Crankcase Vacuum Pump, I've got smoke

[Knight Viper]

I was wondering if anyone was running a vacuum pump on there viper, NA or FI? I have 15,000 on my Roe SC motor and I'm seeing (and smelling) oil smoke after a WOT run . I don't think it's the rings or a valve seal as I don't have any smoke on start up or on free rev and thought I might be generating too much crankcase pressure. I am running the aftermarket (PBJ) air box and Breather tank catch can. Any thoughts or advice will be greatly appreciated.

 

[HP]

I was wondering if anyone was running a vacuum pump on there viper, NA or FI? I have 15,000 on my Roe SC motor and I'm seeing (and smelling) oil smoke after a WOT run . I don't think it's the rings or a valve seal as I don't have any smoke on start up or on free rev and thought I might be generating too much crankcase pressure. I am running the aftermarket (PBJ) air box and Breather tank catch can. Any thoughts or advice will be greatly appreciated.

It's been awhile since someone has commented on this - you might do a search.
Once I tried to run a directional valve (Harley type aftermarket)-one off the pvc line and one off the valve cover vent. That setup generated too much vacuum and my motor
just didn't idle right. I now just use one on the pvc line. A vacuum pump that regulates a controlled vacuum couldn't hurt - and it should help some of your symptoms.

 

[GR8_ASP]

Do you have a check valve in the system so your crankcase nevers receives boost pressure? If not pick one up. There on all factory turbo/supercharged cars.

 

[2000_Black_RT10]

Here's a good article on vacuum pumps.

http://www.dragstuff.com/techarticles/vacuum-pumps.html

If it's only on acceleration something to look at may be the rear valve seals, in which the oil may be pooling up in rocker valley, and submerging the rear seals in oil. Small block Chevy motors were notorious for this along with a clogged oil drain passage.

Vacuum pumps on race cars are typically desired when running with low tension piston rings and excessive blow-by.

Note in the article regarding OEM vs. aftermarket pumps and oil lubrication.

Pull your spark plugs and compare them after a hard smokey run.

Check the PCV line for oil.

Out of curiousity, I would take the oil filler cap off the valve cover and have somone rev up the motor, observing for any excessive smoke coming out of the valve cover indicating a blow-by issue.

Mike

 

[FE 065]

I tried running and electric vacuum pump from Stainless Steel Brakes back in 2003 or so, and posted on it. Best I could maintain was about 8 in vacuum. Adding a second electric pump didn't yield any increase in vacuum, but 8in is still a lot of draw. Not up to ProStock numbers, but enough to relieve the crankcase of any heavy atmospheres.

If you're generating too much pressure into the crankcase there's only one place it's coming from right? Either your breather plumbing is restricted or your rings aren't sealing I'd say.

 

[Knight Viper]

I don't notice a lot of smoke on acceleration (it's a little difficult to look back at WOT) it seems to me most of it is on deceleration which would leave me to believe it could be sucking it past a valve seal or two.?.

 

[Jack B]

I was wondering if anyone was running a vacuum pump on there viper, NA or FI? I have 15,000 on my Roe SC motor and I'm seeing (and smelling) oil smoke after a WOT run . I don't think it's the rings or a valve seal as I don't have any smoke on start up or on free rev and thought I might be generating too much crankcase pressure. I am running the aftermarket (PBJ) air box and Breather tank catch can. Any thoughts or advice will be greatly appreciated.

My guess the catch can has a breather top-end. That is where the odor comes from. Technically its better to trap the oil and blow-by there, the fumes are the negative side. A few have tried the vacuum pump, but, not with a lot of luck.

 

[Knight Viper]

It's enough smoke that you can definitely see it (the size of a small house) I never noticed any smoke before I add the SC but i also removed the cats at the same time. I don't like to drive the car hard with anyone around as it's enough smoke to be embarrassing.

 

[2000_Black_RT10]

Do you have pics of the catch can setup handy? Is there any oil collected in the catch can, is there a tap / drain on the bottom?

 

[ViperJohn]

Damn Kevin, sounds like you have been having some "fun" with the car lately. Hope you get this resovled.

 

[treesnake]

I am having the exact same problem. i took the cats off is when it seemed to start. i to am using a PBJ catch can. i am now leaving a small pool of oil and a mess under the hood. I am going to try and see Joe at PBJ today. Ill report back what he tells me. The worst part of this is that I am getting oil all over the underside of my refinished and painted d-back hood and chrome hinges...and everything else.

