Need opinions and or advice
want to have an efficient breather system for my BBC street strip combo (see sig) this motor should generate a lot of cylinder pressure, was considering pcv valve on pass valve cover and breather on driver side , however concerned my cam will not create enough vacuum to make pcv work ... also using GMPP cast alum BowTie valve covers that have no provisions for breathers etc. would like to retain that clean look on pass side especially since I'm using a cowl plenum AC that leaves little room for breather under snorkle.
I am considering drilling driver side valve cover for combo breather / oil fill cap and tapping rear of block for AN 10 or 12 fitting that would allow a baffled vent tube in lifter valley ( like early small blocks ) and attatch a hose to the fitting venting it to one of my header collecters using a Moroso check valve ???

I purchased welded aluminum valve covers from 66 283 {Ryan}, and there were a couple of bungs welded into the covers, so I bought a couple of fittings and ran braided hose {{#10 I think} down to the Mr. Gasket evac pipes that are welded into my 2" Hooker Comp headers. I guess I will get oil into the motor through them. I hope the cops don't go crazy when they see no PCV in the valve cover!

Did a search graemlins/clonk.gif ... it seems if mufflers are used creating backpressure then a evac system will not work well ...... so back to pcv .... any particular pcv i should use for low vacuum idle ???

We use a GZ Motorsports vacuum pump on our long-distance road racer. It pulls 5" of vacuum at an idle and is limited to about 10" by a relief valve inside the breather. I vacuum tested the engine before it was installed and found the majority of the leaks. I was able to draw the crankcase down to 12" using a 1/4" fitting on the fuel pump blockoff and a 2hp vacuum pump.

I first encountered issues with this (conventional dual output pan evac) with my 427 a few years ago. Between 3000 and 4000 RPM there was a point of high backpressure (that went away above 4000) in the exhaust. Found it the hard way and blew the oil pan gasket out.

The solution that I found effective was to go with one pan evac tube and a breather. You still get all of the benefit from the pan evac set-up without having to worry about a backpressure issues.

In my opinion a vacuum pump is still the answer, however life span on a daily driver is severely limited or highly labor intensive.

Just my two bits.

Adivanman
www.adivanman.com (http://www.adivanman.com)
www.point-cars.com (http://www.point-cars.com)

Adivanman ...... so what you are saying is if I run a good baffled breather on the driver side valve cover and vent the block in the lifter valley to one header collector , which is what I am planing to do ..... this should work with no issues when using mufflers .... sounds like you have done this and it works with no oil blowing out and no internal pressure build up ??

At this stage a vacuum pump is not where I want to go ,but I do understand the value of using one ...... thanks for the info I appreciate it . Bill

Anyone else ?

Hi Bill,
Can't really add anything as I haven't tried this but what I would do before plumbing it all up is tap the exhaust system where you are planning to run the evac & be sure you do not have much back pressure under most conditions.
What I did on the last 427 SB with cast Dart covers is put AN fittings in the back of the vlv covers & run them to one of those small puke tanks with a breather mounted on the firewall with stainless lines. Seems to work great & any misting or blowby that the engine generated ended up in the tank which has a little drain valve in the bottom.
Don't know if you have room between your covers & the firewall but if so it keeps the covers lookin super clean.

If you run 3 inch or larger race mufflers and 3 inch pipes, the moroso evac system will work. It worked for me anyway.

Ok guys thanks for the info ... don't see any reason not to go ahead with my original plan, will take your advice Mike and ensure good vacuum where i tap into the collector

CDN SS,

It's your neighbor from out west (AB). I run a GZ Motorsports vacuum pump - the evacuators plumbed to the collectors will work - to keep the oil in the motor, but if you put a vac pump on it - it will make more power. At least 20hp in most cases.

I've put quite a few street miles on mine and I haven't rebuilt it yet.

