Technical Edlebrock on Nailhead issues.d

Have you considered writing, or maybe already written a book?

 

Thank you for the complement!

Yes, but do not have the time.

Instead, have posted 2 sections to my website that may be of interest. One is the "troubleshooting" page

https://www.thecarburetorshop.com/Troubleshooting.htm

the other is an "articles" page (younger folks may call these blogs)

https://www.thecarburetorshop.com/Carbshop_articles.htm

Both of these answer questions which I have been asked a multitude of times.

Jon

 

Did you ever check to see if your vacuum gauge is also capable of reading fuel pressure?

 

If the carb plates are open to allow more air in to compensate for being fed excessive fuel, your boosters are dumping fuel into the engine. The mixture screws won't do anything as long as this is going on. So far I've noted that you don't know the fuel pressure, don't know if the float level is correct nor do you know if the throttle plates are open too far.

First, verify the fuel pressure and correct with a good regulator (Holley is what I use). Then pull the carb and check the throttle plate position. Adjust the plates until the mixture slots are a little more rectangular than square, then while counting the turns, back the throttle screw off until the throttle plates are closed. Now you know the measurement so you can reset the throttle plate position whenever you need to without pulling the carb. Reset the throttle plates back to slightly rectangular. While the carb is off check the float level and adjust if necessary. Adjust the idle mixture screws to about 1 1/2 turns out from gently seated. Replace the carb and test. You should be able to make minor adjustments to the idle speed and mixture once the engine is warmed up.

At this point if the carb can't be adjusted to an idle with fine tuning because you have to open the throttle plates past the transfer slots to get it to idle then you have a vacuum leak or other problems. These carbs are really simple and if the pressure is right, the float is right and the idle mixture and position is right, they run. Don't trust a vacuum gauge to expose a leak, spray something around the base of the carb to check for leaks. I've (carefully) used WD-40 and even misting water around the carb base.

 

All great advice, thank you . Much appreciated. I got myself a digital timing light that also displays the RPM at the same time. I set my idle speed low around 500, set the initial to roughly 7 degree , took the RPM's up to 2700 and slightly adjusted the distributor to line the timing mark with 0. The car ran much better and seemed really responsive on the throttle, but then overheated. Also the needle on the vaccuum gauge was in the "late timing ignition" part.

Other thing is I cant seem to get any reading at all on fuel pressure. Have fitted a gauge and its not even moving.

 

The overheating might have been it not having enough water in it. I will have to try it again with a full radiator

 

Any thoughts on this guy's theory on using manifold vaccum over ported?

 

Whats the in and out on these? Is the in opposite the adjuster? Or the gauge?

 

Adjusting screw on top, inlet on the bottom.

 

Aaah thanks..i just bought one. Are they ok to use with a standard mechanical pump? Do they have to be mounted a certain way up?

 

Yes, they're fine with a mechanical pump or electric pump. Mount with the adjustment screw up and the inlet at the bottom.

 

So installed a Holly 803 pressure regulator, but Still cannot get a reading on the gauge with regards to fuel pressure. Nothing at all. Its an oil filled gauge. The car runs ok.

I Set the initial timing at 7 degrees, taking the engine up to 2800 rpm and advancing the light to get 0 at TDC, timing light is reading 26 degree of total. I'd put the lighter springs in the distributor to get a bit more total advance but cannot undo the screws holding the rotor arm down. They've been tightened up by The Hulk i think. Unless they have nuts on the underside?

I had it set at 9 initial and was getting 28 total , this made it run a little on the warm side.

 

Lighter springs won't give you any more advance, they'll just give you the advance sooner. Still no pressure reading? Sounds like a fuel delivery issue. Have you done a pressure/volume check with the line pumping directly into an empty jug to see how it's pumping?

 

Hi, nope, not tried that. However, when I havent tightened up the fuel hoses properly whilst playing around with it, and I have started it up, it runs ok, but with even the slightest gaps where the connectioms arent quite tight enough, I get massive amounts of fuel pissing out. So there is plenty pumping through