Diehard, REELAV8R, and 69427 are correct. This is one of the benefits of using a dry sump oiling system. It creates a vacuum while scavenging oil.

To the OP - regarding your low vacuum/power brake issue. If you have an electric fuel pump you can run a hose off the mechanical fuel pump inlet for vacuum. It should provide enough vacuum for brakes and headlights.

I will answer both of your questions.

First I have not quantified the losses or gains, nor do I need to.

Logic dictates that it takes more energy for me to walk up hill vs flat ground. Even more energy to run up said hill. And still more if I run up that hill with a 40 pound pack on my back.
Logic also dictates that since it takes more energy to walk up hill that I will burn more calories vs flat ground. And will burn still more calories running up that hill. And still more running with the pack on.
No arguments right? I didn't quantify the amount of energy used or calories burned, but few would argue the point.

More air in the crank case is more mass to be moved. To move more mass takes more energy. If I try to move that mass very quickly it takes even more energy.
So if I can evacuate some of that mass (air/combustion byproducts) then there is less resistance for crank rotation and piston movement.
If I have less mass to move at very high RPM then I have removed even more resistance to the engines rotation. This lack of resistance is power now available at the crank vs having to move the mass about.

Second;
Although a PCV system has a check valve in the PCV valve it allows flow in the direction of the carb. But that is only one source of contamination. On the other end of the PCV system is a hose from your valve cover to the air cleaner.
So now at large throttle openings, vacuum is nil, crankcase is experiencing significant pressure due to blowby, the pressure has to go somewhere.
The hose that was an was previously an intake for the PCV is now an exhaust. Right into the air cleaner and into the intake system via the carb. Intake contamination is the result.

I quit reading when you started running up and down the hill.

Theory is a wonderful thing that sometimes has no application to reality.

A bogus theory that these dudes have bought into...and now believe is fact.

Vacuum plays the roll of holding the valve open at Idle and high manifold vacuum situations.

At WOT it is the pistons movement that forces the crank case gasses to flow around the crank case and up and out of the PCV system.

The point being made is a vacuum pump is more efficient , removes the task of the engine evacuating it self and because of that you gain lost HP normally used to expel crank case gasses.

I hope that covers it ..


I can see you hate analogizes .. But go peddle your bike to go 8mph. Now add a motor to it and peddle to maintain 8mph . which way is easier ?

Point out where I'm wrong.

I'll wait.

You are so lacking knowledge on this subject it would benefit all of us if you just stop posting about it.

I mean this in as polite a way as possible

You will not take the time to learn and are starting to sound like TBTR ... You have an idea and as wrong as it is you just cant let it go..

Please let it go

Yeah, especially irrelevant analogies.

Ok lets try this one.

Your the smartest person ever to post on this forum. You know it all and every question you ask and every point you make is inspiring us all to want to be just like you. I find stroking your ego and superiority oddly satisfying even more so then facts and proven results.

it is on this basis I am happy to have the chance to post on the same pages you post. Even if facts dispute your questions and claims i know deep down all that matters is giving you our total attention.

You have mine and anyone else who has read this , now please tell us how a vacuum pump is useless and can not add power to a combustion engine and a PCV valve does a better job.

You're the one making claims of a 25 hp increase. You can spout off all of the weak analogies and theories that you want but they wont prove your point. It's up to you to back up your statements.

I said up to 25hp .

I will also state up to 25hp with oil pans as well

This is HP the engine already has but is being used to perform tasks that when eliminated from its list of things to do end up back on the crank shaft.

Take some time research it .. I am not going to debate you because you have zero counter points except to argue.

This is a good discussion. Lets keep try to keep it civil guys.

Bashcraft; You like quantification for proof. Here is some for you to digest.

The number of HP's is going to vary based on many factors. so in diehards case he may have seen 25 HP. That may be on a 500 HP engine. On the video I posted it was 20 HP, which represents 4.3% of the previous HP. That's excess HP. Meaning in excess of the HP being used by the vacuum pump itself.
So if you evacuate the crank case without the loss of powering the vacuum pump it would be greater than 4.3% gain, at least at 7500 RPM.
Less RPM would be less gain. Bigger pistons, bigger crank, and bigger displacement would be bigger gain. Forced induction and N2O would also see a bigger gain.

I may have missed where these guys started talking about "theory". All I have read is scientific fact. Air has mass. An object with mass requires energy to move. Eliminate all or some of that mass, regain some energy. Those are all proven statements.

I can agree that some theories can be just that, a theory, with no practical application. We are not talking about theory here though.