Mike

 

[Knight Viper]

Do you have pics of the catch can setup handy? Is there any oil collected in the catch can, is there a tap / drain on the bottom?

Not the best pic, you can only see the top of the PBJ catch can. it does have a drain and a level tube, I do have a little oil in the bottom but not enough to show up in the sight tube(over 1,000 miles on blower)

 

[Knight Viper]

I am having the exact same problem. i took the cats off is when it seemed to start. i to am using a PBJ catch can. i am now leaving a small pool of oil and a mess under the hood. I am going to try and see Joe at PBJ today. Ill report back what he tells me. The worst part of this is that I am getting oil all over the underside of my refinished and painted d-back hood and chrome hinges...and everything else.

Mike

Hey Mike, I'm not leaving any oil behind in the engine bay, it seems most of mine is coming out of my exhaust. My catch can has some oil residue on the top (draining out of the filter) but that would be it.

 

[GTSnake]

If it's coming out of the exhaust it leads to thinking that it's a ring sealing issue.

The only other way oil can be getting into the combustion chamber is if you had the stock PCV tube routed back into the intake. But since you have the catch can that route is eliminated.

I have a little smoke coming out from my breathers on my valve covers but nothing much out the exhaust. How much boost are you running?

 

[Knight Viper]

I have a little smoke coming out from my breathers on my valve covers but nothing much out the exhaust. How much boost are you running?

Just a little over 10psi
I'm going to have the heads done this winter and while I'm at it probably bore the motor as well so if it's a ring or valve seal this should cure the problem I just didn't want it to smoke the rest of the summer. Driving the car around town is fine it's just coming off of a WOT run when I notice the smoke.

 

[dansauto]

do a leakdown test, I suspect valves over rings as you are not pressurizing the coolent system.

 

[GTSnake]

You won't be able to bore out much since the cylinder sleeves are not that thick. Most people stroke it to get more displacement.

 

[RedSrt007]

I have a PBJ can w/ roe also, and I see smoke from time to time coming out the K&N on top of ther catch can from time to time...

 

[dansauto]

I have a PBJ can w/ roe also, and I see smoke from time to time coming out the K&N on top of ther catch can from time to time...

that is normal, just crankcase ventilation.

 

[2000_Black_RT10]

Sounds like at the valves, since coming off WOT. It may be just a valve seal. Lifting the gas pedal at high rpm creates vacuum because the throttle bodies are shut and the piston is still trying to pull air, and it's probably pulling oil through the valve seal. It's surprising how much smoke can be caused by valve seals. If the valve guides are worn, the seals go, but there are times when the valve seal pops off it's pedestal. If it were me, I'd change the valve seals, it's an easy / quick inexpensive job. Check the spark plugs first, if they are inconsistent, a couple are oily / dirty and others aren't, you can rule out the crankcase oil / venting suspicion.

 

[Knight Viper]

I checked all the plugs and no oil residue a little carbon build up on 9 & 10 but my motor is running a little rich also @ 13.1 at idol.
I reinstalled my RT high flow cats as I didn't want to stink anyone out or get a headache on this weekends crab feast and cruise
I added Jesel Roller Rockers so I hope there is no problem there, I will do the leak-down test next, thanks.

 

[dansauto]

not to be insulting, but are you sure its oil. If you are running really rich and you dont have the vec 2 set correctly (trim fuel at full vaccuum) it could be gas. Is the smoke black or blue?

 

[Knight Viper]

not to be insulting, but are you sure its oil. If you are running really rich and you dont have the vec 2 set correctly (trim fuel at full vaccuum) it could be gas. Is the smoke black or blue?

No insult at all Dan, I appreciate the help. I was thinking the same thing or that some of it could be fuel but I can smell it (oil) and my oil level has dropped about 1/2-3/4 quart and the smoke is blueish. I've been tiring to get a local fellow who is good with FI and aftermarket computers to help me tune it but he has the dyno that bolts to your wheels and no 6 lug adapters yet.

 

[CANTDRIVE55]

Hi,

You might try a laptop dyno from www.nology.com as an alternative to the wheel bolt-on dyno if no true dyno is available.