Thanks John, unfortunately there is nothing for a 261 on that list.
The more I read into it, the more I realize the whole PCV valve thing is a mess. "Get one for your application" yeah right - if you have a 261 pretty much all of them are obsolete by now.
Just learned from DavesTech (he actually measured a bunch of them) that a Standard Motor Products V-237 would be right, and I could get it at Rock Auto, but since I live in Germany - shipping that $2.50 valve is $25 . So I would like a cross reference, maybe I can find something similar over here, but no dice.
Frank, it is not a mess if you can't find it on the Internet. Not everything is scanned-in and posted there freely for your convenience. Some of the Stovebolt members here have the old books, manuals and pamphlets.
Of the valves listed, the CV-609 is about the only easily obtainable NOS part (mostly from ebay). The differences in the valves listed is for type fittings (hose, metal pipe, screw-in etc.).
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
AFAIK in addition to hose etc. connections, there are (at least?) 3 variables that affect how efficient a PCV will be on a specific engine and state of tune: 1. high vacuum (minimum) opening diameter, with restricting cone fully inserted 2. low vacuum (maximum) opening diameter, with cone fully retracted 3. spring tension, which determines how much vacuum is needed to restrict flow
1. & 2. are strongly based on engine displacement 3. includes idle characteristics (hot cam, etc.)
Yep! And it would be nice to have those in a measured test lab values for our 236/261 engines. We also have the problem that one day the NOS supply of PCVs will dry up. The alternative is a $$$$ universal PCV that has adjustable setpoints for high and low vacuum. To be continued...
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
