Dtsnlvrs

It is to be used as an emergency boat anchor...see the Datsun folks figured you were too cheap to buy a spare for your boat, so they provided one with the purchase of a new Datsun.

I am still waiting on my needle valves...darn mail from Italy is slow.

Well I finally finished reading this entire thread...whew. There is some great info here, but I was wondering a few things. Since we are talking about using Bilstein inserts from a VW Rabbit, has anyone considered uning the P30-0137 Heavy Duty insert, instead of the P30-0032 Sport, with stock valving. The reason I ask is I am never going to use spring rates higher than 175f / 200r on my 240-Z. It will never be an all out track car, as I like to drive it too much, and If I did build it into one, I would find another 240 to replace it for my weekend driver and just swap the whole suspension. The setup I am currently runiing is: Tokico "Blue" non adj inserts on shortened struts (88 MR2 rear in front and stock 240 front in the rear) GC coilovers with 150f / 175r rates Stock 240z strut mounts (rubber isolators) may upgrade to camber plates soon. Poly bushings all around except the rear TC bushing (using the NISMO Delrin / Aluminum TC kit) I get my camber adj by using the Delrin / Aluminum offset bushing in the front and have left the rear alone ( neg 2.5deg rear / neg 1deg front) Before anybody says to use Tokicos...I dont like the tokicos..never have even when I used Illuminas, however, I have used Bilsteins in the past (VW and Jeeps) and have a great respect for their quality control and their products in general. On a side note, since we are talking about using VW inserts, has anyone considered the Sachs or even the Boge units for the same application? On a second side note, can I order the EMI camber plates pre-prepared for the Bilstein units?

Reason I say to richen the progression is that at 3k you are on the mains already.

OK where to start. Set your timing at 15-18 deg initial (your cam aint as big as mine) using the starter motor only, and no vacuum advance (disable it permanently) 1: install a 2.00 needle valve, then reset your float settings as per Weber for brass floats. 2: increase the idle jet to a 55f9, and turn the mixture screws in to get best lean idle at about 900-1100 rpm. 3: Re-synch carbs then repeat step 2. 4: Make a new AFR log and report back

After looking at your graph again...I would not mess with your mains sys at all. That is a good looking AFR graph for a carb'd engine. However, I would put a richer idle jet in, than turn your idle mixture scres in a bit...your progression is lean.

My carbs do not have that screw 40DCOE18, yours do 40DCOE151

^^^^ very well put ^^^^

Glad to help with the links. I think we are talking about the same thing but using a different perspective. On our motors with similar cam profiles, Our mains should be comming in at about 3k rpm...just when we start to richen. then around 4k we both go lean, compared to how rich we were. If the jet well is drying up, that would would explain the lean condition...if you cant keep the well at the "right" level, all bets are off. I look at it this way....3 needle valves is a cheap experiment compared to 6 E-tubes. Besides....The English book says we should have the 2.00 valve, and every OEM application for a 450-500cc per cyl calls for a 2.00. I figure its worth a try. If I replace the valve and the leaning goes away...I can reduce my main jet and get the AFR graph more linear. As far as going rich at the end.....we are both past our usable HP and therfore the motor is not as effecient...so who cares. Just my .02

Try adding 5more deg initial advance (15 deg @ idle) the Webers like ALOT of initial advance

NCIS ftw Nigel Mansell or Alain Prost

You are reading the AFR's wrong (I think). Look at both mine and Zredbaron's AFR graphs...his start to lean out from full rich at 4k and mine at 4.5k...we ARE running out of gas in the jet well. But the larger jet we use to compensate, causes the dredded bog as the mains come online in my case at about 3300rpm.

Follow me here if you will. If you are starving the jets at 4500 rpm, and did not know why...you would put in larger main jets to compensate...We all have fallen into this trap...Large main jets...add 50 for the airs...then run out of gas at 4500rpm. zredbaron has a 3.1L engine...so the disparity between jat size and ammount of fuel available is exacerbated. I think if he would install 2.00 or even 2.25 needle valves he would see the end of his issues. I am going to order 2.00 needle valves tonight, and try that with the F-11 tubes.

