bjhines

I think whoever weighed the stock VS aftermarket exhaust manifolds and said they were the same is bonkers.... You can't comfortably pick up the stock manifold with one hand... you can pick up a tube header with 2 fingers... But to dispel all myths...I have a jet coated MSA 3 into 2 header for a round port head... I also have a no name early style square port header .... in addition I have a bone stock 240Z manifold with AIRPUMP tubes and rail on it...all on the shelf and ready to weigh... I will weigh them when my kid takes a nap...

I did not come back to this thread soon enough.... The flow control valve (mounted on the left inner front fender...is key to allowing the system to "vent".... But it only allows gasses to enter the tank...not exit..... Your fuel filler cap also allows air to escape if it builds up more than just vapor pressure...obviously the fuel pump is not going to vent gasses...maybe gasoline... Soo...unless you have multiple failures of all the above parts....you cannot get a "higher than normal" pressure buildup in the fuel system.

Jack up the rear.... remove wheel... look closely at the dust shield that covers the outer lip of the drum.... It will be bent in many places as you look around the circumference of the drum...old age... Go back to tool box....get a flat blade screwdriver and pry out the worst of the dents... DO NOT OVERBEND TO clearance the lip... It is thin and you will pull it out out of shape somewhere else....It is just thin sheet metal... If you are able to remove the drum by yourself... then you will see shiny spots on the edge of the drum and the shield.... again.. easy to spot and fix... For all you naysayers... How many of you have drum bakes on your Z... really...

well... considering he just had his brakes done and now the complaint has come up....You would have to be loopy to even consider just "tryin out" some new U-joints.... Someone been smokin joints... not U-joints. This reminds me of a fella in our club that spent close to $1000 on MSD, ITG filters, plugs, wires, hose, electric pump in front to replace the mechanical pump, LABOR at a shop....all because he lost power at high RPM.. Turns out I fixed it at an event... between sessions by cleaning the original REAR ASSIST PUMP FILTER... FOR FREE IN 5 MINUTES. Some folks love to ""IMPROVE"" things.... not ever fix them....

The guy who did your brakes prolly had to hammer off the brake drum...which can ruin them BTW... He bent the lip of the dust shield riveted to the backing plate... It runs very close to the lip of the drum... It is simple to fix... With some slop in your rear bearings the car will squeak when certain conditions are applied..IT could just as well squeak when you coast or lightly apply brakes...but doing that under acceleration is typical...

Good thought on the linkage...But It did not escape me... The TWM linkage is very high quality...The best I have seen... And it is relatively easy to set by loosening the clamp screws on the arms. Before assembly I carefully checked the throttle shafts and plates to see that pairs worked evenly... I used a wire guage with them open enough to actually check clearances top and bottom...all 3 carbs had their pairs of plates in good order...variance ~.005.... Then I checked the idle speed set screws' contact points and position of throttle plates in relation to the transition holes... 1/2 turn past contact... there was some variance there...soo I set them just downwind of the 1st hole.. ~1/2 turn... The screws are not precision parts... niether are the throttle arms.... I thought that was a very accurate way to set them and I marked the heads of the screws at the same point on each one. If nothing else it makes it a little easier to count turns.. you dont get lost on half revolutions... The problem is that...all the screws are not turned the same to show equal flow with my unisyn meter..... they are up to 1/3 turn different from one another....I checked flow at 900 RPM and had trouble getting a decent reading with the unisyn set as low as it would go....I reset idle to 1100RPM and got a good reading from the unisyn. I was able to see a difference between bores on the same carby. The siamesed throttle bores would show slightly different flows at idle.... This was easy to make up for by opening the air bypass screw <1/2 turn on the low flowing bore. After dealing with this I have my doubts that the transition holes are accurately positioned in the carb body. A few of the idle mixture screws are F***** up...Inexperienced hands without a clue..screwing up far more than they ever fix. I expected them to be a little off...... With them over 3 turns out I think I need a bigger idle jet...60F9 seemed big to me..It is the biggest I have right now... I have dual air/fuel meters installed in the car..I welded bungs onto the rest of the runners and switch them out as I test... If the O2 sensors were less expensive I would put a rotary switch in the cockpit...and install all of the sensors...right now there are 4 spark plugs filling the unused holes. I used my ears to get the Idle mixtures close and tweaked them with the AF meters. part throttle and WOT conditions are very consistent....nice even mixture from all bores...The new spark plugs' deposits look much more even in all cylinders than when I was using the SUs. I used propane and a length of hose to check for vacuum leaks... I found one that I fixed before I started tuning. I believe my compression is very close on all cylinders. The engine has realtively low mileage... but I will check it. I will give the valvetrain a once over and see if that makes any difference...I have run one track event and played around on the street since I last checked lash... I doubt that is an issue... I would like to get a bigger idle jet in them and retune to see if that helps to even them out... Anyone have anything slightly richer than 60F9??? for cheap..

