bjhines

Z-therapy can sell you the correct linkage......

ok I have a set of these beauties....they are DCOE 45/late model 152s made in Spain..... They have 36mm chokes..and a middle of the line set of jets.... I intend to use them on an l24 with an agressive cam....It puts out 142 to the wheels at 6000RPM with SUs....I know it can make more power because only one third of the cylinders get the proper mixture with the little crappy stock manifolds.... anyway...a few questions.... It would appear that the original owner was not all that handy with carb tuning...and they are poorly assembled and set up they way he used them.....the throttle plates were all set to widly varying idle openings... the air bleed screws(#26) are all different heights... The jets all match.. thank god.... The bigest problem I see is that the "SOFT MOUNTS" between the carbys and the manifolds are significantly smaller than the 45mm trottle plates and carb bodies...they are actually forming a lip around the circumference of the manifolds that sticks out into the airstream several MM..... Tell me if I am wrong...but I think he mounted the silly carbs with a set of soft mounts for DCOE40mm... please tell me if the soft mount rings normally intrude into the airstream between the carbys and the manifolds.

The original Datsun throttle linkage was well thought out and made it easy to balance the carbs at idle AND part throttle. You may be able to make a prettier linkage....but you wont make it any easier to tune your carbs and ignition.

Very cool...I can't wait to see some finished pics....

A common way to increase negative camber for the S-30 front wheels is to redrill the mounting holes on the front crossmember....there are several write ups about this.

Beat that dead horsey.....maybe it'll move.... First off...I am sure they quoted the spring rates for a fairly heavy modern "Ricer" mobile....They just threw 240Z in the description to get our attention...of course the person who runs their marketing department would chuckle at the stir this has caused among you guys.... I am sure that they can provide correct spring rates for our lightweight cars.... A problem I see right off... the more pieces there are in your coilover set up.... The more cussing and bitching you are gonna do whenever you jack up the car.... It looks like you will constantly be popping and banging with more pieces to get caught up an misaligned when you try to set the car back down on it's wheels. Another problem comes from the fact that with the extra spacer in there... your stack height will increase.... you may have trouble fitting those 10" wheels under there and have enough clearance to the inside section of the tire. A lot of guys use extremely short rear springs and threaded tubes to keep the spring and lower seat higher than the widest section of the tire.... adding all those parts will increase your stack height and interfere with wide tires and wheels. There have been spring systems like this in the past....Many of them used a short thin guage coil at the top that would compress to coil binding under the normal weight of the car....this thin weak coil was only there to keep tension on the various parts when the car got light over a hill....it sort of addressed the need for a limiting strap and zip ties to keep your coilovers seated on their perches...when you went for big air over a steep hill.... How many of us here have ever seen "big air" in our 240Zs.

Early Z-car Wheels mount to the hubs via LUG-centric pattern....Think about it...there is no hub to center on in the rear...unless you remove the brake drum... It does not take a whole lot of thought on this matter to arrive at this Lug centric conclusion... About spacers.....There is an added risk to using ANY kind of wheel spacer.... The risk has more to do with bending and shear loads on the wheel studs than it does with the strength of the spacers... There is only one slip(shear) plane on a conventional hub mounted wheels...It is the interface between the wheel and the hub....The minimal amount of shear placed on this joint bears on the wheel studs in a very narrow cross section... When you add a spacer... you now have 2 slip planes that will bear on the studs at 2 different cross sections along its length...this can overlaod the wheel stud and cause it to snap under heavy load or shock....over the course of years of careful use it will eventually fail due to fatigue. With high quality factory spacers used on some cars... the spacers are machined to fit both the hub and the wheel in a hubcentric fashion..and they use 2 different sets of mounting holes so that each stud has only one shear plane bearing on it..... Even high quality spacers do not provide as much strength as a wheel mounted directly to the hub...The mounting surface of the wheels is significantly thicker and stronger than most spacers with 2 stud patterns drilled into them.

Well...I have seen video of a recent ITS group in which the first lap has multiple hits and cars are spun off course at high speed...... at VIR up the climbing esses...a car swallows a muffler and skids off track right at the top of the hill in his own fluids....he comes back across the track at a very high speed and misses sideswiping another car at speed by centimeters....another car trailing this whole disaster has to brake hard to keep from hitting him at the same time.... I would rate that as DANGEROUS.....and it is common in ITS...I would say it is not so common in an HDPE event..... I just purchased a wrecked 240Z race car that was creamed in the tail by another car....the whole tail clip is moved over 5 inches to the left....the cage held the passenger compartment together...but the driver woke up in the ambulance....In a typical ITS group there will be a dozen "offs" and a dozen "contacts"...before the race is over.... we may see a dozen offs during an entire 2 day HPDE event... actual wrecks are rare..and contact between cars is virtually nonexistant. One reason I care soo much about your fellings on this matter is because I sincerely hope a majority of folks do not see HPDE events this way....I have only attended events run by THSCC and BMWCCA..... I am sure there are some sloppy events being put on out there.

as far as your "vent line" being open to air.......Well..... you should deduce that from your initial question....It is OBVIOUSLY!!!!!! NOT!!!! open to atmosphere....clogged or not....your logic fails you if you think it is indeed venting your tank....keep in mind that tank vents are designed to let air INTO the tank NOT OUT of the tank. Ohhh... and another thing...if you are really concerned about gas prices....then you really dont want the vent line open to atmosphere.....your gasoline will "vent" (evaporate) from your tank at a rate proportional to the surface area of fuel exposed in the tank.... this is why we have those carbon canisters and check/flow valves.

