Vacuum pump tech; free up that hidden horsepower

[joe117]

"Joe the math may/may not add up. Like every other mod people will just have to make their own decisions."

Well FE065, I'm still trying to get someone to tell me where the power comes from.

I'm not saying that FE065 is wrong. I just can't seem to find the answer to the question.
Where is the power gain coming from?

If it's oil drag on the crank, well, that's not a vacuum issue.
That's a dry sump issue.

If it's ring control, I haven't had it explained to me how the 15 inch vacuum is actually going to change anything.

If it'd blow by, then why wouldn't a good vent system be just as effective?
And how does pressure in the crankcase really inhibit the piston's up and down travel if the crankcase volume doesn't change?

I believe I've already shown that the crank isn't turning fast enough for aero drag to be very important. And by the way, my numbers do "add up".

Please, don't start telling me that I'm against everything.
I just believe that there must be some ball park numbers that we can use to see where the power could come from.

 

[FE 065]

Re:

Dry sumps don't allow this and **** up the oil from the valley and other parts of the engine.


Thanks for your input Tom. I'll admit to now knowing much about dry sump systems, other than thinking they got all of the return oil from sucking it (high vacuum) out of the shallow pan they use, rather also than sucking if from the valley or other areas of the engine. I just haven't seen anything on the plumbing, and can't imagine how they'd catch it anywhere but the pan..


Jason's wording seemed to indicate the HP gain wasn't directly associated with how the return oil was evacuated from the pan.


I'll have to check it out, I took a quick look at the article you pointed at. It does mention losses concerning oil on the crank.

I was under the assumption most of the oil still drained down to the pan in a dry sump, and could fall onto the crank on its' way to the pan. Which would leave alot of room for the primary HP gain from a dry sump system, when all is said and done, to be the high vacuum the multiple pumps create.


None the less, crankcase vacuum pumps are all the rage in motorsports today.


I'll have to read up on dry sumps

 

[Greg Good Cylinder Heads]

Record holding bikes and cars work to maintain 25 inches at top speed. The biggest gain from crankcase vacuum is keeping the top ring sealed to the ring land at peak power and peak rpm. If you cannot hold vacuum at rpm, then you have bad blowby, blowby past the top rings and, or too small of a pump. The flip side to crankcase vacuum is crankcase pressure....that is from poor top ring seal. Most racers think that reduction in ring drag would be the gain here, but in reality it is a way to keep precious combustion pressure on top of the piston....rather than in the pan. GB3

George, far be it from me to attempt to debate with a legend such as yourself, but if you don't mind, I'd like to discuss this subject with you a little. I'm a head porter by trade. I don't build a lot of engines with my own hands, but I work right alongside some really good engine builders. What I'm tryimg to say is that my credentials are far below yours on matters such as this, but I still try to learn. I'm intensely curious about things like ring seal. It's something that on the outside would appear to be straight forward and very simple, but in fact it is very complex. I'm not asking for you to devulge any trade secrets, but any discussion that might help me along in my evolution would be appreciated.

I'm of the opinion that high crankcase vacuum does help top ring seal. It can do nothing BUT help. I'm just not sold on the theory that it "significantly" helps top ring seal. Nor am I convinced from my experiences that top ring seal receives as much benefit as the oil ring does from crankcase vacuum. I remember when people first started experimenting with crankcase vacuum years ago, using 460 Ford emission pumps for the vacuum source. I saw several people put pumps on sealed up NHRA racing engines and not gain a thing on the dyno or the track. When they started reducing oil ring tension by pinching the expander down to levels which would cause the engine to oil severely without vacuum, and running backcut second rings (on the engines that had second rings), which further reduced ring drag, then they did see a very good gain. With no change to the top ring, just tension reducing on the oil and second rings, how could those gains be due to a better top ring seal?

It is my understanding that the oil ring does not really act very well as a scraper, but requires a small amount of combustion gas flow in order to operate correctly. Oil collects in the oil ring groove, combustion gases from above flow into the crankcase through the vents in the back of the oil ring groove, carrying the collected oil there with it to the pan. If we can increase the pressure differential from the area above the oil ring and the pan the oil ring can perform its job with less tension. Am I wrong about this?