66283 ..... BTW I saved your last vid at Raceway Park ... great !! Geez 20hp sounds tempting but this project started out to resto my old Chevelle now it's out of control :D my engine builder wanted to put a vacuum pump on as you suggest ...... I'll talk to him again about it but I really want to retain the stock look

The GZ vacuum pump is a modified smog pump, so it looks at home on a 'stock' motor. I was talking to Greg a couple of days ago and he is working on a line of street pumps with improved vanes. One thing the pump needs is oil going through it to keep the temperature down. We had virtually no oil coming from the motor, so I installed a recirc line to recirc oil from the catch can back through the pump. It worked very well, and the pump stayed cool.

You can see the pumps at:
http://www.gzmotorsports.com/index.htm

Gotta stop asking questions on this site .....I'm getting too many good answers

...I did check out GZ site ....now I'm thinking about it ......street pump, hmmmmmmm

One thing about the GZ's - I think the brackets are junk - the easiest way is to put a motor plate, even a half of one that bolts to the block and mount it to that with some thick bushings. I mounted it with the supplied bracket and then pushed on it and said "ya, right :rolleyes: "

And the pulley has a small pin that goes into a hole in the crank - sheared one off so add a second one 180 deg out before you run it. Word to the wise.

building a new motor this year,tired of running a pcv and caking the intake valves

mr. gasket has an electric vacuum pump designed for crankcase evac.

has anybody tried one?????

The Moroso electric would be brand new if its been released yet. I looked into this last summer and it was not available yet. I ran an electric GM pump (auxilary air pump for late LT1), it worked good for about a month then burned up.

This may sound weird, but now I run a small check valve inside my air breather that opens (lets air into the crankcase) at 6 psi DP and an ordinary PCV on the other valve cover. It pulls a slight vacuum on the crankcase at idle and at cruise speeds which helps reduce leaks, etc but does not have any effect at WOT when there is no vacuum. But the check valve restricts air flow through the crank case which IMO might help reduce the amount of oil mist sucked into the intake (valves caking). This type system combined with a pan-evac might work well on a street car with a very low back pressure exhaust system.

6 psi is about 12" of vacuum, which is a lot for a pcv valve to create in your crankcase. Do you ever get to 12" with the evac system?

Eric68 ... the GM pump you used .was it one of these ?

Dumb Question ...IF we could get an electric vacuum pump to live could it be used to provide additional vacuum for power brakes AND a pan evac sytem for the street

http://www.hardtail.com/techtips/vacuum-pumps.html

Hi Bill,
Interesting article!! Thanks for posting it.
I would try the electric pump & just run it when you are "leaning" on the engine :D
Are you going to Dyno it? Would be interesting to do a pull with & without the pump.
BTW, Did you get down to pick up your lifters?

Hey Mike yes got the lifters, Thanks...... yes I'm hoping to get the motor on an engine dyno before I put it in the chassis ...... The idea of an electric pump intriques me , especially if I can use it to supplement my power brake booster (I have a vacuum camister but this should be better) I like the electric idea because I could hide the pump under the dash or somewhere out of sight .....I'll get with my engine builder to see what he thinks , pbly driving him crazy changing my mind , cause I like his idea of a single evac tube to the header and a breather too.


Mike .... just a thought, if I hooked up the pump to a Hobbs switch to turn it on at a certain vacuum setting would that make sense ?

I don't know how much capacity the electric pumps have but I would think you would want to use manifold vacuum along with the pump for the brakes both for safety & reliablity. Don't know exactly how you would plumb it for both??
The Hobbs switch for the brakes sounds like a good idea for when the vacuum drops to low.
You would want it the other way for crankcase vacuum. It would probably be eaiser to use a pressure relief on the inlet side of your crankcase system.

Run 2 pumps, one for brakes, and one for pan evac. You can buy Hobbes switches for vacuum?

