rsicard

Mike: Good to hear that you are nearly back on the track. Interested in your previous post. "Instal carbon louvered vents in the hood and top of fenders. Install John Washington's Scoops in the fenders trailing the front wheels." Is there positive pressure in the wheel well and therefore the need fo louvered vents in the top of the fenders? Are there pictures of the John Washington's Scoops installed on the Datsun? Very interested in both of these items. Please advise. Thanks.

SUNNY Z: I have purchased a 8.8 inch Ford IRS differential to do what you are. What is the inside and outside diameter and length of the tube in the middle of each up-right? What is the dimension of the tube to one end of the up-right? I will purchase the same rear differential cover that you are using for this project.

Mike: Who made your older block hugger headers? I purchased Sanderson block huggers CC178 which are 1 7/8" primaries. These interfere with the steering shaft for the manual rack. Entertained going to Subaru power steering rack with modified front cross-member to accomodate same. Just went out to look over my 1971 240Z with 383 stroker installed. I am using an Electromotive ignition and fuel injection system which has a 7" toothed wheel between the crank pulley and balancer. There is only 1/4" clearance between this wheel and the Datsun rack. The Sabura rack, which I have, is considerably thicker. This means that I must retain the Datsun manual steering even with a 6" engine balancer. The next smaller toothed wheel is 6" in diameter. Quite likely that the magnetic pickup for the toothed wheel will not work with 6" balancer and 6" inch toothed (Crank Timing) wheel. Will have to go with block hugger headers with 1 5/8" primaries wherein the steering shaft will clear these smaller headers. In the longer term, I will also buy a header tube kit with fabbed head flange and form a custom block hugger set of headers which will also clear the steering shaft but will flow better than the 1 5/8" block hugger headers.

Mike: Thanks very much for the part number and pictures of your long tube headers. I see that the LH header flange is two pieces and separates behind the number 1 cylinder exhaust and the slip joint in the primary tube. I will try to find the build thread which includes the newer oil pan. It is difficult to imagine that the cheater oil pan is effective for road racing.

I am trying to avoid going to a dry sump oil system. The idea of having to add another driven accessory to the front of the engine brings nightmares. I have a two kick-out racing oil pan that has (6) six trap doors. Additionally, I will add a pressurized reservior for those instances when oil pressure drops due to hard stop or corners. I want to road race my 240Z at Firebird in Phoenix. Much work yet to do on the 240Z.

Mike: Have you found a kit or all the components for a dry sump oil system for the SBC engine? Please advise. Thanks.

Well, the testing made me rethink the value of long tube headers. Does not seem to be worth the hassle especially for racing oil pans with two kickouts which is what I have on my 383 stroker engine. I'll stay with the shorty headers.

Mike: Is there a part number for the hooker headers? From the photo the steering shaft should go through inboard the number 1 cylinder exhaust primary and outboard the number 3 primary. Would be interesting to know the hooker part number to see if they are still available from hooker.

"183 according to Garmin GPS on an straight empty road" with a T56 transmission in 5th gear, seems 200+mph is within reach with appropriate aero modifications ala NASCAR who are up to 200 mph on oval tracks. The T56 has a 6th gear (2nd overdrive ratio top gear).

Hot Rod TV just had a show on the dyno difference between short and long tube headers. There was NO significant difference in HP/TQ output between the two different headers.

Just remember, DO NOT connect the oil pressure switch wire to the fuel pump relay with the starter solenoid +12 volt momentary actuate/start wire. If the two are connected the starter will be continually engaged when the engine has started, actuated the oil pressure switch.

The link http://forums.hybrid...tch#entry982976 is misleading and will cause the starter to be energized with the engine running and generate quite a NOISE. "In summary, there is a power (ignition) wire to the distributor which has a tap to the power side of the pressure switch to run the fuel pump. To make the fuel pump run while cranking, there is the Green-White wire that taps into the fuel pump side of the pressure switch." With this summary, the fuel pump will be provided with +12 volts ONLY when the oil pressure has built up to close the oil pressure switch to provide +12 volts to the fuel pump terminal of the oil pressure switch, not during the starting stage when oil pressure has NOT built up enough to close the oil pressure switch. This is why I advocated the relay actuated by the wire going to the "S" terminal of the starter.

