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Re: Summit crankcase evac system: proper way to install?
[Re: Crizila]
#1331449
11/07/12 07:09 PM
11/07/12 07:09 PM
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Joined: Oct 2003
Posts: 7,506
Az
Crizila
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master
Joined: Oct 2003
Posts: 7,506
Az
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I mounted my tubes at the suggested 45 degree angle and depth in to the pipe, but I capped off the leading edge of the tube to creat more draw at a lower exhaust flow ( my guess and not "indoresd" by anyone else ).
Fastest 300
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Re: Summit crankcase evac system: proper way to install?
[Re: 68LAR]
#1331455
01/07/13 11:53 PM
01/07/13 11:53 PM
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Joined: Apr 2009
Posts: 3,433
Toronto
mshred
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Joined: Apr 2009
Posts: 3,433
Toronto
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Quote:
I run Dynomax Ulta-Flo mufflers. At idle there is almost zero vacuum. At around 3000 rpm, the system is pulling around 5" of vacuum. It will pull that much on up the rpm scale. This is one of the reasons that I also run a pcv. It pulls at an idle and drops off at higher rpms. So I have some vacuum all the time. 
Not questioning your method, but seriously trying to learn- by pulling vacuum from the crankcase at idle via the PCV, what is the benefit? Does the motor run cleaner/better?
Did you ever try without the PCV and just the evac to see what happened?
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Re: Summit crankcase evac system: proper way to install?
[Re: mshred]
#1331456
01/08/13 11:10 AM
01/08/13 11:10 AM
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Joined: Oct 2003
Posts: 4,020
South Park, Pa.
68LAR
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Joined: Oct 2003
Posts: 4,020
South Park, Pa.
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Quote:
Not questioning your method, but seriously trying to learn- by pulling vacuum from the crankcase at idle via the PCV, what is the benefit? Does the motor run cleaner/better?
Did you ever try without the PCV and just the evac to see what happened?
Running a pcv will give you a vacuum, (negative pressure in the crank case). If I recall correctly, (it's been a while since I've researched this), with no vacuum, the underside of the piston acts like a "parachute" on the downward stroke, causing a loss of horsepower. By me running a pvc, you have to remember that my car is mostly street driven and the pvc will pull vacuum upwards of 3000 rpm before dropping off and by that time the crank evac system kicks in. So I have negative pressure in the crank case all the time which, hopefully, means free horsepower.
I have tried running without over the years and again, I went back to this system because of the "Free Horsepower" aspect. It's working for me and I'm not changing anything at this time. I'm just passing along some personal experience that I've tried and the results.  
4 speed street legal. Best time 10.99 @ 124 mph on 93 octane pump gas @ 3926# total weight
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Re: Summit crankcase evac system: proper way to install?
[Re: mshred]
#1331457
01/08/13 11:31 AM
01/08/13 11:31 AM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Ok, makes sense now...DOH!
Also I did a study on the e-vac at work trying to get
the most vac out of them... I dont put them in the
way Moroso shows... I squash the tube for about the
last 1.5"(makes it narrower but maintains the same area)
and put the end of the tube in the center of the collector
and doing this I got a bit more vac.. and for every
inch of back pressure the exhaust has, it reduces
the vac on the engine by that same amount... till
you get to zero vac and from then on you will start
to pressurize the crank case
NOTE
The end of the e-vac tube is square to the end of
the collector but the end of the tube is 3" past the
end of the primaries
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Re: Summit crankcase evac system: proper way to install?
[Re: 68LAR]
#1331458
01/08/13 01:28 PM
01/08/13 01:28 PM
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Joined: Apr 2009
Posts: 3,433
Toronto
mshred
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Joined: Apr 2009
Posts: 3,433
Toronto
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Quote:
Quote:
Not questioning your method, but seriously trying to learn- by pulling vacuum from the crankcase at idle via the PCV, what is the benefit? Does the motor run cleaner/better?
Did you ever try without the PCV and just the evac to see what happened?
