Chromed Oil Filler Cap

[Chuck Lutz]

Currently mine is black. Are they available in chrome? Is it a big deal to change?

Now, there is a possibility that someone painted over the original chrome and I'll check that with a little lacquer thinner but more likely it was rusted and refurbished to black. There are so few parts that are correctly chrome in the engine compartment, I'm always happy to see pictures of engines and see the chrome filler.

[Nick DeSpirito]

Chuck,

If it's original, it should have oil stamped on the top. Both the oil and the tranny dipsticks are also chrome.

[Chuck Lutz]

I seem to have the correct dipsticks but I don't think the cap says "OIL". I'll have to check that.
If I can get it out I know plating companies and could have it done. One of the first steps to chrome plating is a flash copper base. I wonder if the originals were brass which could be plated right over.

[Barry Wolk]

Your draft tube assembly is the wrong color, too, if you're going for authenticity. It's supposed to be engine color with a chrome breather.

I'll bet that cap was used on a bunch of Ford products.

http://i244.photobucket.com/albums/gg18/barry2952/_N4U1875_1-001copy.jpg

[Chuck Lutz]

Oh, so the cap is the only thing chrome? The tube is painted. I thought the whole thing was chromed.
Thanks, that's easier to do. Now all I need is to find the cap.

[Barry Wolk]

I'm thinking about blocking off the draft tube at the bottom and using a PCV-type cap and installing a vent to the air cleaner. That should eliminate the oily spray on the underside of the car and drips on my garage floor.

Couldn't hurt to vent bypass gasses into the intake rather than the atmosphere.

[Shawn Newcomb]

Is the draft tube the 3/4" or 1" round angle cut tubing that exits below/beside the engine and looks like it came from a mini bike blowing 2 stroke exhaust?

[Barry Wolk]

Exactly! What a mess.

I don't think there's room for an EGR plate-type of arrangement, but the vacuum within the air cleaner should draw fumes from the crankcase.

I wonder how that would affect the extremely low idle speed?

[Shawn Newcomb]

I have no answer for you, but now I know why I have "an extra exhaust pipe under your car" as someone once commented to me

[Barry Wolk]

If a lot of smoke is coming out your oil rings are shot and probably have poor compression.

[0bird2]

Chuck,
From the picture Barry posted, the oil filler/breather cap looks just like the one that is used on '55-'57 T-Birds with the dress up kit. I just checked online at concoursparts.com for the one they have available and it is about $30. There are several T-Bird parts vendors with online catalogs. I'd check price at several. Others are Larry's t-bird parts, CASCO, NPD, Hill's, and others I just can't think of them all.

[Chuck Lutz]

Thanks. I'll check that out. :)

[0bird2]

Chuck,
I was out in the T-Bird and while checking fluids I noticed that the oil breather cap is marked with 'front' not 'oil'. I haven't checked my Mark to see what is on it.

[Chuck Lutz]

Thanks, I just got one from Jack this week. It's black but I talked to Jack about that and he said the chrome ones he doesn't stock anymore due to plater problems. I checked with my local guy who does plating and he's going to do it for me. It would be cheaper by the dozen so if anyone wants to get in on the action, order the cap and get it to me.

[George]

Hi Chuck I do need one of those crome caps so maybe we can talk about that. I also am starting to look for someone to do some plating for me, there aren't many options here in Sacramento. I know that you live close by in the Bay Area, any suggestions?

Thanks

George Procida

[Chuck Lutz]

Hi Chuck I do need one of those crome caps so maybe we can talk about that. I also am starting to look for someone to do some plating for me, there aren't many options here in Sacramento. I know that you live close by in the Bay Area, any suggestions?

