I'm at a loss and grabbing at straws...

I get that there is a 413 cam involved in the equation, and this is obviously a hotter grind than stock stage 1, but he is still furnishing a quadrajet in this example. I would have thought a good mechanical pump could keep up with that. I would call Mr. Ross and ask him if his modifications require an electric pump. Also, when you tried it on your friends car did he have an electric pump?

I would put the temporary guage on as some have already suggested. If it is delivery related, you maybe masking the root cause (pump, tank sock, line, filter) with the addition of an electric pump.

 

As others have said several times, verify sufficient fuel pressure all the way up the RPM scale before going any further. Well worth the effort to make a simple fuel pressure reading device that you can also use in the future.

 

LMAO

 

IMHO, if the engine is "feeling" like its hitting a rev limiter, THATS electrical, NOT fuel related.
Fuel related issues will make the engine "lay down" or "nose over" meaning a slow rpm drop.
Electrical is more "on/off/on/off, the cycle is VERY fast.

 

I tried to express that same idea earlier, lack of fuel won't rapidly miss and break up. It will just go flat and lay over till you lessen the demand then it will instantly pick back up......so when running down the road at wot you could hit that wall, lift slightly to maintain thst speed and give the system a second or two to recover some, then get back at it and gain speed above where you first ran out. Or if running through the rpms at 5/8 or 3/4 throttle you will run longer and more rpms than wot.

Valve float will break up at the same basic rpm every single time you get there.

Does this happen in 1st gear, 2nd,3rd?

 

I assume that if your coil/distributor requires 12v that you replaced or by passed the resistor wire.

 

If this happens in every gear at the same rpm, not matter how slowly or quickly you get to that rpm. That does not sound like its running out of fuel at all to me. And seeingbyou have had multiple different distributors and coiks and tested your parts in other cars those dont seem likely.

By chance do you have a different rpm source.....another tach or timing light with tach. I've also seen tachs go bad causing similar issue too.

Can you free rev your motor above 4500???? I know its sounds odd asking cause most won't try cause it sounds bad.....

 

I side with Ben ,as it could not be a fuel issue,unless the fuel pump is defective.My car went 11.70 with all original fuel pump and line.It might have gone faster with a bigger fuel line and pump,but I was happy the way it ran.I still have that original pump and racing a Hemy new car,it went past the legal limit with no problems.Bruno.

 

Try this..

Warm the engine up to operating temp, and then remove the Driver side valve cover.. remove the coil wire, turn the engine over, and watch the valves open and close.. Now quit cranking it..

If the valves that are on the cam lobes in the open position, quickly return to the closed position, then your looking at excessive lifter bleed down.

The 413 is a relatively quick cam lobe, and a very good set of lifters is required, or lifter failure in operation will produce the exact symptoms your describing. 4500 is a little early in the RPM, but I have seen tachs read off before, also seen it this early.

I am not worried about 10 year old valve springs.. just checked a set of springs I put on a motor in 2004, 600 HP flat tappet pump gas deal, with a big hydraulic cam.. they are fine, the expected 10% pressure loss we always see.

JW

 

Look at the hei distributor test on progression ignition website. Many of the stock and hp modules break up at 4500, too bad there's no one with a verifiable distributor machine around you

 

Be sure to turn the engine off after warming it up, before performing the rest of the steps.

 

There is a big difference between "new" parts and "known good".

Sorry this sounds very frustrating, but you have a lot of great advice advice in the above thread. Following it will resolve your issue. Good luck!