Topic: Autolite/Motorcraft PCVs reference to NOS EV-8 (65-68 289/302)

[T5owner]

I wonder if there is a reference and or replacement table for the earlier Autolite, later Motorcraft PCV valves and Standard PCV type names for 289/302s.
Or which of the modern is considered accurate (same flow characteristics).

The 68 302 for example was listed in the Shoptips back then with EV8 (C6AZ-6A666-A), for decades the EV50 (D0AZ-6A666-A) was listed from parts suppliers (plastic), now I think it is replaced by Standards EV158.
https://www.smpbuyersguide.com/standard/Air-Management-and-Emissions-Systems-Illustrated-Parts-Guide-2022/260/#

What is the actual Motorcraft part no. for it?

[J_Speegle]

I wonder if there is a reference and or replacement table for the earlier Autolite, later Motorcraft PCV valves and Standard PCV type names for 289/302s.
Or which of the modern is considered accurate (same flow characteristics).

The 68 302 for example was listed in the Shoptips back then with EV8 (C6AZ-6A666-A), for decades the EV50 (D0AZ-6A666-A) was listed from parts suppliers (plastic), now I think it is replaced by Standards EV158.
https://www.smpbuyersguide.com/standard/Air-Management-and-Emissions-Systems-Illustrated-Parts-Guide-2022/260/#

There are dozens of reference books and manuals and replacement list over the decade from MPC's to Ready Reference books carried by aftermarket shops 

What is the actual Motorcraft part no. for it?

To clarify are you looking for something Ford makes currently for an early 289? Or you're specific application.

Don't know what the exact flow rate each replacement or original was. Typically that was not published with the public and I've not seen anyone that tested and measure it and the original engineers  have share any of that. 

Got to ask if there is a reason for the inquiry, any reason, given where your asking the question why you don't just find and buy and original or service replacement?  Interested since I don't think this has ever been asked on the internet or by anyone before you 

[Bob Gaines]

+1 . A original marked C6AE or EV-8 replacement  for 289/302 is still readily available on the secondary market or auto parts store depending on if OEM or aftermarket .

[T5owner]

To explain a bit more:
My interest started with a malfunctional new "Standard"PCV, that stucks occasionally because the metal inner piece is too short or the spring too weak, so it opens not correctly. Bought a new one that is similar (cheap) manufactured, where the pin is a bit longer to go still through ...but with a weakening spring it may have the same malfunction at a time. Would like to change at least to a Motorcraft.

At the same time we had a discussion about malfunctioning PCVs in various applications in our club forum with a large variety of used PCVs from 64-73 owners, which are available at parts vendors. Probably they all work somehow. Some use a EV68 on normal 289/302.

But I thought that Ford had a reason to recommend different PCVs based on opening value and max flow for different engines.

The only value we could find was a opening value of the EV68 for 351C engines of 1,5-2,5HG and that the EV68  has a better (more) flow than EV1-5 (with deep research function on the web).
A replacement was recommended with EV98 for EV68.

Seems Autolite offered in the Shoptips in 68 a PCV tester (which simply measured the vacuum range) for Ford dealers.

Yes, I know that I can buy an EV8 from e_ay vendors for roughly 50-60 Dollar (occasionally for 20-30), so that serves certainly the concours purpose.
For regular usage, I wonder what determines the proper PCV specs, the count of vacuum operated devices, the hot cam modifications with subsequent lower vacuum etc, however that might be too much.

Maybe the answer lies in the Motorcraft catalogue from a certain year, that gives a reference of EV8 to EV50 and the next replacement. (The 73 catalogue has already 39 pages).

I also wonder if there is a logic sequence in the EV numbering, if EV8 has more flow than a EV1-5.

The opinions given are mostly that it makes little difference, but I would think that Ford had a reason and that it indeed matters for some applications in the driven class..
It might help to have the individual flow and opening values to make your own choice.

