Crankcase Evacuation with the LT1 smog pump. How To:

[Pablo]

I was asking about the horse power gain because I think it's alot of work just to eliminate oil leaks. My car leaks oil just like every Buick. I've been interested in doing an electric pump for a while but I haven't seen any results from anyone. If you can get 2in.vac at 25psi, I would think the car would pick up.

That would be a neat side benefit. I don't think its that much work really.

 

[mousemobile]

I am curious why the turbo inlet vacuum level was brought up. I hope that it wasn't a suggestion use the air inlet to evacuate the crankcase.

You do not want any crankcase vapors going into the engine to be burned. This can be a major source of detonation.

For a stocker, maybe OK. But definately not on a 'race type' boosted engine.

BTW, crankcase evacuation makes the rings seal better.

 

[Pablo]

I am curious why the turbo inlet vacuum level was brought up. I hope that it wasn't a suggestion use the air inlet to evacuate the crankcase.

You do not want any crankcase vapors going into the engine to be burned. This can be a major source of detonation.

For a stocker, maybe OK. But definately not on a 'race type' boosted engine.

BTW, crankcase evacuation makes the rings seal better.

I think (hope) we (the other posters) are on the same page with that. Thats why moisture seperator is inline with the pump before it goes to the inlet. The oil thing was a concern of mine too. Any oil in the chamber will cause detonation in a hurry.

I think at least that I am ok with the seperator to pump and then to the turbo inlet. What comes out of the seperator is pure fuel which leads me to beleive im not getting any oil into the turbo inlet unless for some reason the seperator was catching only fuel and not oil but that seems pretty unlikely. I haven't developed any detonation issues since this either.

I will have to put a bung in to check for wot vacuum using the setup I have now and comparing that to just venting it to open air to know for sure if its better. That long hose is pretty restrictive.

 

[Evaddave 87gn]

Lots of good info

Wow lots of good information here guy's. Thanks Pablo for all your hard work. I have been trying to decide what type of evac system to put on my GN. I think I may follow your lead.

Evaddave

PS You mentioned oil leaks as a reason to go to this setup. Was this an on going problem for you? Did you change a gasket only to have it blow again?

 

[Pablo]

Thanks for the kind words.

Yes, I kept getting valve cover and oil pan gasket leaks despite replacing them a couple of times.

 

[SloGN]

what do you consider high boost?



I would tend to think that you have something wrong since you have high amounts of blow by/ crankcase pressure. I have been around buicks for a long time and even ones that run high boost (26-30 psi) thats not ever really had a problem with oil leaks.


oil from the breathers... if you will look at the stock stamped rocker arms they hold a puddle of oil and @ 5k rpms thay puddle gets thrown eveywhere. If one would look at the placement of the stock oil fill hole will notice that the hole is almost over the end of a rocker arm where this puddle of oil is being thrown up to the top of the cover.

I used to have a problem with this @ the race track and i was thinking it was a blow by issue till i ran the car on the dyno with the hood up and i saw very little vapor caoming for the breathers so i know it was not a sealing isssues with the engine. When i swapped out my rocker arms to the kenne bell 1.65 roller tip rockers this problem went away.


http://www.turbobuick.com/forums/engine-tech/233803-breathers-pcv-tube.html

 

[Pablo]

what do you consider high boost?



I would tend to think that you have something wrong since you have high amounts of blow by/ crankcase pressure. I have been around buicks for a long time and even ones that run high boost (26-30 psi) thats not ever really had a problem with oil leaks.


oil from the breathers... if you will look at the stock stamped rocker arms they hold a puddle of oil and @ 5k rpms thay puddle gets thrown eveywhere. If one would look at the placement of the stock oil fill hole will notice that the hole is almost over the end of a rocker arm where this puddle of oil is being thrown up to the top of the cover.

