Hello all. My name's Frank, and I'm new to the slant six board. I'm an engineering student at the University of Houston and I've owned a 1964 Dodge Dart 170 for the past five years. While I've owned it, I've rebuilt the engine (including a slightly hopped-up cam), had the transmission rebuilt, redone the brakes, done some body work, and all kinds of other little details inherent to restoring classic cars.

Anyway, I recently discovered that my PCV valve needed to be replaced; I hadn't messed with it during the engine rebuild. After a little research, I discovered that the 1964 170 wasn't supposed to have a PCV valve, so I'm pretty sure that my valve cover is from a later year (66-69, unless it's not from a 170). My first question is this: should I replace the PCV, or just block it off if the engine didn't come with it?

If I do replace it, there are still some issues. The PCV valve currently on my engine is metal. It is attached to a steel cap, which is friction fitted onto a stack similar to the one the oil fill cap sits on. The valve is threaded so that it sticks through this cap from the bottom and is attached by a nut from the top. All the slant six PCV valves at the local parts houses are plastic, and have no threads. Does this sound familiar to anyone? How are these things installed? Will I have to modify the valve cover? Thanks in advance for your help.

You want a PCV valve.

My 64 225 has a breather up front and the PCV valve at the rear of the valve cover.

The 170's did have a PCV valve, but it was a different one from the 225's........ There was differences between the CA and Fed breather systems. CA had a hose from the breather back to the air filter, the fed version just had a breather.



As for the metal PCV valves, you can take them apart to clean. Unscrew the valve part from the cap part by holding the nut with needle nose pliers.

Then soak the valve part in degreasers, carb cleaners (the nastiest stuff I know of is something called pyroil), dishwashing soap, blast with water,soak, blast........ Basically just do anything you can think of. Keep doing until what goes in, doesn't come out dirty.

When done, rinse well with water, then run some alchol thru it to get rid of the water (won't rust out when drying then).

Reassemble and optionally spray with black spray paint to make it pretty.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

My PCV valve has a hose running to a vacuum outlet on the carb (factory refurbished Carter BBS). I don't think it's clogged up, because it's allowing too much flow rather than not enough. I can blow freely through the PCV valve from the inside, and it rattles when I shake it. The reason I wanted to replace it is because it appears to be stealing all the vacuum and leaving none for my distributor's vacuum advance. At idle, I have no vacuum going to the distributor, and at higher RPMs I get maybe 10-15 lbs. Correct me if I'm wrong, but I thought I was supposed to have more than that.

Do you think the PCV valve is actually bad? If so, what are the ramifications of blocking it off? Will it affect the engine negatively, or is it more of an emissions issue? This car doesn't have to meet CA standards.

I would be most comfortable with installing a new valve, but I can't figure out what the hell I'm supposed to do with these plastic ones. Thanks again.

[quote=SpaceFrank]At idle, I have no vacuum going to the distributor, and at higher RPMs I get maybe 10-15 lbs. Correct me if I'm wrong, but I thought I was supposed to have more than that.[quote]

I'm assuming you mean inches instead of pounds, but yeah, that sounds about right. Remember that the distributor sees "ported" vacuum as opposed to "manifold" vacuum, so it behaves in an inverse manner. Sounds like your PCV valve isn't actually bad, so leave it on there. Running w/o a PCV is a quick way to end up needing to replace every gasket on the thing.

Hmm... and just after I found a NOS PCV valve on the internet. Well, If that's enough for the vacuum advance, then it may not be a problem. Of course, now this means I'll have to find out what else is making the engine run rough.

EDIT:

Now here's a thought. If I need positive crankcase ventilation, should I have a breather cap on my oil fill stack, or should it be a sealed cap? It seems like I'd be defeating the purpose by letting air back in through the oil fill cap.

breather cap.


air goes in the cap, and comes out the PCV......... (plus yucky air from the engine)

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

There were only two PCV valves used from '64 through '69: One for the 170, and the other for all other engines.
Only the original (now scarce) '61-'63 valves originally made by AC, which were screwed together or held together with a snap ring. The '64-up self-cleaning valve cannot be disassembled, though it can be directly interchanged with the '61-'63 valve.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I was just thinking of the splitting the valve part from the cap part......

