Just bought a 521

[Charlie69]

I run the Cannon intakes and I have the DGEV traditional Flatspot if I stop on the throttle but if I steadily increase the throttle it just pulls hard.  Much better pull than the stock carb.

 

I ran the dual plane manifold once years ago and did not like it and changed it out to a Cannon.

 

I believe Peirce Manifolds Cast the Cannon intakes and they might have new ones also.

 

DATSUN 510, 610, 710 MANIFOLD WEBER DGV 32/36 38/38 99002.825 WEBER

 

Or look for a good used one.

[mainer311]

25 minutes ago, Charlie69 said:

I ran the dual plane manifold once years ago and did not like it and changed it out to a Cannon.

Now you tell me. 😀

[Charlie69]

I learned early on in this thread to let you run your course!  LOL

[mainer311]

Last night I had a look at the float. The Weber instructions online don’t look quite right for some reason, since their 2 measurements don’t really jive. A lot of concensus is that when fully depressed the float is parallel with the inside of the cover. Mine was a few millimeters off, so I adjusted it a little. It should actually raise the fuel level a little bit. For the hell of it, I also changed the primary jet from 140 to 145. It’s so lean, I need to get some fuel flowing.

[mainer311]

18 hours ago, Stoffregen Motorsports said:

Check the float level.

 

Add fuel (bigger main jet).

 

I would try those two things first.

 

But timing curve and valve lash also are very important.

Did all this last night. Float was a tad off. Will do more testing today.

[Stoffregen Motorsports]

On 3/6/2020 at 9:04 AM, DanielC said:

I am too lazy to look back in your thread and see what engine you are running, L-16, 18, 20-B, and I also do not know if the Weber carb has a mechanical or vacuum secondary.

A carburetor depends on manifold vacuum, and air flow speed through the venturi to accurately meter the gas into the air at the right fuel to air ratio.

if you suddenly floor the gas pedal at low RPM, with a mechanical secondary carb, especially on a L-16, the manifold vacuum drops almost to zero and the engine simply is not drawing in enough air to get a decent air flow speed through the venturi.   This is overcome by the accelerator pump on the carb.

 

Again, the last thing you do in setting up a carburetor is do a full tune up on the engine.  Is the compression good?  Valves adjusted?  Ignition timing set?  A little more advance can help off idle, and low RPM performance, provided the engine is not too far advanced.  If you hear knock, the ignition timing is too advanced under those conditions.

 

Now, for the carb.  The most important parameter on the carb is the float level.  Too low, or too high float level will affect every every different fuel circuit in the carb.

 

The beauty of a manual transmission is you choose the gear you are in, and you can in anticipation choose a gear you will need coming out of a corner, while you are still deep in the corner, or even before entering the corner.  An automatic transmission can only react to present driving conditions, not anticipate them.

 

With a stock 521/L16/four speed transmission.  The gear ratios are not really that good, there is too large a gap between 2nd and 3rd gear.  With a mechanical secondary carb, you have to learn to ease into the throttle as RPM of the engine increases, and the engine can take the air flow of the carb.

 

 

No fair, I actually started this post before Stoff.

You and I are usually of the same opinion anyway...

 

On engines with limited vacuum, sometimes you have to force feed them fuel. Bigger pump nozzle or larger main jet. Too bad you can't adjust the accelerator pump on a DGV like you can on a DCOE. I suppose you could stick a washer in there to activate it quicker, but it would be a gamble.

[Stoffregen Motorsports]

7 hours ago, mainer311 said:

Did all this last night. Float was a tad off. Will do more testing today.

Sometimes the float is just off. Doesn't matter if it's a new carb. If they dropped the box during shipping, this could bend the float arm.

 

[mainer311]

Technically you can adjust the pump by drilling the nozzle bigger. And it does start squirting fuel almost right away.

 

I don’t think I need to go that route yet.

 

Also, I changed the plugs out for BR7ES instead. The BP6ES that I removed had discoloration all the way down the ground strap. I read that this means the plug can’t dissipate heat as quick as it needs to. Going to try the non-projected in a higher heat range and see what happens.

Edited March 7, 2020 by mainer311

[datzenmike]

Solve the lean and it solves the heat problem with the plugs.

[mainer311]

1 hour ago, datzenmike said:

Solve the lean and it solves the heat problem with the plugs.

That was my thought too. I have so many new spark plugs, I’ll keep them as spares. I like to keep a spare set in all my Datsuns anyway.

[mainer311]

I don’t know why I did this. It just seemed right.

 

[wayno]

So your name is Oscar and your having a bad day?

[mainer311]

5 hours ago, wayno said:

So your name is Oscar and your having a bad day?

No, I think it’s more about: there’s a grouch inside of this trash can. 😂

Edited March 27, 2020 by mainer311

[Charlie69]

That is an odd place for an antenna!  LOL

[wayno]

I think we need to worry about why he is calling his truck a trash can and why he is so grouchy.

[mainer311]

1 minute ago, wayno said:

I think we need to worry about why he is calling his truck a trash can and why he is so grouchy.

The weird part is that the truck is green and I am not.

[wayno]

I thought this was a metaphorical thing.

[mainer311]

4 hours ago, Charlie69 said:

That is an odd place for an antenna!  LOL

 

It was there when I bought it. I just always thought it was factory. 🤷‍♂️

[Charlie69]

The factory is usually on the front fender either left or right by the "A" pillar.  Some radios were installed by the dealers so it could be a dealer installation.

[thisismatt]

All antennas were dealer drilled AFAIK.  The radio kit comes with a template of where to drill the antenna and where to mount the speaker (with instructions on notching the parcel tray if so equipped).

[mainer311]

4 hours ago, Charlie69 said:

The factory is usually on the front fender either left or right by the "A" pillar.  Some radios were installed by the dealers so it could be a dealer installation.

No holes in my fenders, so it must have always been there.

 

 

Edited March 28, 2020 by mainer311

[thisismatt]

[thisismatt]

[BrothersGarage]

This forum is such a beautiful resource of information. Thanks for sharing matt!

[thisismatt]

1 hour ago, BrothersGarage said:

This forum is such a beautiful resource of information. Thanks for sharing matt!

 

No prob!  I took those before I sold that NOS radio kit.  It was a really cool piece, but I knew I was never going to go for a concourse style resto, so it didn't justify keeping it.  Sold it for quite a profit, too 😲