| Re: dry sumped C4 |
Subject: Re: dry sumped C4 by MarkB on 2008/7/19 16:12:57 Hi Brian, I also posted this on the other forum in reply to your question about details: I'd be happy to provide all of the details. First a warning: the Dry sump literally more than doubled the overall work on the engine project due to fabrication and general pain-in-the-butt factor. Also added about $2700 to the cost and that's with me doing all of the fabrication work with basically free welding work from my brother and a buddy (welding alone on the tank would have been another few hundred). That was also buying as much as possible on e-bay, although I ended up rebuilding the pump so it was only a few hundred less than new. Also, with your supercharger, I really doubt it will all fit, but it's possible. Pump: Johnson's HTP 4-stage (3 suction, with 0.8" pressure section). If you ever want a good conversation around dry sump technology and how to set up a system, give Roy a call. The pumps are far from cheap, but much better than the regular stuff like weaver, barnes, etc. www.johnsonsoilpumps.com Pump mount: Custom. Required approximately 5"x6" piece of 1/2" aluminum plus 2"x6" piece of 7/8" aluminum to make it. I have a 'spare' bracket that I made so I could give you dimensions. Of course, due to clearance, the bracket will ONLY work with the Johnson's pump. You MUST have a Delteq or LTCC ignition setup since the pump goes where the plug wires come out on the passenger's side Pump Drive: I actually got the mandrel off of e-bay. None of the mandrels I found will work with the stock LT1 damper. I already had an ATI damper. The drive mandrel press-fits inside the ATI hub. For pulleys, standard 1" ID HTD 19 tooth for the drive mandrel, 35 tooth 5/8" ID for the pump. (drive ratio of 54% which is what Roy recommended for use with 0-30 oil) Motor mounts: Due to lack of clearance with the steering rack as well as scavenge lines on the passenger side, I had to fab up solid motor mounts that move the motor back 1/4". It really needs more, but that's as far back as you can really go without screwing other stuff up. I have dimensions for the mounts -- pretty straightforward to fab. Oil Tank: Completely custom, but I did use the top off of a coleman tank. In hindsight I wouldn't go that route again -- would have just fabbed it completely. I was worried about having a round top for proper oil de-airation, but you could accomplish the same thing with a square tank and round internal baffels. This one is an off-line conversation. Oil Pan: Hamburgers standard post-'86 (one piece rear seal) pan. It only comes with two pickups so I bought an extra weld-in bung and some tube to fabricate an extra one (more welding). If you went with a 3-stage instead of 4, it will save you a bunch of work and money (cheaper pump, fewer lines), but you won't get any (or much) crankcase vacuum. Again, in hindsight my 4-stage is probably overkill, but it's cool Wet sump pump block-off: I used a standard rear billit main cap, but had the machine shop install a plug in it for use with the dry-sump. That way I always have the option to switch back to wet sump if I want. Also, you must retain the oil pump drive (that bolts down in the rear of the valley) since it's necessary for proper lifter oiling, but I just removed the drive gear from it since it's not used (just a press pin holds the gear on). Bottom-end build: Rings are really the only consideration. If you're going with a pump that will make vacuum just let your builder know since he may want to put in looser rings. Not really necessary, though. Also, Roy Johnson really pushes 0-30 Amsoil for use with his pumps. That's a factor when determining bearing clearances so discuss with your builder. Otherwise you can just run the pump a little slower with heavier oil. External oil filter: I bought an external mount fora fram HP6 (huge honkin' filter). Again, overkill. Takes up a lot of space, but never have to worry about the filter. I mounted it down by the power steering cooler (only place it would fit). Breather: Peterson dry sump breather. DON'T use the little can with a K&N filter on top -- it will blow it right off at WOT (according to Roy). Lines: There's 23 feet of -12 braided line on mine (includes the oil cooer and oil thermosta which added about 12 feet total. Also about 5 feet of -16 from the pump to the tank. I also put peterson in-line scavenge screens between the pan and pump. If I recall correctly, there are a total of 21 AN fittings (including the 6 required for the thermostat and cooler). Most of mine are summit, but a few of them are aeroquip since summit doesn't make 180s. Headers: I have EM's like you. With the peterson in-line screens, there is VERY little clearance between the #4 pipe and the scavenge lines. PS resevoir mont: Since the pump mounts to the factory PS tank mount holes in the block, I fabbed up a simple aluminum mount for the tank and ran a normal rubber line from the tank to the pump. That pretty much covers it. The only other thing I would have changed so far is the power steering rack mounts. I installed poly mounts on it, but the drive mandrel is VERY close. So close that I literally have to jack the motor up 1/2" just to get clearance to change a belt. If you've ever watched the steering rack while someone moves the wheel, you know that it moves around more than you would expect. In hindsight I would have made solid mounts for it (still may do). Again, I can't stress enough how much of a pain in the a$$ it was (but worth it in the end). Also, maintenance will be more of a pain due to loss of clearance in many areas. I have a boat-load of pics and more details. If you'd like, PM me and I'll shoot you my number for a chat. |