OK..... Klick and Klack would have this one right off.... The Pressure you talk about is no higher than when the tank is full....If you doubt me then put a gauge on the vent lines..... The effect you are witnessing is called VAPOR PRESSURE.....In other words... gasoline WANTS to evaporate...it will evaporate until a certain pressure at whatever temperature prevents further evaporation.......Keep following me here..... What is happening is that an empty tnak has a great deal more available volume to fill up with a compressable mixture of gasses...(air and fuel vapor)... When you release the cap you are allowing this volume of gasses to decompress.... the empty tank vents a significantly larger AMOUNT!!! of air...but the pressure is no higher.

Well... no one is holding you back from adding all the safety gear you want....in any class or type.

Mike.... I would disagree with the safety issues... Remember... you can wave off a pass and get back in line.... I know an SCCA chairperson who runs ITS with a 1st gen RX7, 1972 240Z, and a Nissan Pulsar. I have shown him videos of my lapping days HPDE events...and he always pulls out videos from his latest races..... There is a lot of contact in the first few laps of an SCCA ITS race.... The drivers are good...but remember that 80+ cars in widely varying groups all heading for the first turn together is hella scary to even watch...much less drive in....eventually they will sort themselves out into a fast group and a slow group with lots of boring open space between them....It isn't any fun to run by yourself....you really want to be in a group to have fun racing...just not a big group. In other words....If contact is not acceptable to you....you better stay in the fake vintage races...because you will get hit, spun, and pushed around in a typical ITS race.....Ohhh...and if you look at the standings....240Zs are NOT the car to run anymore in ITS....You will win much more with a second gen RX7.

Hehe..I was out there cutting some "skid pads" to weld to the bottom of the damaged areas... I measured them at the foremost point before they turn up toward the TC buckets.4" on the passenger side and about 4 1/8" driverside...they are pretty beat up so they may actually be the same...but dented...This is with shortened MSA sport springs installed with Tokico blues.... My exhaust used to drag...but I had that put up tight in the tranny tunnel...so apparently frame rails are next. I have not converted this car to coilovers... I intended for it to be "streetable"... but track capable... I turned an easy going 1:12.7 lap on saturday...I turned a 1:13.1 on sunday....It was a little marbely out there sunday... I never late brake at Rockingham..... It is too rough and there are too many concrete walls looming at you....I am sure I could scrub it down to 1:11.+ with better late braking...

well.... we also have to consider that big tires on a street car may never see suspension compression like we get at the track...especially at 110 MPH on a banked oval....My car probably had 3 times the weight on the outside tires during that banked turn on the oval....I ripped past a C5 Corvette that was throwing a lot of tire smoke from the fender wells in the oval... I was bottoming out comming off the bank and back onto the infield when I late braked... I found that I had to brake early and let the car settle to avoid throwing sparks entering turn one... apparently I was dragging the front edge of the floor pan frame rails....I also swallowed a rock or something big this weekend....My frame rails look like someone took a grinder to them and I have a huge dent in my newly replaced floorpan on the passenger side. Guys who drive on the street only will never see the fitment issues we have in track prepared cars.

Yea.... John took the hit very well....I did not hear him blame anyone else openly...He will get it fixed and have it back on track for our next event... This is just one more reason for John to leave the 350Z in the barn next time and bring out his 260Z for the next event.

Pop N Wood..... is your car lowered? have you added caster, camber, toe to front and rear tires....all of these things will change the way the tires sit in the wheel wells.... It is interesting to me that soo many people have different experiences with fitment of tires.....Obviously suspension changes will affect clearance....but I think part of this is due to the fact that our little metric tire size system sucks major butt....You look at 10 different 225/50/15 tires and you will find 10 completely different sized tires.........even on the same size rim.

Ohh... and +4 offset makes the wheels sit closer to the centerline of the car...NOT OUTSIDE....I am sure that anyone running a ZERO offset wheel will have to cut, bash, or pry away even MORE OF THE FENDER LIP to fit 225/50/15s.... as mine sits...I have lowered the car 2"s and the tires fit without ruining the fender lips...just a neat roll up of the upper lip in the REAR ONLY...completely invisible from outside.

