Advanced Engineering Tech For the more hardcore LS1TECH residents

Another "Does anyone still use this old hotrod trick?"

Thread Tools
 
Search this Thread
 
Old 11-30-2005, 07:02 PM
  #1  
rjw
TECH Apprentice
Thread Starter
iTrader: (3)
 
rjw's Avatar
 
Join Date: Nov 2005
Location: Tinker till it blows, then back it off a notch, maybe!!
Posts: 387
Likes: 0
Received 1 Like on 1 Post

Default Another "Does anyone still use this old hotrod trick?"

With all the talk about pvc and blowing oil, etc. I remember that we used to hook breathers to the valve covers and hoses from them to Chevy retard valves welded in the header collectors.

Does anyone use this type of system anymore? Would it help the LSx PVC issues?
Old 11-30-2005, 07:22 PM
  #2  
TECH Veteran
iTrader: (21)
 
1CAMWNDR's Avatar
 
Join Date: Nov 2001
Posts: 4,247
Likes: 0
Received 2 Likes on 2 Posts

Default

I bet this is only a race car option for the LS1 since it will be spewing oil vapor into the air. It does work, however, and as rpm increases the higher the vaccum pulled through the crankcase hence the tighter the rings will seal. IF I were to put this on an LS1 I would put the breathers at the FRONT of the valve covers to lessen the possiblity of sucking pure oil out the exhaust. I have heard that part of the "oil in the intake" problem with these cars is that upon hard aceleratrion oil tends to pool at the rear of the head/valve cover. Since the stock PCV system pulls from the rear of the valve cover pure oil gets into the PCV system instead of just vapor.
Old 11-30-2005, 07:31 PM
  #3  
TECH Enthusiast
iTrader: (4)
 
SSPEEDY's Avatar
 
Join Date: Mar 2002
Location: Chicago, IL
Posts: 535
Likes: 0
Received 0 Likes on 0 Posts

Default

has anyone experimented with this on an ls1? i never heard of this before and it sounds very interesting!
Old 11-30-2005, 07:32 PM
  #4  
rjw
TECH Apprentice
Thread Starter
iTrader: (3)
 
rjw's Avatar
 
Join Date: Nov 2005
Location: Tinker till it blows, then back it off a notch, maybe!!
Posts: 387
Likes: 0
Received 1 Like on 1 Post

Default

I used to build engines for offroad racing(4 wheel drives) and we used them a lot. Engines would last a couple of seasons, and when torn down, the inerds looked absolutely great.

In some cases we had to put the crank seals in backwards, or dirt would get sucked in through the seals.

Personally, I don't like re-cycling engine air/oil back tothe TB, etc. and this system does create vacuum and a clean engine. I just haven't tried in on an LSx motor.

I've seen them at Jegs/Summit a year or so ago.

Edit: They still sell them
Old 12-01-2005, 08:38 AM
  #5  
rjw
TECH Apprentice
Thread Starter
iTrader: (3)
 
rjw's Avatar
 
Join Date: Nov 2005
Location: Tinker till it blows, then back it off a notch, maybe!!
Posts: 387
Likes: 0
Received 1 Like on 1 Post

Default

Anyone else?
Old 12-01-2005, 01:01 PM
  #6  
Moderator
iTrader: (9)
 
LIL SS's Avatar
 
Join Date: Nov 2001
Location: San Jose area
Posts: 2,966
Likes: 0
Received 2 Likes on 2 Posts

Default

I was thinking about doing this in my setup. Not quite sure yet. If I did, would it be wiser to do it before or after the turbo is the question..
Old 12-01-2005, 01:23 PM
  #7  
TECH Addict
iTrader: (15)
 
LOnSLO's Avatar
 
Join Date: Sep 2002
Location: Gainesville, GA
Posts: 2,538
Likes: 0
Received 1 Like on 1 Post

Default

Put the seal in backwards because dirt would get sucked in? There is no way that a header evac system will pull that much vacuum. It takes close to 25 inches to do that.
Old 12-01-2005, 01:26 PM
  #8  
rjw
TECH Apprentice
Thread Starter
iTrader: (3)
 
rjw's Avatar
 
Join Date: Nov 2005
Location: Tinker till it blows, then back it off a notch, maybe!!
Posts: 387
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by LOnSLO
Put the seal in backwards because dirt would get sucked in? There is no way that a header evac system will pull that much vacuum. It takes close to 25 inches to do that.
I've seen it, and read of others with the same thing, back in the 70's. It wasn't real common, but it has happened. I used toi have pictures, but that was before PC's
Old 12-01-2005, 01:31 PM
  #9  
TECH Addict
iTrader: (15)
 
LOnSLO's Avatar
 
Join Date: Sep 2002
Location: Gainesville, GA
Posts: 2,538
Likes: 0
Received 1 Like on 1 Post

Default

My boss is the inventor of that evac system, way back in the 60's. Dick Moroso was the first to copy and market the idea. They will pull up to about 4" of vacuum if they're designed and installed exactly right. That's not enough to much at all unfortunately. That's why the vacuum pump was invented (Moroso, Aerospace, GZ)
Old 12-01-2005, 02:25 PM
  #10  
12 Second Club
 
NastyNate's Avatar
 
Join Date: Nov 2004
Location: Jax, Fl
Posts: 231
Likes: 0
Received 0 Likes on 0 Posts
Default

