cdr questions and thoughts...

[3500GMC]

my question here is this... does anyone thing that the exhaust will back up the tube, or because the exhaust is bigger it will follow the path of least resistance? i think that it will draw good...

You've got those pesky bends in the exhaust tubing that may think otherwise...

You need one of those fancy Manometers like Ak has....(to see the numbers)

Further, any kind of 'valving' is delaying the inevitable.. It's gonna build crankcase pressure anyway, may as well find a way to KEEP your precious oil in the engine somehow and keep crankcase pressure (positive) to an absolute minimum.

 

[ak diesel driver]

The gas engine works opposite, but doesnt the PCV valve still work the same way? high idle vacuum pulls against some spring tension to restrict the flow and low vacuum at high throttle allows full flow through the valve. Just reverse engine operation and the PCV would be wide open at idle for us, with low vacuum and fully restricted when the turbo pulls the vacuum at high throttle. Thats what my head is telling me anyway. But untested as to whether any valve would shut it off any more than the CDR does. And maybe diesel fuel vapor would eat at the materials.

I think your reasoning is right on but there are still some basic differences tween the two. pcv uses a check ball with no spring (at least none that I've messed with) cdr uses a spring against a diaphram. pcv is usually small dia tube compared to cdr. the spring in the cdr allows it to open if crankcase pressure gets too high while in a high boost situation and I would think the check ball would require more crankcase pressure to overcome it possibly equal to the vacuum produced by the turbo