I think having a top ring groove that maintains its shape under cylinder pressure and high piston temperature, having a second ring that does NOT trap leaked combustion gases between the top and second ring, and not being in detonation are pretty important to top ring seal. That's why I don't believe in gapless second rings. Not only do they hinder the top ring from sealing against the bottom of the groove, they halt gas flow which is critical for the oil ring to function. If an engine has a top ring problem how is application of vacuum going to cure it? I've never heard of vacuum masking or curing a problem with the top ring setup. I wish more engine builders ran blowby meters on their dynos. I live in Houston, and I think Nickens shop is the only one that has a blowby meter. My friends in Charlotte use them religiously.

These Viper engines we're discussing only turn about 6000 rpm. They don't suffer from ring flutter like a 10,000 rpm Comp Eliminator engine, or a 14,000 rpm Pro Stock bike in your case. They don't need tight side clearance to halt flutter, anodized top ring grooves to prevent the rings from galling in the grooves, and gas ports.

I enjoy reading your comments. I have the audio tapes from a Superflow Convention where you gave a seminar back in the early 90's. I still have the printed material around here somewhere that was passed out to the audience there as well. I sure would have liked to have seen that clutch graph that you withheld from us.

I do heads for Johnny Mancuso. I think you might know him. He runs in Top Fuel Harley. That's about the extent of my motorcycle involvement.

Regards,

Greg

 

[Russ M]

Re: Vacuum pump tech; free up that hidden horsepower

FE 065,

Good post!

Too bad RussM is such jealous weasel, he's just upset that you thought of this before he did. Kind of reminds me of another thread where RussM failed to think of something first........

Excuse me?

Are you refering to the failed Vipair product? Which part would I be jealous of? The part where the manufacturer ripped of countless viper owners, or the part where he was proven to be a down right liar?

Russ,

FE 065 posted the info to inform viper owners of something that may help them, he did not sign up to be abused or berated by a self serving individual such as yourself. Your behaviour is childish and unnecessary.

RE the Vipair, I believe you said to me on the phone " I didn't know how to do a proper dyno run for this, you should have given me instructions on how to do it!" , the only liar here is you Russ.

You Sir are a joke,

From my monitor it looks like FE 065 is trying to sell a product that he is claiming will gain 25rwhp. All I asked was for a simple dyno test to show his gains, its not too much to ask.

YOUR Vipair,

Dyno and redyno etc... 0 gains, and mostly looses. Did you know that? Course you did but you choose to keep your results to yourself, because if you posted results showing no gain you would not be able to rip off the people that you did.


PS. You are the one making money under false claims, but I am the one being "SELF SERVING". Right, and exactly how am I doing this? What is it that I am selling again? Try again.

 

[George Bryce]

Hi Greg, I agree with you on the 2nd ring stuff. I think you hit it right on the head. The gains with lots of vacuum in the crankcase don't show at low piston speeds. It shows when the ring is going so fast that it comes loose when the piston stops, at tdc. That is why lighter rings stay sealed longer into the rev range. Negative psi under the ring hangs on to it longer too. Our Viper rings are very heavy and our stroke is long too. My stroke is even longer . So....my rings go out of control even earlier in each gear than a stocker. There are tricks in our trade to help seal it up longer. When I say longer I mean as we sweep through the gear....we will lose ring seal at some rpm.......I hope mine stays sealed longer than yours. The biggest gains are at rpm after or past peak HP. Most of us don't dyno very far past peak.....but , we all run, way past peak. When our engines puke oil out of the breathers, it is when we over rev or run near max rpm. If we can pull lots of negative psi in the pan, we can rev a lil further before we puke some oil......GB3

 

[Greg Good Cylinder Heads]

Russ, it's traditional to test an item such as a hood scoop or airbox at the track, when the car is at speed. A dyno will not give you a complete picture of the gain any type of scoop or airbox can offer, even with a fan blowing into it.

I'm not wanting to get in the middle of any argument you may have with Steve, just pointing out what is the norm.

 

[Greg Good Cylinder Heads]

George, I agree with everything in your last post. I see your point about your engines piston speed. It's up there.

More and more engine builders I see are paying attention to how abruptly the engine falls of after peak power. The engines that maintain good numbers well past the engines peak run better at the track and are more flexible on gearing choices than the engines that nosedive after peak power.

Most "good" engine builders I know have their valvetrain and ring packages under control. Where I see a lot of them go wrong is not having enough exhaust flow. That, and opening the intake valve too early, resulting in a lot of exhaust gas entering the intake port during the initial part of overlap. Exhaust reversion will stop an engine dead. I'm a big fan of exhaust flow, and want to get the residual pressure in the cylinder as low as possible when the intake valve opens. I argue with a lot of engine builders that don't put much thought into exhaust flow.

