Zoomies with evac system

September 07, 2025, 09:35 AM

wideopen231

Anyone running zoomies run evac system? Was told by former member that 5 and 8 worked best,

Wondering if any have dumped vacuum pump and went to pan evac setup? If so see any performance difference?

Thinking less crap to break. Remove pump, belt drive pulley, catch can, two hoses. More room for working on engine. Hell of lot easier to get ratchet on front for doing valves. Also easier to get into oberg to clean filter. Plus how much power am I really gaining without proper ring setup to maximize setup?

September 07, 2025, 06:56 PM

Curly1

My opinion total waste of time. On Zoomies it will not matter what tube you put it in because each cylinder is about the same and separate from all others unlike collectors.
You will not pull much if any vacuum like that. And even if you could get 3 or 4 inches of vacuum that is not enough to help much.

I run 16" to 22" inches of vacuum on my motors. Do you even know how much vacuum you are pulling? Most people do not know. They are difficult to get sealed up good but worth it when you do and start pulling good vacuum.

In fact you will probably make more horsepower with collectors than Zoomies. So if your goal is horsepower dump the Zoomies and get collector headers and vacuum pump. Pick up 50 or 60 Hp. Not only that the collectors will make more torque and mid range power so the ET will more than just the power difference alone.

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September 07, 2025, 11:30 PM

rusty

quote:
Anyone running zoomies run evac system? Was told by former member that 5 and 8 worked best,

what are you talking about 5 & 8 if o2 sensors i run zoomies and have them on 5&6.the better way is to install a sniffer tube tied to all tubes.i do currently use a vacume pump and carry aound 8 to 9 inches in 1/4

September 08, 2025, 06:35 AM

Dave Koehler

The vacupan deal was never about vacuum numbers.
It was more about not having thin aluminum valve covers leak everywhere.
It's a siphon deal via the exhaust speeding by the vac tube. It ceases to be useful above 500 cubes.

WO231, If you are not making back to back to back laps would not a puke tank suffice for your needs?

FWIW I haven't seen a lot of B****in about vacuum pump reliability.
They are pretty much a must have with modern skinny ring widths and diesel range compression ratios.

September 08, 2025, 07:27 AM

Curly1

quote:
Originally posted by rusty:
quote:
Anyone running zoomies run evac system? Was told by former member that 5 and 8 worked best,

what are you talking about 5 & 8 if o2 sensors i run zoomies and have them on 5&6.the better way is to install a sniffer tube tied to all tubes.i do currently use a vacume pump and carry aound 8 to 9 inches in 1/4

I believe he is talking about putting the old style crankcase one way check valves in Zoomie pipes 5 and 8.

( I do not think he is talking about O2 sensors)

Dave Koehler, I absolutely agree with you on vacuum pump and vacupan deal. The vacupan deal is nothing more than a one way pressure valve to let some crankcase pressure out. Do not think it can pull much if any vacuum. Only way I would consider using vacupan type deal is if rules stated you can not use a vacuum pump.
The vacuum pump makes horsepower and stops oil leaks when motor is sealed up good.