Onovakind - the electric GM pump only pulled a couple inches at idle, maybe 3 or 4 inches at cruise speeds. If my setup were a little "tighter" it probably would have pulled more. I just got done changin my oil pan and pretty much all my gaskets - the engine is tight as a drum now and I should probably check to see how much neg DP I can get on the crank case with the PCV setup. I'm certain it never pulls enough to open my check valve except maybe during deceleration; my engine only makes 6 - 8 inches at idle.

CDN SS - no those part numbers are mechanical pumps that could be bolted to your fuel pump boss if you are using a separate electric fuel pump. I looked into this before I bought my electric vac pump. The mechanical pump would work nicely for power brakes - thats basically what they were designed for since those little 4 banger cars didn't make enough vacuum to run accessories reliably anyway. I'm not sure how well they would work for evacuating the crank case - the one I looked at had a small 1/8" inlet/outlet.

Hi Guys, I have to jump in on this one.

I have used an electric Vacuum pump for crankcase evac for 2 years, the pump came from an early 80's caddy diesel. GM used it for brake vacuum. It works great for either evac or brakes but not both together (I tried) The way I plumbed the system is to plug one valve cover (oil fill hole) and put a 90* fitting into the other valve cover, with a 3/8" hose to the vacuum pump. the pump exhuast goes into a seperator (a cheap one from summit). It does get a little noisy at idle but I got use to it.

Now the best part It was worth a .15 sec. in the 1/8 mile and almost .25 in the 1/4 mi.

I have run it with and without enough times, because some of my friends did not believe me so I would run with them in the car to show I was not BS them

Hope this helps some

Mike

I'm using one of GZ motorsports pro series pumps on mine. Unlike 66 283, I had pretty good luck with the brackets for the pump - my alternator brackets need some work though. Greg's made some changes to the crank mandrels he has since I bought mine, they are better design now.

i feel like i should say a few things about my experiance so far with evac systems............

i spent 60 bucks for nothing on this deal...i took my headers off and had bungs welded on them.....bought the check(one way) valves and all the tubing from summit to run both sides of my valve covers on my bbc.....

with 2 1/2" exhaust dumping at the axle with mufflers. there was pressure being built up in the system. at idle with a vacuum gauge i was looking at about 3" and as soon as you stepped on it going down the road my vacuum went to pressure side of about 5".......in return i started to get oil leaks........ now i tried it with out exhaust and i saw a vacuum pull all the way thru the 1/4 mile it varied some 3 to 5" but at least it was on the pos. side........

to me it was a waste of time and money. i took it all apart and put my chrome breathers back on....

on my current ride for daily driving i was playing around with the pcv valve and with it on the drivers side and the other side blocked off i get about 5" of vacuum pull.....(i put a gauge on the pass. valve cover) but the bad thing about it is there is no vacuum at wide open throttle so pressure builds......but as soon as you left of the gas i jumps way the heck up there.......

now my engine in my 80 makes 5.5" at 600 rpms and i run a pcv on the drivers side and a breather on the other side .there is no oil spray anywhere and no leaks on the motor its a good basic set up........

i would be against hooking any exhaust up to the intake valley area on a street driven car with exhaust system.........a plain pcv works just fine on the drivers side and breather on the other......

but im thinking about maybe getting me a smog pump and see what i can do with it.....that would go with my sleeper look......lol

really good info here guys .......thanks for sharing MFCA 72 good info your info helps alot .

i'll call moroso and mr. gasket today about there new electric vacuum pumps

i like the idea of being able to run an open system on the street using a breather,and a closed system at the track,by replacing the breather for a cap.

finally a true street/strip evac system.

i'll call moroso and mr. gasket today about there new electric vacuum pumps

i like the idea of being able to run an open system on the street using a breather,and a closed system at the track,by replacing the breather for a cap.

finally a true street/strip evac system.

[QUOTE]Originally posted by MCAF72:
[QB] Hi Guys, I have to jump in on this one.

