do i need a vacuum pump?

[Camaro_Dave]

been asking around a little bit if i should run one with my setup. whats the pros and cons? never worked with one before so i have no idea.

408 sbc
1050 dominator
13.5:1
.753 .691 w/1.6 rr dur. @.050 281*in 292* ex 113 lsa
6" rod
in a heavy 74 camaro

[Zeke1]

I put one on to stop the leak's from the crank case pressure when squirting it and no one drop since I will never run with out one again and they seem to pick up about 10 to 30 horse depending on cube size

[Chris Uratchko]

The success level of a vacuum pump is all relative to the design of the ring package, health of the engine, application and how well the engine is sealed(to the outside world ie... gaskets/seals)

The big gains will be if you take advantage of the vacuum pumps ability by utilizing a very low tension ring package. In this case, the 30-40 horsepower claims out there, may be based on the fact that the ring package used, is just not capable of working well without a vacuum pump. They dyno it no pump, it's a sloppy mess in terms of ring seal, and then they stick the pump on it and it picks up 40 horsepower becuase now the rings are sealed. That's probably a more realistic viewpoint for the big hp claim folks.

But there is some hp in it regardless of the ring package, and with a nitrous engine it really improves oil control.

But that is a double edged sword. Now you have a condition where oil is being pulled from the cylinder, and that includes the pins. If you have a vacuum pump I always tell my guys to keep it unhooked unless you're making a pass... let the oil get up into the pins, let it soak the cylinders good... this has improved the pin bore wear DRAMATICALLY upon teardown, versus just leaving it connected all the time.

If this is a street deal, then put a regulator on it and keep the vacuum at just around a couple inchs.... that will be alright for street duty, and then when you get to the track crank the vacuum up to where you prefer to have it.

So to answer the question, do I recommend one? Always, but keep in mind what I'm suggesting for both a track car and street car.

Chris

[fn4ever1]

IS THERE ONE PUMP BETTER THAN ANOTHER? WHAT KIND OF PUMP WOULD YOU RECOMMEND?

[Chris Uratchko]

The Moroso is it in my book. Get a 4 vane regardless of anything.

[fn4ever1]

THANK YOU, JASON

[Camaro_Dave]

so how much should i run on the street and at the track? does it just depend on my setup?
i have heard that the moroso is the only way to go. only been researching it for a little bit but that seems to be the most popular.

[Chris Uratchko]

I stated my opinion for the street.... a couple inchs max. A regulator will hold that value regardless of rpm.

On the track, not knowing anything about your engine I would recommend 12 inchs max.

[Camaro_Dave]

ok sweet. thanks

[Camaro_Dave]

bringing this back from the dead....

looking into buying one real soon. you say buy the 4 vane? even if its a wet sump?
chris i think i've told you a little about my engine now. so should i just go ahead and buy the moroso 22641 pump? and what size pulley should i get?

also if i'm running a motor plate do i need to buy the brackets?

thanks a lot.



PS:
things are going to be moving a LOT smoother now...changed machine shops! the guy is 10 days out on machining so thats awesome. and me and my buddy measured stuff to prove to them a 6" wouldn't fit with a nitrous piston. gettin my block to the new shop monday!! and this guy actually has TONS of experience with nitrous applications and sbc's and stuff.

[swish]

What about a electric air pump off of a LS1?

[Chris Uratchko]

Excellent news Dave....

I'd rather have too much vacuum pump and back it down, than not have enough.... get the 4 vane.

[Camaro_Dave]

thanks chris. ill be gettin the 4 vane then.

[94guy]

what could i use to plug off my dipstick hole on the dart lil m block? my dipstick is loose in the block so i don't think it seals up.

[dmc_racing]

Try a freeze plug. I think either a 1/2 or 5/8 will fit ... The next time the motor is apart, you can tap it for a pipe plug. Just watch the shavings.