank is completely clean of junk if you can't clean it.

Good point, thank you. I found an old Piper Winners Handbook (tuning catalogue dated 1974) in my collection, where they detail their own manufactured 'open and clean' oil tank which was designed to be taken apart for cleaning. They incorporated a large gauze filter in the very bottom of the tank leading to the outlet connection, so they obviously thought it was essential. I also found in a 1992 Burton price list that AP manufactured 6" and 3 1/2" long tubular filters for inlet or outlet oil tank connections at 1/2" BSP, but these have not been listed in Burton catalogues since about the mid 90s or so. (I keep a selection of these old catalogues/magazine articles much to the chagrin of my better half! Must be a mental condition similar to the 'man drawer'?). I'll mull over the options.

Lee Nicolle, I personally don't think you are being dense here - I thought the same as you, but when I traced out the oil route on a dry sump plumbing system drawing, the oil travels back into the sump after it has been filtered (in my case a remote fitted filter - but just the same as if it was attached to the pump), and then it is pumped from the sump - where I assume any small metal pieces may accumulate (before the engine self destructs??) then through the oil cooler - if so fitted - into the oil tank. From the tank of course it goes back into the pump. This standard plumbing scheme is why, I assume, Cosworth et al suggested re-filtering the oil before it goes back into the pump. I don't mean to bore you to death with this thread, and I thank you all for your input. Maybe I have too much time on my hands thinking about these things, but I don't want to finish my project, only to have the whole thing seize up for the sake of a filter. It's taken too much blood, sweat and tears (I liked that group - saw them at the Albert Hall in the early 70s - ah to be young again!). Cheers.

Edit note: Apologies Lee - it should have read Tony Matthews, but great ideas from all of you - many thanks for this- SS.

Edited by Spaceframe7, 22 August 2010 - 17:45.

[Tony Matthews]

Lee Nicolle, I personally don't think you are being dense here -

I am sure that Lee has never been dense, or demonstrated it on this forum, whilst I, on the other hand... The reason I mentioned it is that I can't remember much about the modified engines that I've worked on in the past, but most of, if not all the pure racing engines that I have had dealings with - all, naturally, dry-sumped - have also had standard or near standard oil filters.

[Lee Nicolle]

The setup I used [on a 350 Chev] blanked of the std filter pad and from the pump pressure out used 3/4 hose, a Y fitting which then used 2 x 1/2 hoses into remote filters then into the front and rear of the main oil gallery. This set up takes away several sharp internal bends in the block which in itself helps oil pressure and loses less horsepower to drive the pump. Also feeding the oil in both ends stops the minimal oil starvation to no 1 main that Chevs can suffer. And really the same on most engines.
Dry sumping will always consume more engine power but if done right will mean you never have an oiling problem which means you can drive the car harder instead of always worrying about oil surge and cavitation. Hence the car goes faster!! Plus ofcourse you can mount the engine lower in the car.
I still see so many dry sumped engines done by 'professionals' that are dumb as they seem to go out of their way to make the oil turn 90 deg corners everywhere. Or mounting the tank miles away from the engine using so much power to move the oil back and forth. The tank should be slightly above the pressure in and as close as possible. I always laugh about people waffling on about having the tank in the rear of the car [tintop] for weight distribution! The weight of all the lines and the oil in circulation largely nullifies any advantage. And is defenitly far more borderline in oiling.

[J. Edlund]

The setup I used [on a 350 Chev] blanked of the std filter pad and from the pump pressure out used 3/4 hose, a Y fitting which then used 2 x 1/2 hoses into remote filters then into the front and rear of the main oil gallery. This set up takes away several sharp internal bends in the block which in itself helps oil pressure and loses less horsepower to drive the pump. Also feeding the oil in both ends stops the minimal oil starvation to no 1 main that Chevs can suffer. And really the same on most engines.
Dry sumping will always consume more engine power but if done right will mean you never have an oiling problem which means you can drive the car harder instead of always worrying about oil surge and cavitation. Hence the car goes faster!! Plus ofcourse you can mount the engine lower in the car.
I still see so many dry sumped engines done by 'professionals' that are dumb as they seem to go out of their way to make the oil turn 90 deg corners everywhere. Or mounting the tank miles away from the engine using so much power to move the oil back and forth. The tank should be slightly above the pressure in and as close as possible. I always laugh about people waffling on about having the tank in the rear of the car [tintop] for weight distribution! The weight of all the lines and the oil in circulation largely nullifies any advantage. And is defenitly far more borderline in oiling.

