If I understand you correctly, the smoke is coming from the side panel holes that go around the spark plugs.  There should be round gaskets behind the side panel around for each sparkplug that should seal any oil or smoke.

good luck

Rich didn't say but from previous posts he has a 29 so no gaskets at the plugs. I would think a little smoke at idle would be normal. I haven't started my 29 so don't know from first hand experience.

Dave

What years did they start using the gaskets around the spark plugs?

My 29 has a no vented rocker arm cover and no gaskets around the plugs and my 31 has a vented cover and gaskets around the plugs. So somewhere in between. The catalog I have wasn't clear on the change but talked about retrofitting the new to the old.

Dave

Yes It is a 29… sorry I was not clear. So no gaskets around the spark plugs. My 53 does have the cork gaskets and breathers in the valve cover. 

This has no gaskets and no breathers in the valve cover. I do think a little smoke is expected. It really is just a wispy smoke you really have to look to see it. 

An update… I had my buddy come over and we listened to the motor with his scope. He had a 29 just like this for a few years. It sounded fine to him except for a slight ticking in the valves. He thought it was more prominent in the front than the back. I really couldn’t tell the difference between the front and the back. I think I need to drive this a bit in the spring and then change the oil and see what comes out. So far it has only run a few hours and the oil on the dipstick still looks like new. 

I pulled the plugs and they are not quite as I would like them. A bit on the black side and they have some residue on them. It looks more like oil than gas and there is some fine grit that concerned me. As I said before the exhaust is clean no smoke or carbon. See pics of 1 plug attached. They all looked pretty much like this. Idk how long this engine sat with no oil in it before I got it. It starts on the first crank. Oil pressure is good. I need a temp gauge but everything seems to work properly. The carb may need a little tweaking. I usually adjust my carbs with a vacuum gauge. Can i do that on this with the vac port in the manifold? I may also just check the lash in the rockers to see is one or 2 is way off. 

With my 53 the more I drive that the better it gets. It really sings after being on the road for 10 or 15 minutes. I haven’t had the chance to run the 29 much. I did drive it around my yard and it has decent power and all the gears work. I don't seem to have to dbl clutch. I thought that was a requirement on these. 

Thanks for the advice guys. 

Rich 

PS. With all the plugs looking the same Im thinking carb adjustment and checking the valves. I don’t think 1 or 2 rockers out of adjustment will make all the plugs looking like they do. They are almost exactly the same. 

@stovebolt-6 

Hi Rich

Sorry I didn't reply earlier, just got back in from the farm.

It's been a long time since I've run my '29, but I don't remember any fumes venting around the plugs.

That said, I don't think you have anything to worry about.

Normally the "smoke" would be drawn out of the crankcase and into the air stream going into the carburetor at the "air cleaner" (which is a generous description of the apparatus in my opinion).

So...

You might check the oil separator just to make sure it isn't plugged with sludge.

Depending on whether you have an early or a late '29, the separator will be at the back left of the block (rearward of the carburetor), or on the crankcase oil filler (forward of the carburetor).

If it is clear, then your blow-by is just a little more than the system can handle...

But again, nothing to worry about.  🙂

Hi Ole, 

Thanks for the response. Yes I have a later 29 engine, May 4th casting. It doesn’t have the oil separator it has the tube going to the oil fill from the air filter. (Yes I agree, a very ambitious name for that tin can with holes in it.) That is all clean and clear. I think you’re right, the tiny amount of smoke is likely not a concern. I will see how it progresses with more running time. I did squirt mystery oil in the spark plug holes when I got the engine. And again when I did the compression test so the wetness on the plug threads is probably ok too.

The small amount of grit on the plugs is a little concerning. I don’t think I have seen that before. But it could be carbon burning off surfaces that have been idle for a long time. Chip did the carb for me and it starts right up. The only adjustment I have made is to increase the idle a bit. I may need ot lean out the mixture just a bit.

I know there are oil additives out there that are meant to free sticky valves and such but I hesitate to use any modern detergents in an engine this old. I am running straight 30 weight oil in the crankcase as I only plan to drive this in the summer months. In the spring I will drop the pan and clean out any left over debris. 