Maybe it is not really a good question for the concours Mustang forum, but I thought the PCV expertise might be here...and it might be worth some research.
At least I like to solve things for others that are not asked for before:-)

[krelboyne]

I believe that the OEM PCV valves were recommended to be replaced at every tune up.

All vintage Ford PCV valves were not the same. Some are larger, some have threads for attaching to an elbow, another that I have seen has a fitting for a flared line. The used ones that I have do not hold air one way.

I cannot see any advantage to using a modern plastic 'Motorcraft' PCV valve over the SMP version. Both are colored plastic and can't really be identified when installed. Both scream aftermarket. We are more about concours or sneaky concours. Sneaky concours is a very accurate clone or imitation part that will fool a few people.

Just because PCV valves haven't been researched by the Concours forum, doesn't mean that anyone here is under any obligation to provide that research. We freely share information with each other for the general well being of the hobby.
By all means, feel free to volunteer or get the ball rolling. Collectively, many here have things to share and contribute. Hardly any deep dive research is done solely by one individual.
We have arrived at this point in time by being a collective wikipedia.

[OldGuy]

I don't understand why you have so much concern for the flow rate of the PCV valves. It has been my experience with PCV valves that most of them actually flow too MUCH air. Remember, the crank case gases enter the intake manifold BELOW the carburetor so that you essentially have a giant air or vacuum leak. That means that the crank case gases i.e. air, is leaning out the air/fuel mixture provided by the carburetor. Over time, this situation can be destructive to the engine.

For what it is worth, I usually install a restricting orifice in the PCV hose to lessen the flow of air that does not pass through the carburetor. This generally results in better overall engine performance.

[jwc66k]

Way back when, I drove a 66 Mustang Fastback (DSO 11, Metuchin built, "A" code, 4 speed) from the East Coast to the West Coast. I plugged the rubber hose that went to the PC valve to the carb, based on what a local speed shop owner (his mom and my mom were both RNs at the same doctors office - aka family) told me to do. The driving "numbers": vehicle weight, 4100 lbs (everything I owned that would fit in a 66 Fastback), 3182 total miles, 48.1 hours actual driving time, 66.2 mph ave, 18.1 mpg. As far as I could tell, the PCV did nothing positive. 
Jim

[T5owner]

"just because PCV valves haven't been researched by the Concours forum, doesn't mean that anyone here is under any obligation to provide that research."

A misunderstanding, I just thought there must have been done already some research. No one is obliged.
So let me share my status of knowledge..
As mentioned the above listing was in the July 68 ShopTips from Autolite. Here is the full reference list attached and the tester.

The plastic PCVs were available from parts vendors  for a long time, but I heard that some failed and the inner parts fell down in very few instances.
Meanwhile you get mostly the metal PCV valves.
I was only concerned about the current STANDARD valve and questioned a Motorcraft listing in relation to the original Autolites.
I assume that in some classes Autolites are mandatory, in some classes Motorcraft....to limit my question to this forum.

And that is why I asked about a source for the cross-reference for the 64-73 289/302 and their later replacements. Sorry, if misinterpretion was possible.

[rhjanes]

Way back when, I drove a 66 Mustang Fastback (DSO 11, Metuchin built, "A" code, 4 speed) from the East Coast to the West Coast. I plugged the rubber hose that went to the PC valve to the carb, based on what a local speed shop owner (his mom and my mom were both RNs at the same doctors office - aka family) told me to do. The driving "numbers": vehicle weight, 4100 lbs (everything I owned that would fit in a 66 Fastback), 3182 total miles, 48.1 hours actual driving time, 66.2 mph ave, 18.1 mpg. As far as I could tell, the PCV did nothing positive. 
Jim

It gives a method for the motor to burn off the air, and with it the fine oil mist and combustion by-products, that exist in the crankcase.   Cars up into the 1950's just vented that into the atmosphere, usually with a tube off the back of the intake leading down the bell-housing towards the road.  I remember seeing the puffs of smoke from around the transmission on my grandads 1953 Pontiac as it vented with the rotation of the crank.   So the PCV doesn't add to or subtract from HP or fuel economy, but it does help the environment.   And the engineers factor in the air intake from the PCV system. 

