[roadrage david]

At what rpm do you whant to see the 12inches of vacume!!.
Im asking becuase i run the same star pump set up for some time now and i was adivised not to go higer then 7 ore 9 inches of vacume!! during my street/ highway blasts!.
I do have a mild oil pan leak, but thats because the engine stoot still 3 years afther it was build with no oil in it .
So the gasgets at the oil pan are probely dried out a bit.
top level oil spray out of the valve cover breathers and dip stik was gone like imidiatly!!.
mind you i used Tinn Indian performance heavy aluminum valve covers and there rubber gasgets. very good stuf also im sucing vacume out of both valve covers and have no breathers..

[67 Lamnas]

Originally Posted by roadrage david

At what rpm do you whant to see the 12inches of vacume!!.
Im asking becuase i run the same star pump set up for some time now and i was adivised not to go higer then 7 ore 9 inches of vacume!! during my street/ highway blasts!.
I do have a mild oil pan leak, but thats because the engine stoot still 3 years afther it was build with no oil in it .
So the gasgets at the oil pan are probely dried out a bit.
top level oil spray out of the valve cover breathers and dip stik was gone like imidiatly!!.
mind you i used Tinn Indian performance heavy aluminum valve covers and there rubber gasgets. very good stuf also im sucing vacume out of both valve covers and have no breathers..

I'm going to start out with a 44% drive ratio and see if I get the 10-12" at 5800-6000 RPMs. Will have the relief valve set for 10" until I get it sorted out.

[roadrage david]

Ok final question who told you that those nrs of vacume are safe!! at that rpm.. because raising my vacume to arund 12 just might help me to close that last leaky point!!!.

[Cliff R]

Running a PCV system doesn't help if the troubles are related to hard runs at WOT. There isn't any vacuum to the PCV valve at WOT, and the crankcase pressure created is forced out at every vent in the engine.

Some engines for a variety of reasons will create enough crankcase pressure at full throttle to push some oil out here and there. A common location on these engines is the oil dipstick.

For most engines a good breather in each valve cover is more than enough to vent the engine on hard runs, and a vacuum pump is not needed. The PCV in the valley pan will handle crankcase evacuation for "normal" driving. I don't see the vacuum pump as being a problem for this particular application. They have proven to make more power on the dyno, and if it helps reduce some of the oil being pushed out here and there, that's even better.....Cliff

[Cliff R]

"mind you i used Tinn Indian performance heavy aluminum valve covers and there rubber gasgets. very good stuf also im sucing vacume out of both valve covers and have no breathers.."

Just a tad confused on this one. Instead of breathers you pull from both valve covers to the vacuum pump? Is there a third breather in the valley pan to take in fresh air? If not, where does the intake air for the crankcase come from?.....Cliff

[roadrage david]

Cliff i gues no where!!!!........ aint it the purpose to create a vacume?? i have 1 air tight leakfree oil filler plug and 1 vacume hose on botch Covers here is the set up http://www.youtube.com/watch?v=LkLQXSygmQM . no vally pan air intake!!.

[Cliff R]

In order to pull crankcase vapor/air out of the engine, some air has to vent into the engine. No engine is completely air tight, it will pull some in someplace, or it would such a gasket in.

It's venting no doubt. I'd use a vent in the valley pan, for two reasons. This insures the engine has fresh/filtered air going in to be pulled out by the vacuum pump set-up.

If crankcase pressure did develope on a hard run, it would have someplace to vent and not tend to push out any gaskets.....FWIW.....Cliff

[67 Lamnas]

Originally Posted by roadrage david

Ok final question who told you that those nrs of vacume are safe!! at that rpm.. because raising my vacume to arund 12 just might help me to close that last leaky point!!!.

I've taken information from others that have more experience than I with vacuum systems. I spoke with Steve at Star Machine and others, and folks that have posted their own personal experiences......

Most recommend a maximum of 15" vacuum with a wet sump oil system...more is OK if it's a dry system......It sounds like much over 15 with a wet sump system runs the risk of inadequate oiling to the piston pins and other areas that rely on splash lubrication......

Maybe the splash thing is not so critical with such a long stroke (4.5"), but I might get brave and see.....LOL

[Probird]

Originally Posted by Cliff R

In order to pull crankcase vapor/air out of the engine, some air has to vent into the engine. No engine is completely air tight, it will pull some in someplace, or it would such a gasket in.

It's venting no doubt. I'd use a vent in the valley pan, for two reasons. This insures the engine has fresh/filtered air going in to be pulled out by the vacuum pump set-up.

If crankcase pressure did develope on a hard run, it would have someplace to vent and not tend to push out any gaskets.....FWIW.....Cliff

The only time you need a vent is if the vacuum pump is capable of pulling too much vacuum. It would take a lot a vacuum to suck a gasket in. At lower vacuum levels you want the engine sealed up as best as it can be with no vent. That's why you want an adjustable pressure regulator in one of the valve covers, to keep the pressure in check. If you put a vent in there that is open all the time the vacuum pump will have a hard time creating a "vacuum" in the crankcase. The less airtight the engine is the less effective the vacuum pump is.

