baezi z06

iTrader: (2)

Hi

i just installed GZ motorsport vacuum pump on my car

itīs Vette C5 404ci nitrous build (.026-28" ring gap) had alot of blow by before

itīs adjustable valve pressure

But where should i set it, i donīt wante it to suck from the bearings

but off course i wante it to pull as much out of the crankcase as i can

thanks
Baezi

Big Al

iTrader: (1)

Suck what from the bearings? The worst it can do is suck air past the seals. If you're drawing all the vacuum from one valve cover it could suck up oil trying to drain back into the block from the drain holes. You need to check the crankcase vacuum and see where it is. 12" is considered the most you want. That's less than 1/2 pound.

Al 95 Z28

subhumanzz

iTrader: (46)

i have the gz pump in my car and i have it pulling 12" with no problems. just keep an eye on you oil psi.

baezi z06

iTrader: (2)

what i ment was so i wouldnīt loose oil pressure.

iīm sucking from oilcap (passenger side) -10AN line to vacuum pump
valve covers are connected whith small -6AN line
monitoring the vacuum from valley cover nipple

whatīs your psi at WOT

trying to understand this

some motors tolirate more vacuum sucktion then others, for example in some race motors people are sucking 15" out of it but others just 10"-12" , and i was told to set it 8-10" to keep it save

so if i monitor the vacuum and the oil psi at the same time when adjusting the sucktion i should just start in 10" and work my way up .

thanks
guys

JL ws-6

iTrader: (50)

If you start to see any oil pressure loss you are pulling too much, too much vacuum can pull the oil from the wrist pins and start issues that way... 8 to 10 inches most all good engine builds will be fine with, 12 is fine but any more then that I would not do unless the engine builder specifically told you to do. There are certain parts which tolerate more vacuum the others, coated wrist pins for example.

mrdragster1970

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Here's what I did with my Camaro.
Back before I towed up & back, I had a valve that I opened when driving.
After the burnout, I closed it, and had it set for 15".
On the Lumina I don't need it, I must tow it up & back.

The valve let's you get max power, and windage control while racing, especially with power adders,
and lets you get better oiling when you're just driving around or putting heat in the engine.
Like you said, you definitely don't want to starve the pins!!
Without the valve, I would definitely set it much lower, but that's because you have to compromise for off track use.

I can draw up or explain better if anyone is interested in a combination system.

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baezi z06

iTrader: (2)

i did build the engine myself

this is a daily driver and a weekend warrior so i have to find the good middle way

i have a wiseco pistons , eagle h beam rods and ported LS6 oil pump

iīll set it first 8-10" and monitor the oil pressure and then see what it does at 12" decide from there

thanks guys
guys

JL ws-6

iTrader: (50)

Nothing wrong with building the engine yourself! At least you KNOW what's in it, and how it went together, and that's priceless!

I would start it off around 6, and work your way up, for driving on the street, I would keep it on the low side, just to be safe. 6in. of vacuum on the street won't do any real damage, and you have to remember that's 6 inches at full rpm when the pump's doing the most amount of work.. pully it accordingly so this is the case.

When you find a comfortable level for the track, 10 to 12 I would say, then just change the pulley when you're going to the track. GZ setup looks like that would be pretty easy to do.

That's how I would manage it, there's several ways, dragster's vent valve would work as well, be easy enough to have a ball valve in a line that runs to the catch can from the vacuum pump on a seperate line, open that when you are driving around, and you could just pull the vacuum pump's belt off... that way you don't have to worry about any wear and tear on the pump while driving as well... that would probably work pretty good.

ATwelveSec02Z28

iTrader: (17)

I have been told 10-12max or risk burning wristpins.

Then I heard from reliable source that they run as much as possible.

Tensec94z

iTrader: (1)

I have been driving my car on the street fo 6 years with the GZ kit and have never had any engine issues,you are not going to be pulling that much vaccum at cruise speed, maybe 5 to 8. I have my regulator set at 15 for WOT, just my 2 cents.

JL ws-6

iTrader: (50)

IF, you build a motor with the proper parts, like coated wrist pins, or have oil squirters in the motor tossing oil at the back of the pistons you can run as much as you want without having to worry about anything... but to do that with a motor that wasn't set up for it is taking a chance with very little return.

Firehawk441

iTrader: (41)

I use 15" hg. in a Nitrous drag race application.

