Oil breather cap smoke and carb drip questions

[adam_knox]

First of all, thanks to everyone on the valve cover and fuel pump tips! Everything is assembled and thus far no leaks on that end.

Here's my two questions:

1. My oil breather cap has some good 'ol grey smoke rising from it after I drove it around the block (has not gotten up to operating temp yet). Is this normal? I know its a "breather" cap, just haven't noticed it before. Previously I attributed any fumes to the exhaust leak coming from where the heat riser should be, which is now hopefully sealed. Where the valve covers were, everything looked clean, as the one thing I actually know how to do well and often is an oil change!

2. I put on a rebuilt carburetor because my old one was leaking. This one appears to drip once the engine is off. Is that expected our carbs? If not, I guess I have to mail it back to them to adjust the float/seals as it voids the warranty if I take anything off.

Caveats: I haven't done a tune-up yet, so it's still running rough.

Just curious if either of these are issues that need to be of concern or if they are normal for 60+ year old cars...

[Tom Skinner]

Adam,

When smoke comes out of my breather after I shut my engine off, its usually because I'm running a little rich and gas seems to be saturating the crankcase. The other part of your question if I have a full gas tank and its real hot out my carb will drip out some (maybe call it boil over) after the heat weight goes back up. If however its cooler out and I only have a half tank of gas it doesn't do it.

Maybe your carb bushings are a bit worn? I have had a couple of 1948 Chrysler Royals since 1973 and they always smoked a little out of the breathers and weeped a little gas out the carbs after shutting down the engine. Right now though I have the choke and carb mixture set just right and its not doing either, but that's probably because I have it set a tad lean and the choke and timing are just right.

Set your points, time it, then use a vacumm gauge to set the Idle mixture screw. Find your highest vacumm setting - say 20" or so and it should burn pretty clean. Another way to tell if your too rich is remove a spark plug and "read it". Is it dark and sooty? Is it light brown/whiteish brown? Adjust accordingly. I find running my timing about 4-6 Degrees in advance helps.

[adam_knox]

Thank you so much Tom! I shall hold off my concerns then until it's properly timed and such.

[Robert Horne]

Adam,

The smoke coming from your oil breather cap is exhaust gas that has gone

around the piston rings, or valve seals, and into the crankcase. This is

normal on an engine with alot of hours on it. The oil breather cap is for

letting air into the engine, but with our old engines the reverse happens,

crankcase gas excaping there. I added a PCV, to a vaccum line to help

catch some of the gas smoke rather than ending up in my engine compartment.

A gasoline leak, even a small drip, would scare the heck out of me, especiallly

if it was anywhere near a hot exhaust. A gas drip, engine off or on is not

something I would want. The float may be just a little too high, if all lines/

filters are ok.

[adam_knox]

Robert, thanks for explanation and word of caution. Sort of bummed that mine is doing that, since the engine was rebuilt prior to my ownership, probably about 12,000 miles ago. Oh well, you can't expect a 60 year old car to hide its age for too long. I'll keep an eye on that carb and get it fixed one way or another.

I do have a small exhaust lead between the exhaust manifold and tailpipe, and a new muffler that needs to get put on as the old one is apparently blown. Will that greatly impair the timing/tune-up process? I'm looking at the calendar and my list of things to do and I may need to take it to a shop for a tune-up. I was really hoping to do it myself, but realistically I won't be able to give it the attention it deserves.

When looking for a place to do a tune-up, how many hours of labor is "normal" for job for a "tune-up" (set points, adjust carb/vacuum and timing)? Would you guys say 2 hours is a fair estimate? I'm gonna try to contact the local car club around here and see if someone with experience can walk me through it or if they have a place to recommend. Really bummed too, I found a 6 volt dwell/tach and was looking forward to learning how to use it. I just know I won't have four hours of head scratching to spare. The crash course may have to wait a bit.

[Robert Horne]

A tune up usually takes about an hour. A dwell meter is a big plus when installing a set of points. It will let you know if you have a good setting on the points.

You can take your time and do it yourself. If it takes more time, no problem, good practice, do part of the tune up each day.. Spark plugs are easy to get to.

[Tom Skinner]

Adam,

Robert is right, if you can endeavor to learn and do a little each day by yourself.

Our cars are pretty high maintenance - kinda like a Lady that needs attention.

Therefore to, do -it - yourself, will save you an awful lot of money in the long run and bring a whole lot of satisfaction knowing you did it yourself.

A Service Manual is a good place to start, they are not hard to find on ebay.

From there (Our Flathead Engines) are quite simple straight forward engines to work on. Setting Points, Timing, and Tuning the Carburetor with a Vacumm Gauge is not difficult (about 45 minutes). Changing plugs (15 minutes) and your on your way to being a great mechanic. Of course it helps to have a experienced car club guy/buddy to show you the way the first time.

In fact if possible if you can't find a free helper, ask the guy your paying to show you what he is doing (if he's willing) then you will know just how easy it can really be.

