Holley 520-1 system

[BUDDY]

OK, so I may be getting this system in a trade. The problem is, I can't find ANY information about it. The guy that has it says that he's had it for about 10 years, (which would mean it's analog), and it has never been out of the box.

My question(s) for you guys is, what would you do with it? Does anybody have any experience with a holley system this old? How'd it do? I would really like to get FI, but if it's going to be hard to get parts/support for it I'd have to pass.

Thanks in advance,
Buddy

 

[dyeager535]

I vaguely recall hearing that the Analog setups had real problems, and were, in essence, crap. You might try searching "analog" and "holley" here to see if any of the posts I seem to recall do indeed exist.

Cadillac used an analog EFI system back in the 70's (that 8-6-4 or whatever system) and the computing power simply wasn't there for it to work right.

 

[BUDDY]

I've heard that as well. I was just hoping to hear something different. On to the next idea.

Later,
Buddy

 

[Thunder]

Are you sure it is not a 502-1 system? or a 502-20 Check the numbers. The 502-1 is the basic analog holley Projection 650 cfm system. It has been around for many years. They work pretty good and you can get parts from GM and Holley. They are not a closed system(no 02 sensor) so require more tuning than newer systems. You adjust the fuel mixture with knobs on the control box. You have to retune for different elevations fuel ect. But its not hard.
The injectors on the older systems had problems with leaks but if they start leaking you can upgrade them to a newer better style.
The analog 520-1 systems have a rectangular control unit with a square top.
The later projection2D 502-20 is a digital controller has a rounded top. They can also be set up to run with a 02 sensor. They work better and have upgraded injectors. but you still tune them with knobs on the FMU. It is just simple basic FI.
hope this helps..