Well.... Webers are now installed....I got some tuning done to them before a rain storm cut my day short... I have installed 30mm chokes 115 main jet F16 E-tube 175 air corrector 60F9 Idle It pulls GREAT at low RPM...it has a much wider torque curve. and it idles rock steady... I have the idle speed screws out ~2/3 turn it varies from carb to carb... I used the air bleed screws unique to the 152 series to balance the bores The Idle mixture screws are out 3-3 1/2 turns..which is a bit too far out I think. There is a slight stumble when coasting...but it has perfect mixture at low speed part throttle. I can get it rolling without even using the gas pedal. My AF meters show very lean conditions when holding the throttle just enough to take all load off the engine in a level coast... This seems odd I think I have a huge idle jet size in there now...60F9...and the lean condition is only present when coasting with a TINY AMOUNT of pedal.. all other low speed conditions are perfect. anyone who has any ideas please chime in... anyone who has 32 or 34mm chokes...please PM me....I have your money in my hand...

Start it and then disconnect the battery ground....see if the starter pinion retracts before the engine stops..that would let you know if the soleniod is energized and holding the pinion against the flywheel. Otherwise you can remove the starter and try lubricating the gear and the shaft it slides on.

I am building my third 240Z in my career.... It is a gen1 SBC swap and my second track built streetable car... I have fought with braking and wheelspin enough to realize that it is well worth investing in the Willwood racing brakes and a good LSD.....You will spend almost as much money on swaps like the 240SX rear brake set ups... Check out the Willwoods on a lot of members cars...Everyone who runs a 240Z on track in a class that allows big brakes uses them...You cannot find reliable lsd units used for cheap...I have seen plenty of them well worn on E-bay going for enough money to warrant rebuilding an R200 and installing your own fresh 4 pinion LSD unit... I have been collecting parts and the project is comming together...I am using all fiberglass front end parts...FG hood, FG fenders, FG headlight scoops, FG air dam with splitter and ducts, aluminum radiator, removed hood hinges, removed bumpers and mounts to try to shed some of the increased weight form the V-8 conversion... I have already aquired the LSD, 280Z rear stubs and half shafts, GC coilovers, AZC camber plates, I am buying the AZC 4 lug full race Willwood kit. The conversion to a capable track car cannot be done for $4k... You are better off getting a stock 240/280Z set up and driven correctly...$4k will go a log way towards rebuilding and race prepping using mostly stock parts and systems.

I'm sorry Tube80Z... I have read a lot of your posts and found them very interesting...I like your web log about your fathers Z exploits and your continuation.. Well.... the carb size 45mm...They fell into my lap and thats what I have to use... as far as choke sizes...I am getting the 30s because they are available cheaply...and they are closer to the 29mm in DCOE40s used on most L24 engines... I really think that flow will be the same between the 40s and the 45s with similar chokes installed... therefore the 30mm chokes on DCOE45s are actually a step larger than the "normal" set ups for these engines... As far as what carby to use for what size chokes...I agree it seems silly to spend the extra cash on the 45mm bodies when the 40mm bodies will work just fine... but Weber made chokes all the way down to 28mm to fit the DCOE45s... I have em I'll use em...But I will indeed try tuning them at the track with the 36mm chokes installed...I may end up with 32mm or 34mm installed one day... BTW... if anyone has any 32 or 34mm chokes to use in DCOE45 bodies...I will buy or trade.. I also need to find jets of various sizes..I will request as I tune though...

