Re: Thirdgen Smog Pump as Vacuum pump?
 

Seems like I overlooked some recent replies.

To answer everyone's questions, the pump ran great and pulled around 7-8" of vacuum on the crankcase. Unfortunately, even running an oil separator it locked up, threw the pulley and the belt in only 500 miles. I have since switched to a GZ pump which surprisingly pulls the same amount of vacuum give or take albeit with a larger diameter pulley.

In hindsight, I'm wondering if normally revving north of 6k combined with a 5.5" diameter crank pulley overdrove it and caused the failure. the factory smog pump pulley is quite small.

Re: Thirdgen Smog Pump as Vacuum pump?
 

I will say I had one off I believe a 74 Impala I took apart and figured out where the entrance was. I epoxied a piece of sheet metal in front of the intake part then added my own port for the vacuum. After that I got roughly the same results the poster above me mentioned. I didn't get a ton of miles on it and I ended up stopping using it due to not using that home brew accessory bracketry any more.

As a question to the person who empties their catch can every outing and has a bunch in it, what's the story on your oil pan/control and your valve cover baffling? That sounds weird to me in my experience but it's admittedly limited.

ED:Also Re:electric pump the Buick Grand National guys liked the LT-1 electric pump back in the day. They seemed to have success with it as well. There was a piece of foam in it they would remove as well if memory serves right.

Re: Thirdgen Smog Pump as Vacuum pump?
 

Allow me to share my experience with the vacuum pump and oil consumption.

After I installed the GZ pump, my oil consumption skyrocketed from 1qt every oil change, to 1 qt every 6-700 miles. Literally if I didn't empty the catch can AT LEAST once per tank of gas, it would start blowing out the breather and oil down the passenger side of the engine bay (Man, was I pissed). When I'd empty the can, it was probably about 90% oil. The oil I run is over $12/qt so that alone is a big problem. At the time, I was running your standard stamped steel baffle on the underside of the valve covers.

Then, I had the idea to purchase a 10AN baffled fitting and install it into the cover. See photos. I got that all mounted and sealed, then I took the standard stamped steel baffle and re-installed it over top of the fitting. You can also see where I JB welded the sides of the steel baffle to the underside of the cover to seal them off, only allowing air to be drawn around the top and bottom of the baffle before reaching the fitting with additional baffling built in.

With this setup, I have put over 200 miles on the vehicle and ALL my consumption issues disappeared. I rigged up a hose that passes through the frame rail and goes to a petcock mounted in the passenger side wheel well for easy draining. When I opened it, only a few drops came out. Fearing it was clogged I removed the filter from the top of the catch can for a peek. There was almost nothing in it but a few drops of typical watery, condensation filled crud you get with a proper catch can setup. Before the baffling modifications, the catch can would have completely filled itself up with BLACK contaminated oil and began spewing it all over the engine bay.

The pump still pulls the same amount of vacuum as before, measured at the opposite valve cover. I think the key is to completely isolate the port from oil sling/pooling as much as possible.

https://cimg0.ibsrv.net/gimg/www.thi...e0b7e671c3.jpg
https://cimg2.ibsrv.net/gimg/www.thi...9cddbf589a.jpg
https://cimg5.ibsrv.net/gimg/www.thi...1e3e4540f3.jpg
https://cimg9.ibsrv.net/gimg/www.thi...82239efd06.jpg

Re: Thirdgen Smog Pump as Vacuum pump?
 

Nice work. :thumbsup:

Re: Thirdgen Smog Pump as Vacuum pump?
 

:D:burnout:

Re: Thirdgen Smog Pump as Vacuum pump?
 

I just wanted to update my post, I added a water separator for air compressor with a ball cock valve on bottom so I wouldn't have to keep removing pump and cleaning it, also my reason for doing the conversion was I had to have someting there why not make it work for you, I see talk of pulley size my 3.1l is 6.5" and with better vacum gauge it only pulls 7" on crankcase