PCV valve

[Ball Racing]

Okay, lets say during a rebuild,,you have misplaced your pcv valve.
If you go to a NAPA or other parts store, whats a car or truck that would cross reference over??

Thanks

[smosher]

Why not call Indigo and get the correct one without guessing

Steve

[Ball Racing]

It's not a indigo kit.
And if someone on here has ever replaced the valve, I won't be guessing.

[Marian Claire]

Please do keep the wood boats alive. The MC will enjoy the company. I have to ask, why does a rebuilt engine need a PCV system? I realize from posts here that even new engines have some blow-by but enough to need a PCV??? Am I being environmentally insensitive? Dan S/V Marian Claire

[Ball Racing]

Any engine with a vacuum being pulled in the base will automatically achieve a better ring seal.
Better seal,= better performance,= better mileage,= less oil usage etc...

[msmith10]

I sent you a PM

[Dave Neptune]

All four stroke piston engines need one as it keeps them running CLEANER on the inside!!! The little attempt at ventilating the crankcase in the A-4's is just a less efficient way of venting and the PCV valve hadn't been developed yet. A new engine benifits as much or more than an old one because it keeps the inside so much CLEANER. No packed in sludge building up like in the old days. The PCV system is good for all engines and it is wonderfull that someone took the time to find and develope a kit for these A-4's.

I have done many upgrades to my ole beastie and the PCV was the first, as soon as I swa one available, I ordered it!!! And now the engine runs so much cleaner and no oily smelling cabin fumes!!

Dave Neptune

[ILikeRust]

My understanding is it is not just blow-by from worn piston rings. You've got a crankcase full of oil that gets hot as the engine gets up to operating temp. You've got a crankshaft and reversing gear assembly spinning around in there, slinging that hot oil all over the place inside the crankcase.

Seems to me that will generate some hot oil vapor, whether or not you've also got blow-by. Without a PCV valve assembly, where does that hot oil vapor go? Seems to me it would tend to waft out of the front end of the engine (since it's not sealed) as well as the little vent on the side plate - some of which might get sucked into the carb inlet, but some (a lot?) of which will not.

The PCV valve kit assures that there is a much more positive "suction" that prevents that hot oil vapor - as well as blow-by, if you have it - from wafting out of the crankcase. It makes all that vapor and mist and gases, etc., go only one way - through that closed loop, to be re-burned.

Anyhow, that's my understanding. I didn't hesitate to stick one on my engine after reading so many positive reviews of it. Seems to make sense to me.

[sastanley]

You got it Bill.

My engine was over 32 years old when I got the boat, but my father owned it from brand new. There was a layer of sludge all over the entire engine room from years and years of the "slash tube" being there from day one.

My wife said, "we are gonna have to do something about this 'oil cloud' in the boat." The PCV kit was also the very first modification I made to the boat and it has made a world of difference..the entire boat, cushions, curtains, everything, literally smelled like burnt oil. Now all I smell is all the paint burning off the engine.

[Mark S]

Okay, I'm convinced, especially when I consider the greasy film on the interior of my engine space.

Who has what kit, and how do you like it?

Mark

[Esgbradford]

As I understand it, PCV valves have basically three pressure ranges. Open, Float and Closed. Open occurs when the engine is off, and when the engine is at full throttle. Float is a proportional opening of the valve to the speed of the engine -- where the slower the speed (as in Idle), the more restriced the flow through the PCV valve, but also the least amount of blow by would be happening -- and full throttle, where the greatest amount of blow by would occur, and the PCV valve would likely be fully open -- and all point in between.

Now, Closed is a safety feature. If there were a back-fire we wouldn't want fuel and flame going into the crank case. So, the PCV valve closes when the manifold pressure exceeds a the crank case pressure by some certain pressure amount. Each model of PCV valve has different pressure settings. You may be able to use any variety of PCV models successfully, but remember, it will change the float response to manifold and crankcase pressures.

