Vacuum pumps and blow by..can it be done on our diesels

[riotwarrior]

With the ample blow by our rigs see at times and my particular trucks current engine is one that has plenty of blow by would it be sensible feasable to device some type of sump evac. Something like the Moroso or GZ Motorsports makes.

Could we not draw a cacuum in a canister that then colated oil and drained back into the pan???? Like in a compressor that we run pnuematic tools has a colescing water seperator.

This could change things by freeing up some oomph and cleaning up our polutants and help abait costly oil leaks too due to crankcase pressure may even help with oil consumption.

After watching the video here
https://youtu.be/oJRMLfrlPvg

and seeing the results mid dyno testing I started reading this here

http://www.dragstuff.com/techarticles/vacuum-pumps.html

Kinda made me think is all....

Whats yer 2CW on this?

 

[laserjock]

Hmm. Intriguing thought. They make a fuel pump block off plates with fittings for vacuum pumps on BBCs.

Subscribed.

 

[laserjock]

Did a little reading Al. Looks like it's been tried. Main failure seems to be finding a pump that will take the continuous duty. There was also some question about boiling the lighter fractions off the oil over time. This is interesting enough, I may do some more reading.

Did a Google search for crankcase vacuum pump diesel I think and it turned up a couple threads. One was a guy who used a gm smog pump on a 6.2.

I would think an early 80s smog pump like off a 300 I6 might be a good choice. It was continuous duty as far as I remember.

 

[OLDBULL8]

[QUOTEhttp://www.dragstuff.com/techarticles/vacuum-pumps.html][/QUOTE]

Most all that talk was for race engines, very little on street engines.

They talk about the wrist pin oiling in a street gasser. Shouldn't be a problem in a diesel with cylinder wall oiling spouts.

I wonder what effect in a diesel with the cylinder oil spouts would have with a vacuum pump, since there would be a lot of oil in the crankcase air.

IIRC I read somewhere, the max CC pressure in a diesel is 6 PSI. That would cause main sealing leaks.

Sure would like to know what Ford did when they used to run a diesel in NASCAR racing years ago.
Way back in 81 or 82 at (LEP) Lima engine plant, we actually ran a 6.9 in one of our dyno rooms. Wish I could remember what all the testing was about. It was kinda secrative then.

 

[jaluhn83]

I strongly doubt it would be remotely worth the trouble with an idi.

The main benefit as I understand it is reduced losses due to less drag from moving the air around in the crankcase. This is going to be a much greater loss for a high rpm engine however, so for an idi turning at 3k rpm I'd suspect the actual loss from this to be under 5 hp, possibly much less.

On the flip side, you're going to need a pretty good sized vacuum pump that will undoubtedly require a fair bit of power. From https://www.dieselnet.com/tech/engine_crank.php I get hp/40 - hp/60 for the blowby flow in cfm, which gives ~5 cfm for a 200 hp engine, although this is lower than I expected. Common AC vacuum pumps are rated for free flow, so I estimate 5 cfm @ ~10" means 10-15 cfm free, which looks like about a 1 hp motor which is actually less than I figured it would be.

Major issue would be dealing with the amount of oil and general crud in the gasses though, so you couldn't just use a standard pump. You would also probably want a separator of some sort since the amount of oil vapor and such in the blowby gasses would only increase from what there is now, especially with all the splatter from the piston oil jets.

I am also not sure of the effect of long term vacuum exposure on the oil. It seems likely that this would cause increased loss of the light oil components, which could be detrimental. Not sure how much of an impact there would be, but worth considering.