Very Nice stick out of the Kumhos...I have video of my car with my camera mounted in Marks E-30...I passed him and then took it a little easier to keep him behind me the rest of the session....Mark was out turning me when I was running the Azenis tires...but I can easily out turn him with the Victoracers... In fact the E-30 was constantly over rotating comming out of turns 2 and 4...I never fishtailed during the normal run groups...although i did get it a little out of sorts with trail braking during time trials in turn 5. Rockingham ate most of the tread life of the new tires in one event. I am a little disappointed that they are going away soo quickly... I spoke with Rex about his experience at Rockingham in ITS a few weeks ago... He said he corded a set of Hoosiers on the front wheels during practice. He corded another set of fronts during the race...15 laps I think. I don't feel soo bad now...Apparently Marty corded a set of Hoosiers this weekend on his Miata too.

A size that I use on one of my 240Zs with stock spring perches is.... 15x7 +4 offset....225/50/15 Victoracers....less than 1/2" clearance to the stock spring perches.....I had to roll the wheel well lips to provide clearance.....fattest tire and wheel combo you can get in there without actually cutting the lips or converting to coilovers.

A size that I use on one of my 240Zs with stock spring perches is.... 15x7 +4 offset....225/50/15 Victoracers....less than 1/2" clearance to the stock spring perches.....I had to roll the wheel well lips to provide clearance.....fattest tire and wheel combo you can get in there without actually cutting the lips or converting to coilovers.

I have a variety of wheels from stock Z car wheels, slotted 14x7" mags, to 4 sets of performance wheels in 15x7,15x7.5, 15x8, and 15x10. They have back spacing that are anywhere from 4 1/8" all the way to 5 1/4". The idea is to keep the center of the wheel the same location as stock... Most people running 15x10" wheels are using 5"+ backspacing to keep the bearing loads correct. This backspacing will not only require coilovers...but it will also require very short spring perches in the rear to allow the tire to come as close as possible to the strut housing...within 1/2" to the actual TUBE... Of course...all of this changes if you decide to mount brakes with thicker "hats" than the stock rear drum...as many willwood set ups do. The front disks mount to the rear of the hub so they do not interfere with offset. I can also assure you that you will have to cut away the upper fender lips and bond on some flares to provide clearance to the outside edge of the tires.... Keep in mind that big slicks require extra camber, caster, and toe in rear ,and toe out in the front. These changes can end up moving the wheels forward in the wheel wells...so be sure you have all the parts set up when you cut the wheel well lips away.

Hmmmm....check links on some of the Z web pages...I found plenty of distributor options for any year Z-car...I use a relatively good example of my original dist. with a pertronix module installed, hot coil, bypassed resistor, NGK plugs and wires, brass posted dist cap..I never have ignition problems...EVER! I am not at all sure that the aftermarket dist. are worth the money..I am also very leery of their reliability and repairability. Rebello may have some recurved factory dist. for sale...

Motorsport Auto sells an adaptor to fit those carbys....

For god's sake....Is that a bumble bee on the plate.....Tell me that was not in your filter housing!!!! Mud wasps are skinnier than that bug...but they are a real problem in North Carolina....They will plugg up any hole 1/2" or less with their mud nests...They only way I can store anything in my garage is by oil fogging and bagging every part.

Timing can be tricky if you have changed harmonic balancers from a different year...Some were marked for scales mounted on the left side of the front cover...others were marked on the right. You can check TDC easily enough with a paperclip in the #1 spark plug hole..... just dont get it jammed against the cylinder wall. You can make a new TDC mark with a file or dremel tool. sometimes the keyways in the end of the crankshaft have been "rebuilt"....they are rarely perfect after such a rebuild.... a partially sheared crank Key...or a damaged balancer can also screw up the marks... I have seen balancers that "tore"...the outer weight could twist around... The red stuff is bad...soo is the black stuff...You need to have the tank reconditioned...both colors of sludge will pass through fuel filters easily...right into the carbys....If you just can't wait to have the tank done...there is a drain plug...remove it and replace the copper gasket when you reassemble it....The upper vent lines are easy enough to replace....there is one odd sized section of hose that is very hard to find....there is also a line that passes through the right rear subframe into the rear Q-panel area(vapor tank line) ...use a soft string and a shop vac to pull the string through..attach hose to string and pull it through... As far as fuel return lines go...You should set your system up to use the fuel return system...It maintains constant flow of cooler fuel in the system...the return branch and restrictor should be the last thing in line...after the furthest carby..the individual carby branches should be as short as possible...(less than 6")..to keep the supply of cool refreshed fuel as close to the inlets as possible. You should insulate all of your lines in the engine compartment...feed and return should have fireproof insulation... You should have a heat shield mounted between the carbys and headers...a good heat shield design would also drain leaked fuel away from hot exhaust pipes....your brakes and clutch cylinders could use heat shielding as well. the lack of a fuel return system and heat shielding are not gonna keep the car from running...but when it is pushed to its limits.... they help keep it reliable and consistant....