VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 More questions from a Newbie

I want to thank all for the help so far on my new baby. a 1930 Roadster. I've owned many an old car, truck and motorcycle, but this is my first old Chevy. There are a few mysteries I'm curious about.

The metal tube coming from the oil fill tube. Is that some kind of breather for the crankcase? If so, it doesn't (on my car) extend below the frame like most do and if it is a breather, can I extend it as it seems like the oil smell is being directed basically into the cab. Not a nice odor as we all know. In the owner's manual, it says it's some kind of what we call, a pcv valve, but the one on my car is not attached to the manifold. It's curved down to the catch-all panel below the carb.

On the carb, the lean/rich large adjusting screw....the car when I got it was burning very rich as the plugs were very sooty. I turned the adjustment in all the way and out about 1 and a half turns. Hoping that should do it.

Last for now, the old gentleman said he had disconnected the spark advance, but it looks to be connected but froze in its cable. He's been running the car for a few thousand miles, after a complete rebuild, with no apparent problems. I know from owning a Model A you have to adjust the spark while under load. This set up, while froze is at least in full retard position, so no kick back at start up.
Should I try to free it up or leave it, as I didn't notice a problem either, when I drove the car?

Oh.....and I assume the hub caps just pop off the rims? One is a bit loose, and I want to try and secure it tighter so It won't rattle around.

Thanks as always.....Don

Mine's a '31, but I assume that the cars are similar.

I've never used the spark retard cable. Modern fuel allows an additional 6 degrees of timing advance with no pinging. I've heard that if you are going to use the handcrank, then retarding the timing is a good idea. I've never tried.

The hub caps just pop off, but mine are very tight.

The metal tube from the oil fill tube is indeed for crankcase ventilation. It should connect with a port on the air cleaner so fumes are directed into the carburetor.

The large spring loaded screw adjusts the amount of additional air that blends into the air/fuel mixture drawn up the low speed jet (aka idle tube). If there is little change in idle speed when adjusted from closed to 1 1/2 turns open there is a problem in that circuit. The majority of used carburetors have the screw closed to only slightly open, primarily due to wear on the throttle shaft and carburetor body. As long as a reasonably smooth idle is found the extra expense to replace the throttle shaft and bush the carburetor body is not justified.

Because of the octane rating of modern gas 85+ it burns slower than the engine is designed to use. That was in the 50 - 60 range which burned much faster. The result is incomplete combustion or carbon formation. That can be reduced or eliminated by increasing the timing to ~ 18 deg. btdc and increasing the gap on the spark plugs from 0.025" to 0.040". The hotter spark at the plugs and timing increase recovers the power that higher octane gas causes.

Your 1930 distributor has a mechanical advance in addition to the spark retard cable. With the mechanical advance working properly there is little reason to even touch the "spark" knob on the dash. It is there to be able to retard the spark if hand cranking the engine. Chevrolets have advanced features compared to Model A Fords.

The hub caps use spring loaded retention tabs. If the springs are weak or tabs worn the caps can be loose on the wheels. Some have used electrical tape or other materials to shim out the space and tighten loose caps.

"The result is incomplete combustion or carbon formation. That can be reduced or eliminated by increasing the timing to ~ 18 deg. btdc and increasing the gap on the spark plugs from 0.025" to 0.040"."

Must the timing be increased, or can I increase the plug gap, up a bit, but below .040 with resetting the timing?

Also, the tubing to connect the oil breather with the air cleaner....specific kind or any old tubing?

Here are photos from my 1930 Air Cleaner and Breather Tube.

The 1929-31 Engine runs best as chipper noted, on a AC C86 or C87 gapped around .040" and timing near 18 BTDC. you may have to tweak it a bit an make adjustments, on my 1929 it is happiest with gap around .038" and timing around 15 BTDC, also point gap is set to .018" have to set it up and adjust it so it sounds happy and runs happy and strong, you will be amazed at the difference the timing and gap will make !! my friend had a 1931 and been driving it for years and loved it, I tuned it up and he was floored at the pick up and response it has now.

old72er,
You can do what ever you want as it is your car. I can only give advise based on my 50+ years driving early 6 cylinder Chevys.

If you have a weak coil then the larger spark plug gap may cause problems as it takes higher voltage to jump the 0.040" spark plug gap.

Just one question on the breather tube connection. I did exactly what Bears Fan shows in his pics. I'm wondering if there are any small particles being drawn up from the block that could potentially affect the carb jets or its operation, or is it strictly fumes?

To answer Chipper......I tested the coil and it's good. I ordered a new one from The Filling Station and plan on installing it (keeping the old one as a spare) just in case as I'm not sure how old it is.

Highly unlikely to have any particles in the carburetor air from the crankcase or for that matter affect the carburetor operation. Particles might cause wear in the engine but with paved roads even that is not too big a concern.

Just think how long between air filter changes on your modern vehicles? That is an indication on the quality of air being ingested from modern roadways.

So....I noticed some kind of reservoir on each side of the front of the car. Looks like maybe for the mechanical brakes? If so, what should be in them as far as fluids or grease?

Also, what's the easiest way to fill the gear box?

reservoir ? do you have a picture ? typically a grease fitting or two for lube at certain points on the frame and pivot points all shown in the manual.

do you have the shocks on the springs ? (pict attached of early Chevrolet shock/dempener)

Yes.....just like that.

ok, then you have the shock/dampeners for the front leaf springs !!
there was an article/info on how to service/rebuild them, not familiar with that aspect as neither of my early Chevrolets have them.

Originally the shocks were filled with shock fluid. I have been using hydraulic jack oil. Some use motorcycle fork oil. Try filling them up and see if they leak. I don't remember if you have the owners and shop manuals but they would show how to do it. The filling station and others have the reprint manuals.

If they leak around the shock arm shaft the filling station does sell the kit with instructions to replace that felt seal and some other gaskets and screws. The hard part is getting the seal retainer off in good shape. I had to use my torch to get it hot enough.

Dave

Looks to be fluid in the front two. Getting to the back two is not going to be easy. I don't see any leakage around any of them. The car had a frame off resto about 5 years ago, so they might have rebuilt the shocks then.