Engine and Transmission Tech

By acting as a de facto vacuum pump and by eliminating drag on the crankshaft due to oil splash, a dry sump system should increase engine output. On the other hand, the dry sump oil pump and the flow of oil through tubing cost power. There's obviously some trade-off. Where do I need to look if I want to see it quantified? Have you guys ever seen a credible dyno comparison?

Many really savy race engine builders state NOT to go over 15" of crankcase vacum, as this creates a new set of problems. This "does" allow use of low tension oil rings and compression rings,(saves power). One problem with "V" motors, is oil control in the lifter valleys. In the turns, it's too easy for oil to climb the 45 deg. banks, and prevent proper oil drain back. That long sweeping turn, will likely be the deal breaker, in a wet sump. Onward, roverman.

Curtis, I think the Aviad site had something along the lines of the information you're looking for.

In any case, the knock on dry sump for horsepower rob is a bit disingenuous. True, each stage of the pump (2, 3, 4, 5, etc.) adds some theoretical drag because each rotor causes friction. But if we're talking about a 400-425HP motor in an 1800-2000 pound car and a resulting 3-4 horsepower loss, is it really relevant? Seems a lot like the reverse claims of horsepower gains by adding this or that or removing this or that. Mathematically accurate but not relevant to performance.



Edited 1 time(s). Last edit at 11/07/2012 06:46PM by DC Townsend.

David and clan, "many" dyno test have shown how wet-sump oil windage loses, can be much higher, than that. Onward, roverman.

"David and clan, "many" dyno test have shown how wet-sump oil windage loses, can be much higher, than that."

Exactly Art. There are numerous paper claims about this part or that part and their relate parasitic HP losses (or gains) but you have to consider the whole package when you think about this stuff. How efficiently are you putting down your power? What kind of drive train (FWD, RWF FWD) are we talking about? What kind of tires/pressures are you running? If I added up all of the incremental horsepower claims for all of the aftermarket geegaws that are available for my 302 I'd be pushing 500-600 horsepower from a stock block. Not impossible in an SBF but certainly not by add-ons.

The equation needs to be the "sum of the parts".

For those who may be following this thread, thought I'd post a schematic of how my three-stage system is/is going to be plumbed. The only thing not shown is the line to the breather (typically from the very top of the oil tank). I will NOT be running the second, optional return line. As previously acknowledged, this system is already overkill for the car's intended use so there's no sense making it any more complicated than it already is.

One of the more important pieces of information missing from the drawing is the flow of each line, particularly at the oil filter adapter plate where there is only one line, meaning the second port is plugged.



The next diagram (credit to Moroso) shows you the flow of oil through the system and you can clear see the flow of oil into the filter plate through the single port. This is a small but important detail as you need to be sure you connect your incoming line to the correct port on the adapter plate. This diagram also shows you the breather plumbing as well as the inclusion of in-line filters on the two outgoing lines from the oil pan as well as a third line coming from the pan and a scavenge manifold which can be used but are not mandatory for the system to work well.





Edited 2 time(s). Last edit at 11/23/2012 12:07PM by DC Townsend.

For those who expressed an interest in my dry sump system, I took some time to do a write up. I still need to add the parts list and a shot or two on the oil filter relocation but, other than that, it's pretty complete.

The article can be found on my Garage site here: [tempusfugitgarage.com]

As promised, here's my parts list. A few caveats:

• When I could I bought parts on sale, especially fittings and hose, but the prices shown are for what's available today
• The oil tank I have is not offered anywhere I can find (Speedway used to have them), but you can buy what's called a "lefty" (for circle track cars) that's
pretty similar.
• The fittings listed are unique to my system and configuration but should serve as a good starting place for someone undertaking a similar system.
• The pan I have is no longer offered so what I priced is what is currently available. The only difference between the part listed and what I have is $200 and a coat of black paint. Go figure.
• I also couldn't find the part number for the oil filter adapter I have but it ports to the sides and not the top, something you need to consider
• I didn't include small stuff like the clamps I'm using to keep the hoses tight to the sill, various line clamps to help tie up hoses here and there, large AN washers needed for the bulkhead fittings, and the like so you'll need to budget for those as well.

Keep in mind that I bought two of my major components used - the oil tank and the 3-stage pump. Purchased new, you're probably looking at $300 or more for a decent baffled oil tank and about the same for a 2-stage oil pump. Those two parts would add another $500 to the price tag. As I've said a couple of times, it's not the hard parts that cost - it's the fittings and hoses that sneak up on you.

You should be sitting down when look at the bottom line. I'll also be adding this to my original post over on my Garage site for those who may be reading this for the first time and want to wander over there and get the whole story.

An update on the dry sump.

Upper oil lines are in. The two with the filters (Petersen) are from the pan, the last one is from the tank. All of the lines pass through the fender well using bulkhead fittings. It makes for a bit of extra work but reduces the length of the line runs and, in the case of the lines from the tank, keeps them away from the exhaust. All of these lines have been reinforced with an inner coil to prevent them from collapsing.

I also plumbed the filter bypass (no pic) so all that's left is to run the two lines from the pan and the line from the tank to the fittings in the fender well (they're made, I just ran out of steam tonight). and finish plumbing the remote oil filter.

Finally was able to get out in the garage and get some things done. Among which was locating the remote oil filter adapter and filter in a place that is convenient for plumbing and service. I know it looks like it will interfere with the tire but it's not so. Just to be sure, I mounted the tire and wheel and ran through the full range of suspension as well as the well arc. All is well.

I might have finished the last of the plumbing had I not come up short a couple of fittings and few feet of line. Ah well, something to do next weekend.