Ruben

I'm new to welding with a MIG welder and cannot seem to find any definitive answers to my questions. Here's my situation. I would like to put together my own exhaust system and do all the welding. The mandrel bent pipes are aluminized and I need to know what is the best wire and shielding gas mix to use. Also, do I need to coat the welds afterwards to restore the protection of the aluminized coating? I currently have a C-25 (75% argon, 25% CO2) gas bottle and E70S-6 wire in sizes .030 and .023. However, I don’t know if any of it will work well with aluminized steel. I have seen on a couple websites the recommendation to use A-675 Airco Wire, but could not find any info on the gas mix. Any info and tips would be greatly appreciated. Ruben ’72 240Z

Hey Marcos, I also have SK Racing Carburetors and can attempt to give you some info. First off I am by no means an expert on SK Carburetors, but I have managed to gather some knowledge of the SK’s. With that in mind here is what I know of the SK’s. The SK carburetors are a hybrid between the Mikuni PHH and Weber DCOE, where the best of both designs was taken to create the SK's. Unfortunately, the SK carburetors are no longer imported into the USA. However, TWM Induction was one of the distributors and may still carry some parts for the SK carburetors. You might also be able to get a manual from them, if not I can try to scan mine and email it to you. In order to troubleshoot any problems you will need to find out what size all of your jets are and what size SK carburetors you have, i.e. (40mm or 45mm). You should also invest in a Synchrometer Tool to balance the carburetors. Top End Performance sells a good one. Since you are new to multiple sidedraft carburetors you really need to get several books on tuning and troubleshooting DCOE type sidedraft carburetors. I have listed below some books that will start you off in the right direction. The following SK Carburetor parts are interchangeable with the Weber DCOE carburetors: Main jets Air correctors Idle jets Emulsion tubes Pump exhaust valves Pump rod, spring and piston Auxiliary venturis (45 DCOE only) The following are interchangeable with Mikuni PHH late model carburetors: Pump jets (Mikuni calls these pump nozzles) Floats Needle Valves Fuel Union Banjos (I think Mikuni calls these Fuel Pipe Assembly) Some sources for parts: TWM Induction 325D Rutherford Street Goleta, CA 93117 (805) 967-9478 Ask for Gary twmindsb@aol.com www.twminduction.com Carry some SK Racing Carburetor jets, gaskets and Manual Rebello Racing 110 Second Ave. South Unit D-8 Pacheco, CA 94553 (925) 682-0103 www.rebelloracing.com Carry Mikuni Carburetor Jets Top End Performance 7452 Varna Ave. North Hollywood, CA 91605 (818) 764-1901 topend@racetep.com www.racetep.com Carry Weber Carburetors, jets and the Synchrometer Tool Good books on Weber, SK's and Mikuni's: Weber Carburetors By Pat Braden From HP Books Try www.amazon.com or www.barnesandnoble.com. Good information on theory, troubleshooting, tuning and rebuilding Weber Carburetors. How to Modify Your Nissan/Datsun by Frank Honsowetz From HP Books Try www.amazon.com or www.barnesandnoble.com. Has a good chapter on Weber, Mikuni and SU's. Weber Carburettors (The spelling is weird but that’s the title) By John Passini From MRP (Motor Racing Publications) Try www.amazon.com or www.barnesandnoble.com. Has a lot of design theory and functionality of various Weber carburetors. As for your specific problem, I think Mike has a good point in that your throttle plates are open too much. You should also check for float level, fuel pressure and any intake manifold leaks. If you go to www.zcar.com and do a search for the user id of ZR8ED you will find some very well written instructions on setting up and balancing Weber carburetors. These will also apply to the SK’s. Hope this helps. Let me know if you have any questions and I’ll try to answer them or direct you to someone who can. Ruben '72 240Z

Anybody? I need to take the tank back to the shop, but I want to be able to describe what the baffles look like. Ruben '72 240Z

I just got my '75 gas tank back from the shop after getting it cleaned and coated with Renu. Unfortunately, I did not look inside the tank before sending it out and now I'm wondering if the shop did not screw up the baffles. So, my question is, how many baffles are in the tank and what do they look like. I see a "can" like enclosure around the pickup pipe and some fragments of what is left of one baffle. Is the baffle just a ~1" wide strip of metal with holes in it sitting on the bottom of the tank? What should be in the tank? Any insight would be greatly appreciated. Ruben '72 240Z

Umm.... It sure does not sound like SK jets. Perhaps what you have are early SK models which, I believe were nothing more than Mikunis or Solex models with SK's name on them. Or perhaps the OER carbs are not SK's. Sorry Dan, I guess I'm not being much help. Ruben '72 240Z

Hey Dan, I just replied to your post in the Datusn L6 section, LOL. I'll repost it here also. The following SK Carb parts are interchangable with the Weber DCOE carbs: Main jets Air correctors Idle jets Emulsion tubes Pump exhaust valves Pump rod, spring and piston Auxiliary venturis (45 DCOE only) The following are interchangable with Mikuni PHH late model carbs: Pump jets (Mikuni calls these pump nozzles) Floats Needle Valves Fuel Union Banjos (I think Mikuni calls these Fuel Pipe Assy) Hope this helps. Let me know if you have any more questions. Ruben '72 240Z

Dan, The following SK Carb parts are interchangable with the Weber DCOE carbs: Main jets Air correctors Idle jets Emulsion tubes Pump exhaust valves Pump rod, spring and piston Auxiliary venturis (45 DCOE only) The following are interchangable with Mikuni PHH late model carbs: Pump jets (Mikuni calls these pump nozzles) Floats Needle Valves Fuel Union Banjos (I think Mikuni calls these Fuel Pipe Assy) Hope this helps. Let me know if you have any more questions. Ruben '72 240Z