I have used an electric Vacuum pump for crankcase evac for 2 years, the pump came from an early 80's caddy diesel. GM used it for brake vacuum. It works great for either evac or brakes but not both together (I tried) The way I plumbed the system is to plug one valve cover (oil fill hole) and put a 90* fitting into the other valve cover, with a 3/8" hose to the vacuum pump. the pump exhuast goes into a seperator (a cheap one from summit). It does get a little noisy at idle but I got use to it.

Now the best part It was worth a .15 sec. in the 1/8 mile and almost .25 in the 1/4 mi.

I have run it with and without enough times, because some of my friends did not believe me so I would run with them in the car to show I was not BS them

Hope this helps some

Mike

Mike I'm very interested in your set up, does your pump run all the time or do you have a vacuum switch on it ?? do you also have a power brake car and if so does the vacuum pump pull vacuum out of the motor so much that it effects brake booster. I am going to see if I can locate the pump you describe to see how big it is etc. Assume electrical how prety basic . Anything you can add would be appreciated BIll

ttt

I have never used one of these pumps for Crank Evac but they work great for brakes and only cost $10 to $15 bucks at the yards.

http://www.gmcmotorhome.com/tech/vacuum_pump/index.html

Sorry guys I went to Turkey Run this last weekend

Yes the pump runs all the time, it comes on when the car starts (+12v ign.).I did put a toggle switchin line so I could shut it off if wanted. that is how I discovered the performance improvement, I left it off accidently graemlins/clonk.gif

The pump cost $120.00 from the caddy dealer parts counter (this was a few years ago. It proubly costs more now)

My engine only pulled ~6" of vacuum so my power brakes did not work well to begin with. That is why I tried to run the brake vac. and the engine vac. at the same time. It would work great for brakes OR engine but NOT both together

The wiring is simple 2 wires, ground and hot. with a weather pac connector

Hopes this helps

Mike

Thanks for replying Mike .....Appreciate it... I'm going to give this a try as a pan evac system .... ..... I'm going to assume the pump you used is one of the ones mentioned in this link , same as Bob mentioned for brakes .

http://www.hardtail.com/techtips/vacuum-pumps.html

Bill

Yes it is similar to the ones in the link

Good luck with the project

Mike

called moroso on the electric pump,they said it was just a rumor that a magazine had printed.

called mr. gasket,they are redesigning the pump that was supposed to be released last spring,this will be a drag race only piece.

i guess i'll have to run the caddy pump,is this only avail. from gm???

called moroso on the electric pump,they said it was just a rumor that a magazine had printed.

called mr. gasket,they are redesigning the pump that was supposed to be released last spring,this will be a drag race only piece.

i guess i'll have to run the caddy pump,is this only avail. from gm???

Ok here is what my local GM connection tells me, most of the pn's in that article I posted a link to on GM electric vacuum pumps are discontinued ...
PN 24505066 is available it is for the Camaro Z28, corvettes,w bodies !! can't imagine why they were used on these cars ??

$130.00 cdn,( approx 100.00 us) goodguy price so I told him to order it, hopefully it is complete and is similar to the one Mike used , should have it in a day or so will see what i get .

Mounting the pump was the hardest part I stuck mine inside the drivers fender on the fire wall. You cant see it looking under the hood. :D I took off the stock mounting bracket and fabbed my own from aluminiun and some hose clamps, with some rubber gasket material for vibration insulation.

Mike

I used the Caddy one for my Camaro for Brakes, just about all of the 4.1L Caddy motors had the Vacuum pumps, not just the cimeron. it was expensive new, but they can be had @ the wrecker.

the vac pumps that are in the late model Camaro's & Vettes are actually pressure pumps for the air injection system (smog pumps). they dont pull a great deal of vacuum & dont work terribly well as a crank case evacuation system.

gains vary a lot with motors that have these pumps added. typically motors with low tension rings get the best gains from evacuating the crank case. another benifit is that most motors will not leak oil with a bit of vacuum on them.

