Driller looking for 1-1/2 mph

MonsterMark

MonsterMark

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JP mentioned on another board that he was 1-1/2 mph shy on his trap speed in the 1/4 mile. I've been playing with crank vents recently on a Nascar dyno and we found 4 hp the Nascar boys could never find. We had 40 guys packed into a little dyno room for the test. If you never heard a Nascar motor wind up to 9100 rpm's, let me tell you, it is deafening. And what was truly unbelievable is these motors, running up the rpms from 3000 to 9000 rpm never even quiver. A glass of water wouldn't even rippel the surface....with NO engine mounts, just a cradle. Fantastic!

In the end, one of the guys thought it might be good for as much as 10 hp on a worn motor, or 6-8 hp on a 'dart' type block. The negative pressure in the crank sucks the rings out and makes them seal alot better. I am playing with them on my Mark right now. I pulled soo much negative pressure the motor was wheezing thru the front crank seal. Unscrewing the oil cap was unreal. Pooof. Tons of suction. I would say almost as much as a wetvac. 2 vents (one in each valve cover) created so much negative pressure in the crank that it scared me. I need to get a read on oil pressure and A/F before I go further. However, the initial 'seat of the pants' felt like there was a good 6-8 hp there. Should have some dyno numbers next week after some Xcal2 tweaking. Might be the answer JP is looking for in the quarter. I get my GTech Pro SS in a couple of days so I will at least get a 'close' read on Hp and Tq numbers before the dyno session. Plus, these puppies are easy to install. I am working on a kit if things pan out.
 
Sergmark said:
Bryan,
Sounds similar to the old days when the covers had breathers :eek: :eek:
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thats what i was thinking....but now the pcv changes that...getting more vacume the higher the velocity is in the intake.
 
Dominus said:
So what exactly are we talking about here? Basic open vents? Vacuum pumps?
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One-way check valve that acts as a vacuum pump. You keep the PCV.

We're still playing with this. It is not new, just a new application for this kind of valve. My problem at this point is it creates too much vacuum. I'm also concerned about the oil pump. Should get that info this week. In talking to the dyno tech, they said guys spend $2000 to dry sump their motor. This will do it for a tiny fraction of the cost.

I brought up the topic to see if anybody had any info on doing this. Until I get my own dyno results, I'll remain safely skeptical myself. There is cheap power to be made it seems, just how to do it safely is the big concern.
 
Moroso offers a kit for header style air scavaging thru the valve cover, This has been very successful thru the years in providing better ring sealing. Dry sumps actually are used for some different reasons (Increase oil capacity, cooling, reduced oil on crankshaft etc.) All these are tricks that the top engine builders have been employing for many years.
 
Yeah, but the header scavenging systems do not work very well of a muffler car.

The one way valve is very interesting. If ti delivers vacuum then, it should be just fine.

You should install a vacuum regulator from somebody like Moroso or Goza in the cam cover. Automatically regulates the crankcase vacuum. Nothing more, nothing less.

DO you have a catch can system to prevent accumulation of crankcase oil? With normal vane vacuum pumps, the oil misting is so heavy, that oil misting is actually their only form of lubrication! :eek:
 
Dominus said:
You should install a vacuum regulator from somebody like Moroso or Goza in the cam cover. Automatically regulates the crankcase vacuum. Nothing more, nothing less.

DO you have a catch can system to prevent accumulation of crankcase oil?
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That is the problem at this point. We are holding 20 lbs of negative pressure at idle. The motor has to breath thru the front crank seal. The vaccuum is unreal is JP can attest. The problem we have is controlling the vacuum at idle. We ran the same vents on a Nascar motor and held a -3 lbs of vaccuum at 9100 rpm. They work. They just can't be controlled at this point, imho.
 
driller said:
Any more word on these? :rolleyes:
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Still working on them. I know there is 10hp there. But can it be controlled so as to not starve the pump? Like I said, working on it.
 
driller said:
Any more word on these? :roll eyes:
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I need to run them on a dyno or get over to Great Lakes for a couple of passes.

Did you know my former uncle-in-law was Broadway Bob of Great Lakes Dragway fame? The guy was quite the character. We were always wasted 3 hrs before anyone else which made the family get-togethers a little more tolerable, if you know what I mean.;)
 
Just installed the 3/8 valves vs the 1/2" before and playing with the new 'vac adjust' screws we built in. Don't know what is going on fully yet. I'm still pulling on my crank seal. I'm told I should turn it around and that will take care of the issue. Might solve the problem for me but doesn't seem like the right solution for the everyday guy. I ordered Moroso's version to see how it works. We need to work in a dyno session to come up with anything definitive. Engine does pull smoother from 5500 to 6000. Before the motor was straining working its way up to the 2-3 shift. Now it runs right to redline. So something is happening. Oil pressure throughout the curve is still a concern I have although I am told by several it is unfounded. Couple more weeks.
 
I'm REALLY not seeing the correlation between crankcase pressure (or lack thereof) and oil passage pressure.
 
hmmm

Have you considered using a vacuum control valve...like the ones that control the egr. You may be able to hook one up using a pot off the throttle...like the tps to have it introduce atmosphere at idle and part throttle and close off at higher throttle to allow for maximum vacuum at upper rpm's...where the engine needs it the most. I don't remember exactly what signal does what for that type of valve...but it should be easy to figure out. Then you'd have your "controlled" vacuum leak that you need to top this system off.

Justin:)
 
If it is an electric vacuum pump you could run an rpm switch to shut it down at lower rpms or run a rheostat or resistor setup. Just thinking out loud I guess.
 
97quadcam said:
Have you considered using a vacuum control valve...like the ones that control the egr. You may be able to hook one up using a pot off the throttle...like the tps to have it introduce atmosphere at idle and part throttle and close off at higher throttle to allow for maximum vacuum at upper rpm's...where the engine needs it the most. I don't remember exactly what signal does what for that type of valve...but it should be easy to figure out. Then you'd have your "controlled" vacuum leak that you need to top this system off.

Justin:)
Click to expand...
Sounds like a good idea. I am going to check that out. Thanks
 
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