 

[George Bryce]

I agree Greg, on exhaust flow. The biggest gains have come from intake work in the last 10 years or so. If you dont rev your engine past peak power on the dyno ...you will not see the gains from all of the ex work. Pro stock cars and bikes rev 1000 rpm past peak power on the track. Most of us have no idea how much power we have at 9,800 to 10,000 on a 500 inch V8. Most of us have very close to the same power, at peak......but the one that has more after peak will out run you bad. On our 92 inch 4 cylinder we only gain 5 or 6 HP at peak with 25 inches of vacuum but it goes a whole tenth quicker on the track.....because we over rev every gear. We may gain 15 or 20 HP 500 or 600 rpm past peak. Oh yeah this with only 310 HP. Happy hunting, GB3

 

[Greg Good Cylinder Heads]

Yeah, that's right in line with what I've witnessed.

Nice talking with you.

Greg

 

[George Bryce]

Oh by the way, we, us Viper owners, have very old timey ring tech....about 40 years old in our cars. Our rings are heavy, industrial strength, loose in the ring lands, and we do have a lot of blow by. I do think that a big pump will make us go faster. My 542 stroker has lots of piston and ring speed at shift rpm. I turn the car 6300 to 6400 rpm in 1st. I also hit the limiter in 4th ******* the drag strip. I am going back to my 3.31 sprocket in the rear soon. One day, Greg I want to tell you about our INDY low qualifier 2 cylinder with 5.125 bore with a 2.7 intake valve.........GB3

 

[Greg Good Cylinder Heads]

Oh my GAWD, I didn't know you had switched over to the dark side. Get out of town! I need to gossip on the phone more and keep up with the skinny on things.

Yeah, I'd like to hear some stories sometime. 2.7 inch valve, eh? That's gotta be good for WAY over 600 cfm. 50 degree valve job, no doubt.

Keep up the good work.

 

[Hostile]

George
I think I may have seen that bike at Earlville Iowa in July at a test and tune.

Skeeter

 

[99 R/T 10]

I am one of those that are on the fence on something like this. I just bought a puke can to catch any oil that may get blown out, but if a vaccume system would be better(still looking for a link, I seached for one too) convince me with some dyno numbers.

Edit: Pictures please

 

[ROCKET62]

FE065:

Thanks for the interesting post. Unlike others, I did not get the feeling like you were trying to sell us anything, rather raise a question about a potential source for a little extra horsepower with little effort required.

How did you plumb your system in? Would this also potentially help with small oil leaks?

Thanks.

 

[FE 065]

FE065:

Thanks for the interesting post. Unlike others, I did not get the feeling like you were trying to sell us anything, rather raise a question about a potential source for a little extra horsepower with little effort required.

How did you plumb your system in? Would this also potentially help with small oil leaks?

Thanks.

Stainless Steel Brakes imports (I guess) the pump I use for cars without enough engine vacuum to evacuate a power brake booster.
It's caught on as a simply installed alternative to a belt driven pump. The local speed shop Ramchargers sells it, as does either Jegs or Summitt, I forget which.



I don't have any to sell, sorry. Unfortunately for me my dyno timetable for this and other mods is not until next year when I get the new 18" M/T Drag Radials and can test changes both on the dyno and at the strip during the same week to satisfy my own curiousity; not anyone's demands.



It may turn out, as other's have found, that more than 8 in/Hg at WOT may be needed to realize maximum gains, requiring a change to a belt driven pump.



My electric vacuum pump attaches to the engine via the OEM hose coming from under the intake manifold on my 2002. The discharge hose from the pump runs along the top of the crossmember to the driver's side and into the aluminum catch can. I have an ON/OFF switch in my lower steering column cover.

 

[FE 065]

Re: Vacuum pump tech; free up that hidden horsepower

From my monitor it looks like FE 065 is trying to sell a product that he is claiming will gain 25rwhp. All I asked was for a simple dyno test to show his gains, its not too much to ask. What is it that I am selling again? Try again.

It would appear that you are trying to sell that 15hp for $3000 AEM unit that you're posting on every forum you can find. Going to an expensive new stand alone computer is kind of an out-of-sequence third step for someone who'd only added a catback and tubes beforehand isn't it? People do make big leaps at times, but not very often.