I used to have a problem with this @ the race track and i was thinking it was a blow by issue till i ran the car on the dyno with the hood up and i saw very little vapor caoming for the breathers so i know it was not a sealing isssues with the engine. When i swapped out my rocker arms to the kenne bell 1.65 roller tip rockers this problem went away.


http://www.turbobuick.com/forums/engine-tech/233803-breathers-pcv-tube.html

So are you saying that anyone that has an oil leak issue must have an engine problem? That's a pretty broad brush you are painting with. Do a search and you will see plenty of big names using vacuum pumps and reporting a decrease in oil leaks. Are you saying that they all don't know how to build an engine that seals well? I'm not just talking about turbo buicks either, I have seen this issue on LS1s and Fords.

What do I consider high boost? I run around 30 psi at all times, times are in the sig and that mph is with the converter unlocked. Is my engine in perfect condition? Probably not, but it sure runs pretty good. If I have a severe blowby issue then I must have the fastest stock long block car on the planet considering the handicap.

For the record. Before this setup I ran two open breathers without a pcv valve (i thought the pcv was leaking so I removed it). On the dyno it didnt look like it was blowing a ton out of the breathers but it was enough to start leaking oil out of the rear main at full tilt.

This whole issue is kind of frustrating because plenty of people have oil leakage issues and then we have folks saying that this isn't possible unless we have a damaged engine. Lots of hurt engines are running pretty good mph's then. Can both of those be true? That seems pretty unlikely to me so either people are lying about their mph's or they are making up the fact that their engine leaks. Which one is it?

 

[SloGN]

So are you saying that anyone that has an oil leak issue must have an engine problem? That's a pretty broad brush you are painting with. Do a search and you will see plenty of big names using vacuum pumps and reporting a decrease in oil leaks. Are you saying that they all don't know how to build an engine that seals well? I'm not just talking about turbo buicks either, I have seen this issue on LS1s and Fords.

What do I consider high boost? I run around 30 psi at all times, times are in the sig and that mph is with the converter unlocked. Is my engine in perfect condition? Probably not, but it sure runs pretty good. If I have a severe blowby issue then I must have the fastest stock long block car on the planet considering the handicap.

For the record. Before this setup I ran two open breathers without a pcv valve (i thought the pcv was leaking so I removed it). On the dyno it didnt look like it was blowing a ton out of the breathers but it was enough to start leaking oil out of the rear main at full tilt.

This whole issue is kind of frustrating because plenty of people have oil leakage issues and then we have folks saying that this isn't possible unless we have a damaged engine. Lots of hurt engines are running pretty good mph's then. Can both of those be true? That seems pretty unlikely to me so either people are lying about their mph's or they are making up the fact that their engine leaks. Which one is it?

I'm not saying that their engines are bad. i'm just saying when an engine gets some pretty good wear on it your gonna have some blowby issues thus causing the leaks., So putting a vac pump on it still does not cure the reason for the blowby. Thats all i'm pointing out.

Alot of the fast guys out their are putting vac pumps on to reduce pumping losses in the crankcase to get every last horsepower from the engine.



BTW is your rear main seal stock? if so the rope seal needs to be replaced and that will be a start to help curing your oil leaks that your saying is cause by crankcase pressure. In stock form the rope seal leaked like crazy with a stock turbo @ 15 psi of boost.


but i understand it tho you rather put a vac system on the car and band aid the problem instead of fixing the actual problem.

 

[Pablo]

So what is my actual problem then?

Why was I leaking from the valve covers prior to the pump and not afterwards?

Bad blow by?

I definitely know my engine is no spring chicken and wont have 4% leakdown... but if it is such a problem don't you think that would be reflected in power production?

I put down 460 to the wheels at 4800 rpm before the spark got blown out on some bad plugs. 500 hp to the wheels doesn't sound like a stretch to me now with my engine with 'severe blow by'.

 

[TurboBuRick]

So what is my actual problem then?

Why was I leaking from the valve covers prior to the pump and not afterwards?

Bad blow by?

