The additional anti-dive is not a very desirable thing, and I believe you're right about the reason for it. It acts like a "geometric spring" by sending vertical forces through around the chassis and bypassing the suspension when the brake is applied. It's better to counteract brake dive with a proper spring rate, IMO.

The additional caster would be fine, except for a parameter your software may not be showing you: steering axis (or kingpin) inclination angle (SAI). In front view, draw a line from the upper ball joint to the lower ball joint and you'll see this angle. It was something like 7-8 degrees on the early C4s, but it was more like 14-15 degrees on the later cars. That's really high! This was necessary to get the "zero scrub radius" front steering geometry. However, SAI causes the front wheels to lose camber as the steering angle increases: the more SAI you have, the more camber you lose. If a car has similar caster and SAI, it won't really have this problem, but you can't realistically create 14-15 degrees of caster in the car (it would cause other problems if you did). Also, you can't fix this problem with more static camber: the more static camber you dial in, the more SAI you create as well! On big, sweeping turns on a road course where steering angle is low, it won't present as big a problem. On an autocross or tight hairpin it will break your heart. I got some improvement on my car by moving the upper control arms back 1/2", which added an extra 2 degrees of caster: I think it was 8.5 or so, which is around the practical limit. It helped, but the early geometry would still be a lot better. Note that the C5+ cars went back toward early-C4 levels of SAI, and I think they had less anti-dive also.

Believe it or not, a roll center closer to ground (but not below ground) is generally good for performance. Most race cars are designed this way. RC height actually works the same as anti-dive or anti-squat, except it's lateral. It also jacks the whole car up during lateral acceleration (cornering). In general, the fewer (or lower magnitude) vertical force components we send directly into the chassis from lateral or longitudinal forces at the contact patches, the better. However, you need to run stiffer springs to use less of it; and as we know, the C4 kept getting cushier throughout its tenure. Street cars are always a compromise! The camber curves are related, too; and so it's all hard to sort out.

 

Probably to far off topic but working on my project I found it was impossible to install the Engine and Trans in one unit when using the Canton RR wet sump pan. I think it would work if one or both Motor Mount brackets were removable and If I was building a Car to be raced I would probably go this route.

 

Seems like the 1992+ style crossmember would give you more room if you're using an earlier version, unless installation angle interferes with the flat horizontal plate perhaps. I haven't found any specifics on one piece motor plate failures, as it's a 1/4" 6061T6 plate, so it doesn't seem to be substantial. I may install a fore-aft limiter (tie rod between engine and frame)as otherwise the rear batwings act as the limiter for forward and aft forces (braking and acceleration). The 1 piece motor plate bolted to the engine is very strong in torsion, but would flex under longitudinal forces. It also requires fabrication of all accessory drive mounts (which I'm sure you've already done most of at least one time or another), and of course that has a lot of other benefits.

On a different topic, I keep a detailed list of all parts used for the dry sump, motor mount and related things, and I will share that when I get to the point of high confidence in the configuration.

 

It’s been a few months, but back at it this weekend. Found a problem with using the intakes designed for the L98, on a block with a dry sump oil pressure inlet at the front. I think I can make it work without welding, with barely enough meat on the intake, and also since I plan to have dual front and rear oil feed, I can use a -8 input at the front and a -8 input at the rear of the block also.

Here’s the problem in pictures;





Here’s what I’ve been able to do, couple of pipe plugs installed, ground down and 10AN fitting shown at the inlet… need to get an 8AN flare to 8AN ORB fitting and double check with a 90 degree 8AN hose fitting, didn’t have one on hand but the smaller fitting should provide the right clearance.

 

The engine and most of the dry sump system (not the tank installation) is finished, so coming back here to provide an update, and things that I've learned... my experience applies to a roadrace configuration, drag racing configurations may have some different solutions.

1. 5 stage pump is possible but a 3 or 4 stage system will make life a lot easier. Best answer may be a Dailey integrated pump assembly with billet oil pan. Otherwise it's a commpromise... Difference/advantage of the 5 stage conventional dry sump is the ability to crate vacuum, and the added assurance that the system is well balanced with regard to oil in tank versus oil everywhere else... in other words, 4 times as much scavange as supply. The draw back is the size and location, and I struggled with this, got it to fit by using a motor plate, spacing it forward exactly in the right spot at the right angle, and it gave me the motivation to install a badass Woodward steering rack with quick ratio and tunability/adjustability.

2. The scavange lines are usually -12an and this is tough to work with a PTFE hose, much easier with a CPE hose. However, the CPE hose MUST have a support spring installed inside. Many people have ruined dry sump engines getting this wrong: as the oil gets hot, the CPE hose gets a little more pliable, and the scavange vacum will pull the hose closed, and oil pressure drops at higher RPM. Vibrant and Jones Racing both make the support springs, the Jones Racing is a lot nicer but double the cost. Once again, best solution may be a Dailey dry sump pump integrated with a billet oil pan with machined scavange built in. BTW the suction side of the water pump should always have a support spring also, the OEM hose does but many Autozone and Oreilly hoses do not. This has probably ruined many engines also.

3. Not much room on a C4 so plan on lots of trial and error figuring out where everything will fit, it's pretty tight. I've only seen two other C4 dry sump setups completed, and there was another one here on the forum many years ago, but pictures are gone.

I have a list of parts used that I kept on a Notepad file, should be 90%+ accurate... now don't go out and buy all this and expect to put it together, but it's a good reference as to what was involved, there may be a couple of items in here that are over kill or optional.


