Vaccume or breathers? - ZR-1 Net Registry Forums

2lpzr1s · 05-28-2006

Have way too much time on my hands and was thinking? has anyone ever tried just running breathers or an electric vaccume pump instead of the PVC set-up on an LT5? If so what were the results. AND yes there is an elect v-pump out now.

tomtom72 · 05-29-2006

I guess that's why LocoBob came up with his "oil recovery" system?? In Heart of the Beast the crankcase pressure problem was due to small oil pan volume???
I wonder if lotus had that problem in the early DOHC/4v/injected F1 motors from the mid 60's & what did they do about it?? I should have paid more attention last night while watching Victory by Design as the show was about Lotus. Is it that the LT5 really needs a dry sump system?

Tom

2lpzr1s · 05-29-2006

I guess what I don't like about the system as it's set now is the brown goo that cakes the inside of the plenum. I know the first time I pulled on off Isaid WTF. THIS is FUBAR and a few other things. I have 2 cars both 90s Both the same mess . Every time Iv'e gone to chassis dyno both cars hit the knock sensor @ 5300 no matter what chip Marks -zindustries-or stock in fact the stock chip makes the best power on both cars. 1stk ex BORLA 1 jeal headers-rc inj-flowmasters. I thought maybe getting rid of any trace of oil would help. i guess i might try that vaccume pump .It might free up some hp .I know we got 17rwp out of a 68 mustang we did a while back. Was hoping that someone had explored this before that might be willing to share the results.?

ZR1 MK · 05-30-2006

The pvc system on any car only operates at part throttle. A breather or vacuum pump is only needed during full throttle (no vacuum) conditions. I currently use an oil catch can, but in addition, plan to install a vac pump to operate during full throttle conditions.

Locobob · 05-31-2006

Kurt White rigged one up a while back. I believe he used a C5 electric air pump switched to come on at full throttle, got something like 10hp on the dyno out of it. I have been playing with this idea for a while now. Don't have a system worked out just yet but I found that the stock ZR-1 electric air pump will only produce a bit over 1in of vacuum. I also have a C5 air pump laying around but I have yet to wire it up to see if it does any better. Both of these units are cold start emissions pumps designed to blow fresh air into the exhaust, turned around they can be used to create vacuum. Probaby not the best choice but worth playing with as I have them on hand. It may also be possible to use the vehicles exhaust system for a crankcase evac system, it's been done on other cars with some success.

2lpzr1s · 05-31-2006

that c-5 pump sounds interesting. the trouble with using the exhaust is it tends to clog in a street car. I will contact a friend that ran into that problem to find out all the ?s. Opps time to go pay the bills/

05-28-2006	#1
2lpzr1s Join Date: May 2006 Posts: 18	Vaccume or breathers? Have way too much time on my hands and was thinking? has anyone ever tried just running breathers or an electric vaccume pump instead of the PVC set-up on an LT5? If so what were the results. AND yes there is an elect v-pump out now.

05-29-2006	#2
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: Vaccume or breathers? I guess that's why LocoBob came up with his "oil recovery" system?? In Heart of the Beast the crankcase pressure problem was due to small oil pan volume??? I wonder if lotus had that problem in the early DOHC/4v/injected F1 motors from the mid 60's & what did they do about it?? I should have paid more attention last night while watching Victory by Design as the show was about Lotus. Is it that the LT5 really needs a dry sump system? Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

05-29-2006	#3
2lpzr1s Join Date: May 2006 Posts: 18	Re: Vaccume or breathers? I guess what I don't like about the system as it's set now is the brown goo that cakes the inside of the plenum. I know the first time I pulled on off Isaid WTF. THIS is FUBAR and a few other things. I have 2 cars both 90s Both the same mess . Every time Iv'e gone to chassis dyno both cars hit the knock sensor @ 5300 no matter what chip Marks -zindustries-or stock in fact the stock chip makes the best power on both cars. 1stk ex BORLA 1 jeal headers-rc inj-flowmasters. I thought maybe getting rid of any trace of oil would help. i guess i might try that vaccume pump .It might free up some hp .I know we got 17rwp out of a 68 mustang we did a while back. Was hoping that someone had explored this before that might be willing to share the results.?

05-30-2006	#4
ZR1 MK Join Date: Aug 2005 Location: NY Posts: 143	Re: Vaccume or breathers? The pvc system on any car only operates at part throttle. A breather or vacuum pump is only needed during full throttle (no vacuum) conditions. I currently use an oil catch can, but in addition, plan to install a vac pump to operate during full throttle conditions. __________________ Mike 427 cu in LT5 [URL="http://zr1mk.weebly.com"]http://zr1mk.weebly.com[/URL]

05-31-2006	#5
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Re: Vaccume or breathers? Kurt White rigged one up a while back. I believe he used a C5 electric air pump switched to come on at full throttle, got something like 10hp on the dyno out of it. I have been playing with this idea for a while now. Don't have a system worked out just yet but I found that the stock ZR-1 electric air pump will only produce a bit over 1in of vacuum. I also have a C5 air pump laying around but I have yet to wire it up to see if it does any better. Both of these units are cold start emissions pumps designed to blow fresh air into the exhaust, turned around they can be used to create vacuum. Probaby not the best choice but worth playing with as I have them on hand. It may also be possible to use the vehicles exhaust system for a crankcase evac system, it's been done on other cars with some success. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368 Last edited by Locobob; 05-31-2006 at 05:04 AM.

05-31-2006	#6
2lpzr1s Join Date: May 2006 Posts: 18	Re: Vaccume or breathers? that c-5 pump sounds interesting. the trouble with using the exhaust is it tends to clog in a street car. I will contact a friend that ran into that problem to find out all the ?s. Opps time to go pay the bills/