So you could put some gauges on your engine and determine crank case and manifold pressures at different RPM. From that, you could compare the differences and determine what the thresholds are that you would like the PCV valve on your engine to behave. I'm sure you could find a PCV valve that fits nearly exactly how you want your engine to run. After that, it's a simple matter of engineering the tubing to connect the PCV valve to you engine. One of the key parts of the system is the carb adapter that permits the gasses to enter the intake just after the throttle valve.

If you could get ahold of 1/2" thich aluminum, you could make your own by using the gasket as a template for the shape of the spacer. Then drill and tap a horizontal hole for which to attach the tube. This kind of engineering is fun. And, I like this kind of challenge, and might just make one for S&Gs. But, realize, that if you make one for yourself, you won't save much money (it might actually cost more if you have to buy tools). You'd do it just for the fun of spending several hours to create something with your own hands. That way, you can be like Han Solo, when some says to you, "What a piece of junk," you can reply, "She may not look like much, but I've made a lot of special modifications..."

Or, you could do it the easier way, and buy the kit -- eliminate the possibly errors or testing, calculating and fabricating, and save a lot of time.

This mod is on my list of things to do, and it may be fun to try to make it myself, but I have other things to do with my time (like polish my carb), so I'll just buy the kit.

Eric
Aries Newport 27
Portland, OR

[Dave Neptune]

Mark, I bought the Indigo long ago before I ever heard of MMI. Today I would get it from MMI for all they have done regarding this forum and answering members herin.
I'll bet a liquid bread that they use the same valve.

Dave Neptune

[hanleyclifford]

Originally Posted by Esgbradford

This mod is on my list of things to do, and it may be fun to try to make it myself, but I have other things to do with my time (like polish my carb), so I'll just buy the kit.

Eric
Aries Newport 27
Portland, OR

Between polishing carburetors and sail tracks (Neil!) this is enough to make an old soldier cry. BTW, here is a graphic description of the above (well written) discourse.

[ILikeRust]

Originally Posted by Dave Neptune

I'll bet a liquid bread that they use the same valve.

Looking at the pics of the MMI kit and the Indigo kit, it certainly does appear to be the identical PCV valve. The particular of each kit are, of course, a bit different.

[Marian Claire]

Thanks for the info. I now have a much clearer and more complete understanding of the PCV valve. I wonder if having the old style vent and carb is why I have not had issues with fumes and oil film. So much to learn. Dan S/V Marian Claire

[ILikeRust]

Re: polishing carbs -

I didn't polish my carb, but I did polish the flame arrestor - not to a high shine, but I did spend some time getting it good and clean and somewhat shiny, just because once I got rid of the few bits of paint that were still clinging to it and the grime and gunk, I liked it bright:

[hanleyclifford]

Bill - Your manifold vacuum plug, water jacket plug and crankcase plug are also looking fairly STRAK.

[ILikeRust]

I did, in fact, spend a fair amount of time with the wire wheel in the drill press.

Pretty much every nut, bolt, stud or washer that would show got the treatment. Much rust and grunge was flung. A few nuts that were too pitted were replaced with new.

I have no delusions that they'll stay looking that good. In fact, last Saturday when I was working on the boat, I noticed that the two nuts holding down the thermostat housing were starting to show a little orange dusty hue...

[smosher]

Looking good !!!!

[lat 64]

Ya ever notice that Bill(rust) never misses an opportunity to get another shot of that pretty motor up on a post.

jus teasin'

[ILikeRust]

Hey, with the amount of time, money and effort I have in the damn thing, yer damn tootin' I'm gonna show it off!

[Kelly]

Man, Russ, did you ever get that one right! I really hate it when Bill does that

[Ball Racing]

I was just looking at the online Moyer catalog, and can only find the pcv kit that comes with the flame arrestor and all,,,
then I see the aluminum spacer for sale to adapt a scavage tube to a new carb- old block,,,

Wasn't there a Moyer pcv kit that didn't include the arrestor????

[jpian0923]

Bill is such A bragger...I'm not!

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[jpian0923]

More of my opinion: Detergent oils keep sludge out of the engine. That includes blow by fumes "in" the crankcase and the interior walls of the engine.

So, the pcv does nothing for the inside of the engine but does keep engine compartment and cabin clean. (Sorry Neil).

By the way, I don't have a PCV system.