Hot Rod magazine did the research on the 381ci SBC, and published the gains. That engine used a belt driven pump at 10 in/Hg. If you'd subscribe to some of those magazines for like $9/yr each you'd already know about vacuum pumps.


I don't have any to sell. It's just that simple.

 

[Greg Good Cylinder Heads]

Re: Vacuum pump tech; free up that hidden horsepower

FE, don't worry, you know you're right. Pulling a vacuum on a crankcase has been around for a good while, and isn't going anywhere soon.

I'm just wondering how much a stock Viper only turning 6000 rpm with high tension rings is going to gain.

It can't hurt though, that's for sure.

 

[Russ M]

Re: Vacuum pump tech; free up that hidden horsepower

From my monitor it looks like FE 065 is trying to sell a product that he is claiming will gain 25rwhp. All I asked was for a simple dyno test to show his gains, its not too much to ask. What is it that I am selling again? Try again.

It would appear that you are trying to sell that 15hp for $3000 AEM unit that you're posting on every forum you can find. Going to an expensive new stand alone computer is kind of an out-of-sequence third step for someone who'd only added a catback and tubes beforehand isn't it? People do make big leaps at times, but not very often.


Hot Rod magazine did the research on the 381ci SBC, and published the gains. That engine used a belt driven pump at 10 in/Hg. If you'd subscribe to some of those magazines for like $9/yr each you'd already know about vacuum pumps.


I don't have any to sell. It's just that simple.

If you are saying that I own AEM, boy do I wish.

All I am doing is posting verified and tested results for a product, nothing more and nothing less. As always in the past the money spent on testing the product was all mine, and I have not made 1 cent of any of it.

I am not your average car owner, my goal is to make my cars run better than stock. Knowing what speed density systems are like, it would be going against all I believe if I left the fuel/timing system stock. When all the factory ECU can do is look at 02 sensors and give almost meaningless compensation.

I am very familiar with the benefits of Vacuum in the crank case, but all the ones I have seen on the dyno were as a result of a dry sump oil system. And the gains achieved were not from just Vacuum alone.

As I said before, if you build it and it works I will be one happy camper and will be glad to run it on my car.

PS. One thing you are forgeting is, on very hi Vacuum coditions as you are trying to achieve gaskets can get sucked in, along with oil seals. On my dry sump race engines, we install certain items backwards cause if you do not, they will get damaged.

 

[joe117]

Re: Vacuum pump tech; free up that hidden horsepower

I agree with RussM,
How much of the gain is due to dry sump and how much is from vacuum?

And I also agree with Greg,
Is a vacuum system going to do anything for a 6000rpm street engine?

Of course, if the electric pump gives a hand full of hp, it will be worth it to more than a few folks.
And as Russ says, a few dyno runs with the pump switch on and off will tell the story.

By the way, I couldn't find a way to read more of the HotRod article. Was there more than the first page with the picture?

 

[VIPER D]

Can these pumps work on supercharged cars?? More boost needs more vacume?

vd..

 

[George Bryce]

Re: Vacuum pump tech; free up that hidden horsepower

Hey guys, I was trying to show some different veiwpoints on how and why on the crankcase psi + and - issues. Just fyi, My 542 @ 6300 has the same piston speed as a typical small block Chevy does at 7700. Stroke x rpm divided by 6 = average piston speed. More of it gives more sealing trouble. More so with our "low rpm OE style" ring combos.
Very interesting subject. It has been around forever. Back in the old days we would just hook the valve cover breathers to the collectors in our headers and go race. We tested this set up recently and found 5 inches of vacuum from it. GB3

 

[AJT]

Re: Vacuum pump tech; free up that hidden horsepower

Greg you have a PM

 

[Torquemonster]

Russ, it's traditional to test an item such as a hood scoop or airbox at the track, when the car is at speed. A dyno will not give you a complete picture of the gain any type of scoop or airbox can offer, even with a fan blowing into it.

I'm not wanting to get in the middle of any argument you may have with Steve, just pointing out what is the norm.

Greg great point - and like you - I couldn't care about the outcome as I have no vested interest. However, that issue got personal and so those two will never agree. Your excellent point has been made several times (by me at least twice if not 3 times - and by others) - and nobody except a few racers (hahahah) bothered to do the only thing that can really test it - go fast!!

