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-   -   Vacuum Pump Benefits (https://www.racingjunk.com/forums/showthread.php?t=18018)

JLSTOEC 08-07-2007 10:13 AM

Vacuum Pump Benefits
 
Im considering adding a vacuum pump to my 13:1 540 BBC and wondering what the benfit is other than about 20hp. Does it add to the longevity of the engine? Any manufacturer you can recommend? Have you guys noticed much of a difference in ET and MPH?

bjuice 08-07-2007 10:39 AM

the reason for the increase in HP is that is allows you to run a loser ring set up ( less friction)..the pump will help create a tighter seal by creating the vaccum...which results in greater HP...the longivity of the motor coming into play would be where it pulls out any excess oil ( blow by etc..) that would normally cause an engine to detonate..it WILL NOT with a vaccum pump in place..which results in longer engine life..DETONATION = ENGINE FAILURE..

be sure to run the vaccum pump relief valve...Moroso is the choice i would go with..

if there is any other benefit ..i have not heard of it...

thanks brian

curtisreed 08-07-2007 11:26 AM

We run our pumps mainly to pull excess moisture out of the engine. We run alcohol.

Curtis

billhendren 08-07-2007 02:55 PM

The other gain is in windage,in a perfect vacuum [which you cant get] there would be no friction from the crank rods and pistons moving through the air. if you don't think thats a lot just hang your hand out the window at 60 mph then imagine the crank at 8000 rpm.Bill

bjuice 08-07-2007 03:00 PM

good contrast Bill..everyone can relate to that one.

thanks brian

sg6085 08-07-2007 03:11 PM

One thing to keep in mind is the more vacume you pull the harder it will be on pin bushings. Thats the only down side i've seen.

topsportsman1 08-07-2007 03:15 PM


Originally Posted by billhendren
The other gain is in windage,in a perfect vacuum [which you cant get] there would be no friction from the crank rods and pistons moving through the air. if you don't think thats a lot just hang your hand out the window at 60 mph then imagine the crank at 8000 rpm.Bill

Good example Bill.

LMAO

topfool 08-09-2007 11:37 AM

From what I have heard it's not really adviseable to go much more than 14 inches of depression with the Vac pump, two reasons

1) the trade off at anything much more becomes negligable
2) it will have to be well sealed as at much more you may start to suck air past seals etc..

this was on an Austrailian touring car engine, small block ford, about 600 hp and 8000rpm (similar to nascar)


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