The sad part is I leave for several months tomorrow so all this needs to wait until I get back. I will miss this project while I’m gone. 

Rich

@stovebolt-6 

Hope you are going some place nice!

We're supposed to get an inch of snow here later today, so I guess the '46 will be parked for the duration of the winter.  ☹️

My recommendation (and that of many others including Doug Bell who was one of the original founders of the VCCA and who drove a 1931 Chev in California) is to use a light oil in an old Chevrolet.

Bell used a straight 10W in his '31 year round in California even though he said he drove at pretty high speeds.

Oil pressure in a '29 is irrelevant, it's all about flow.

And with the small size of the lines supplying the dipper troughs and reservoirs above the main bearings, a lighter oil will give better flow and lubrication.

Don't worry about hurting your engine with a modern detergent oil.

Detergent is your friend and will keep those small lines from plugging with sludge.

In many engines there is the worry of the detergent lifting deposits from the oil pan etc and then having them pumped through the system and into bearings etc. if you don't remove the pan and clean it out first.

You don't have to worry about that as the '29 doesn't feed oil directly into any bearing.

Anything loosened by the detergent will merely settle out in those reservoirs above the main bearings and oil will continue to flow into the bearings through the standpipes in the middle of those reservoirs.

And, as you said, you'll be cleaning out the pan in the spring anyway.  🙂

And, modern detergent oils give much better corrosion protection while the car is parked.

Hope that helps!

@ole-olson yes we are on our way to Florida. My wife hates the cold these days. 

thanks for the advice on the oil. I will switch over in the spring after I drive it a bit. I do have good pressure but I see what you mean about the tiny tubes. I don’t feel like there’s enough oil getting to the top but I have only my 235 to compare to and that is a high pressure oil system. 

I will need some tires and tubes when I get back. my tires are in rough shape  I am looking to see if someone near me in Maine can do an alignment for me. I remember it made a world of difference in driving my 53.

all has to wait til spring.

Stay warm

Rich

@stovebolt-6  In case this helps.  I too have a 1929 Chev Truck which I acquired in Feb 2025 from an estate sale.  The engine was also cast in May of 29. 

My Truck was not running, mostly due to poor maintenance from the past owner.  When I did get it running, from help with many experienced members here, I had similar issues relating to some of your concerns with your 29.

This past spring and summer I used my Truck weekly.  Runs great but I have steering issues I'm currently repairing.  But....

When I got my truck in February, since it would not start, the first thing I did was change the oil, plugs, replaced the distributor condenser (the cap, rotor and points were like new), replaced the coil, cleaned out the glass gas filter and replaced its screen, rebuilt the fuel pump and cleaned out the carb bowl.  My truck had been sitting for almost 1.5 years.  I was told by the family it was only 9 or 10 months.  Then with the help of members (the operation of the choke, throttle and dwell), I got it started. 

I have no smoke coming from the exhaust pipe or even at the spark plugs.  There are no gaskets at the plugs (1929).  But, I had a very noticeable, loud, miss fire.  I thought it was a possible stuck valve.  Before I entertained the stuck valve issue, I changed the spark plug wires to insure I had copper wires.  The old ones were not.  The miss fire disappeared to this day.  Note, I'm not an enthusiast in using oil additives to resolve engine mechanical issues.  Back in the late 60's to mid 70's, GM sold a special oil, 1-2 oz if I remember correctly, which was refined whale oil which we used to eliminate valve tapping.  If it worked, we sent the customer on their way. If not, it then became a valve job.  That whale oil was pulled off the shelf, say 76-77, due to environmentalist.  But bare in mind, that was an oil additive.  I'd say it worked about 50 percent of the time.  And those customers never came back for a future valve job.

When I start the truck, after sitting for 5 or 6 days, the engine has knocks.  The knocks go away after about 10 seconds from starting.  Never during driving do I here that knocking.  If I start the truck a day or a few later, I hear no knocking as I do when it's many days from previous running.