I also suggest looking into your blow by issue or you'll be filling that catch can quickly.

baezi z06

iTrader: (2)

fired the car up today and went a little driving around got it well warmed up, and then i stopped to do some tests whith adjusting the valve relife

but i noticed right away one strange thing i had the valve adjusted at the smallest suction first 6" or so and when i reved it up (in park position )i only got 43psi oil pressure at 6500rpm itīs not climbing whith the rpm.

just changed oil and filter (10-30 oil)
im running (ls6 ported pump btw) and the oil pressure has always been like this before around 55-60psi cold and when its hot around 40psi cruising around and 25-30 ideling but not sure what it did @wot before though but it always did climb a bit better then this

but i made few adjustments went to 10"@6500 and it didnīt change the oil psi i was in the 40-45psi but when i stepped of the pedal it went up to 12-13"

so i ask two things

isnīt my oil pressure strange, (too low) it doesnīt climb whith the rpm after 40-45psi??

if it sucks 10" @6500 and then when you step of the pedal it goes up a bit 12-13" is tha normal

maby i need to replace my oil pump to something more flowing like melling for example.

what to you guys think

mrdragster1970

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Oil pressure is usually lower with a vacuum pump.
That's why we pull the line when breaking in and warming up.


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baezi z06

iTrader: (2)

ok iīll pull the belt off and see if it makes any diffirence

but 40-45psi oil pressure @ 6500rpm on hot ls2 motor is that ok ?
thought it should be 10psi@1000rpms so a 55-60psi should be more like normal

it climbs up to 40-45psi whith the rev and there it stopps, but i havent tried a load in gear on the motor yet

but thanks guys

Baezi

mrdragster1970

.

That's something I would not be any help on.
I've used a dry sump for many many years, and don't want to screw you up.
10 per 1000 is common, and we are usually above that, but for max power some guys do go a little less.
I've seen guys that use 10 per 1000 minus 10-20, so I know a 9000 rpm guy that uses 70 psi and so on.

.

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baezi z06

iTrader: (2)

i went out for a little drive in the rain

did a bit of testing

took the belt of the pump and iīm getting 50-52psi whith belt off iīm loosing 7psi whith the vacuum pump on

i set the valve relife at 5" first and then up to 11" of vacuum and it didnīt change itīs was always between 40-45psi at 6000-6500rpm whith the vacuum pump running


baezi

studderin

iTrader: (28)

ya thats normal, your going to loose oil psi on what the gauge reads, from the vacuum present in the oil pump inlet. Same deal on inlet restriction on a blower, or any other pump. I dont have a answer for you on what to do, and whats "ok" for your stuff. But now your getting into the volume vrs pressure com paired to what you and most are used to working with.
I want to get a vacum pump too, Im looked into this alot but kinds got busy to know for sure before I order parts. But was going to get a moroso pump, everyone with the GZ and cheaper setups, don't really show a HP gain. Guys do with a better moroso pump. I found some info for a stock motor, back when he was cam only, LS1joe. honeycutt, t56 rebuilds. Put a good moroso pump setup on his car and gained 11whp back to back, (belt on/off making 470whp, be went 132-133mph's fyi) I know he wasn't street driving the car but raced it a bunch. I never looked into when he pump the pump on, and how long the motor lasted. if it did blow up I dont know what happened to it? I'm planning on just talking the belt off, or tuning it down for street driving. I think the wrist pin thing is a myth, found zero times anyone hard or heard of anyone having a wrist pin issue from lack of oil, or to much vacuum pulling oil of the the air. Pin issuer are from install wrong, or flexing (lightweight, you find alot of engine guy learned not to use the hard way.) Kinda light lighter pushrod to valve train guys. Weight there don't matter as much for a racing engine, the other things the part has to do, and deal with a vary more important!
On a stock motor or built, but then again not many people are going to put a good setup ($$) that can pull 11-15" on a stock motor. Maybe look into the mustang guys, NMRA/NMCA. I think they have some stock classes, you can run a pump on. But Its gona be hard finding any on a forum talking about tech into like that for a headsup class.

You can fine some good on yellow bullet about this, and maybe speed talk years ago, but lots of retards. George Bryce (sp? The prostock bike/STAR) talks alot of good stuff about this on YB, ATV racer sent me a link to the thread but I'm sure you can fine it, its long.