Done right, the drag reduction in the crankcase will by far outweigh the power consumed by the pump. The scavenge pumps actually don't consume that much power since they operate with a much smaller pressure difference than the pressure pump.

[mariner]

If you can find or buy a copy the Chevrolet Power book has an excellent chapter on dry sump design and fitting. It is under lubrication system, page 178 in my 1994 edition but other editions have similar info.

The chevy book actually advises against screens before the scavenge pumps on the grounds that they will get blocked but recommends screens on the oil drain back holes and magnets near the scavenge pick ups.

I may put too much faith in this book but it comes across as written by people who realy know theie stuff , on Chevy engines anyway.

[McGuire]

If you can find or buy a copy the Chevrolet Power book has an excellent chapter on dry sump design and fitting. It is under lubrication system, page 178 in my 1994 edition but other editions have similar info.

The chevy book actually advises against screens before the scavenge pumps on the grounds that they will get blocked but recommends screens on the oil drain back holes and magnets near the scavenge pick ups.

I may put too much faith in this book but it comes across as written by people who realy know theie stuff , on Chevy engines anyway.

Yep. The Moroso dry sump schematic diagrams and recommendations are also pretty sound and widely available on the web -- just google.

I hate finger screens, especially the fine wire gauze ones. Moroso suggests a coarse screen cartridge filter in each scavenge line. Additionally, you can use a telltale screen like an Oberg in the return line between the scavenge output and the tank where it is easy to get to. (Convenient for engine monitoring.) But in any case the real oil filtering is performed by the main filter (cartridge or spin-on) in the pressure line between the pump and the engine oil galleries, just as Tony says. Additionally, most people like to put the main filter upstream from the cooler in the hope of catching the swarf before it gets into the cooler.

But the truth is 17 filters and screens will not prevent an engine failure. At best they can only limit or delay the collateral damage. In the typical catastrophic engine loss, loose material will be everywhere in the dry sump system. Some years ago a NASCAR team owner was talking about his engine problems with one car, which was leading and eventually won the title that year. He had blown up two engines big time on Friday and was installing a third one for Saturday. I didn't say anything, just fixed a level gaze on him (sorta like your dog when he needs to go to outside). He looked at me like what? for a moment, then nodded and went off to get the backup car unloaded.

[Tony Matthews]

An engineering company that I occasionally worked for was instructed that the race engine that they built had to use a cartridge filter of a specific brand. After several mysterious engine failures it was discovered that the filter, meant for road use, was not up to the job and the core was collapsing under pressure. Unfortunately, when removed for inspection it would resume its original shape, so a degree of detective work was needed to solve the problem

[McGuire]

Done right, the drag reduction in the crankcase will by far outweigh the power consumed by the pump. The scavenge pumps actually don't consume that much power since they operate with a much smaller pressure difference than the pressure pump.

I don't think there is any doubt that a current, well-engineered dry sump setup off the shelf will produce a measurable power gain, due to the improved scavenging and decreased windage. However, the big advantage is in engine life. Just this past week we were testing a car -- 200' skid pad, slalom, braking, acceleration. Wet sump, of course, and the driver periodically reported the oil pressure going to zero, while I could hear the lifters ticking after each skid pad run. While we did our best to be careful, you know full well we put many years' wear on the engine in just one afternoon. This car will rarely if ever see this kind of use on the road, but if it were, a decent dry sump system would more than pay its way.

In racing categories where the production wet sump system must be retained, there are all kinds of workarounds -- trap-door oil pans and all that -- but they are mere band-aids compared to a good dry sump system. To see the problem in person, a curious person could fill the wet sump to capacity, then rotate the engine 45 degrees on the stand to roughly simulate a 1 g cornering load. Then look inside the engine where the oil went -- pretty scary. Engines were rotated this way on the dyno to sort the oil systems.