I definitely know my engine is no spring chicken and wont have 4% leakdown... but if it is such a problem don't you think that would be reflected in power production?

I put down 460 to the wheels at 4800 rpm before the spark got blown out on some bad plugs. 500 hp to the wheels doesn't sound like a stretch to me now with my engine with 'severe blow by'.

Pablo, you are a very bright individual and I read allot of your post's but your chomping at the bit and it's only a matter of time. I do like the evac pump idea and would love to do something like this but it would be more for vapor not to keep oil in the motor. I'm sure a leak down test would show it's ready for a refresh.
I would yank it out. Turbo cars can still make big power with worn rings. When you force feed fuel and air, they have no choice.

 

[SloGN]

Pablo, you are a very bright individual and I read allot of your post's but your chomping at the bit and it's only a matter of time. I do like the evac pump idea and would love to do something like this but it would be more for vapor not to keep oil in the motor. I'm sure a leak down test would show it's ready for a refresh.
I would yank it out. Turbo cars can still make big power with worn rings. When you force feed fuel and air, they have no choice.

that is what i'm tring to say.


but the way he is writing out this information is that is the solution for every buick out there that has a oil leaking from the motor.

 

[SloGN]

So what is my actual problem then?

Why was I leaking from the valve covers prior to the pump and not afterwards?

Bad blow by?

I definitely know my engine is no spring chicken and wont have 4% leakdown... but if it is such a problem don't you think that would be reflected in power production?

I put down 460 to the wheels at 4800 rpm before the spark got blown out on some bad plugs. 500 hp to the wheels doesn't sound like a stretch to me now with my engine with 'severe blow by'.

your talking power numbers now huh. if you making that kinda horsepower why the low mph in the 1/8? i don't think i make those kinda numbers and i have run 96 mph in the 1/8 and i know that my car is heavier than your is. i still have all the a/c stuff on my car . also i noticed that you have NOS solonoids on the car . so are you running the gas also.

last time i dynoed my car it made 365/497 torque with 18 psi of boost on pump gas. and when i ran my 7.36 @ 96 the boost was @ 22 psi through out the run. this was also with the stock cam and 1.65 roller rockers with a gt61-52 turbo and stock headers.


so i don't think going from 18 psi to 22 psi is gonna make me gain another 100.

You brought up the numbers thing so i would show you some more numbers. I only posted here is to state that you don't need a vac pump to keep oil leaks away if every thing is in working order like it should be nothing more and nothing less.



Also for the record i saw a 86 t with a stock engine with 130k on the clock with a big set of injectors fmic a 9/11 convertor and a te-45a run in the high 6's @ 99-100 mph with 30 psi of boost in low 90 degree heat and that car got beat on all the time and didn't have a problem with oil leaks. it didn't have nos on it.

 

[Pablo]

Rick, thanks for the compliment. I am not surprised that oil leakage is likely a consequence of worn rings. What I was getting at is the extent of the ring wear or leakage. From the way some have made it sound, to have this kind of blow by means the engine is on it's last leg. This would run contrary to the kind of things I have seen in other cars that leak as well. Maybe relative to a fresh buildup this is on its last leg, but I have seen far worse. I will be pulling this thing out soon for a 4.1 so I don't deny that it is tired. This still doesn't explain how many other people with relatively fresh builds have seen leakage reductions with the vacuum pump setups. To me it seems unreasonable to believe that all of them need to re ring their engines. I could be wrong though.
At the end of the day, the vacuum pump set-up still works for a number of us that still have fun running our cars hard. And to me, that is what ultimately matters.


SloGN

My times were run with nitrous only activating till about 16 psi and then it turned off. I launched off the foot brake. I assure you that I can replicate or better that time without nitrous using my trans brake. I only did cut a 1.7. My MPH was 96.5 and I think you should consider that my torque converter was unlocked on that run. It's not much of a stretch to see 2 mph from locking the converter, maybe more. So I think that is more in line with the 86T you have witnessed.

