Who is running an Evac system?
Re: Who is running an Evac system? It's not worth it unless you run special low tension oil rings. Figure out a way to run more boost. <img src="gr_images/icons/wink.gif" border="0">
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 134
Likes: 0
From: Corona
Re: Who is running an Evac system? I think it is worth it for 10-20 hp. I am more concerned with controling the oil consumption and pressure under boost. I am getting a lot of pressure in the valve covers during my passes and I want to alievate it.
Re: Who is running an Evac system? [quote]Originally posted by SCZ28:
<strong>I am more concerned with controling the oil consumption and pressure under boost. I am getting a lot of pressure in the valve covers during my passes and I want to alievate it.</strong><hr></blockquote>
Thats my problem too. I'm pushing the dipstick out of the tube and spraying oil on the hood. The only evac pumps I can find are belt driven. I'm looking for an electric pump.
How much vacuum would be needed to put the crankcase in the negative?
How much volume must the pump be?
I can fabricate my own system if I can just find a strong enough electric vacuum pump.
<strong>I am more concerned with controling the oil consumption and pressure under boost. I am getting a lot of pressure in the valve covers during my passes and I want to alievate it.</strong><hr></blockquote>
Thats my problem too. I'm pushing the dipstick out of the tube and spraying oil on the hood. The only evac pumps I can find are belt driven. I'm looking for an electric pump.
How much vacuum would be needed to put the crankcase in the negative?
How much volume must the pump be?
I can fabricate my own system if I can just find a strong enough electric vacuum pump.
Re: Who is running an Evac system? [quote]
I think it is worth it for 10-20 hp. I am more concerned with controling the oil consumption and pressure under boost. I am getting a lot of pressure in the valve covers during my passes and I want to alievate it.
<hr></blockquote>
A breather is fine. An evac system is used when you have low tension rings and need vacuum to help them seal. If you have a lot of blow you might want to try running heavier oil.
I think it is worth it for 10-20 hp. I am more concerned with controling the oil consumption and pressure under boost. I am getting a lot of pressure in the valve covers during my passes and I want to alievate it.
<hr></blockquote>
A breather is fine. An evac system is used when you have low tension rings and need vacuum to help them seal. If you have a lot of blow you might want to try running heavier oil.
Re: Who is running an Evac system? I have been planning to use the Caddy 4-6-8 pump for a while...
It pulls 4 volts... I have been told.
I have one friend who has one, I will forward the thread to him.
Terry with a blower car it's a great idea. I think this time you are maybe pontificating but in fact have never run one?
Using one to alleviate crankcase pressure could make some decent power for about $150 in mods.
It pulls 4 volts... I have been told.
I have one friend who has one, I will forward the thread to him.
Terry with a blower car it's a great idea. I think this time you are maybe pontificating but in fact have never run one?
Using one to alleviate crankcase pressure could make some decent power for about $150 in mods.
Re: Who is running an Evac system? [quote]
Terry with a blower car it's a great idea. I think this time you are maybe pontificating but in fact have never run one?
<hr></blockquote>
I've used both header mounted and electric evap pumps in my LT1 cars (both NA, turbo, and supercharged). I never saw any gain. Supercharged cars are not supposed to have a lot of blow by. If they do, a vacuum pump is not going to help much with that problem. <img src="gr_images/icons/wink.gif" border="0">
If you run special low tension oil rings and the vacuum pump needed to make them seal, I've heard of guys picking up 10rwhp in some cases.
LS1 engines are actually really easy to build pressure in, but those that have done evap systems in them have not picked up much. Building vacuum inside an LT1 motor is a nightmare. Valve covers, intake manifold, dipstick, etc all tend to leak. In one case I think I sucked in my rear intake manifold sealant.. (whoops!).
I think Brett needs to figure out a way to run more boost, and build up his drive train. <img src="gr_images/icons/wink.gif" border="0">
Terry with a blower car it's a great idea. I think this time you are maybe pontificating but in fact have never run one?
<hr></blockquote>
I've used both header mounted and electric evap pumps in my LT1 cars (both NA, turbo, and supercharged). I never saw any gain. Supercharged cars are not supposed to have a lot of blow by. If they do, a vacuum pump is not going to help much with that problem. <img src="gr_images/icons/wink.gif" border="0">
If you run special low tension oil rings and the vacuum pump needed to make them seal, I've heard of guys picking up 10rwhp in some cases.
LS1 engines are actually really easy to build pressure in, but those that have done evap systems in them have not picked up much. Building vacuum inside an LT1 motor is a nightmare. Valve covers, intake manifold, dipstick, etc all tend to leak. In one case I think I sucked in my rear intake manifold sealant.. (whoops!).
I think Brett needs to figure out a way to run more boost, and build up his drive train. <img src="gr_images/icons/wink.gif" border="0">
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
TECH Fanatic
Joined: Nov 2001
Posts: 1,190
Likes: 0
From: Las Cruces, NM
Re: Who is running an Evac system? Question for you guys that are pressurizing the valve covers. Do you have the throttle body port that goes to the valve cover capped and also do you have a check valve in the line with the pcv valve. In this configuration the valve covers will have to have a breather or be tied into say the air cleaner. If the throttle body is not capped then the valve cover will pressurize. If the there is not a check valve inline with pcv valve then you will pressurize the crankcase.
This assumes that your are runnning boost, if not then you probably dont need to do these things.
Gary
[ March 06, 2002: Message edited by: red ws6 99 ]</p>
This assumes that your are runnning boost, if not then you probably dont need to do these things.
Gary
[ March 06, 2002: Message edited by: red ws6 99 ]</p>
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 134
Likes: 0
From: Corona
Re: Who is running an Evac system? [quote]Originally posted by red ws6 99:
<strong>Question for you guys that are pressurizing the valve covers. Do you have the throttle body port that goes to the valve cover capped and also do you have a check valve in the line with the pcv valve. In this configuration the valve covers will have to have a breather or be tied into say the air cleaner. If the throttle body is not capped then the valve cover will pressurize. If the there is not a check valve inline with pcv valve then you will pressurize the crankcase.
This assumes that your are runnning boost, if not then you probably dont need to do these things.
Gary
[ March 06, 2002: Message edited by: red ws6 99 ]</strong><hr></blockquote>
I am running a check valve and a breather on the passenger valve cover(with a cap at the TB). After a pass there is residual oil that has been pushed out around the oil cap and through the bolt holes of the valve cover. My motor has always burnt too much oil since it was built so if I could contorl any on it would be a good thing.
FWIW I run 10W 50 oil now.
<strong>Question for you guys that are pressurizing the valve covers. Do you have the throttle body port that goes to the valve cover capped and also do you have a check valve in the line with the pcv valve. In this configuration the valve covers will have to have a breather or be tied into say the air cleaner. If the throttle body is not capped then the valve cover will pressurize. If the there is not a check valve inline with pcv valve then you will pressurize the crankcase.
This assumes that your are runnning boost, if not then you probably dont need to do these things.
Gary
[ March 06, 2002: Message edited by: red ws6 99 ]</strong><hr></blockquote>
I am running a check valve and a breather on the passenger valve cover(with a cap at the TB). After a pass there is residual oil that has been pushed out around the oil cap and through the bolt holes of the valve cover. My motor has always burnt too much oil since it was built so if I could contorl any on it would be a good thing.
FWIW I run 10W 50 oil now.