Crank case evac - Moparts Forums

Register Log In Moparts Forums Unlawfl's Race & Engine Tech Crank case evac

Print Thread

Page 1 of 2

1

2

Crank case evac #609076 02/09/10 07:06 PM 02/09/10 07:06 PM
Joined: Dec 2008 Posts: 1,200 UK 6 602heavy OP pro stock
602heavy OP pro stock 6 Joined: Dec 2008 Posts: 1,200 UK	Are most of you guys welding the evac tubes into the collectors or further down line? , will be easier if i could weld em in around 3" passed collectors. How much vac do these pull generally? , will hook up a manometer when done. TIA.

Re: Crank case evac [Re: 602heavy] #609077 02/09/10 07:10 PM 02/09/10 07:10 PM
Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH WILD BILL Senior Member of the Junior Dragster Club
WILD BILL Senior Member of the Junior Dragster Club Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH	I've lways put them into the collector. Never had any pipe after that Even on the tightest sealed motor they won't pull a lot of vacuum. Never measuered it though.

Re: Crank case evac [Re: 602heavy] #609078 02/09/10 07:46 PM 02/09/10 07:46 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	If I can ever get out from under the friggin snow, I wil continue with my evac testing. 5793794-evacpipe.jpg (105 downloads) Fastest 300

Re: Crank case evac [Re: Crizila] #609079 02/09/10 07:52 PM 02/09/10 07:52 PM
Joined: Dec 2008 Posts: 1,200 UK 6 602heavy OP pro stock
602heavy OP pro stock 6 Joined: Dec 2008 Posts: 1,200 UK	"never had any pipe after that" , that's funny. Crizila , that is the exact set up i'm talkin about , i see you have 3 1/2" exhausts?

Re: Crank case evac [Re: Crizila] #609080 02/09/10 07:54 PM 02/09/10 07:54 PM
Joined: Oct 2003 Posts: 4,013 South Park, Pa. 68LAR master
68LAR master Joined: Oct 2003 Posts: 4,013 South Park, Pa.	never had much luck with welding the bungs past the collector. Mine are in the collector about 2" before the flange. At idle there is zero inches of vacuum. At around 2500 rpm there is about 2" of vacuum. I also use a PCV valve along with my evac system. Works real good now for about 10 years. 4 speed street legal. Best time 10.99 @ 124 mph on 93 octane pump gas @ 3926# total weight

Re: Crank case evac [Re: Crizila] #609081 02/09/10 07:56 PM 02/09/10 07:56 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	This is the tube I am working on right now. Kinda did my own thing on the exit section of the pipe. It's in the header extension ( I run with the extensions on at the track )about 1/2" and I have 1/2 of it capped off. Had the car running on the stands yesterday with the rest of the exhaust system in place and got about 1 - 2"hg at idle. Didn't change when I wound it up. Been snowing like a banchee here, so I can't take it out - nor have I tried it with just the extensions and no exhaust. 5793820-evacpipe2.jpg (71 downloads) Fastest 300

Re: Crank case evac [Re: 68LAR] #609082 02/09/10 08:01 PM 02/09/10 08:01 PM
Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH WILD BILL Senior Member of the Junior Dragster Club
WILD BILL Senior Member of the Junior Dragster Club Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH	Quote: I also use a PCV valve along with my evac system. Why? Kinda defeats the purpose doesn't it?

Re: Crank case evac [Re: 68LAR] #609083 02/09/10 08:04 PM 02/09/10 08:04 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	Quote: never had much luck with welding the bungs past the collector. Mine are in the collector about 2" before the flange. At idle there is zero inches of vacuum. At around 2500 rpm there is about 2" of vacuum. I also use a PCV valve along with my evac system. Works real good now for about 10 years. I was running a PCV, but had reservations with a closed crankcase system? I did buy a vacuum relief valve and have it set at about 12". I'm sure I will never see that number with the full exhaust in place, but until I get a chance to run it at the track, I won't know how much it will suck with just the shorty extensions. Last edited by Crizila; 02/09/10 08:05 PM. Fastest 300

Re: Crank case evac [Re: Crizila] #609084 02/09/10 08:09 PM 02/09/10 08:09 PM
Joined: Dec 2008 Posts: 1,200 UK 6 602heavy OP pro stock
602heavy OP pro stock 6 Joined: Dec 2008 Posts: 1,200 UK	Quote: This is the tube I am working on right now. Kinda did my own thing on the exit section of the pipe. It's in the header extension ( I run with the extensions on at the track )about 1/2" and I have 1/2 of it capped off. Had the car running on the stands yesterday with the rest of the exhaust system in place and got about 1 - 2"hg at idle. Didn't change when I wound it up. Been snowing like a banchee here, so I can't take it out - nor have I tried it with just the extensions and no exhaust. Would it of been more effective if the evac tubes entered into the ex pipe as opposed to welding them in flush? Thanks for the pics.