At least one of those racers posted results - they picked up a few mph on a the straights - enough to make the gains claimed - but only at high speed.... imagine that

Trying to test gains of a cold air system on a dyno is like a toddler trying to take a constipated dump sitting on a flat stool - aint't gonna happen. But the experts can argue all that in their own thread - not hyjack this one

 

[Torquemonster]

Re: Vacuum pump tech; free up that hidden horsepower

Greg - great points you made and also great points made by George.... I love this stuff It helps real knowledge advance on the forum and reading a lot between the lines on what was NOT said - it is great to know we have a couple of people this talented on the forum to comment.

I have some head projects coming up Greg and I'd like to talk to you about those - your comments on this forum lead me to believe that you know more about creating port flow and velocity than just getting peak flow and making them look pretty.... which BTW your heads are some fo the best looking out there!

George - very few engine builders know anything about the kind of ring prep you alluded to - I'm confident we are on the same page on this one - and that tells me a lot about the level of engines you have been involved with. Not because I consider myself up there - I am not - I'm just a student - but I know the level where that knowledge comes from...

The guy I learned about race ring prep from has made over 1000hp from a 388 small block Ford on race gas and carbs, 980 on 1 carb. Not sure if that is a world record for the Ford SB - but it's dang close ;-) (runs 7.0 in A/D, may have hit a high 6 by now) Thanks for sharing your knowledge here - BTW - I take it you are running some form of vacuum pump (or equivalent) on your LPE engine?

I can see an advantage on boosted Viper engines and on big strokers for different reasons... one to combat excessive boost pressurising the crankcase via blow by and affecting ring seal, the other to combat blow-by caused by excessive piston speeds that also reduce ring seal.

I see little advantage in a vacuum pump for a stock sized naturally aspirated V10 that does not see more than 6000rpm.... unless you are getting crank windage. Running vacuum pumps can also have sealing problems - that has to be addressed or the whole point is wasted.

A maintenance free way of oil control is in having perfectly round, nice flat rings that seal well and, in controlling oil drain back via various means already mentioned in another post, plus (for a select few) via additional "tricks of the trade" which is why people pay the big money to go to the top engine builders

 

[Marv S]

Re: Vacuum pump tech; free up that hidden horsepower

I think Al Box (Fat Albert's Motorsports in Phoenix602-402-7692) has been working this or something similar with his Viper.

 

[joe117]

Re: Vacuum pump tech; free up that hidden horsepower

Barry,
"Trying to test gains of a cold air system on a dyno is like a toddler trying to take a constipated dump sitting on a flat stool"

Also not to hijack or start any of that over.....

But remember, the guys selling the Vipair claimed street speed SOTP and dyno gains.

I think that was the problem that some folks had with their claims.

OK, I promise, no more Vipair talk.

 

[HOdbleFman]

Re: Vacuum pump tech; free up that hidden horsepower

It's a conspiracy.

 

[George Bryce]

Re: Vacuum pump tech; free up that hidden horsepower

Torqueman, Greg, all you good guys of the Viper nation, I want to say, I don't have a pump on mine yet...but I want one. I think any Viper will run better with a big enough one....I do not know which is the right one yet. I think if you did like one of our brethren and put it on a switch and turn it on when you race. I think it will work great. Please remember a couple of things.....the higher you rev it the more it helps....and....if it don't cost much, it probably is worth about as much as it cost. On our NHRA bike, we pump it down to 25 inches at the staging beams....then switch it off in the shut down.
Seems to me that you would need to have it vent well when you don't use it. Maybe unhook it for daily use? GB3

 

[GR8_ASP]

Re: Vacuum pump tech; free up that hidden horsepower

I really don't want to enter the fray but here is a thought. That is that any leakage into the engine will be unfiltered air and will probably be entering through rotational seals, which fare very poorly with any kind of dirt (not that it does the oil any good either). Reversing the seals may also be problematic as the seal lead will now be trying to pump oil out of the engine, and the added pressure due to the vacuum may help it pump effectively. If you run a high vacuum you need to have seals designed for that condition.

 

[Jack B]

Re: Vacuum pump tech; free up that hidden horsepower

I don't know if it was brought up, however, in the early stage of Roe installations, due to the blow-by someone added a vacuum system and they had to back off the vacuum level because the engine started making internal noises. He reduced the vacuum and the system worked fine. It appears the vacuum at some level started to redirect the natural path of gravity lubrication.