[njbloodline666]

does anyone know of a way to run vacuum advance with a predato carb? does anyone make an advance that works backwards, manifold vaccum =base timing, no vacuum = full advance..anything will be helpful, thanks?

 

[coldknock]

You could tee off the fitting behind the carb for manifold vacuum. A more consistent source would be to drill and tap the plenum chamber for a barbed pipe fitting.

Larry

 

[bracketeer]

vacuum port

I had the same problem but with power brakes using a victor jr intake. I bought a 1" carb spacer with a vacuum port for about 15 bucks.

 

[njbloodline666]

thanks guys, could anybody recommed a chevy ignition that i should run. i have 2 hei's sitting in my closet, one mechanical and vaccum advance, and the other is one of thoes electronicly controlled ones....im probably gonna have to go with the electronic one, could anyone recommend a good ignition box that will control my timing curve?

 

[coldknock]

We need more specific info on the engine, vehicle and what you're doing with the them.

Larry

 

[njbloodline666]

92 camaro, 383 stroker 10.5: compression edelbock performer rpm vortec manifold, short tube headers.4.56 lift int/ exh . a friend of mine got me a predator street carb for 50 bucks and i would like to use it. my only problem is not being able to run vacuum advance, unless i can figure a way to put a potentiomoter on the throttle arm i have noway of running a tps and therefore no way to run an electronic ignition. i was wondering if there is a way to create a ported vacuum source or if anyone makes a timing computer that creates a curve based on engine rpm and not sensor inputs. i have two distributors that i could use....the mechanical/ vac or the esc hei. i would like to use the esc, i know msd makes a timing computer, but i do not think it works with gm hei and it requires an msd ignition box, i would rather run a dui module so i can have a longer duration rather than an msd so i can run a wider gap. i havnt hooked an ignitionscope up to this motor because it is not running yet. but based on my other hei motor with a .065 gap i estimate that i can have a 3.5Kv firing line and a pretty long duration. it was a perfect burn and i do not want to spend the money on an msd box. ................. humm i might be able to get a ported vaccum source off of my exhaust i will try that

 

[DoubleVision]

If you use the electronic HEI you will have no advance period,
The computer controlled the spark timing, the module was designed to give a few degree`s of advance to limp home on if the computer went out, but in this case it would cause the engine to run hot and be a complete dog on power. Also I would check to make sure the hood will close with the predator as camaro`s don`t have much hood clearence.

 

[lluciano77]

Run the mechanical advance only distributor.

At 10.5:1 you will be detonating like mad with vacuum advance.

 

[njbloodline666]

ok thanks for the suggestions, you are right i will probably get a lot of detonation