We have a EVAC system on the 74 Formula that my cousin drives. 476 cube big block. I would expect a tall version of the LS1 valve cover would help with a LS1 version EVAC.
Old 12-01-2005, 02:30 PM
  #11  
rjw
TECH Apprentice
Thread Starter
iTrader: (3)
 
rjw's Avatar
 
Join Date: Nov 2005
Location: Tinker till it blows, then back it off a notch, maybe!!
Posts: 387
Likes: 0
Received 1 Like on 1 Post

Default

I've seen more than 4" out of them, but in any case, any vacuum in the crankcase vs pressure is a good thing.
Old 12-02-2005, 07:33 AM
  #12  
TECH Addict
iTrader: (15)
 
LOnSLO's Avatar
 
Join Date: Sep 2002
Location: Gainesville, GA
Posts: 2,538
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by rjw
any vacuum in the crankcase vs pressure is a good thing.
Agreed...
Old 12-02-2005, 08:09 AM
  #13  
rjw
TECH Apprentice
Thread Starter
iTrader: (3)
 
rjw's Avatar
 
Join Date: Nov 2005
Location: Tinker till it blows, then back it off a notch, maybe!!
Posts: 387
Likes: 0
Received 1 Like on 1 Post

Default

How about with a complete exhaust system?

Open headers worked fine and I have had some success with closed exhaust on other setups, but no experience with the LSx.
Old 12-02-2005, 10:58 AM
  #14  
TECH Addict
iTrader: (15)
 
LOnSLO's Avatar
 
Join Date: Sep 2002
Location: Gainesville, GA
Posts: 2,538
Likes: 0
Received 1 Like on 1 Post

Default

No way will it work with an exhaust system. It may pull a little, but ANY restrictions and it won't function. You'd be better off using an LS6 valley cover, and plugging the fresh air intake on the valve covers.
Old 12-02-2005, 09:41 PM
  #15  
TECH Senior Member
iTrader: (18)
 
DONAIMIAN's Avatar
 
Join Date: Jun 2002
Location: NW Houston, TX
Posts: 10,036
Likes: 0
Received 0 Likes on 0 Posts

Default

I thought about doing this, but then some issues came up when I thought about how I would drive the car on the road course and didnt think it would help much at all.
Old 12-03-2005, 01:27 PM
  #16  
rjw
TECH Apprentice
Thread Starter
iTrader: (3)
 
rjw's Avatar
 
Join Date: Nov 2005
Location: Tinker till it blows, then back it off a notch, maybe!!
Posts: 387
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by LOnSLO
No way will it work with an exhaust system. It may pull a little, but ANY restrictions and it won't function. You'd be better off using an LS6 valley cover, and plugging the fresh air intake on the valve covers.
You've made yourself perfectly clear on this, and many including Moroso agree with you.

Then there is a whole other camp, including Mr. Gasket who think otherwise.

So who is your boss that invented this?

I've been looking at the GZ vacuum pump and some others as well. I may invest in a pump and fab the rest myself. Don't want to spend over $300 or $400, that's for sure.
Old 12-04-2005, 12:34 AM
  #17  
On The Tree
 
Tom L. Busby's Avatar
 
Join Date: Nov 2002
Location: Corpus Christi Texas
Posts: 115
Likes: 0
Received 0 Likes on 0 Posts
Default

You can put a filter inline with the pcv line, like an air compressor filter from Home Depot for about $20. The filter media is too fine though, so you can drill about 20 holes in the filter with your smallest drill bit. It captures the oil but leaves the vaccum intact in the crankcase. Of course you need a couple hose clamps, some hose barbs, and about 12 inches of rubber hose too.
Old 12-04-2005, 01:51 AM
  #18  
12 Second Club
iTrader: (8)
 
The Sad's Avatar
 
Join Date: Feb 2004
Posts: 580
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by Tom L. Busby
You can put a filter inline with the pcv line, like an air compressor filter from Home Depot for about $20. The filter media is too fine though, so you can drill about 20 holes in the filter with your smallest drill bit. It captures the oil but leaves the vaccum intact in the crankcase. Of course you need a couple hose clamps, some hose barbs, and about 12 inches of rubber hose too.
Can you explain to me the reason behind drilling the holes? I have a filter on my car now, but no holes.
Old 12-04-2005, 08:54 AM
  #19  
On The Tree
 
Tom L. Busby's Avatar
 
Join Date: Nov 2002
Location: Corpus Christi Texas
Posts: 115
Likes: 0
Received 0 Likes on 0 Posts
Default

I found that my gas mileage would decline about 1+ mpg and then go back to normal after I replaced the filter. I realized that the filter would plug up after 2-3,000 miles. Then I drilled some holes so the filter wouldn''t plug up so soon.

The amount of oil being filtered out is the same, with or without the holes.

The decline in gas mileage also shows that the slight vacuum from the pcv is helpful. But I think the vacuum is so small that it helps mpg and power mostly in lower rpm ranges.
Old 12-04-2005, 06:20 PM
  #20  
Teching In
 
SappySE107's Avatar
 
Join Date: Nov 2005
Location: Indiana
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Default

I have read elsewhere to replace the filter used in the water seperators for air compressors with steel wool. Have yet to do it but this oil out of the PCV is a real issue with my V6.


Quick Reply: Another "Does anyone still use this old hotrod trick?"



All times are GMT -5. The time now is 02:19 PM.