Thanks

George Procida

I'm not sure there are many options these days. It's an environmentally undesirable industry. On straight-forward stuff we can usually talk the customer into stainless and high polish it but these caps are stampings and fairly thin. I just use a local plating shop from time to time for some for my metal shop needs. He told me he’d do a dozen for about $21 each (which I figure is his minimum [$250]). They are in San Carlos, The name says it all…Industrial Plating. The process is pretty simple (with the proper equipment and chemicals). Usually, there is a “flash copper” plating that goes first to which the chrome sticks. Then it’s polished out. On the more delicate pieces, this becomes the tricky part. Not too much friction heat to warp the metal and a sincere desire to NOT get the part caught in the buffer :eek:

[Don Keller]

George, Chuck & others,

I was wondering how it came out for you guys as far as the breather caps? Mine is original with the "OIL/OIL" on the top and the canister is engine color. The cap itself is somewhat rusty and looks to me more like it was originally painted silver rather than having been chrome. I will take the word of those who say they are indeed chrome plated. I noticed a chrome plated breather cap at Advanced Autos the other day with "OIL/OIL" on the top. I doubt that they are identical, but in most of the pictures of Mark II engine compartments, it looks to me like the caps have been painted silver (a lot like mine). What makes me question the silver color is that chrome generally tends to bubble or peel wiith age rather than just gradually become rusty with faded silver color underneath. I don't want to start an argument, I'm just trying to do some inexpensive things that I can afford and stay as original as I can. I see that Barry's is definitely chromed, but I have to think that it has probably been replated at some point to be that perfect. But, I don't know that. The chromed dipstick handles seem to have held up very well over the decades with virtually no rust. Have you all seen enough at shows and looking at other Mark IIs to confirm that all were indeed chromed during production? Any thoughts on the over the counter generic chrome caps?

Thanks.
Don Keller
C56R3838
Jackson, TN

[Sean Rollins]

Mine is chrome as well. The big thing to watch for at the auto parts store is to be sure the cap they are selling you is NOT vented or else the draft tube only pulls air through itself instead of emptying the block of harmful vapors. Most of the caps I have seen are vented, so turn it over and be sure there is not a bunck if punched holes around the perimiter to allow air in.

[SLK]

Mine say 710.... :D

[Don Keller]

Ben...you had me scratching my head there for a second! Thanks Sean, I will check on that and wasn't aware of it. So they really aren't "breather" caps, just filler caps?

Thanks.
Don

[Pat Marshall]

They are indeed filler caps and should NOT have holes in them. They should be chromed.

[Pat Marshall]

BTY - I have had surprisingly good results cleaning up a rusty filler cap in a lapidry tumbler.

[Don Keller]

Hi Pat,

Sorry, but what is a lapidry tumbler? I guess I must not have one, but if I know what is maybe I can do it by hand. Just to make sure that mine is original, if I hold it upside down and look in it should I be able to see the wire-like filter material? I can, so maybe mine is a replacement with "OIL/OIL" on the top? This is confusing as I thought most all cars of that era had blow by pipes and I had never noticed a breather cap that was enclosed at the bottom. Live and learn.

Thanks.
Don Keller
C56R3838
Jackson, TN

[Pat Marshall]

A lapidary tumbler is also known as a rock tumbler. It uses different kinds of medium (tumbling grit) it can de-rust small parts, smooth surfaces, and using the proper pollishing medium even polish chrome parts. I put all nuts, bolts, screws, etc. through this and it takes old yucky things and makes them look new (with the exception of wear damage.

I have also attached a picture of the underside of a Mark II oil filler cap. BTW this was cleaned up with the tumbler. It was coated with surface rust. Notice how thoroughly it was cleaned up.

[Don Keller]

Pat,

Thank you very much. Now I know what they are and have seen them at Harbour Freight, but didn't know if they were worthwhile. Sounds good. Just what I needed to see what the breather cap should look like. I appreciate the help and hope it will benefit others as well.

Don Keller
C56R3838
Jackson, TN

[Barry Wolk]

I use a vibratory parts cleaner. I'd love to have a tumbler, though.

Through this whole thread I don't believe anyone has explained why a vented cap doesn't work. The V shaped end of the draft tube creates a negative air pressure behind it at speed. That draws combustion bypass gas from the crankcase that gets past the rings and vents it away under the car.

If the top of that tube were vented there would be no draw of fumes out of the engine as air follows the path of least resistance. The vent in the valley pan is for intake air at speed, so you don't suck out oil of the engine. At idle the tube will vent some smoke out of the tube.

I'd like to find an PCV cap that I can vent to the bottom of the snorkel. If I plugged the bottom of the vent tube I would be recirculating crankcase gasses to the air intake.

That would go a long ways in keeping the bottom of the car clean.

