Oil Filler Tube

[joltesvig]

My oil filler tube has baffles in it.
I take it those are to keep oil from splashing up and out of the breather cap.
I notice that a LOT of smoky oil fumes normally come out of the breather.
The fumes are normally HEAVY to the point where they come up through the floor boards and can be seen on a sunny day inside while I'm driving.
Is it normal for Model A's to give off a lot of fumes out of the oil filler / engine breather tube?

[redmodelt]

If you are getting a lot of fumes and smoke in the car that might mean that your rings are bad and getting a lot of blow by into the crankcase. Time to check your compression. For now you may want to get one of the breather caps with the tube to put the fumes down under the car.

[TinCup]

Even easier is to put an old tube sock over the cap. Works great!

[joltesvig]

So it may be blow-by exhaust getting around the piston rings? Is compression difficult to check? What do I need? Or can most auto garages check the compression or do they need special tools to check an old Model A engine? I would like to do a ring-job on her if she needs it. Again, can a good auto engine garage do a ring-job on an old Model A engine? I assume the engine would need to be pulled out to overhaul the engine. If the rings are worn, other things should be checked & replaced? But maybe I'm getting ahead of myself...I need to get the compression checked first.

[Tom Wesenberg]

If you have that much blowby, you need rings for sure. Unless the engine has been setting and the rings are stuck, but even then you need to remove the pistons to unstick the rings. I have a 29 Chevy Coach and a 63 Studebaker Lark, both with stuck rings. This was my fault for running the engines only about 10 minutes and letting them set for 6 months. Tought lesson learned back in the late 70's.

[Tom Endy]

Sponsored Links (Register now to hide all advertisements)

Be careful what you put over the breather pipe or jam inside the cap. A restriction of the vent will cause oil to pour out over the rear main seal.

Tom Endy

[CarlG]

I've got one of these -- works like a charm, keeps the engine nice & clean.

[Bob Bidonde]

Do a compression test to determine the cylinder pressures, and to see if each cylinder will hold its pressure for a few seconds. The average pressure should be 55 psig or more.

It is not unusual to have some oil vapor come out of the breather tube. Oil is vaporized by:
> Heat;
> Splash lubrication of connecting rod dippers;
> Reciprocating motion of pistons and valve lifters.

It is better to divert the oil vapor out of the engine compartment using an extension tube that directs the vapor under the car. Such a tube is a common Model A accessory and can be seen in Bratton's catalog, Page 45, PN 9920. The tube works by using the combined effects of the crankcase pressure and the less than atmospheric pressure under a moving car to achieve flow of the vapors away from car.

A more difficult technique of ventilating the crankcase is to have a positive crankcase ventilation system. This entails routing the crankcase vapor into the intake manifold where it goes into the engine as a part of the fuel mixture. A check valve is necessary to prevent back-flow.

Anything restrictive to ventilation of the crankcase will increase the pressure within and force oil out of the rear main bearing, and past the front main bearing rope seal. So covering the breather with cloth or inserting a scouring pad into it are not the best way to solve the problem.

[hardtimes]

Hey John,
If you do not have the time/money , at this time , to do rings, etc..., get the device shown by Carl ! As he says, it is effective and inexpensive and correct method to solve your immediate problem...till you can dismantle engine.

BYW..there is ONE other way to control 'blowby' on a well worn and even a good running engine. Install a PVC system on your engine. Check the back threads on how this is done.

[bettlesr]

Hartimes:
PVC plastic or PCV? LOL
Dick

[Fred K-OR]

Hi John,

You asked about being able to do a compression check on an old Model A. It can be done by just about any shop now days that has a compression check tool. But you may need to order a compression tester adaptor, Bratton's catalog page 165, part number 8471 $6.50. This will allow any modern tester to tie into the Model A plug hole. Bob above gives you the pressures and how to do it.

[harleytoprock]

CarlG, I like that breather. Where can I get one?

[CarlG]

Originally Posted by harleytoprock

CarlG, I like that breather. Where can I get one?

That is one of the original "Unauthorized Accessories". They are available occasionally on eBay (which is where I got mine & one other for a friend), but they don't come up very often. And when they do they are usually priced way out of my range. No one that I am aware of currently makes them. It has been deemed as one of the few accessories that actually work. It's called a Fumaze.

[Y-Blockhead]

Check here; http://www.oldcarcentre.com/ModelA2010web.pdf Part#A-6766 FM on page 17.

Carl can you use the engine pans with the Fumaze?

I have the flexible breather. I got it from Mike's http://www.mikes-afordable.com/product/A6764.html

[CarlG]

Originally Posted by Y-Blockhead

...Carl can you use the engine pans with the Fumaze?...

Yes, it actually works better with the engine pans as the air flow is directed back rather than down, even when idling.

[joltesvig]

You guys are a wealth of information !!! I'm ordering the oil breather tube as a short term fix to direct the oily fumes down into the slip stream under the chassis. Ordering from page 45 of Bratton's like you said. Then I'll get my act together and do a compression check on each of the 4 cylinders to see if I have a stuck ring or if I need to do a ring-job. If it's just a sticky ring or two, is there an oil treatment I can add to my crankcase which might unstick it?...or are those a waist of time & money? I've heard of something like Gumout way back when I was a teenager...is that still available?