Mike, I have an extra 280ZX e-brake cable, would it be longer than the 240Z cable? Just a thought, I don't even know if it will work in a 240Z. I had bought it to use on my current rear disk conversion (280ZX caliper), but I got my 240Z OEM cable to work for now (sort of). So I never checked to see if it would work. Ruben '72 240Z

Hey John, what gear ratios did you end up with? And what diff are you going to mate it with? You'll have to report back when you get it installed and tested. I was looking at them when I bought my A.T.B. diff. Now I can wait and see how your install goes and if you like it (right like you won't) . Ruben '72 240Z

Tim, The Quaife is not a clutch type LSD, it is a worm gear style (Gleason, Torsen). So it also does not have any wearable "friction parts". But you're right it is still a chunk of cash. Ruben '72 240Z

Ross and anyone else that is interested, Here's an update on the Quaife install. I don't have a P/N breakdown yet but here is what I got. I had Unitrax install the Quaife and replace all bearings and seals on the R200 3.90 differential. Well, the cost was more than I expected but not by much. I now have a completely rebuilt differential with LSD to boot. The cost break down: Parts: $301.94 Bearing Kit Pinon Seal Pinon Nut Shim Kit Crush Sleeve Axel Bearings Axel Seals Lucas Stablizer Posi Additive Oil Labor: $195.00 Environmental Fee: $3.85 Total: $523.44 Unitrax used all Timken bearings except one, of which only a Nissan would fit. The labor cost was fixed, so even if I had only wanted them to install the Quaife it would have still cost me $195.00. So it looks like my total cost including the Quaife was $1,486.10, plus $100.00 if you want to add the purchase of the used R200. At this point the Quaife discount really helped a lot. Well, I won’t know if it was all worth it until I get a chance to install the differential and try it out. But, from what I have heard I will not be disappointed. Ruben ’72 240Z

Thanks again John. I'm going to take your recommendation and take my diff to Unitrax in Anaheim for the install. I can't wait to try it out. Ruben

Thanks John for setting it straight. I was close though. Ruben

Tim, Does the $500.00 include the cost of any additional mods. I thought I read that the CV shafts required modifications and a custom flange adapter. All these mods add up. Don't get me wrong, I did consider the R230 conversion. However, I already had invested in a good R200 and CV shafts. So for me the Quaife was the best solution. However, I do think that the Quaife will probably always be more expensive that doing the R230 or 300ZX R200. Ruben

I just purchased a Quaife A.T.B. “LSD” differential for my R200. Quaife has dropped the price to $995.00. That’s $200.00 off the list price of $1195.00. And for about another month Autotech Sport Tuning/Quaife America will take off an additional 10% for a total of $895.00. I know it’s still a lot of money, LOL. But if you compare it to the Nismo LSD unit selling for $750.00 then it’s a great deal. I don’t know what some of the other options like the R230 and 300ZX R200 conversions are costing, but if it’s anywhere close to $800.00 then this might be another option to consider. If anyone is interested, contact Scott Brunet at Autotech Sport Tuning/Quaife America, (800) 553-1055 or (714) 240-4000. They also have a website at www.autotech.com or www.quaifeamerica.com. Ruben ’72 240Z

Mike is correct the Quaife is a worm gear (Gleason Torsen) type LSD. I seem to recall reading a post from John Coffey indicating that the 45 lb/ft breakaway for the Nismo unit is an old recommendation and too low, at least for autocross. Nissan Motorsport recommends 70 lb/ft breakaway which takes into consideration the better tires that are available nowdays.

David, Used open R200 diffs go between $100.00 to $300.00 depending on condition. Motorsport Auto sells the Nismo limited slip assemblies to install in a R200 for ~$750.00. Hope this helps. Ruben '72 240Z

Thanks guys. That's exactly when I'm getting the white smoke. I did a dry compression check, so I'll do a wet test next. Maybe the rings are also leaking. Ruben '72 240Z

What are the symptoms of leaking or bad valve stem seals? The engine in my 240Z had been sitting for couple years before I got it running. It appears to be running fine except for some white smoke that comes out of the exhaust. The engine is a Nissan rebuilt L28 (N47/F54) with only ~25,000 miles. I have heard that white smoke among other things could be a result of leaking valve stem seals. It does not appear to be a blown head gasket and compression is 160psi on all cylinders. I suppose it could still be leaky rings but I'm hoping it's the valve stem seals. Any thoughts? Ruben '72 240Z

Mike, I know the control arms are a work in progress but I need to ask anyway. I saw the pics and did not see any provision for mounting the rear sway bar links. Will this be added? Ruben

Great! Thanks Mike. Ruben

slamb, I seem to recall seeing a post from John Coffey in zcar.com where he mentions having used one in autocross and on the track. He considers the Quaife best among the different LSDs but expensive. I have seen him post here but don't know his ID. Perhaps you can do a search here or at zcar.com. Ruben '72 240Z

Owen, You definitely have it wrong. It does not matter where you physically put the APV, however it must be installed in line with the rear brakes. As Jeromio and others mentioned you need full pressure in the fronts and have the rears adjustable. On the street and most racing situations you want the fronts to lock-up first. The proportioning valve on a 240Z is in the rear toward the passenger side above the diff. Ruben '72 240Z

Pete, I'm sure you're right. My mistake, the manual I have includes the '73 240Z as having it in the rear. Must be up to '72 since mine is in the rear and it's a '72. Ruben

Mike My offer still stands to send you an original new Maxima bracket (Nissan #44155-04S10). Just let me know if you want it and where to send it. Ruben