Bob

I meant to mention this before, but spaced it. I checked into running an evac system, but the ones that give the best performance, run about $1000 when all is said & done. I figured that there was other things I could do with $1000 to get a LOT more than 20 or 30 maybe HP.

if there is a puking issue with oil coming out of the valve covers, then this might be a good solution. I would think though that there is an issue to fix & maybe a simple PCV or puke tank might take care of it.

Bob

Originally posted by CaptCrunch:
</font><blockquote>quote:</font><hr />Originally posted by CDN SS:
Thanks for replying Mike .....Appreciate it... I'm going to give this a try as a pan evac system .... ..... I'm going to assume the pump you used is one of the ones mentioned in this link , same as Bob mentioned for brakes .

http://www.hardtail.com/techtips/vacuum-pumps.html

Bill </font>[/QUOTE]Anyone ever pulled one of these from a junkyard? I was looking at 4 or 5 of the listed models and can't for the life of me locate this pump on the driver's side fender or by following lines off the booster. These are on the old 2.5L iron dukes right?

Bob ...... thanks for heads up on Camaro pumps .dbl checked with my GM guy he tells me the pn he ordered also is used on late model Caddy's so should be a true vacuum pump .....FWIW

Update .....finally found a source for these pumps new .... 82-85 Cadillac turns on at 5" hg and shuts off at 20"hg ... can be adjusted .old pn AC Delco # 215-119 discontinued but replacements available under the brand names of Standard Motor Products or Bluestreak Parts both have same part # VCP 103 ... $180.00 cdn or $140.00 US .... comes complete except carbon filter which is available anywhere ....works excellent and way cheaper and quieter than the one Master Brakes sells for 389.00 !!!

Engine done will be on dyno in a few weeks will report back if any benefit from my homemade street pan e-vac with electric vacuum pump

Is there a problem with the GM one you ordered?? Part Number 24505066 ???
Because I ordered one...

Ressurecting this one from the dead.. does anyone have anything to update on the electric pump performance?
I have a 3" full exhaust system and large case mufflers on my 72.. Is there any reason a pan evac system wouldnt work on there?

A pan evac wont work on a full exhaust system, the back pressure up front at the collector wont let it pull vacuum and not enough flow at the back of the exhaust system to create a vacuum. A buddy of mine uses a cadillac electric vac pump on his blown Poncho, he turns the pump on after the burnout and turns it off at the end of the track. I dont think they are designed to run full time, he's on his second electric vac pump.

I have been going through the same thing.Blowing oil out when I run my car with the dip stick trying to come out.I have just settle on the gzmotorsports vacuum pump,after talking to Greg you can get a complete kit which is the sportsmen kit for 669.00.I wanted to be able to drive my car and not worry about it.Thanks to a lot of help from the guys here on the forum I found that to be the best bang for the buck.That may help you it did me.Good luck with yours.

Im trying to figure out how to mount one using the march stuff I already have... Looks like a project unto itself..

http://www.starvacuumpumps.com/catalog.php

I'm using a star machine vacuum pump, they are self lubricating, dont need oil from the crankcase to lubricate and they go much farther between rebuilds. I like how the mandrel bolts to the face of the harmonic balancer/pulley instead of using the harmonic balancer bolt.

Whats the status on anyone using a electric vacuum pump??

A buddy of mine is using a Cadillac electric pump on his blown 461 Pontiac, he turns it on as he enters the waterbox, and turns it off at the end of the track, it serves the purpose but wont last under continuous operation. This is his 2nd pump.

Im helping a buddy on his 66 nova project he is finally getting around to after 20 years..were building a 383 with ported track 1's and he wants to drive it on the street..i have had my head so buried in race cars the last 20 years i have no idea what is the best solution for Positive crankcase ventilation on a street car..I like my vacuum pump but i know that wont last on a street car so any help and ideas would be greatly appreciated
Dennis

Thanks for the help. Always good info on this site..

I'am a the evac stage now and want to know if there any good or better ideas out there for a street cruiser and weekend grudge racer?