Thread: holley 4150 question

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hi everyone,
I have a 94 camaro with a carbed lt1, its all set up for the blow through supercharger but its not bolted on yet.i purchased the car the way it sits my question is, on the back of the carb is the pvc? port, i dont have a pvc only breathers in my valve covers, so do i cap off that port? and also the mallory 85 series distributer i have seems to have the vac advance but the the little port on the distributer is capped off the vac port on the front of the carb is capped also, shouldent that be hooked together with a vacume line? thanks in advance

Yes.. and.. Yes!

if the distributer has had the springs adjusted the vac. advance may not be working be a good idea to take the cap off and check why the vac. line is not hooked up.

blow threw ..you need to buy or make carb for blow threw . vac advance could be pinned or locked out the advance plate out as under boost you will not need it . your putting pressure threw carb you need to watch things that work under vacuum in a stock carb suck . now will be under pressure and blow. the vacuum advance lets you pull more timming past 35 with it working right its not hard to be at 45+ the advance on some dist can be set for how much it pulls or buy one you can adjust so when the engine is not under any load or much you can just it were it works the best . this is used to help the engine just off idle not much load to help run cool and better gas MPG? .the springs and weights in the dist will let the curve come in faster or slower there can be a limit to curve with a slot or bushing or stops using screws to stop the dist curve.race stuff many do not use vac advance and put faster springs in the dist to come in faster . blower boosted or Nos engines make boost or add cylinderpressure so they do not need alot of advance as if it comes in at the wrong time or will not drop out it will blow up the engine