[Matt Cashion]

I think connecting to the air intake tube would be a mistake. If your engine has blow-by it would travel thru the carb and not only leave deposits on the throttle plates and bores but also do a good job of upsetting the fuel/air mixture.

Matt---

[Barry Wolk]

I don't know, that's the way PCV works. The debris is pre-filtered and filtered again by the air filter or oil-bath. How would that disrupt air/fuel mixture? There's very little combustable fumes in blow-by gasses and the PCV valve is spring-loaded for stopping the flow at idle. The total flow is miniscule compared to the cfm of the carb.

[Matt Cashion]

I don't think that if you attach the hose from the oil filler cap/pcv valve to the intake tube you will have the vacuum necessary to close the valve at idle. All the pcv systems, with a pcv valve, I'm familair with have full engine vacuum below the throttle plate(s) provided to the pcv valve. I've seen engines that due to sticky or worn piston rings, worn cylinder walls, or both produce enough blow-by that engine performance from idle rpm up is adverseley affected. If the pcv valve was allowed to draw fresh air and the blow-by was allowed to vent into the atmosphere (for testing only) the engines ran much better, considering their internal conditions.

Paper air filters may do a better job than and oil bath filters in trapping the particulates in the blow-by gases but with all the efforts to keep the "tea pot" carbs in good order I don't think I would want anything other than good fuel and fresh air running thru and in it.

On a similar note-- When I first bought my Mark II the idle was very poor. I soon found that I had exhaust gases comming out of the tube that was intended to provide clean air for the choke heat tube. Neat! I had one of the earliest EGR systems and the car developed it by itself-- Primitive, unmetered, warped the top of the "tea pot" carb--- Had to go. Replaced the burned out heat tube in the intake, repaired the damaged carb, and put the Trunk Monkey on notice to never let the car modify itself again. Just curious if there are other Mark II owners who may have had idle issues and carburator damage from the same choke heat tube failure?

[Barry Wolk]

I'm sure that many of my old cars had breathers, maybe they weren't PCV valves, just a means to get crankcase gases to the air filter housing. They always end in some type of coarse filter that clips into the housing.

I'm sure all of my 460s have that. It doesn't matter where you pull the gasses from, the heads and crankcase are all connected through the oil gullies.

Frankly, I don't see the difference.

[Matt Cashion]

OK, now I understand-- The filter, I think you're referring to that's mounted inside the air filter housing on newer engines, with a tube connecting it to a valve cover provides the fresh air that will be drawn thru the engine by another tube usually attached to the other valve cover. The pcv valve will connect to this line, usually at the base of the carburator in a spacer plate below it, where full engine vacuum is provided. Only if the pcv valve is restricted will crankcase vapors push back up into the small filter in the air cleaner housing.

Matt---

[Barry Wolk]

I think you're confusing EGR with PCV. But, I could be wrong.

The tube you speak of brings crankcase gasses into the air cleaner, not the other way around.

[Matt Cashion]

I didn't mean to combine pcv and egr when I included the burned out choke heat tube problem my Mark II had in a previous post. If, with your 460 running, you remove the tube connected to the filter in the air cleaner housing and put your finger over the end of the tube, leave it there for about 10 seconds, when you remove your finger you should feel a slight vacuum has built up, not pressure if your pcv valve is working properly.

[Eyelawdoc]

Oh, so the cap is the only thing chrome? The tube is painted. I thought the whole thing was chromed.
Thanks, that's easier to do. Now all I need is to find the cap.

You're in luck. The chrome oil filler cap on the Mark II is the same FOMOCO chrome oil filler cap used on the 1955-57 Tbird Engine Dressup Kit. Oirginals are hard to come by, but it has been reproduced. Try Casco Thunderbird parts:

http://www.classictbird.com/

They have an online catalog. You need part number 6766. $28.45 They also offer a PCV kit with an under carb adapter plate to fit the Teapot carb on a 55-56 Bird. The draft tube is removed from the rear of the engine valley cover and an adapter fitting with PCV valve installed in it's place. It looks like it would also work for a Mark II. Part number is 6758AA, $48.58. This is a simple bolt-on plug and play, for not much work or money.

[Pat Marshall]

See attached pictures. The TBird and Mark II filler caps are different.