Re: Crank case evac [Re: 602heavy] #609085 02/09/10 08:10 PM 02/09/10 08:10 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	Quote: "never had any pipe after that" , that's funny. Crizila , that is the exact set up i'm talkin about , i see you have 3 1/2" exhausts? Actually 3". They go back to a pair of Summit chambered muffs and just dump in front of the axle. Only have them on when I'm street testing and so I don't piss the neighbors off too much. 5793851-exhastsys.jpg (46 downloads) Fastest 300

Re: Crank case evac [Re: 602heavy] #609086 02/09/10 08:22 PM 02/09/10 08:22 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	Quote: Quote: This is the tube I am working on right now. Kinda did my own thing on the exit section of the pipe. It's in the header extension ( I run with the extensions on at the track )about 1/2" and I have 1/2 of it capped off. Had the car running on the stands yesterday with the rest of the exhaust system in place and got about 1 - 2"hg at idle. Didn't change when I wound it up. Been snowing like a banchee here, so I can't take it out - nor have I tried it with just the extensions and no exhaust. Would it of been more effective if the evac tubes entered into the ex pipe as opposed to welding them in flush? Thanks for the pics. I don't know? I have several sets of extensions, and plan on trying some other ways. Moroso's instructions ( with their evac kit ) suggest they be in 1/2" off the pipe wall - that is with them located just down stream of the primary tube junction in the headers. Fastest 300

Re: Crank case evac [Re: 602heavy] #609087 02/09/10 08:28 PM 02/09/10 08:28 PM
Joined: Jan 2003 Posts: 24,562 Brookeville, Md Mr.Yuck Not enough dumb comments...yet
Mr.Yuck Not enough dumb comments...yet Joined: Jan 2003 Posts: 24,562 Brookeville, Md	How much does the evac help? I mean say on a 11.90 car? [IMG]http://i66.tinypic.com/pui5j.jpg[/IMG] Coming soon!!!!

Re: Crank case evac [Re: 602heavy] #609088 02/09/10 09:43 PM 02/09/10 09:43 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	I did alot of testing on the evac and found that if you weld the tube in with the face of the tube mounted so its parallel with the exit of the collector(or in a collector extension), try to get it away from the side wall some.... doing it this way gives you the greatest negative pressure(vac)... it will pull about 5"hg max but if you run a exhaust system, for every inch Hg of back pressure you have on the exhaust you will decrease the vac by that amount that the engine would see. Try to get it at least 3" from the point where the primary tubes end... also if you use a O2, have the O2 up stream of the evac otherwise it will give the O2 bad numbers

Re: Crank case evac [Re: Mr.Yuck] #609089 02/09/10 09:51 PM 02/09/10 09:51 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	Quote: How much does the evac help? I mean say on a 11.90 car? I've heard all kinds of claims on this board from nothing to over 30HP and I'm sure there are a million variables as to why. My car only runs low 11.70's, so I'm not expecting much, but I don't see any negatives. If I could get get a tenth or so out of it ( for the $ I have in it )I'd be a happy camper. Fastest 300

Re: Crank case evac [Re: WILD BILL] #609090 02/09/10 10:23 PM 02/09/10 10:23 PM
Joined: Oct 2003 Posts: 4,013 South Park, Pa. 68LAR master
68LAR master Joined: Oct 2003 Posts: 4,013 South Park, Pa.	Quote: Quote: -------------------------------------------------------------------------------- I also use a PCV valve along with my evac system. -------------------------------------------------------------------------------- Why? No, it doesn't defeat the purpose. At idle, there is a negative pressure in the crankcase due to the PCV valve. Anything above idle, there is also a negative pressure in the crankcase due to the crankcase evac. system. 4 speed street legal. Best time 10.99 @ 124 mph on 93 octane pump gas @ 3926# total weight

Re: Crank case evac [Re: MR_P_BODY] #609091 02/09/10 10:26 PM 02/09/10 10:26 PM
Joined: Feb 2007 Posts: 6,295 U.S. M moparniac master
moparniac master M Joined: Feb 2007 Posts: 6,295 U.S.	Quote: also if you use a O2, have the O2 up stream of the evac otherwise it will give the O2 bad numbers so the o2 sensor cloer to the collector than the evac nipple? Mopar Performance

Re: Crank case evac [Re: moparniac] #609092 02/09/10 10:30 PM 02/09/10 10:30 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Quote: Quote: also if you use a O2, have the O2 up stream of the evac otherwise it will give the O2 bad numbers so the o2 sensor cloer to the collector than the evac nipple? Up stream... OR in front of the evac(towards the primary tubes)

Re: Crank case evac [Re: 602heavy] #609093 02/09/10 11:42 PM 02/09/10 11:42 PM
Joined: Dec 2008 Posts: 603 Central Oregon R Rodney mopar
Rodney mopar R Joined: Dec 2008 Posts: 603 Central Oregon	Quote: Quote: This is the tube I am working on right now. Kinda did my own thing on the exit section of the pipe. It's in the header extension ( I run with the extensions on at the track )about 1/2" and I have 1/2 of it capped off. Had the car running on the stands yesterday with the rest of the exhaust system in place and got about 1 - 2"hg at idle. Didn't change when I wound it up. Been snowing like a banchee here, so I can't take it out - nor have I tried it with just the extensions and no exhaust. Would it of been more effective if the evac tubes entered into the ex pipe as opposed to welding them in flush? Thanks for the pics. we've always had them in about an inch with the taper parallel to the pipe.

Re: Crank case evac [Re: Rodney] #609094 02/09/10 11:56 PM 02/09/10 11:56 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	we've always had them in about an inch with the taper parallel to the pipe. Yeah thats the way Moroso wants you to install it... it works that way but in testing I found that I could get 1.0" - 1.5"hg more if it was done with the tube parallel with the exit of the collector but I made sure it was square to get the added numbers... their way is a little more forgiving

Re: Crank case evac [Re: MR_P_BODY] #609095 02/10/10 12:13 AM 02/10/10 12:13 AM
Joined: Dec 2008 Posts: 603 Central Oregon R Rodney mopar
Rodney mopar R Joined: Dec 2008 Posts: 603 Central Oregon	didn't the moroso also have slice cuts out of the pipe some where on the pipe that fit inside?

Page 1 of 2

1

2

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1