If you ran 96 mph @ 22 psi on the stock long block then I am highly impressed and I commend you on that. I will take you for your word that that is all you did. Honestly, it doesn't sound possible to me but I have been wrong before.


If you don't believe me that I made 460 hp at 4800 rpm I can scan my dyno sheet. This was done at JDM concepts in Oceanside California on a dynojet with the converter locked. Plenty of witnesses.

 

[Turbo1dr]

If your valve cover gaskets leak... THEY NEED REPLACING!
If your rear main oil seal leaks... IT NEEDS REPLACING!
If your oil pan gasket leaks... IT NEEDS REPLACING!
The list can on and on and on for oil "leaks"...BUT if you have excessive crankcase blow-by you need to address the following BEFORE INSTALLING A VACUUM PUMP!


Fix what's causing the oil leaks/blow-by problem...plain and simple! A bad PCV system will cause crankcase pressures under boost. Make sure that is working 100% first. If you've already got that PCV system working as good as possible then you must have other issues.

Piston rings: They need to seal very good to eliminate blow-by. If they don't seal properly high cylinder pressures blow past the rings and into the crankcase causing pressure. This forces the oil out of the breathers. To help cure this you'll need to install Total Seal gapless piston rings.

Valve Guides and Seals: Another cause of pressure in the crank case is worn out valve guides and valve seals. Since there is positive pressure in the intake, the pressure can travel up the intake valve stem and past the seal into the crankcase. Remember, 20psi of boost can leak past a worn guide/seal quickly. This is especially true on the exhaust since the exhaust pressure is usually almost twice as much as the boost pressure. Burnt gases from the exhaust can enter the crankcase through worn valve stem seals.

Head gaskets: Leaky cylinder head gaskets. High cylinder pressure can leak past the head gasket and into the crankcase also. Obviously, this is probably the majority of where all the pressure comes from in a Turbo Buick engine that's been pounded to death.

Misc: Most likely not the cause but worth mentioning. Leaking intake gaskets, a crack in the intake manifold or head. Even the turbo could be causing some but again it's a possibility that could be true. Got to cover everything...


In simple terms...it means you need to keep the air in the engine where it belongs...IN the cylinder and cylinder head runners!

 

[TurboBuRick]

Rick, thanks for the compliment. I am not surprised that oil leakage is likely a consequence of worn rings. What I was getting at is the extent of the ring wear or leakage. From the way some have made it sound, to have this kind of blow by means the engine is on it's last leg. This would run contrary to the kind of things I have seen in other cars that leak as well. Maybe relative to a fresh buildup this is on its last leg, but I have seen far worse. I will be pulling this thing out soon for a 4.1 so I don't deny that it is tired. This still doesn't explain how many other people with relatively fresh builds have seen leakage reductions with the vacuum pump setups. To me it seems unreasonable to believe that all of them need to re ring their engines. I could be wrong though.
At the end of the day, the vacuum pump set-up still works for a number of us that still have fun running our cars hard. And to me, that is what ultimately matters.

I agree but a good set of breathers should do the job. Like Turbo1dr said, I think the problem most people have is related to a bad pcv leaking boost into the case. I run a industrial ss check inline with the pcv. I also have a catch can in line. I only have one breather in one valve cover and the other valve cover is pluged. Very minimal laekage. My motor is a couple years old now with some good beatings on it. I run around on the streets 23-24 psi.

 

[SloGN]

Rick, thanks for the compliment. I am not surprised that oil leakage is likely a consequence of worn rings. What I was getting at is the extent of the ring wear or leakage. From the way some have made it sound, to have this kind of blow by means the engine is on it's last leg. This would run contrary to the kind of things I have seen in other cars that leak as well. Maybe relative to a fresh buildup this is on its last leg, but I have seen far worse. I will be pulling this thing out soon for a 4.1 so I don't deny that it is tired. This still doesn't explain how many other people with relatively fresh builds have seen leakage reductions with the vacuum pump setups. To me it seems unreasonable to believe that all of them need to re ring their engines. I could be wrong though.
At the end of the day, the vacuum pump set-up still works for a number of us that still have fun running our cars hard. And to me, that is what ultimately matters.


