Dry Sump Scavenge Plumbing

[postal123]

Looking for opinions with dry sump scavenge plumbing. SBC street car for autocross. 4-stage SCP 204A left side mount and now using Champ CP150KO pan with 3 right side pickups. Because its a street car with A/C I'm having a custom front drive built and pump will mount directly to block at normal location and spaced forward 1/2". Because of this I chose not to stack a relocation bracket on top of front drives Alternator support in an effort to move pump out/up. The result of keeping pump close to block complicated pan choice and either requires a standard shape at front left pan edge or using 90 degree ORB fittings to exit pump's aft two sections. For this reason, I abandoned a really nice Moroso pan and chose the simpler route.
Here's the new pan:

First option has hoses wrap around front near balancer, with 45 degree pump hose ends facing forward, hoses hang no lower than pan bottom and connect to pan outlets with 90 degree hose ends.
Not mine but would look like this:

Second option has hoses run under pan, with 45 degree pump hose ends facing aft, cross under pan bottom and connect to pan outlets using 180 degree hose ends. IMO second option will look much cleaner, but hoses are obviously lower to ground less protected.
Not mine, but here's an example (disregard the fact that pump is right side mount):


C3 on SRIII chassis so fitment around mounts, steering and crossmember, etc not typical.

I'm leaning toward second option for cleaner install. Chassis rails are well below pan bottom. Opinions please.

Thanks,
Rob

[BLSTIC]

If you were to make an undertray that went under your engine, it would act slightly as a bash guard and also be really good at stopping loose hoses catching on things in scenario #2.

Also undertrays can have noteworthy aerodynamic benefits in handling and cooling if you do them right.

[postal123]

A undertray sounds like a great idea. I’m also torn between rubber and ptfe hoses. I know with aircraft ptfe has no life limit but also takes shape after heat cycles and doesn’t like to be disturbed. I’m almost thinking that rubber with a planned time change after 3-5 years is a better way to go.

Dry sumps setups don’t get same level of discussion as everything else and not sure why? I’m planning to vent valve covers to tank and have two -16 vents/cans off of tank. From everything I have read this route is open to criticism.

[fabr]

Why do you not wish to take advantage of the vacuum the dry sump can/will provide?

[billet]

I would 2nd the vacuum also but not only from a performance stand point but an oil in the breather tank issue, being a street car.

Venting the engine to the dry sump tank, just makes the tank and tank breather/overflow have to deal with a ton of air. The more air that it has to move generally means higher velocity thus the air will carry more oil particles in the air going thru the system and will fill the over flow faster.

[Dave B]

It's all been done 100s of ways. It all works. I'm never a fan of fittings and lines, under the pan. Simple basics are shortest hose possible with least bend in fittings. I try to use 45s everywhere possible. That being said 120 deg well made fitting still flows decent. Your first pic makes more sense to me. They could be tidied up a hair. I'm a fickle bitch on how my dry sump stuff looks. Cost to damn much to have it look like a 6th grader did them. If I scratch the anodized fitting it won't go on my stuff. The whole idea of dry sump is utilize vac capability. And oil aeration is the other thing you work on also. I hate pan's with fittings on side. If pump is driver side I like my fittings on right frt of pan in vertical fashion. That moroso pan looks pretty cheezy for 2024. I guess that's why I build my own pans.

[Warp Speed]

All Cup and Busch cars used to run them around the front as in the first pic in the 90s and early 2000s. This created excessive scavenge line length packaging problems around the stearing shaft. While it was always good to have the pump mounted on the left side for weight on a circle track car, the challenges of the steering shaft and plumbing forced us to mount them on the right side. Way cleaner, and not over on the busiest side of the engine (steering shaft ect).
If mounting on the right isn't an option, under the pan is fine as long as you can properly protect the lines.

[Dave B]

Pic for reference. I run all mine into pan here. I always have more kickout and fittings on my own stuff. Makes lines short and simple. If running msd type crank trigger you would have to get a little creative.

[postal123]

Thanks for all of your help. Most of the typical suppliers I spoke with steered me to left side mount. Not sure why other than fuel pump boss on block? Left turn weight bias makes sense as to why it’s so common. Right side pump is possible otherwise.

Its a c3 corvette and I bought a Coleman 3 gallon tank because it fits under right fender, adjacent to right rear of block, and has sight tube visible through fender gills—and no space on top of tank to use dipstick. This puts tank slight above pump but allows catch can(s) to be mounted above tank.

I wasn’t ready to open up the vent vs sealed can of worms yet, but here’s what’s guiding me so far. I’ve never done a dry sump and I’ve never done a max effort build. I know that valve covers vented to tank, with tank vented to catch can(s) is a proven setup on low dollar race engines. Since I’m not a short duration drag application and I won’t be employing all the trick piston oilers and special coating I assume are used in no budget race builds my thinking is vented is a good compromise. My ignorance in this area gives me hesitation on he sealed up vacuum route. I’ve just never heard a thorough and detailed explanation of what make a sealed setup work over the long haul.

Oil control and drain back alone—I’m a career pilot so I see the affects of lowered atmospheric density, with air alone, and I know that gravity still works in a vacuum. Actual windage and the affects of piston pulses I don’t have a handle on. Block is shp with big valley vents so between head oil drains and pushrod slots I’d think there’s plenty of crankcase to head communication. Of course I’d like to learn more on this.

v/r,
Rob

[Dave B]

In a sprintcar or Nascar deal as Warp stated, left side has its advantages. In drag race I scale car first before I decide. More times than not some right side engine weight helps offset driver weight. Always things to look at.

[Dave B]

Our high school neighborhood kid who works for us is stepping up this yr. He built up old Nova we have and will be getting 960hp sbc this season. I help him make decisions but we pretty much cut him loose. We had this on scales and it will help this one having oil tank on passenger side. We are going to hang elec vac pump on this side also for weight bias. Like I stated above it's been done hundreds of ways through yrs.