[jwc66k]

It gives a method for the motor to burn off the air, and with it the fine oil mist and  combustion by-products, that exist in the crankcase.   Cars up into the 1950's just vented that into the atmosphere, usually with a tube off the back of the intake leading down the bell-housing towards the road. 

I know what a PCV valve was designed to do. It's most effective in city traffic, aka stop-and-go, and some commutes. In my cross-country venture (it was August), I was maintaining 66 miles per hour for two continuous hours, then I stopped for gas, stretched my legs and made use of the restroom facilities. I drove "half tank" then filled up. The PCV valve was not "used" much.
Jim

[T5owner]

Not all (especially original SB engines) are that healthy.
I think this video of a 1971 302 with 120.000 miles may (since 84) show what in a worst case  the PCV has to direct elsewhere. BTW the engine is subject to an overhaul anyway now.
There was no smoke coming from the exhaust, so the PCV got a job. I assume that when it got clogged (Fords maintenance intervall was 12.000 miles with a healthy engine, things get worse with a used engine more quickly.
ponysite.de/302_PCVblow.mov
(you might have to download it in another browser window, the forum does not take http links, sorry)

Anyway, it seems Motorcraft used the same EV codings with the respective C5, C7,D0 prefixes with the 6A666-A for the 289/302 (EV8/EV50/xx) and C9/D0 for the 351 (EV68/98). Yet the current delivered part from Mustang parts vendors is very often the V156 from STANDARD, where I and a few other 289/302 owners here had issues with (clogging, weakening spring, bending internals).

Will try to get the respective Motorcraft unit for my current specs, which are different than the above 1971 302 overall with about 200.000 miles on it. (Compression between 9,0 on 3 cyl. and 10.5)


I read elsewhere that some original cars carried Eaton and AC Delco PCV valves, not sure if that is true, but at least they were manufacturing them as well or for Ford.

[Bob Gaines]

Not all (especially original SB engines) are that healthy.
I think this video of a 1971 302 with 120.000 miles may (since 84) show what in a worst case  the PCV has to direct elsewhere. BTW the engine is subject to an overhaul anyway now.
There was no smoke coming from the exhaust, so the PCV got a job. I assume that when it got clogged (Fords maintenance intervall was 12.000 miles with a healthy engine, things get worse with a used engine more quickly.
ponysite.de/302_PCVblow.mov
(you might have to download it in another browser window, the forum does not take http links, sorry)

Anyway, it seems Motorcraft used the same EV codings with the respective C5, C7,D0 prefixes with the 6A666-A for the 289/302 (EV8/EV50/xx) and C9/D0 for the 351 (EV68/98). Yet the current delivered part from Mustang parts vendors is very often the V156 from STANDARD, where I and a few other 289/302 owners here had issues with (clogging, weakening spring, bending internals).

Will try to get the respective Motorcraft unit for my current specs, which are different than the above 1971 302 overall with about 200.000 miles on it. (Compression between 9,0 on 3 cyl. and 10.5)


I read elsewhere that some original cars carried Eaton and AC Delco PCV valves, not sure if that is true, but at least they were manufacturing them as well or for Ford.

Yes those were OEM mfg's. At least as it pertains to the 1960's cars.

[jwc66k]

Attached is my first pass at documenting PCV valves. Sources were the 1964, 1965, 1966, 1967 and 1969 Mustang Engine Assembly manuals and 1960-68 Ford Car Parts, the infamous MPC. I need to review my data. Unfortunately, the 1975 edition of Ford Car Parts list mostly service replacements and was not very useful. The Motorcraft stock numbers are also difficult to cross reference.
Jim

[T5owner]

Thank you, very much. The Eaton and AC Delco were mentioned as being pulled from original 1968s (GT) on ebay.

Maybe this could help, but I myself did not want to spend the 40 bucks at this moment.
The content page 2 looks interesting.
https://www.ebay.com.au/itm/153452662402