road draft to pcv

I'm putting together a early 289, customer has purchased the aluminum finned valley cover and vlv covers. The cover is set up for a road draft tube but we'd like to go to a pcv valve. Anybody ever done this and if so can you clue me in on the details. The original valley covers have a baffle the aftermarket alumn does not. I'm a bit concerned that with out the baffle it may try to pull oil thru the pcv valve. Also were mounting the partial flow filter on the firewall and I need a good place to return the oil without running hoses all the way to the timeing cover and dumping it there. My idea was to put a fitting in the valley cover for both the return and the pcv valve, but again with the oil return that close to an unbaffled PCV fitting it might use oil. Any ideas are appreciated. Thanks Russ

Reply to
rustynutgarage
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The vent system for the "R" engines is worth imitating. The idea was to use the air flow to help move oil back to the pan. It's explained in the SAE paper on the Avanti. I think the idea came from the Lark V8's that were prepped for compact stock car racing, (Holman & Moody?). The air goes in the valve covers, down the push rod holes to the valley, to the crankcase, and out a baffled stack on the side of the oil pan. The PCV draws air at low speeds, and the air intake for the carb at higher speeds. If you make a stack, the idea is to make big passages, to slow the air flow down, so oil can drop out. You also want it to change direction a few times. Baffles work better than stuffing. Head dowels with slightly larger oil return holes, were part of the oil return improvement; but I think they were one of the changes that came with the full flow blocks. It's worth noting that the Granatelli's just added breathers. I doubt the system works as intended on R3 & R4 engines. It would be best to return oil from the filter directly to the pan; but you already have a hole in the valley cover. Mike M.

Reply to
Mike

I have road draft tubes on all my Studes. IMNSHO, Studebakers (other than R series) do not have adequate ventilation when using a PCV. I would leave it alone or maybe chrome plate the tube if you're into "shiny" stuff..

JT

Reply to
Grumpy AuContraire

JT wrote -

Interesting thought. Funny though that one of the same size PCV valves can control a much larger cubic inch and crank case volume....AT a higher RPM, (big block Fords, Chevys and Chryslers)...but can't keep up with a little Stude engine? Sumthins wrong here.

If it can't keep up and the system (crank case) pressure builds to the point of leaks....the cause of the pressure needs to be found and corrected!

Wether its from leaking rings or leaking head gaskets, (the only two places extra pressure can come from), they need to be fixed.

A road draft tube is just a small breather tube that may or may not be effected by the wind roaring past as you are driving down the street at

50mph.

For me...a "properly" designed PCV system...OR breathers on each rocker cover (NOT both), will work fine. A PCV valve in the valley cover and "one" inlet location, like a rocker cover and into the air cleaner is the other way to go.

The engine I'm building for my Conestoga....will have a single large breather in each rocker cover AND an "R" series breather tube from the oil pan. I've also changed the way air moves around inside the crank case a little. The NASCAR guys found some things, in that "all" areas (or chambers) need to have as open a passage as possible so as to not be able to store built up pressure. All areas need to be able to evacuate pressure as quickly as possibe. My block has a few holes not originally designed in!

The air actually moving the oil around.........not unless you've got a drysump system working. The oil mist "will" move around where ever air is present (!)...but slow moving air will not driect oil on it's own.

Mike

Reply to
Mike

Au contraire... The extra ventilation features found on R series engines solves the problem. Studebaker just never got around to fixing it on the standard engines.

The only other provision for ventilation on PCV valve equipped standard engines are the two oil filler caps and hardly anyone keeps them cleaned.

JT

Mike wrote:

Reply to
Grumpy AuContraire

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