Tom

[ptwothree]

Or, just run a hose from the breather pipe to the back of the car:D. Maybe disguise it as a second exhaust pipe fooling people into thinking your running duals!

[adam_knox]

Thanks Tom for the encouragement. I think I've got all the tools and books, just not the time at the moment. I have to move with sort of short notice, thus the work space and tools will no longer be available for about 8 months. Under normal circumstances I would putz and tinker until I think I got it right (only to find out a hundred miles later I actually didn't, and then get it right the second time! ) Unfortunately, I sort of would like/need the car to be in the best condition possible since I will not be able to bandage and fix any problems for while. But if I do wind up taking it to the shop, I'm hoping they won't mind me watching, even if its from beyond the shop floor doors!

Thanks for the break down of hours of labor. I would make mint as a mechanic; I can turn any 1 hour job into a 3+ hour job easily!

[Young Ed]

According to my p9-p15 flatrate book an engine tune up minor is .9 hours. This covers clean and adjust spark plugs, adjust breaker points, check distributor cap and rotor, inspect distributor wires, reset ignition timing, clean air cleaner fuel bowl, and adjust carburetor idle. The muffler is listed as 1.2 hours. In 1940s dollars the .9 hours will cost you $0.90-$2.70

[adam_knox]

Ed, you got the name/business card of the mechanic whose book that was by any chance?

[Don Coatney]

Heat saturated expanding gasolene causing the carburetor to leak has been discussed many times on this forum. To retard this leak simply lower the carburetor float level. Simple procedure and should not require use of the USPS or the brown truck. If you dont learn some of these simple procedures you will end up stuck on the side of the road and a hook job will be required to return home.

The B&B carburetors are vented unlike later model carburetors that are sealed. I, and many others, have never had success in completely sealing these carburetors to prevent any leakage. I challange anyone to post a picture of a non leaking B&B that has been driven several thousand miles. Pictured below are my carburetors after a fresh rebuild and after 40,000 miles.

A tune up is straight forward and very easy to do. I recommend you do it yourself so you understand how everything works.

[greg g]

A wise friend and fellow member of this board has stated on more occasion "If yer gonna own one of these old cars, sooner or later yor gonna hafta mechanic on it." That said doing a tune up is pretty easy for a person of normal mechanical interest and aptitude and shold be able to be accomplished in under two hours. Especially if most of your parts, ie plugs, wires, dist parts.

The simplest way to deal withthe distributor points is to remove the dist from the engine and do the dist work on the work bench with good light and easy straight up access. Just femove the cap witht he plug wires attached and move it aside, mark the rotor direction to the dist body, and the vacuum advance position tot he block and mark them with chalk, tire crayon or other suitable marker. Disconnect the wire from the coil, loosen and remove the clamp bolt and pull the dist from the engine. You can then mount the dist in a vise or stick the drive tang through a small cardboard box. This will allow you to use a feeler gauge and set the point gap with the points cam directly on top of a cam lobe. You can also inspect the points to see of they are in good condition or need to be filed or replaced. Putting the dist back in is a matter of realligning the rotor to your mark, and aligining the vacuum advance to its reference mark and replacing the clamp bolt. If that takes more than a half hour, I would say you were all thumbs as my mother used to say about folks who had less than optimal hand eye and or motor skills.

As to your carb question, like Don's pictures show, these carbs tend to weep at the top seem due to fuel heat expansion. If yours is leaking there check that all the screws are good and snug. Use a cross the carb everyother screw to tighten them rather than a circuit around the screws in order. If gas is puddling on the trottle plate and dripping wet from the throttle shaft bushings you need ot adjust your float, to allow the needled seat vavle to close with less fuel in the bowl.

Neither of these proceedure are rocket surgery nor very time consuming. The results of doing them correctly can be very gratifying as it will result in a easier starting, better performing engine.

[40P10touring sedan]

Wonder if a resin spacer between the carb base and the manifold would help any...as an insulator.

Don, per your 1st pic, I hope you installed the circlip back on top of the throttle bellcrank.

[54Illinois]

Some of the "smoke" could be steam. I know I smell gas vapors in mine sometimes. That is what the air breather cap is for.

IMO I think any engine, old or new will belch something.

[adam_knox]

Update!

Back on the road! Looks like the problem was the carb I had rebuilt, it was dumping gas out the adjustment screw. Took it to a local mechanic who helped me piece together one of my older carbs and do the timing. Was very grateful I had someone with experience helping me out, had a broken ground in my distributor and helped explain the what's, how's and whys. He really saved you guys from a flood of questions coming from me! Plus, there's no way I could have gotten it figured out in time before my tools had to packed away and us moved out. Anyways, just wanted to say thanks to everyone for their advice and experience. i'm now the wiser and can do a tune-up with confidence.

[BobT-47P15]

When mine recently began emitting smoke from the oil fill pipe,

son in law determined the carb (a used one just installed) was

putting gas into the crankcase. The car has gone since 1973

when I got it till just lately without smoking from that location.

So I agree it probably was the old and not rebuilt carb.

[54Illinois]

You mean vapors?