b81crx: The Datsun Z V-8 Conversion Manual (Seventh Edition) is somewhat misleading and inaccurate. The wire going to the "S" terminal of the starter is a momentary +12 volts to energize the starter ONLY for the time to start the engine. Tying the bottom of the chrysler three terminal oil pressure activated switch to the "S" terminal provides a continous +12 volts when the engine starts and has built oil pressure to close the three terminal from the top to the bottom terminals of the three terminal oil pressure activated switch providing a continous +12 volts to the fuel pump and IMPROPERLY to the starter keeping the starter engaged when the engine is already running yielding a REALLY BAD noise from the engaged electric starter. The proper way to provide +12 volts to the bottom terminal of the three terminal oil pressure switch from another source ("S" terminal of electric starter) ONLY during the time to start the engine and activate the fuel pump for this short period of time, is to install a 12 volt automotive relay activated by the wire to the "S" terminal of the electric starter to supply the 2nd momentary source of +12 volts for the fuel pump ONLY during the starting period. Once the engine is started, the relay must revert (relaxed/unenergized) to NOT supplying +12 volts to the fuel pump because the oil pressure switch should provide a circuit between the top and bottom terminals providing a continous +12 volts from the ignition HOT wire to the HEI distributor through the activated oil pressure switch to the fuel pump for the engine run mode.

Mike: Discovered these Dynomax headers. If the picture is accurate and you use a oil pan WITHOUT kickouts, then maybe it may fit your application. http://www.speedwaymotors.com/Garage-Sale-Musclemaxx-1968-72-Nova-Headers-SBC,54467.html

Mike: Reuse the 383 stroker. The only real advantage to a LSx engine is the aluminum block for weight. Otherwise displacement for displacement both the SBC and LSx are equal. The LSx engine design (GM) finally went back to high flow rectangular intake ports on the cylinder heads for the newest LSx engine series. Maybe best to work out the oiling issues for the SBC. I am using a racing oil pan with 6 flapper valves to keep oil at the pickup. Hope this works as I intend to road race my 383 stroker 240Z. Otherwise I will set it up for a dry sump system. Please advise on which oiling system to use based on your experiences.

Sure would be nice if there was a lot more detail in your post. Where are these bushings located that we talked about? There looks to be some spelling mistakes that make the post somewhat confusing. What is a full-tilt boogie kit and what EXACTLY does it do? Care to clean up the confusion?

See http://www.gmhightechperformance.com/tech/0405htp_mti_stage_3_heads_install/viewall.html http://corvette.shofr.com/houston/motorsport_technologies_inc/ Motorsport Technology Inc Houston Texas

SUNNY Z: Oops, made a mistake. The last sentence of my previous post should read: Would be nice also to X-ray or Sonic test the Z31T inboard shaft of the CV half shafts. Or figure out which shafts are milled versus rolled during manufacture. Of note is that the drivers side shaft DOES NOT go through the CLSD clutch pack. The drivers side half shaft goes directly into the ring gear. The passengers side goes through the clutch pack. Still doing research on the Ford 8.8 IRS differential. The 31 spline Diff is used on the Trucks and the 28 spline is used on the cars. On the Ford 8.8 IRS Diff, I think the ring gear is on the passengers side, the opposite of the Datsun/Nissan. A complete 8.8 IRS Diff 31 spline with CLSD is EXPENSIVE. About the same price as I paid for the Z31T R200 Diff.

John C: Thanks very much for the info as we all can use same.

John C: Do you have any personal experience with the Wavetrac differentials? Please advise. Thanks.

SUNNY Z: It is significant to keep these posts up to date. For now I will use the Z31T CLSD R200, CV half shafts and beefy stub axles. I am VERY interested in the Ford 8.8 31 spline Differential as a replacement for the R200. The use of an appropriate rear cover for the 8.8 is a starting point for this conversion. Then brackets will need to be fabricated to tie down the nose of the 8.8 to existing Datsun 240Z structure. In looking at your failed inboard shaft of the CV Half Shaft, it appears that it failed along the spiraled groove on the shaft. If these grooves were rolled in rather than milled in, that may explain introduction of a failure point due to the process of rolling in the grooves. Would be interesting to X-ray or Sonic test some of these shafts to see if a fault was introduced during the fab process. Then test some of these shafts that pass the tests. Would be nice also to X-ray or Sonic test the 8.8 inboard shaft of the CV half shafts. Or figure out which shafts are milled versus rolled during manufacture.

Need to elaborate on your request.

The Ford 8.8 differential rear cover plate will not bolt to the mustache bar for the R200. Dimensions for both differentials is needed to know where to locate the two bolt bosses on a custom 8.8 diff cover.

SENZA PARI: Dimensions of the 8.8 Ford Differential would be valuable to those interested on the forum. Just the differential alone could be mounted in place of the R200 differential. There would need to be detailed dimensions of both the 8.8 and R200 differentials. The goal is to fabricate a steel rear cover for the 8.8 which has the two mounting bosses on the rear cover nearly same as R200. The forward mounts can be mounted in the same manner as the short nose R200 or Q45 rear differential. Digitizing both of these differentials and publishing the 3D frames in a PDF document. Custom Half Shafts with 8.8 mating shafts can be constructed.

SUNNY Z: Looks like the best bet is the later year Cobra differentials. Research first then invest if they spec out OK.