1972 Datsun 240z Original Camshaft and Hitachi SU Carb stock needles

[jalexquijano]

Where can i purchase the original Camshaft for my 1972 Datsun 240z? My car has been upgraded with the following specifications:

New Datsun L24 motor with crank and rods from a L26, special oversized 84mm flat top black coated pistons from D.L. Potter Engineering with E88 Head and Far 311 New Race Cam.

2 original SU Hitachi round top carburetors rebuilt with race jets / needle.

I am having stalling problems and really want to go back to stock!! What parts will i need to purchase in total besides of the camshaft based on the above upgrades? Who sells them? I really prefer high quality parts and Genuine Nissan if available.

[madkaw]

PM'd you

[Bruce Palmer]

What exactly are race jets? And Race needles?

[jalexquijano]

What exactly are race jets? And Race needles?

OKAY. Problem solved! The mechanic readjusted the Hitachi su carbs and check on the electronic distributor. He found a loose wire inside that was part of the original distributor and had nothing to do with this electronic one. He also changed one of the front 3 spark plugs which that had turned black due to the misadjustment of the carbs. Now the car is really stable between 1,000 RPM to 6,000 RPM. Once it reaches 6,000 RPM it fails a Little bit. Which direction shall i take? Any advice?

[madkaw]

Where do you figure your power band is at?

do you have forged aluminum psitons?

If you do have a 'race cam", how well do you think the SU carbs will keep up with it?

Have you done a searching on the Datsun motors and their limits.

[Bruce Palmer]

If those carbs are running stock needles, they could be going lean up top. That was very common for stock needles. Fat at idle lean up top. SMs just reverse that.

[Zedyone_kenobi]

I would ask you what are you doing with the car. IF it is pulling from 1-6k I would leave it alone. You will not find enough additional HP to warrant a huge change like a cam/rockers/lashpad. IF the car is reliable enjoy it. You are polishing the apple now. You can move the power band around more, but if you pull nicely from 1-6 then I say go with it. Making a car pull harder above 6 grand will make it less drivable at idle. Not UNDRIVEABLE mind you, but less drivable.

Enjoy what you got working. Large gains will not be had with a cam. You can get more, but think about the cost. Every mod away from stock costs you something and gains you something.

Just saying, there is not magic formula of a cam that will get you 260 HP from your block and pistons.

Play with your mixtures or needles, that is cool and fun. But you are talking carb tuning now, so get an O2 sensor and let the games begin.

[jalexquijano]

I would ask you what are you doing with the car. IF it is pulling from 1-6k I would leave it alone. You will not find enough additional HP to warrant a huge change like a cam/rockers/lashpad. IF the car is reliable enjoy it. You are polishing the apple now. You can move the power band around more, but if you pull nicely from 1-6 then I say go with it. Making a car pull harder above 6 grand will make it less drivable at idle. Not UNDRIVEABLE mind you, but less drivable.

Enjoy what you got working. Large gains will not be had with a cam. You can get more, but think about the cost. Every mod away from stock costs you something and gains you something.

Just saying, there is not magic formula of a cam that will get you 260 HP from your block and pistons.

Play with your mixtures or needles, that is cool and fun. But you are talking carb tuning now, so get an O2 sensor and let the games begin.

Just got stucked in a traffic jam for 20 minutes on saturday, bumper to bumper. RPM tended to lower from 1,100 to 800 and then 500 RPM. Had to pull the choke or step on the gas so the car engine wont shut down. I know its difficult to idle on a car that has a race cam but how do i do then? I want to load an AC System on the car but with this type of idling issue it seems i am screwed up. Any advise on how to determine if the is some vacumm escape?

[jalexquijano]

Where do you figure your power band is at?

do you have forged aluminum psitons?

If you do have a 'race cam", how well do you think the SU carbs will keep up with it?

Have you done a searching on the Datsun motors and their limits.

Okay, Im just about to change this Far 311 Race Cam which was installed by DATSUNLLC and was advised the following:

"a L26 crank makes your motor 79 mm stroke instead of the stock 73.7 mm

stock bore is 83 mm for the L24 and the L26 motors

your block has been bored out 1 mm to compensate for wear

that makes your motor a 2.627 liter motor

your E88 head from 1972 will give you about 8.7 to 1 compression

FAR performance went out of business in 2002 so I have no cam specs

311 could be their advertised cam duration

if it is the same as BRE 311-------

BRE 240Z 311/C-1 cam: At 0.001" lift: In open 33 deg Bef TDC In close 66 deg Aft BDC Ex open 66 deg Bef BDC Ex close 33 deg Aft TDC IN Lift at TDC 0.108" Total Lift 0.463"

At 0.050" lift: In open 14 deg Bef TDC In close 45 deg Aft BDC Ex open 45 deg Bef BDC Ex close 12 deg Aft TDC

IN Lift at TDC 0.108" IN Lift Total 0.463"

EX Lift at TDC 0.097" EX Lift Total 0.469"

Okay, bottomline, my car is not presenting a smooth idle even though i removed the EGR system. So i believe i should go back and install a stock cam from a 1973 240z which i was sold from a friend. What else will i need. My main purpose is obtaining a smooth idle and being able to install an AC system to the car.

Please advise what parts will i need besides the lash pads?

[Zed Head]

So this a DatsunParts LLC engine? I don't think that you've mentioned that in any other posts. Interesting that he used a cam from a company that went out of business.

Your best option would probably be to buy a complete kit from one of the well-known suppliers, like MSA or Schneider. It will be expensive, you'll need the cam, 12 rocker arms, and 12 lash pads. Might be cheaper to just buy a whole head.

[Oiluj]

As you surmised, a less than smooth idle is a typical compromise you expect when using a higher performance cam. How bad is the idle? Just a bit rough or loping?

Also, the previous question about where in the rev range your power band falls can make a difference in drivability.

For what it's worth, mine has a slightly rough idle that initially bothered me. Now I kinda like it...

[jalexquijano]

Its a bit rough. The symptoms are the following:

Start the engine, drive on free way and everything is fine. Under this circumstances it idles between 1,100 and 1,200 rpm. However, if i get caught in a heavy traffic jam the car starts stalling and decreasing from 1,100 to 800 rises again to 1,100 and occasionally goes to 500 rpm tending to shut the engine down. In this situation i reach to my destination and let the car idle at the parking. RPM starts lowering and eventually shuts down. It does start back again but i have to give it some gas pedal.

I have already sprayed carb cleaner to all the hoses and connections looking for vacuum leaks and have found none. I did remove the EGR system including the servo diaphgram as it was broken as shown:

Hope one of you can point me out to the correct direction so i can solve my problem.

Edited October 4, 2014 by jalexquijano