An engineering company that I occasionally worked for was instructed that the race engine that they built had to use a cartridge filter of a specific brand. After several mysterious engine failures it was discovered that the filter, meant for road use, was not up to the job and the core was collapsing under pressure. Unfortunately, when removed for inspection it would resume its original shape, so a degree of detective work was needed to solve the problem

Very common at one time. Really, you want to see a metal sleeve or other means to support the filter element. The problem is not necessarily exclusive to cartridge filters as the spin-on type is essentially a cartridge element in a disposable case -- so while less common it does happen. It's a recurring issue with fuel filters as well, even now.

Overall, I wonder what percentage of racing development over the years has been devoted to trying to make the sponsor's junk work.

[OfficeLinebacker]

magnets near the scavenge pick ups.

I've always been a fan of magnets in the crankcase (and the trans and diff for that matter). The new Neodynium magnets hold up quite well under heated conditions and can be gotten from hobby/science places.

[Tony Matthews]

My first car, a Mini that had been quite highly tuned by a friend, had a magnetic drain plug - the first time I changed the oil there was a two-inch length of mangled tab-washer stuck to the magnet...

[dosco]

I've always been a fan of magnets in the crankcase (and the trans and diff for that matter). The new Neodynium magnets hold up quite well under heated conditions and can be gotten from hobby/science places.

I would suggest a bit of caution before making a purchase ... many years ago I purchased some small "rare earth magnets" from Radio Shack for use in model airplanes (rubber powered, to be precise).

Since my modeling exploits tend to move as fast as a glacier, the magnets sat around for many years.

I pulled them out last year, and all that remained of them (still in the original blister pack) was dust.

Edited by dosco, 16 August 2010 - 15:52.

[OfficeLinebacker]

I would suggest a bit of caution before making a purchase ... many years ago I purchased some small "rare earth magnets" from Radio Shack for use in model airplanes (rubber powered, to be precise).

Since my modeling exploits tend to move as fast as a glacier, the magnets sat around for many years.

I pulled them out last year, and all that remained of them (still in the original blister pack) was dust.

I still have some NeOB magnets from several years ago that will still pinch my hand quite severely if I am not careful. The good magnets are shiny like chrome. Not the old black kind.

[Lee Nicolle]

A properly done wet sump can be pretty good but the pan has to be deep to get the oil away from the crank. Plus then oil scrapers windage trays baffling and the like. A good wet sump will make more power, which is why most drag racers use them. But a dry sump will always be better for the engine as you will have less aerated oil and ofcourse extreme G force keeps the oil under more control.
Several years ago I 'invested' in a 25lb oil light switch for my classic [1968] Supermodified which had a fairly simple basic sump. First track I went too was a tight hooky little bullring [Mt Gambier] and I had the light flashing on both turn 2 and 4 at 6500rpm. I had ran that engine for about 10 shows so it is a tribute to decent oils. But the engine came out and got a new set of bearings and a far more advanced pan. Which is fine until you spin!! But the oil pressure is constant now at speed.
As an aside my other toy these days is a Ford Falcon which I use for circuit Sprints and hillclimbs. The amount of work to make that wet sump work was horrendous. All because Ford put the well of the pan at the front instead of the logical place of the rear. It works ok but still scares me. Particularly as the engine is a Cleveland which needs all the oil they can get.
Though these days GM use front pan engines too. DUMB. DUMB !!!

[gruntguru]

A properly done wet sump can be pretty good but the pan has to be deep to get the oil away from the crank.

One of the advantages of dry sump systems is the opportunity to mount the engine lower in the car and reduce the CGH. (Assuming the pan depth can be reduced from its wet sump dimension)

[Greg Locock]

DUMB. DUMB !!!

steering rack behind the wheel?

[Lee Nicolle]

steering rack behind the wheel?

Nah, just inferior cars . You should build the chassis around commonsense designed engines and most of these cars can have pan well behind the crossmember too.
Commodores, both 6 and V8 always show worse bearing wear than previous rear welled Holden because of the pan design, as do most engines with front pan well engines.
Hence the 5.7 alloy handgrenade, the Vette engine has a rear pan well and is an ok engine, the Commodore has a front one and have always had a LOT of lubrication problems. The early ones the pickup was too small which made it worse. Even when you have oil pressure the oil is far more aerated.
Why manufacturers insist on building basic flaws into cars amazes me.. And all front drive cars are the same.

Edited by Lee Nicolle, 19 August 2010 - 00:10.

[McGuire]

A good wet sump will make more power, which is why most drag racers use them.

