coop

Rob, "Old School" wisdom said that the mechanical pump would start to drop off above 6,000 rpm. Years ago, I verified this on my car by placing a T in the fuel line just before the carbs and duct taped a pressure gauge on the windshield. Then I ran the stink out of the thing and found that the pressure did drop off at high rpm. Rolling dynos may not show the drop off because the runs are short and the carb bowls don't have time to deplete. Try that on a long straight at the track and the bowls can get sucked dry. I now run two Carter rotary pumps into a Holley regulator and then into the carb floats(no mechanical pump). Absolutely no drop off!!! I regularly out pull cars with higher HP ratings at the track and this may be the reason. An interesting tid bit here: You can set the float level(SUs) by flipping on the fuel pump and with the suction pistons removed, you can peer down into the jets and see the level in the jet looking back up at you. Very accurate and of course, the engine doesn't have to be running. Cool! Coop

Hey Rob, why are you using the mechanical fuel pump to feed those Webers? I've always understood that the mechanical pump isn't up to the task, especially for any sort of sustained spirited driving. Coop

I'd be very, very leery. About two years ago my wife agreed to let me get my dream car, a GT40(SPF, can't afford an original). She even co-signed on the refinance of the house to get the extra cash. The next day she said that now she wanted her dream cabin built out back on our property and also don't I feel guilty spending that sort of money considering some of my friends are out of work?! The next day I wrote a check and put the entire amount right back in the principal. Did I dodge a bullet or what?

I'll be in line when the gates open Friday evening. I'm in the red F350 pulling the black enclosed trailer. Another friend of mine from Reno will be there with his Z too. He does everything at the last minute so he hasn't signed up yet. Good guy - Lee Mitchell

Hey John. I can see paying a little more if I wanted to keep a street car "authentic" but since I go through these things like crazy, I can't see paying much more than the steel drums I recently bought. They go for $97.50 at Motorsport Auto. I could go only $25 - $50 above that. Seriously, $225 each!? Maybe a quantity deal though might work? Let's see what others say. Coop

Hey Ron. I'm there! #7 in your race group. Can't wait. The car is ready to go. Took it out for testing last weekend at Reno-Fernley and scrubbed some tires and bedded some shoes and pads. Also, I burned up some 15+ year old rain tires in three laps. Good experience for the future. A guy in a GT3 Porsche decided to follow me and grabbed some funny video of me sliding the thing around. Here is the link: www.youtube.com/watch?v=vJW1J0LojEQ BTW, I am signed up through SCCA. Where can I go to see all the entries from other organizations? Looking forward to meeting you and seeing your car. Coop

When you say in the Pacific do you mean during the Korean war? The Bearcat never saw combat in WW II.

Just rode the thing out in my hotel room bath tub in Narita. Not a fun ride. Scary as hell. Then got to enjoy the 150+ aftershocks, many over 6.0. What fun:paranoid: With almost no sleep, flew the jet to Guangzhou first thing in the morning. Never thought I'd say I'm glad to be in China. Must say that I was lucky. Sure do feel for those further north on the island.

66 GT40. Lit the tires up in 2nd gear then eased off. Not my car so couldn't afford the $1 mil + to find out how fast it could go . I'd settle for an SPF.

That is exactly the axle I am about to install today. Wish me luck. It would just be nice to get a replacement nut for my backup axle. I guess I need to spend some time at the fastener store. BTW, all three of my bearing spacers have the "B" stamped on them so re-installation should be a no-brainer.

This is where it get really weird Carl. Basically, I have three different axles. I'll call them axles A, B and C. A - small diameter SPLINES and LARGE diameter THREADS (sheared on track) B - small diameter SPLINES and small diameter THREADS (cotter pin hole with cracked castle nut) C - large diameter SPLINES and LARGE diameter THREADS (good lock nut) I also have two types of companion flanges, small for A ad B, large for C. Note that the same nut works on A and C. Just guessing here but perhaps A and B are from a 240 Z and C is from a 280 Z. Then someone may have used a die to alter the threads on B. Don't know but it is strange that B has the same thread pattern as A and C but is smaller in diameter(slightly). Also, all bearings and spacers are identical. Thanks.

After years of racing without a DNF, I finally sheared a stub axle on the race car. That axle had even been cryo-treated. So, I dipped into my spare parts bin and found two stub axles that look like they would do the trick. But wait, it appears like they are slightly different. The threaded ends have the same thread pattern but the diameter of the threads are slightly different and I mean slightly! The stub axle with the larger diameter has a lock nut on it which is identical to my sheared axle. The axle that has threads ever so slightly smaller in diameter has a castle nut on in which BTW, makes sense as that same axle also has a hole through the end. Here is my problem. I have several good lock nuts for the larger diameter axle but the castle nut is cracked and the larger nuts wobble too much to be useful on the smaller diameter axle. Duh! So - why are these axles different in this way? In the Black Dragon catalog, only one nut is listed and it is good for all Zs 1970 - 1978. I'd really like to get a few good castle nuts that would fit properly - Anyone? Also, anyone want to sell me an axle and nut combo? One can't have enough spares. Thanks all!