Ok....things are starting to come together for me now... I managed to find a couple of Hybrid Z members who have some parts I need and have been VERY gracious about selling them to me cheap. The information I have found has been VERY helpful..... I really don't know what I would do without this site... Thank you EVERYONE!!! I think I have located a set of 30mm venturis for cheap... I was thinking I needed 32 mm chokes...but I will start with the 30s and move up if need to.... I have a huge list of parts on the way from all over the globe... correct 45mm soft mounts new studs and nuts for TWM manifold new studs and nuts for the E-88 head new Header style intake gasket one DCOE 45 152 rebuild kit...just to get gasket templates one fuel union tee..to allow return to tank Holley red pump screw on type fuel filter holley regulator carby fuel rail holley rail mount guage High quality hose hose insulation F.I. quality clamps I have 30mm chokes on the way I am adding a few O2 sensor bungs to my header I already have 2 A/F meters..I will add a third and move one existing I am adding an EGT gauge to the collector I am making up an equalizer/vacuum manifold. considering the TWM has a bung only on the #6 runner. I have a cold air box on the way...along with 4" tubing and a cone filter. I am making a heat shield in addition to the airbox The header is already jet coated and wrapped the TWM manifold will get insulated as well. I would like to know if anyone has ever found 5mm thread-vacuum ports/nipples to screw into the #48 vacuum cap hole on the DCOE bodies. This looks like a good place to plumb vacuum lines to a manifold block for dizzy vac signal...they may have enough flow to use for the brake booster and PCV as well... although I intended to make an equalizer tube for the TWM manifold anyway.

ok ... here are the numbers.... DCOE 45 152.. made in Spain... close set of serial numbers. TWM manifold and linkage...in good condition... 36mm chokes, 130 main, 175 air, F9?? E-tubes... L24 balanced and punched .020 over... polished crank... shot peened rods...new pistons and all Nissan internals. E-88 head...very slightly shaved...3 angle valve job...stock lift cam with aggressive timing... Currently running in HPDE events and TT.... I ran a minute 12seconds at "The Rock" in Rockingham NC...I never pushed the envelope with late braking there... so it is worth at least another second...

I have a set of DCOE 45 152s I am putting into a 240Z with a cammed L24.... The carbys came off of an L28 flat top with mild compression and a mild cam. I think I need 32mm chokes to start tuning these beasts...but they have 36mm chokes installed. Does anyone here have a set of 32mm chokes to fit DCOE45s...Money or trades....

I found the thread you reference earier... Very good info.... I purchased a 240Z Race car that was wrecked in the rear...recently...The carbs were functioning well enough for me to sell the engine for a good price...They were mounted on a 2.8 F54 flattop with the standard low compression head... there was a mild cam installed... Dyno said close to 200hp at the wheels...Which is respectable... considering I only get 142 HP to the wheels with my L24 and well tuned SUs.... The DCOE45s have 36mm chokes installed.... A handy carb refence webpage had a chart to determine choke sizes...Mine comes in at 31mm... 32 is the smallest I can get for the DCOE45s. They are available but they are $25 each...I checked on sizes too...36mm chokes are hard to find...apparently they are the most popular. If you look at the same chart I found...you will see that a 2.4litre engine is the biggest size they list for...it does indeed say that the chokes should be around 38mm.....BUT!!!! that is info for a dual carb 4 cylinder engine...you have to look at the info for a 1600cc 4 cylinder engine to match the same 400cc per cylinder volume as the 2.4L inline 6 cylinder.... Soo...I would say that a 38mm choke is wayyy too big... Most of the 2.4L triples are DCOE40mm with 29mm chokes.... I have run Mikuni/Solex carbs on Toyota 22R eninges...They can take big chokes because the cylinder volume is much bigger than the 400cc per that the Z L24 has.

Is that crickets I hear..... Well...... I answered my own question today.... Pierce Manifolds came through...nice fella actually measured the soft mount rings for me....The Weber DCOE45 rings will not interfere with the airflow as they are 47mm inside diameter...The DCOE40 series had 40mm inside diameter rings...soo there is my problem... I dont know what kind of moron would have forced 40mm soft mounts onto 45mm carbys...but that explains why they are somewhat crooked on the manifold... I mean really..you just have to be retarded to do that...

ohhhh... another request....I NEED 32mm chokes to fit the 45mm DCOEs....I can get them from Pegasus.... but I was hoping some Weber fanatics might have a set lying around for cheap.