Will a vacuum pump increase how much the piston rings wear into the cylinder bores?
Phil

 

I wouldn't think so, unless your pulling like 24+ inches at any point in time

 

yes it can if your not getting proper lubrication. a dry sump oil system should be used with anything over 16" vacuum IMO. too much vacuum on a wet sump will cause excessive wear on the oil pump and anything that needs lubrication. the vacuum pumps negative pressure will eventually prevent the oil from pulling through the oil pump, both systems end up playing tug of war with the oil.

 

I posted two articles on this a while back.
http://www.dragstuff.com/techarticles/vacuum-pumps.html
http://www.rehermorrison.com/techTalk/05c.htm

 

Well while this may be true ,I don't know, the stocker was pulling 20+ and I don't think they would do anything that would adversly affect longevity etc... With that said I would be curious about some factual info on it. I am just going off a Autometer gauge so I don't know how acurate they are and if the vacum reading are in LBS or inches of mercury (?) or what ever. Hmm just kinda got me curious now.

 

How so? I cant see this happening since the reduced pressure will be throughout the entire engine. Youre not pumping the oil to the outside of the motor, where you would be pumping against standard atmospheric pressure.

 

I asked a similar question here. https://ls1tech.com/forums/advanced-engineering-tech/449946-why-negative-crankcase-pressure-hard-rod-bearings.html

 

When running a vacuum pump it does cause a lubrication issue. What typical happens is most people pull from the valve cover and as the engine runs the oil that is pumped to the top of the motor stays there because the pump holds it there. Over small time you have 6 quarts of oil floating around the engine and can not return to the bottom of the pan. It has the same effect as you see in the space shuttle when you see liquids float. Dry sump is the primary way to do this as most of those pumps will pull enough vacuum and the pump is sucking the oil up and returning to the tank to be reused. You can run a vacuum pump on an external oil pump (no dry sump, oil stays in motor) But there is a trick to making it work and we pull 22" from idle to 10000 rpm. Most engines will not gain power from vacuum pumps unless you pull 12" and at 12" is when you experience these problems. As for the ring issue it is hard to say because I have never run a vacuum pump on the street just in extreme drag cars. I would think that it would have the same effect as a gas port on the top and gas ports wear on the street. In most cases I try to talk people out of running a vacuum pump because there are to many risk for the pay off unless you dry sump.