I agree with this completely, the gain is arbitrary, the higher the power made by the engine the higher the gain, all engines leak some past the rings and the larger the explosion in the cylinder the larger the loss. Most engines gain peak efficiency at horse powers peak which in most cases is above 5k rpm and usually above 6k. The amount of times a second multiplied by the amount of Gass ecscaping every revolution is like compound interest, it builds up so it takes being above atmospheric pressure to to force it's way out of the engine, that pressure acts against the piston and would build faster at higher rpm, faster than the engine could expel the gas, how ever small or large that pressure is takes away from power. On a bone stock engine losses 1 maybe 2 horse at peak rpm, on a 7500 rpm engine could see as much 40 horse a 7500 rpm. This is not mention that pressure in the crank case usually causes oil leaks. All engine benefit from a slight vacuum with the escaped gasses being replaced by fresh air so that it sweeps the engine clean. The only proof I've got toward this is search for vacuum pump on yellowbullet.com

PCV only works when you have a motor in a vacuum operating range. Not at all when a motor will have max blow by at wide throttle openings. You also have the dilution problems with setting up a carbs to have linear A/F ratios.

PCV is the worst option for performance.

The next best is large volume breather setups. You can achieve very little crank case pressure even at WOT

The next best which are actual power adders and can make sure that vacuum operated systems like the brakes and lights work fine are the electrical or belt driven vacuum pumps. significant free HP like Diehard stated when you actually have a vacuum on the crank case.

The best is the dry sump oiling which creates a high vacuum on the crank case. Most race cars use a air bleed system to limit the CC vacuum level

Well, here's a little tidbit for you, fellas. I ran the video posted above and, guess what? The video results are 'doctored'!! You can check it for yourselves:

Play the video and watch the end of the second engine run. Before the final table of results are shown, put your cursor over the "Pause" button and get ready to hit it. When the final screen of numbers shows on the dyno readout, it will show the entire group of numbers....then pan down to read the final output. Just before that point, PAUSE the screen and read the HP number at 7500 rpm. IT READS 449 HP!!! Now, if you continue the video, it pans down to show ONLY the HP number. And what do you see??? Magically, the 449 HP value NOW SHOWS 481 HP!!

How can this be? Well this video is actually trying to sell you snake-oil...so they doctored the last screen in the dyno run to CHANGE the HP output to something higher then they actually got BY THEIR OWN COMPUTER SCREEN DATA...before it was doctored. (between time 2:32 and time 2:33) You can actually see the obvious difference in the images.

Another case of trying to "prove" something that works when it really doesn't. Sorry guys, to burst your bubble on this useless piece of hardware. But, you can spend all the money you want on FREE energy. People have done it for many years--only to make the shysters rich and their engines heavier.

Oh, BTW, you can apologize to me for spouting trash when I only tried to show your the error in your logic. But, I won't hold my breath. Folks like you just keep on 'trashing', even though you're proven wrong.

7t1vette you must also think we never landed on the moon and that 9/11 was an inside job. LMAO ..

No one said free hp except you.

And like TBTR you just cant deal with being wrong .. Sad

Check the video, dumbass.

I'm just a bystander reading but I will say every time the name calling and tantrum behavior comes out the point gets lost and statements become less credible regardless of whos making them. Just saying ..

It sure seems now that the pumps can help now even though it was stated in the beginning of the thread that the notion was myth and that was backed up with an incorrect theory about one piston equally displacing another without any type of resistance... (and that was not even considering the blowby pressure) That theory has been proven to not follow the rules of physics in this application and intelligent explanations of this have been given by at least a few people.. Yet the argument now seems to have now changed to attack the "25HP" statement, to save face?

I dont know any of you from Adam but I'm just telling it like it plays out here that egos have taken over and the point of discussion has become a one way argument with one side demanding more proof again and again than just physics alone when they have shown absolutely no proof themselves that their believe that it doesnt work has any merit? That video may have been doctored to exaggerate things to sell a product.. but it doesnt mean the science behind it is all bogus someone could have done a poor job putting the video together or their could have been multiple runs of the same test and maybe they showed the best examples of each to show the best case scenerio? lots of possibilities.
Just my 2 cent although im sure its not appreciated by everyone... Sorry for that

This reminds me of the *** I made of myself when I got all bent out of shape about a members claims about their homemade CAI... turns out I read the estimated HP gains incorrectly and based my negative comments made on a few thread off of that incorrect data I had to suck it up and eat crow.
Point is we are all wrong at times..