SloGN

My times were run with nitrous only activating till about 16 psi and then it turned off. I launched off the foot brake. I assure you that I can replicate or better that time without nitrous using my trans brake. I only did cut a 1.7. My MPH was 96.5 and I think you should consider that my torque converter was unlocked on that run. It's not much of a stretch to see 2 mph from locking the converter, maybe more. So I think that is more in line with the 86T you have witnessed.

If you ran 96 mph @ 22 psi on the stock long block then I am highly impressed and I commend you on that. I will take you for your word that that is all you did. Honestly, it doesn't sound possible to me but I have been wrong before.


If you don't believe me that I made 460 hp at 4800 rpm I can scan my dyno sheet. This was done at JDM concepts in Oceanside California on a dynojet with the converter locked. Plenty of witnesses.

Pablo
I'm alos not doubting your HP #'s but i'm think one's car would be traping a faster mph with those kinda of numbers considering the amount of power that my car was making @ 18 psi .

When i ran my 7.36 @ 96 mph that was with the stock cam,1.65 roller rockers and stock headers. I did however have ported heads on the engine. But you made it sound like one must have 450+ horsepower to run 96 mph in the 1/8 mile. I was giving you my combo that i ran 96 mph with and what i dynoed @ 18 psi on pump gas. sorry that i didn't mention that i had ported stock heads. I was thinking that you would have read my sig for the mods.


I recently had a headgasket failure and while it was apart i install a lunati 200/200 cam and got my intake ported along with the egr tower removed.

 

[fc227]

Here is what I am running.

I have the vacuum pump on a relay that is triggered by a Hobbs switch set @ 4#.

I draw from the pass. Side valve cover breather though the pump. The output of the pump, pumps into a breather tank (vented catch can) that as a breather on top.

I run a check valve inline with the PVC valve also.

 

[chasmat2316]

any new info on this setup? more pic's?

 

[Pablo]

what else do you want to see?

The setup is still working great just as it was pictured at the beginning of this thread.

 

[Nick Micale]

Gee Pablo, you do an informative post with lots of details, pics and good info, all for the "privilege" of getting bashed because someone does not think it is necessary or ????

You did a great job, thanks!:smile:

We do LOTS of race engines for lots of racers, and a lot of the faster cars have a vac system of sorts even if they are not turbo charged.

Actually most GN owners remove the factory vac system - the pipe from the passenger valve cover to the turbo inlet. When you take 1960's technology, like our V-6, it takes a different approach and solutions than the 21st. century performance cars that were "born" with computer pollution controls.

With the turbo Buicks, from low 11's and faster, crankcase becomes an issue be it leaking oil, or increased performance, or both.

Based upon personal experience with low 10 high 9 sec. GN's, I have seen 1 to 2 tenths improvement with a proper vac system. Just a side note, just a few weeks ago my vac pump quit on a 10.0 run and blew out a VC gasket at the top end [at 20 psi boost].

All of our 8 and 9 sec. engines are built to run with a vac pump. This also applies to most of other brand engines built to run these speeds or better.

A boosted engine runs stupid high cylinder pressures, even if it is for a second or less, and this equates to higher than normal crankcase pressures. I have seen many street driven GN owners complaining about a rear main leak or VC leak when it is actually oil from both after market breathers leaving a small trail of oil.

Certainly the imports, and domestics, have developed better ways of crankcase pressure management the Buick did 40 years ago. We were lucky to get a 90 day factory warranty on our cars, and certainly NEVER 3 years [or 5 years or even lifetime!].

So Pablo, do not be distressed by posters with "more internet" experience than what we have and do - working on 20+ year old turbo Buicks to improve them.