Topic: 1967 GTA 390 Oil Fill Cap

[travnemi]

I'm sure this will be a super easy question.
I have a 1967 GTA Fastback S Code San Jose Dec Build.
Which chrome Oil Fill Cap belongs on the motor? For what ever the reason I cant figure it out.

[J_Speegle]

Since yours is a Thermactor car the cap would be the version with the hose attachment - for the nipple at the front of the air cleaner base


Didn't look into your particular build date period and the top markings but this one was used during the production year



Might be available in reproduction form

[preaction]

Jeff, its easy to see the flash in your pic is that cap chrome plated and did all caps of this type have FoMoCo or autolite on them ?  Also is this a two piece part, the cap with nipple and a oil fill tube.

[travnemi]

Thanks Jeff,
When I received the engine it had a cap similar to that but the PCV tube 90 degreed up. I couldn't locate the model that was on it so I purchased the one like in your picture. Though it will require a breather tube adapter like the one pictured below.

Thanks for your quick response,
Travis

[J_Speegle]

The C5ZZ version is for the push on. There is a later (sorry I don't have the part number this moment) version used up into the late 60's that is a "screw" (quarter turn) version. Have seen them in FoMoCo and Autolite markings.

But I was incorrect (forgot for the moment) I don't think the screw on is reproduced but haven't checked

[Bob Gaines]

Jeff, its easy to see the flash in your pic is that cap chrome plated and did all caps of this type have FoMoCo or autolite on them ?  Also is this a two piece part, the cap with nipple and a oil fill tube.

Caps in picture are push smallblock type and not applicable to the BB. I have only seen the cookie cutter non emission cap used on thermactor BB engine valve cover . see picture . Not to say there wouldn't be another but I am not aware of another appropriate type used . The cap with the swivel elbow is a 68 style. Just to confuse things I have also seen on a number of occasions the typical open emission BB cap used in period photos. A open emission cap is not designed for a thermactor system but none the less it is seen in some period photos as well as in the field. These are all Shelby applications that I have observed but a 390 may be the same . In the case of the open emission caps seen -some were chrome and some were black.

[travnemi]

But I would need a closed emissions cap, or do you plug off the tube from the air cleaner?
I'm getting a little lost here.
Travis

[WT8095]

Back in the mid 80s I ran across an S code motor that I got for a very good price. It was in a '67 GTA when I went to pick it up. As far as I could tell, it was original to the car. No idea of the build plant, unfortunately. As shown below, it has the chrome twist-on cap with the plastic elbow coming out of the top. I know this is the correct style for '68, but is it correct for this '67 motor? The casting date on the intake is "7C2", no smog equipment when I got the motor, don't know if it originally had it or not.

Please excuse the miscellaneous pieces laying on top of the engine. The extra PCV assembly to the far left is not from this engine. The one that is attached and the loose hose ARE from this motor.

[Bob Gaines]

Back in the mid 80s I ran across an S code motor that I got for a very good price. It was in a '67 GTA when I went to pick it up. As far as I could tell, it was original to the car. No idea of the build plant, unfortunately. As shown below, it has the chrome twist-on cap with the plastic elbow coming out of the top. I know this is the correct style for '68, but is it correct for this '67 motor? The casting date on the intake is "7C2", no smog equipment when I got the motor, don't know if it originally had it or not.

Please excuse the miscellaneous pieces laying on top of the engine. The extra PCV assembly to the far left is not from this engine. The one that is attached and the loose hose ARE from this motor.

The date code on a intake would not be relevant to other parts that are easily taken off and replaced like a breather cap. The typical 68 would have the metal block nipple.  The late 68-70 cap had the black plastic nipple like in the picture. With that information you can easily come to the conclusion that the cap in the picture had been replaced.

[Bob Gaines]

But I would need a closed emissions cap, or do you plug off the tube from the air cleaner?
I'm getting a little lost here.
Travis

I do not think there is a twist on cap with a nipple used in 67. With that said I am not sure about any hose to the aircleaner base.

[WT8095]

The date code on a intake would not be relevant to other parts that are easily taken off and replaced like a breather cap. The typical 68 would have the metal block nipple.  The late 68-70 cap had the black plastic nipple like in the picture. With that information you can easily come to the conclusion that the cap in the picture had been replaced.

I didn't realize there were two different elbows used in '68. Which one would be appropriate for a Feb. '68 SJ build? I can repost this question as its own topic if it is straying too far from the original question.

[travnemi]

Bob,

 The Marti Report says I have a closed crankcase emissions system, what does that mean?

Thanks Travis

[Bob Gaines]

Bob,

 The Marti Report says I have a closed crankcase emissions system, what does that mean?

Thanks Travis

It means that none of the engine fumes are expelled to the open air. Fumes are closed off or recirculated back into the engine. Does your aircleaner have a fitting for a hose from a breather cap?

[Bob Gaines]

I didn't realize there were two different elbows used in '68. Which one would be appropriate for a Feb. '68 SJ build? I can repost this question as its own topic if it is straying too far from the original question.

As it relates to a BB ,the one with a metal block elbow.

[J_Speegle]

............... A open emission cap is not designed for a thermactor system but none the less it is seen in some period photos as well as in the field. These are all Shelby applications that I have observed but a 390 may be the same . In the case of the open emission caps seen -some were chrome and some were black.

Bob - have never seen that cap on a Mustang. It would not have the connection needed for emissions and connection with the air cleaner as required for a Thermactor car.

The Marti Report says I have a closed crankcase emissions system, what does that mean?

No open fumes into the atmosphere . All were to be recirculated into the engine (reburnt) In the manuals the hose between the air cleaner and the breather cap is highlighted as for "Closed systems only" This is the way I've always found original 67 390's I've owned and seen in this state.


One of many diagrams - just the one I picked.   JUST A GENERIC DRAWING not specific to this engine nor even Ford engines


- By 68-69 they started to refer to this type of system as a Type 4 system or a closed or combination one. It worked in conjunction with the PCV system on the other side of the engine.

- The system Bob showed on the 67 Shelby is described or identified by Ford as a Type 2 system where they used a restricted oil filler cap and a PCV system on the other side of the engine


All this (description) from Ford manuals - in this case Engine Emission Control Systems volume I



Have another 6-10 manuals, course work (class manuals and teaching guides) that cover 66-72 emission systems
In the picture from left to right 67, 68, 69 & 74 versions. Loose leaf in back I believe is the teaching guide for the 67 course


Guess we should at least ask/address do you have the correct air cleaner for the application?