I just found some "new" info with respect to the needle valve selection. According to the Speed Pro Series "How to Build & Power Tune Weber & Dellorto DCOE, DCO/SP & DHLA Carburettors" Chapter 4, Needle Valve Seletcion, p77-78. "One Choke Per Cylinder applications - Up to 300cc per cylinder use a 1.50. Up to 400cc per cylinder use a 1.75. Up to 500cc per cylinder use a 2.00. Up to 600cc per cylinder use a 2.25. Up to 700cc per cylinder use a 2.50." So using this chart...a L-24 would require the 1.75, but a L-28 or L-30 and larger should be using the 2.00. This would make sense...if you look at my AFR graph and remember that my Air Corr is only .10 larger than my main jet...I am running out of fuel in the jet well at 4500rpm.....then we get start to get rich again after peak HP at 6000rpm. I think what WE ALL should do is switch to the 2.00 needle valve, ensure we have good fuel pressures, and test. Then make the final judge on our E-tube selection.

Well I just opened my carbs up, could not find my data sheet, and have compiled all my numbers. I will include specs about the car as well cause that will influence jet selection too. Mind you I am in Las Vegas, 2200-2500 ft elevation. I run the car on pump premium 91. f-54 block flat top all stock (nissan parts). '71 E-88 Head originally built by Sunbelt (large valves) stage 1 port by me on kitchen table with a dremmel tool. 2mm HKS head gasket Isky 490 / 290 cam with 109deg lobe seperation '81 NA 5-speed, 4.11 R-180 diff 225/50/15 tires Euro (6deg) 240-Z dizzy, Pertronix firing a Jocobs Ign Unit. Magnecor Wires TIMING: 20deg initial 32deg total "all in" by 2500rpm DENSITY ALTITUDE DAY OF RUN. 3600ft 40DCOE18 Main Venturi: 33 Aux Venturi: 4.5 E-tube: F-11 Mains: 140 Airs: 150 Idle: 55f9 Accell Jet: 45 Accell Bleed: 40 Needle Valve: 1.75 We got our best (safest) AFR's with the setup above. I am leaning one of two ways...either change to a 2.00 needle valve, and or F-2 E-tubes. My "guy" in Italy suggested years ago that I switch to the F-2 tubes....I will probably do both.

I agree with JC, you are too stiff. The nose is bouncing under braking. I Auto-x on street tires and 150f / 175r springs....nice and soft..but then again, when I show up at an auto-x, i lower my tire pressures too...It is all about keeping it plyable.

BTW...having a large set of jets is very expensive, but the cost can be mitigated...for starters...dont buy crap from a US company....most of their rebuild kits are junk and their jets are now cheap chinese copies stuffed into "gen Weber" bags, or overpriced OEM Weber....I only buy my stuff from England or Italy. My jet selection covers 28mm, 30mm, 32mm, and 33mm Main Vents, but I buy my jets direct from italy at half price over the states. http://www.dellorto.co.uk/ rebuild kits..itg filters and misc parts http://stores.ebay.com/ALFA1750S-CARBURETORS-PARTS-STORE Jets and stuff http://stores.ebay.com/FAST-ROAD-CARS another English Supplier

I also did a tune using the 33mm vents and the F-9 e-tubes.....forget the f-9...I would suggest the f-11 or the f-2 (BTW the F-2 is what came in the original Z-car conversion) and increase the needle valve size to at least 1.75.

The one thing nobody has mentioned is the Needle valve size. Even my "almost" perfectly tuned trips lean out a bit (13.02 AFR) at 4500rpm-6000rpm. I am thinking of increasing the needle valve size to a 2.00 from a 1.75. Thought process goes like this....E-tube sits in a well of fuel....under WOT that well level gets lower and is filled thru the Needle Valve...the bigger the valve the faster it can be re-filled. Also...I think most of you are using WAAAAY too large a Venturi for your application...there two really good books out there http://www.dellorto.co.uk/merchandise/products_details.asp?PartNo=Powertune&CategoryID=5&PartsectionID=7 http://www.dellorto.co.uk/merchandise/products_details.asp?PartNo=9500005400&CategoryID=5&PartsectionID=7 Just my two cents....I will post my setup numbers as soon as I find my data sheet.

Dammit Joe, I am gonna have to get that Rebello 3.2L and drive the piss out of it just to keep up with ya'

Daphne. Weber or Mikuni or Dellorto

Panzer G all the way. Yokohama or Toyo?

Taking 2nd for Street Mod 240 at the Tidewater show in Spring 2006.

I used to DD my 70 when I was stationed in WA for 2 yrs and Italy for 4. Now it sits in the garage and only comes out once a week to work plus Auto-X and club outings.