ICT Billet SBC Engine Plate 551800
Jones Racing Products #AL-9101-E-NS 2045s5 Alternator 80 amps at low RPM and 140 amp max. Weighs 11 lbs.
Jones Racing Products Alternator Bracket MP-9101-C
Richard Childress Racing water pump
Allstar #31070 water pump spacer 0.125
Allstar water pump spacer 0.250
Jones Racing Products #WP-6104-36S 36 tooth Deep HTD Water Pump Pulley
Jones Racing Products #640-20 XHD 20mm wide HTD belt (Water pump to crank hub)
Speedway Motors #91032954 GM Type II Power Steering Pump w/Fabricated Reservoir
Jones Racing Products #PS-6106-B-40 40 tooth Power Steering Pulley

AVIAID 52109 Dry Sump Pan SBC 3PU DS PAN RSO 2PC RMS 4 1/2" three -12 RHS outlets
Oil Pan 1/4-20 x 1/2" 14 ARP 434-1803 - Oil Pan Bolt Kit (longer for blue felpro gasket)
Oil Pan 5/16-18 x 3/4" 4 ARP 434-1803 - Oil Pan Bolt Kit (longer for blue felpro gasket)

ATI Super Damper Standard Harmonic Balancers #ATI917789
6.325 in OD, 3-ring design, 6 lbs. weight, 2.40 lbs. inertia weight. 1.245 in. crankshaft, 2.280 in. counterbore. For use with dry sump system. Use standard length crank bolt.
Moroso Balancer Bolt 38770 2.250 in length, 7/16 in.-20
Summit Racing #SUM-B64261 - Summit Racing� Adjustable Timing Pointers
(ARP Crank Pulley Bolts #430-6801)
ARP 642-1250 3/8-16 12-Point Bolts 1.25"
ARP 642-1500 3/8-16 12-Point Bolts 1.5" (hub to balancer X3)
ARP 642-2750 3/8-16 12-Point Bolts 2.75"
ARP 642-3000 3/8-16 12-Point Bolts 3"
ARP 642-3250 3/8-16 12-Point Bolts 3.25"

Barnes 9017-5BR 5 stage oil pump with regulator, 1.375 wide sections with 1.2 valley scavenge and cast iron pressure housing.
Podavelle -12AN ORB Block Off (X3)
Weaver Brothers #1289 Aluminum Mount Adapter Plate (milled thinner and welded to the motor plate, bolts threaded through the motor plate)
ARP 642-1500 3/8-16 12-Point Bolts 1.5" (front crank hub bolt)

Jones Racing Products #OP-6103-33-1-1/4 33 tooth HTD Oil Pump Pulley 1.250 wide
Jones Racing Products #WP-6104-36S 36 tooth deep HTD WP Pulley
Jones Racing Products #PS-6106-B-40 40 tooth HTD PS Pulley 1" wide
Jones Racing Products #BG-6108-40S Belt Guide for PS puley
Jones Racing Products #PSH-8001-C-R SBC Head Mount Bracket Power Steering Pump
Jones Racing Products #DH-8101-WC-SB-H 3.5" Drive Hub 3-bot 1 1/8" with 1/8" square keyway, length reduced
Jones Racing Products #CSN-6103-A Crankshaft Nut
Jones Racing Products #BG-6108-C 3.50 Crank Pulley Belt guide (X3)
Jones Racing Products #CS-6102-AS-34 34 tooth HTD Pulley 1 1/8" bore 0.825 wide puley (Alternator Drive)
Jones Racing Products #CS-6102-AS-35 35 tooth HTD Pulley 1 1/8" bore 0.825 wide puley (Water Pump Drive)
Jones Racing Products #CS-6102-AS-18 18 tooth HTD Pulley 1 1/8" bore 0.825 wide puley (Oil Pump Drive)
Jones Racing Products #600-20 HD 20mm wide HTD belt (Oil pump to crank hub)
Jones Racing Products #640-20 XHD 20mm wide Extreme Duty HTD belt (Water pump to crank hub)
Jones Racing Products #680-20 HD 20mm wide HTD belt (PS to WP)
Jones Racing Products #840-20 HD 20mm wide HTD belt (AL to crank hub)
Jones Racing Products #AL-9101-E-NS 80 amps at low RPM 140 amps max 1 wire alternator
Jones Racing Products #AL-9100-CL-C SBC 65 and 80 amp Alternator Mount to Water Pump
Jones Racing Products #AL-6105-22-B 1" 22T HTD Alternator Pulley
Jones Racing Products #BG-8108-22-CAP Belt Guide for AL-6105-22
Jones Racing Products #MP-9101-C Motor Plate Alternator Bracket

Peterson Fluid Systems #910-91501 Filter Mount and Primer
Peterson Fluid Systems #09-0408 -12AN 90 degree scavange filters (X3)
Peterson Fluid Systems #09-0402 -10AN inline scavange filter
Coleman Racing -16AN return filter (would not service but in case of engine failure, this can save the oil pump)
Moroso #85465 Breather Tank with 12AN fitting
Moroso #68815 Breather Filter

Manley Lifter Valley Vent Kit (svreens and epoxy) #42235-8

Vibrant -16AN CPE hose
FLF -12AN CPE hose with Vibrant support springs on scavange lines (they make a lot of different angles for hose fitting)
Cheap E-bay -12AN CPE steel braided for oil tank to breather (do NOT use these for scavange)
Cheap E-Bay -10AN CPE steel braided for oil priming (oil tank to Peterson remote primer/filter)
Evil Energy -10AN PTFE hose
Evil Energy -8AN PTFE hose
FLF -8AN PTFE hose (two oil feed lines one at the front one at the rear) with DEI heat shielding
Vibrant -3AN PTFE hose for the vent can drain back into the valley scavange