My car has the Solex Carbs. Let me try to explain how to balance the carbs.
Most people would start fiddling with the adjustment between the carbs
without a thought as to what they were doing. Here is how I do it. Have
someone sit in the drivers seat, and depress the Accelerator pedal to the
floor.(Engine Off) or you can manually hold it(First Carb Butterfly,
closest to gas pedal linkage) open under the hood. While holding the first
butterfly fully open, adjust the balancing screw located between the carbs
until the second set of carbs are fully open. If you go too far with the
balance screw I believe you will begin to close the Butterfly on the first
Carb. You must get them the same. After you accomplish this and setting
the Lock nut, you can start your engine and adjust your air screws. I am
sure this will improve the performance as well as the mileage on SOME of the
cars out there.
When I bought my Corvair 140 HP engine, I set it onto a Milk crate and put
some gas into a coke bottle with a line from there to the fuel pump, and
fired the engine up. It ran great, or so I thought. I thought it had power
to spare as It was revved up. I have a habit of feeling the exhaust for
heat differences. One side was hot to the Max, and the other side was stone
cold. I realized why the PO sold it. I found there was paper lodged in the
fuel line from the fuel pump to one side of the carbs. After blowing the
line with compressed air, the other side then began to function after it had
drawn fuel into the carb. The difference was staggering. I thought I had
unleashed the Tiger from the tank. The Point is: Had I put that engine into
the vehicle without finding that problem, I may have thought the way that
engine ran was normal, and just let it be. Pat
From: datsunmike <email@example.com>
To: Patrick P. Castronovo <firstname.lastname@example.org>; Robert.Long@CSDInc.com
Date: Thursday, June 07, 2001 5:05 AM
Subject: Re: valve adjustment/ smog plugs x-mac-creator="4D4F5353"
>No, nothing with the balance of the engine as many books I rread on Datsuns
>say the engines are well balanced from the factory. It's probably due to
>dual carbs. Dave Pesky owns a single SU 1500 and his car runs well at 600
>I had the same problem with my Z too until I put on a single Holley 4
>barrel. Although in the Z it did idle much better probably due to the fact
>it's a 6 and has a better firing balance or internal movement balance.
>Straight 6s are the smoothest of all engines.
>----- Original Message -----
>From: "Patrick P. Castronovo" <email@example.com>
>To: "datsunmike" <firstname.lastname@example.org>; <Robert.Long@CSDInc.com>;
>Sent: Wednesday, June 06, 2001 10:14 PM
>Subject: Re: valve adjustment/ smog plugs x-mac-creator="4D4F5353"
>> Would that have anything to do with engine out of balance? Pat
>> -----Original Message-----
>> From: datsunmike <email@example.com>
>> To: Patrick P. Castronovo <firstname.lastname@example.org>; Robert.Long@CSDInc.com
>> <Robert.Long@CSDInc.com>; email@example.com
>> Date: Wednesday, June 06, 2001 5:01 PM
>> Subject: Re: valve adjustment/ smog plugs x-mac-creator="4D4F5353"
>> >"Valve Clearance Intake & Exhaust .017 Cold"
>> >Should say HOT.
>> >BTW, can any of you get your car to idle well at 600 RPMs? I can't and
>> >----- Original Message -----
>> >From: "Patrick P. Castronovo" <firstname.lastname@example.org>
>> >To: <Robert.Long@CSDInc.com>; <email@example.com>
>> >Sent: Wednesday, June 06, 2001 3:52 PM
>> >Subject: Re: valve adjustment/ smog plugs x-mac-creator="4D4F5353"
>> >> Linda:
>> >> In my tune up book it reads:
>> >> 1965-1969 SPL311(1600 engine)
>> >> Spark Plugs NGK BP-6E Gap .28 -.32
>> >> Distributor Point Dwell Degree 49-55
>> >> Point Gap Inches .018 - .022
>> >> Basic Ignition Timing Degrees 16BTDC @ 600 RPM
>> >> Compression Pressure (PSI) @ 350 RPM 181 PSI
>> >> Valve Clearance Intake & Exhaust .017 Cold
>> >> Idle Speed 600 RPM
>> >> Firing Order 1 3 4 2
>> >> #1 Cylinder is the front, #2 is next, #3 is next, and #4 is last.
>> >> Distributor turns Counter Clockwise
>> >> As you put your finger over each hole in the firing order, 1 3 4 2.
>> >> will feel air come out of the Spark Plug hole. That means the valves
>> >> both closed. Adjust them now, in this position. Rocker arms up off
>> >> Valves. When the valves are open, allowing movement of Air and Gas
>> >> of the chamber, the rocker, or Cam is pushing down on the valve
>> >> the spring. The spring moves the Valve to the Closed Position so it
>> >> an airtight seal in the Cylinder.
>> >> >List,
>> >> >A question on the cold valve adjustment- Is it 0.20 or 0.21, and on a
>> >> >1600 can you adjust the intake and exhaust of the cylinder the dist
>> >> >rotor is pointing to together? Also I am still confused about being
>> >> >that valves are fully open or closed-Is that when the pushrods are
>> >> >up, the rockers are down and springs are compressed? So at TDC,
>> >> >compression stroke, #1, are #1 valves adjusted or not? Someone
>> >> >the 9 rule, or something like that, is that the only way?
>> >> >Second question on plugs. What is the exact size for the intake
>> >> >so I know what to ask for. I know about the injector plugs in the
>> >> >already, they have not been done yet.
>> >> >Questions form A to Z...
>> >> >Linda