Running a pcv will give you a vacuum, (negative pressure in the crank case). If I recall correctly, (it's been a while since I've researched this), with no vacuum, the underside of the piston acts like a "parachute" on the downward stroke, causing a loss of horsepower. By me running a pvc, you have to remember that my car is mostly street driven and the pvc will pull vacuum upwards of 3000 rpm before dropping off and by that time the crank evac system kicks in. So I have negative pressure in the crank case all the time which, hopefully, means free horsepower.
I have tried running without over the years and again, I went back to this system because of the "Free Horsepower" aspect. It's working for me and I'm not changing anything at this time. I'm just passing along some personal experience that I've tried and the results.
Thanks for the info man, I really do appreciate it! I guess I am just trying to decide if I want to ditch the PCV altogether and run the evac on both valve cover's, as I am not sure if there is a benefit to just having the 1 evac tube (or maybe there is, since I guess it is still pulling something, even if only on one side)...I know yours didn't pull vacuum till about 3000rpm, but Crizila said his was pulling from idle (or could that have been the mufflers doing that??)
Did you ever get a chance to pull off the hose and see if you had oil from running the evac on the rear of the valve cover?
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Re: Summit crankcase evac system: proper way to install?
[Re: MR_P_BODY]
#1331459
01/08/13 01:31 PM
01/08/13 01:31 PM
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Joined: Apr 2009
Posts: 3,433
Toronto
mshred
master
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master
Joined: Apr 2009
Posts: 3,433
Toronto
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Quote:
Quote:
Ok, makes sense now...DOH!
Also I did a study on the e-vac at work trying to get
the most vac out of them... I dont put them in the
way Moroso shows... I squash the tube for about the
last 1.5"(makes it narrower but maintains the same area)
and put the end of the tube in the center of the collector
and doing this I got a bit more vac.. and for every
inch of back pressure the exhaust has, it reduces
the vac on the engine by that same amount... till
you get to zero vac and from then on you will start
to pressurize the crank case
NOTE
The end of the e-vac tube is square to the end of
the collector but the end of the tube is 3" past the
end of the primaries
Thanks for the info Mr. P!
With your testing, were you using a straight through muffler and still finding that eventually it would pressurize the crankcase with rpm? I am running Borla XR-1 race mufflers, thinking about switching to bullets, but don't want to have problems either way
Also, where are you guys tapping into and measuring crankcase vacuum from with a gauge?
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Re: Summit crankcase evac system: proper way to install?
[Re: mshred]
#1331460
01/08/13 02:57 PM
01/08/13 02:57 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Thanks for the info Mr. P! With your testing, were you using a straight through muffler and still finding that eventually it would pressurize the crankcase with rpm? I am running Borla XR-1 race mufflers, thinking about switching to bullets, but don't want to have problems either way Also, where are you guys tapping into and measuring crankcase vacuum from with a gauge?
I was using a adjustable orifice to control the
back pressure... this was on a dyno but back pressure
is back pressure.... I take my vac reading from the
back of the valve cover so its out of the way
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Re: Summit crankcase evac system: proper way to install?
[Re: bigtimeauto]
#1331462
01/08/13 03:52 PM
01/08/13 03:52 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Quote:
I squash the tube for about the
last 1.5"(makes it narrower but maintains the same area)
No it doesn't. If you *smash* a tube it loses volume. So i would guess the smaller tube was able to pick up velocity.
No... you dont squash it flat... you oval it and
it still has the same area... I oval it to help the
exhaust flow past it
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Re: Summit crankcase evac system: proper way to install?
[Re: bigtimeauto]
#1331464
01/08/13 04:18 PM
01/08/13 04:18 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Quote:
Quote:
Quote:
I squash the tube for about the
last 1.5"(makes it narrower but maintains the same area)
No it doesn't. If you *smash* a tube it loses volume. So i would guess the smaller tube was able to pick up velocity.
No... you dont squash it flat... you oval it and
it still has the same area... I oval it to help the
exhaust flow past it
No, as soon as you change it from round it loses volume
Yes you are right... it looses .01 in area... is
that worth saying
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. They work great with no mufflers at all. My car is not a street car. Only time it see's a quasi exhaust system is when I have to do a little T&T on the street. Personnelly, if I were driving a street car with occasional track time I would not go with an Evac system. Just a PCV system.