Last I heard, Quaife quit building for the R180?

Does anyone out there have a stock cam shaft they want to part with? My L24 ITS cam is in bad shape so can you help me here? You all probably know that not all "stock" cams are created equal so here are the measurements I made on my cam and I'd like to get one with no less lift than what I have. Here are the dimensions: Base circle diameter = 3.306mm/1.303" Base to lobe = 4.03mm/1.582" Therefore lift = .724mm/.279" I think it's basically a .28" lift stock cam without oil passages. I have a spare cam but it has just a little less lift so I'd really like to replicate my primary cam if possible. Just trying to stay within ITS rules and go fast too. Thanks everyone.

Were those older photos taken at Seattle International Raceway?

Sorry for sounding so lame on this subject in my older age but at one time I knew the answer to this problem. I addressed it in a technical blurb on the IZCC site. Here is my old disertation: "Many years ago I found out that there are at least two types of tachs for the 240Z and 260Z. One type is a four wire positive trigger tach and another is a three wire negative trip tach. The 4 wire type has one wire that sends positive voltage to the tach, one wire is for ground and the other two leads are the trigger loop, one coming and the other going. I can't say off hand exactly where these two feed to/from but they are shown in both my 72 and 73 factory manual wiring diagrams. They are also poorly pictured in these manuals. From past experience I have found that this type of tachometer is very unreliable. I have found this true in Mazdas and Datsuns. I have found the 3 wire type of tachometer to be much more reliable and more adaptive to aftermarket modifications to the ignition system. The 3 wire type has a positive lead, a ground and a negative trip lead that runs directly from the negative terminal on the coil. Strangely, however, I have not found a Datsun wiring diagram or picture depicting this three wire tach. Has anyone out there seen one? OK, here is what I have done with my 72 240Z. I removed my old 4 wire tach and replaced it with the three wire. I ran all new wires to the tach to assure proper circuitry. One wire from a trustworthy + supply, another to a nice ground, and the third directly to the negative lead on the coil. Here is where a problem crops up. Remember those two wires, on the 4 wire tach that formed the positive trip circuitry? Well that loop is needed to keep your car running. Apparently the primary ignition circuitry runs through this loop (weird). I had to just complete this loop and the car started right up. I now always use a 3 wire tach. You can easily hook up a shift light to it as well as the Jacobs electronic ignition. " Presently, my Pertronics works great with my 3 wire tach. I have no clue, however, how to run a Pertronics with a 4 wire tach which I suspect you have. Check to see which type of tach you have before going any further. Maybe by then, you will get some other responses on this subject.

I don't know John. I've had the thing for some time as it is my #2 backup 4.375 diff. I've never even used my #1 backup as the Quaife has held up so far. The diff in question was even topped off with fluid. It has 78 painted on it so maybe it is out of a 280Z(nah, not with that ratio) but it is definitely an R-180. Today I removed the ring gear from the gear case and it bolted up perfectly to a spare welded gear case w/ bearings already installed. This setup is much lighter than the "mystery" diff so Ill go with what I know. I'm still curious to know what it came out of - perhaps some sort of 4x4 as it had large/wide flanged out put shafts?!?!

Had some spare time on my hands so I thought I'd take apart, then weld up, a spare R180, 4.375 differential that has been sitting around my garage for some time. What I found inside was strange to me. The guts of this diff are much heavier than any I've ever seen. They include a two piece gear case and lots of extra bolts to mount the ring gear. Take a look at the pics. What gives? Is this still a useful R180 for my 240Z?

Can anyone point me in the direction of how to get my windshield wiper to run at a decent speed? Mine is dog slow. I'm sure there is a post around here somewhere. Thanks

The guy in the RX7 pulled something on Greg that has twice happened to me. He left a huge hole on the outside leading into a brake zone then as Greg committed to the pass there, the guy squeezed him into the grass as Greg entered the brake zone needing all four tires on the pavement. Greg is lucky he didn't head off into the weeds. I hate it when people give you a little room and then slowly squeeze you off the track after you're committed. Down right rude and can be very dangerous. I don't think Greg would have made any contact had the RX7 driver just held his line on the inside. In fact, he may have even held Greg off from the pass altogether. I'd be interested in Greg's input.

That picture is from the Goodwood Revival in England from a few years ago. The guy was OK but beat up a bit. I was at Goodwood for this year's Revival and it was amazing. Those guys drive 100% in multi-million dollar equipment. In one race the drivers included Bobby Rahal, Derick Bell, Jackie Oliver, Richard Attwood(I think) amongst other greats.

Thanks for the response. The spare cam I have has ever so slightly more lift than my old one which has some nasty scoring due to my neglegance. I think I'll try my spare but will also talk to Dave Rebello tomorrow morning just the same. Can't get enough advice.