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

My 65 PVC valve diassembles by unscrewing a lock nut and wheeling out the tube. You can clean the whole thing...its kinda neat...its all metal and slides onto the valve cover just like the breather....mebbe its a Canadian thing.

You should have no vacuum to the distributor at an idle.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Welcome onboard!
A good idea every four decades or so
Not correct; they did come with a PCV valve as standard equipment from the factory starting in '61 in California, in '62 in New York and '63 clear across North America.
Same valve cover used with or without PCV valve on '61-'67 170 + 225. Those early cars that did not ship with PCV valves had a road draft tube attached to the rear chimney, instead of the PCV cup and valve.
DEFINITELY run a PCV valve!
Yep, the old type. Difficult and expensive to buy in the large-bore variety that was used with the 225 and larger engines; just about impossible to find in the small-bore variety that was used with the 170.

Not a big deal. Go get a Standard V253, an ACDelco CV1001C, or a NAPA Echlin 2-9325 PCV valve and a Motormite 42344 or NAPA Balkamp 6301411 PCV valve grommet. The new PCV valve will be either plastic or metal, but will look very different to the old one. Don't worry.

Remove the metal valve from the metal cup. Clean the cup and put the engine (non-hose) end of the new PCV valve through the top of the cup, so that most of the new PCV valve sits atop the cup. Press the new grommet, smooth side up, onto the bottom of the PCV valve until it snaps over the lip on the valve. In most cases this will provide satisfactory valve retention; in a few cases you may need to shim the valve by placing a washer between the shoulder of the valve and the top of the cup, to provide less wiggle room for the grommet.

Now, simply place this assembly onto the rear chimney of the valve cover and connect your PCV hose to it. The cup won't sit quite as tightly on the chimney as it did with the 2-legged spring steel retainer originally used with the metal valve, but it won't fall off, either, and it'll work just fine.

This PCV valve is used on 2.2 and 2.5 litre 4-cylinder engines and has very similar flow characteristics to the original 170 PCV valve.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

You will more likely than not soon discover that "factory remanufactured" parts are garbage. Try to avoid them.
That's not how things work.
That's normal and correct.
Whoah, pardner! There's no such thing as a "lb" of vacuum! You mean 10-15 in. Hg. ("inches of Mercury").
No, that's about right.
Once every few decades whether it needs replacement or not. Seriously, the shuttle spring can grow weak with age, and see above for discussion of 170 vs. all the rest of the engines' PCV valves. The 170 valve is supposed to have a lower flowrate to avoid upsetting the idle mixture.
Improper engine idle, much quicker and more severe oil contamination, accelerated engine wear, increased oil consumption...are we havin' fun yet?

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Wow. Thanks for all the info. I'm obviously not an expert on engines, just the son of a shadetree mechanic who stumbled upon a classic car!

Anyway, with all this info I have only one more question. is there any difference in quality between the old metal PCV and newer plastic one? The reason for this question is that I found an Ebay auction for a new old stock PCV valve, the exact same metal one that I'm replacing. My inclination is to spend the extra money to get the NOS one rather than putting on an aftermarket plastic valve.

The new-type valves are better, IME; as long as you buy a quality brand they tend to be more consistently calibrated and the shuttle valve generally seats better than the metal ones. Also, don't be fooled by appearances: The metal valve for the 170 engine looked exactly the same as the metal valve for the 225-and-larger engines; the differences were internal. There were many, many more 225-and-larger engines made than 170 engines, so virtually every NOS metal valve you find nowtimes is the larger-bore item.

You can see the late-type valve installed in my '62's original valve cover Here.

Also, NOS valves tend to be expensive because they're in demand by people who have to have factory-correct-appearing PCV valves, factory part numbers on their shock absorber grommets, factory checkmarks of orange chalk on the rear axle housing, etc., otherwise they get marked down on their point sheet by judges at high-dollar car shows.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Alrighty, well I'll probably pick up those NAPA parts you mentioned. Just to evaluate my options, however, can anyone tell me if Mopar part #2808622 is the proper PCV valve for a 170? This is the part that is currently for sale on Ebay.

The auction is here:

http://cgi.ebay.com/ebaymotors/ws/eBayI ... %3AIT&rd=1

Nope, it's the larger-bore valve.

And if you pay $28 for a PCV valve, I'm going to .gzip myself, send myself to you as an e-mail attachment and smack you upside the head.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.