The top drag cars in the States run dry sumps. It's been decades since I've seen a competitive Pro Stock engine with a wet sump. Far superior oil control and scavenging = significant reduction in losses. Dry sump also allows extremely low crankcase pressure, permitting lower ring tension. In Sportsman racing, a somewhat decent system can be faked with a wet sump pump and auxiliary vacuum pump, but it's an approximation at best. A guy will need some kind of edge elsewhere to be able to run with the top dogs in his category.

In the nitro ranks, the Funny Cars run dry sumps while the Top Fuel dragsters run wet, but that's a rules thing.

Edited by McGuire, 19 August 2010 - 07:23.

[NTSOS]

The top drag cars in the States run dry sumps. It's been decades since I've seen a competitive Pro Stock engine with a wet sump. Far superior oil control and scavenging = significant reduction in losses. Dry sump also allows extremely low crankcase pressure, permitting lower ring tension. In Sportsman racing, a somewhat decent system can be faked with a wet sump pump and auxiliary vacuum pump, but it's an approximation at best. A guy will need some kind of edge elsewhere to be able to run with the top dogs in his category.

In the nitro ranks, the Funny Cars run dry sumps while the Top Fuel dragsters run wet, but that's a rules thing.

Before you corrected your post........I actually never paid any attention to the fact that top fuel has a wet sump and a funny car has a dry sump system.
Anyway, I ran across this statement when I was trying to find out which one was wet/dry:

"Oil quantity is another important factor when dealing with a fueler, you want to deliberately overfill the crankcase with oil.
Typically, 10 quarts will meet the needs of a shallow pan 426-style engine while 12 quarts is required for a deep pan.
An early-style 392 will require a full 14 quarts (mostly due to poor drainback qualities).
The reasoning is that by submerging the crank in oil you are creating a vibration damper that helps suck some of the more evil harmonics from the reciprocating assembly."

Wow, seems like a lot of drag for top fuel.....could this possibly be true, or is this back in the day type stuff?

John

[OfficeLinebacker]

Before you corrected your post........I actually never paid any attention to the fact that top fuel has a wet sump and a funny car has a dry sump system.
Anyway, I ran across this statement when I was trying to find out which one was wet/dry:

"Oil quantity is another important factor when dealing with a fueler, you want to deliberately overfill the crankcase with oil.
Typically, 10 quarts will meet the needs of a shallow pan 426-style engine while 12 quarts is required for a deep pan.
An early-style 392 will require a full 14 quarts (mostly due to poor drainback qualities).
The reasoning is that by submerging the crank in oil you are creating a vibration damper that helps suck some of the more evil harmonics from the reciprocating assembly."

Wow, seems like a lot of drag for top fuel.....could this possibly be true, or is this back in the day type stuff?

John

Also, would it be special oil that doesn't foam up too much?

[McGuire]

Wow, seems like a lot of drag for top fuel.....could this possibly be true, or is this back in the day type stuff?

John

Yep, before folks knew better.

[McGuire]

Before you corrected your post........I actually never paid any attention to the fact that top fuel has a wet sump and a funny car has a dry sump system.

I may well have this wrong in my poor old memory so please correct me if you find otherwise, but how this weirdness came about, as I remember it: dry sumps were prohibited in the nitro pro classes to limit the size of track oildowns, but then were eventually allowed in FC as a safety issue.

Many TF cars run a pressure accumulator that blasts a quantity of clean oil into the center mains midway through the run -- works off the clutch timer, hits about 2.0-2.5 seconds after the step. An FC engine may use the same block galleries via an additional pressure stage.

[Spaceframe7]

I have just received information from Burton Power - sales@burtonpower.com (I have no connection to this company - just a satisfied customer) that they do not stock - but can obtain, an inline gauze filter in various sizes for dry sump oil systems. These are fine mesh filters and may be removed and easily disassembled for cleaning. The thread is JIC (UNF), and the filter is listed in the Goodridge U.K. catalogue in sizes from 7/16" to 1-5/16" part numbers from FF572-4 to FF572-16 if anyone needs one of these in the future. I am guessing that one of these units will be a lot simpler for me to install than trying to fit a gauze filter inside my oil tank. Regular cleaning will have to be a maintenance priority, but I think it will be worth it for peace of mind. Thanks again for all the input. SS7