[roadrage david]

The star pump i used hase a internal bijpas!! so no need to have a vent and of a air suply to the crank case.
as pro bird sais you whant as tight sealed engine if posible if you DO happend to have a oil leak like i do raising up the vacume might reduce ore seal it.. my question on how many vacume 67 lamnas is going to run on the street was out of consirn as i was told not to run higher then 7 to 9 inches of vacume any higher would indeed have the risk of inadequate oiling of the piston pins and other areas that rely on lubrication...... as the advice he got is higher then the one i got i might be able to cure my oil leak rasing the vacume up to 13 ore something insted of 9...........

[Cliff R]

Yes, I fully understand the vacuum deal and airtight to be fully effective. In theory that all works fine unless the vacuum pump lacks the cfm capacity to get rid of the blowby being produced......Cliff

[75TA]

I went with the Butler system for the street on my 505. Just got the valve covers back with the welded bungs. When I reseached the proper vacuum for the street, I found that you do not want to go much over 6 or 7 inches. Was told at the time that over this is usually used for only drag racing and could cause oiling problems during long runs such as street use. Also, you will have to watch if your system sucks oil. I run the system for a short time and found you can suck alot of oil.

[2nd67GTO]

The majority of this conversation is above my knowledge level, but feel I need to comment based on a recent experience. Strictly drag motor, not even sure of the displacement as I just help with the car occasionally, but the pin location within the piston was high enough into the oil rings that a removable ring land, or oil ring back up ring so to speak, was required. During the initial teardown, the presence of these was missed and they got tossed. After rebuild, we had oil leaks very similar to what you're experiencing. Rear main, dipstick, even 4 corners of the pan. Vac pump helped very little. Leaked-down at 10-12% in all but one cylinder, Highest at 15%. Not great, but not terrible. After much discussion, arguing and near fist fight, motor got pulled and tore down. It was pretty obvious alot of blow by through the pin/oil rings.

May or may not apply, just thought I'd throw it out there.

[67 Lamnas]

Originally Posted by 2nd67GTO

The majority of this conversation is above my knowledge level, but feel I need to comment based on a recent experience. Strictly drag motor, not even sure of the displacement as I just help with the car occasionally, but the pin location within the piston was high enough into the oil rings that a removable ring land, or oil ring back up ring so to speak, was required. During the initial teardown, the presence of these was missed and they got tossed. After rebuild, we had oil leaks very similar to what you're experiencing. Rear main, dipstick, even 4 corners of the pan. Vac pump helped very little. Leaked-down at 10-12% in all but one cylinder, Highest at 15%. Not great, but not terrible. After much discussion, arguing and near fist fight, motor got pulled and tore down. It was pretty obvious alot of blow by through the pin/oil rings.

May or may not apply, just thought I'd throw it out there.

Thanks for the input. My build was spec'd out with 6.700 rods, to eliminate piston "rock" seen on 535s built with 6.800 rods. Although it wasn't mandatory, we still used oil ring supports......

My cylinder leakdown was in the 3-7% range...........

[67 Lamnas]

Originally Posted by 75TA

I went with the Butler system for the street on my 505. Just got the valve covers back with the welded bungs. When I reseached the proper vacuum for the street, I found that you do not want to go much over 6 or 7 inches. Was told at the time that over this is usually used for only drag racing and could cause oiling problems during long runs such as street use. Also, you will have to watch if your system sucks oil. I run the system for a short time and found you can suck alot of oil.

I'll be running a max of 10-12.....at WOT....not sustained......

During normal street driving it will be considerably less

Also will be running clear hose as a tell-tale....

[67 Lamnas]

Got the pump mounted....need to come out another 1/4" to line up perfectly with the drive gear........

Should have the proper length spacers and be able to finish plumbing, etc. this weekend. Yes....I'm one of the few idiots that's gonna NOT run electric fans and water pump......haha....I always gotta be the odd man out.....

[roadrage david]

67 lamnas at first when you start it up it wil make a claking noice this is normal its running dry at that momend as soon as the engine oil gets a bit warmer and oil air moister will reatch the pump it wil stop making the claking noice, also it might happen in the eurly stages of useing your pump that it wil such a bit to mutch oil . your pump wil loose vacume, witch you wil notise on your guage. you should disconect the in;let hose at the pump and spray break cleaner in it for 2 to 3 sec. and it wil work ok again. so far so i had to clean it 2 times. in 4000miles of hard driving.. last but not least i have the pump conected to both valve cuvers ..

[Pontirag]

Your engine should create enough vaccuum through a proper PCV system to solve the problem If that is the problem. Take a look at the various factory set ups and choose one that is workable with the parts you already have. analyse the problem you have befor you apply a solution.

others have brought up some good ideas i would not have thought of

[67 Lamnas]

I don't think you get it.....