Mopar Action On-line – Tech Questions


Tech Question

Jim Nicolaus, DuPont, WA, 1972 Plymouth Valiant 318

Love your magazine. Best “hotrod” magazine since the first one I ever readwhich was in the Valley Childrens Hospital while I was waiting to have mytonsils out in 1958 and featured one of the Art Arfons “Green Monster” dragcars with an Allison I think and a ’36 Ford coupe with a 420 HP Hemi. Funnyhow I remember that and can’t remember what I had for supper last nightnowadays, haha. Only one I read these days even though I love my ’65 ElCamino too.

The question:

I want to get some Mopar polished cast valve covers for my ’72 318.Looking at the ad on Mancini’s website It looks like no holes for thebreather gizmo on the starboard side that has a hose from the air cleanerand the PCV valve on the port side. What to do? Take it to machine shop andhave holes made? How about the redundant oil filler hole? If it was 1962 I’dtake it to school with me and poke a couple hole with an end mill, butnowadays alls I got is a one-car apartment garage and a tool box and themanager would get after me if he saw me changing a tire in the garage.Thanks and keep up the good work. Jim


As long as there’s a flat boss, you can make the hole with a $5 Home Depothole saw…it’s no big deal. The redundant oil fill hole: just use aredundant oil fill cap!

The breather can either be the “holes” type that sucks directly from theatmosphere, or the nipple type that lets you run a hose to the air cleaner’sperimiter. Each have their advantages and disadvantages:

The direct-to-atmosphere type has less restrcition and is less likely tocause oil leaks elsewhere in the engine from excessive crankcase pressure.However, some blowby may dribble out and collect on your nice polished valvecovers.

The style with the make-up air hose to the ‘cleaner keeps the slime offthe v’covers, and helps keep you (and everybody else) from breathing blowby.But it can soak the air cleaner if the rings are not sealed tight. (Awashable foam over-wrap, or oiled cotton element, is the fix in that case).

You should be aware that most aftermarket valve covers – MP’s included -have poor PCV baffling, which sometimes allow the PCV to suck oil. Do yourbest to improve the baffles, and/or make a small restrictor to slip in thePCV hose.



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