I presently use 10W30 oil - no detergent.  The original oil pan gasket had a bad leak so I dropped the pan, cleaned out the sludge (about 1/4 inch deep in the center) with a cut piece of plastic from a milk gallon jug.  I dropped the oil filter screen and found it was severely clogged resulting in the oil having to go over the edge of the "gunk" to to pan.  I easily cleaned that gunk out of the screen with a tooth brush and thinner.  I'm still having issues with the oil pan leaking at the new gasket in the rear at the block bearing gasket area.  Yeah, the oil pan gasket is 4 pieces - poor design.

My original oil pressure, the gauge, originally showed me 15psi at start and slowly dropped to 12-11 psi.  The members informed me that was ok.  I now have 25-28psi.

I'm missing the air cleaner assembly and oil fume pipe.  I'll eventually make one.

I have to double clutch for all my shifting.  My truck is geared so low, if I'm not carrying a load, I don't use first gear.  Down shifting, even with dbl clutching, is horrible.  Mostly does not work.  I have to wait for very low speeds to accomplish this feat.  With out a load in the back, I'd swear I'd blow the tranny if I held my speed at 45MPH.  The tranny wines so high I chose to run at a max speed of 35-38.  With a good load in the back, say 1000lbs, I don't here the tranny at all at any speeds.  And with that load, first gear is amazing.  With only 46HP max, I understand the engineering design of the tranny for the farm work and commercial work the truck was intended for.

Next spring I will change my oil specs to 10W20 no detergent.  When I had the oil pan off, I noticed my engine had been service not to long ago.  Since the previous owner restored this truck by 2015 and used it for events only, the engine is like new.  Therefore the 30W spec changing to 20W would be best suited for oil return throughout the engine.

Here's some of my pics.  Gary (Junky)

Posted by: @junky

↑

 

I presently use 10W30 oil - no detergent. 

 

You might want to rethink that. Non detergent oil being beneficial is an old wives tale. People far more knowledgeable than I have repeatedly told me that the detergents in oil do not make existing sludge break loose and cause issues. They keep sludge from building up. Using non detergent oil allows sludge to build which is never a good thing.

@junky Gary, Thanks for all of the information. Your truck is a beauty! Mine is running pretty well. I think I need to drive it a bit and see if the valve tick subsides. It is a very slight ticking. I’m hoping it is just some stickiness from sitting so long. The engine sat for years in a shed with no oil in it. I did run the oil pump with the valve over off to ensure I was getting oil to the top. I couldn’t really drive it much as it is not registered or insured and there is a big bubble on one of the tires. I did drive it all over my yard in Maine and it was a ton of fun. I am in Florida for a few months. When I get back I will continue to tinker and keep my eye on all the expertise here on this site. 

I have a similar issue with my 53 Chevy that you describe with the knocking. The 216 that was in it originally ran better after a few miles on the road. The current 54 235 in there has hydraulic lifters (its a high pressure engine) so the more it runs the better it runs. It really runs like a new engine once you get it on the open road. 

I do plan to drop the pan as I’m sure it’s full of sludge. I am developing a punch list of things to do when i get back. 

Thanks again!

Rich 

@junky 

I'll second what Tiny says.

The need for non-detergent oil in an old engine is worse than an old wives tale, it's a dangerous and destructive fallacy.

I won't even use non-detergent oil to oil the chains on our combine.

Changing to a lighter oil is however a very good idea.  (see below)

While we are here, we might as well address another fallacy... that synthetic oil shouldn't be used in old engines.

Some early synthetics were apparently made completely of PAO base stock, which allowed seals to shrink and start to leak.

All synthetics I know of now have some ester or some other base stock or additive that keeps seals from shrinking and keeps them pliable.

And, synthetics have much better viscosity indices... meaning that they can flow much better at cold start ups and still maintain their viscosity at higher temperatures and be less susceptible to shearing down to a lower viscosity over time.

The end result is that today's synthetics are much superior to non-synthetics.

For these reasons, and because my '46 only does light service around town and is never heavily loaded and never gets hot, I've actually been using a synthetic 0W-16 since I acquired it and it works fine. 

I originally put it in as a flush oil after I had the pan and head off, but seeing how it worked, I couldn't see any reason to switch to anything heavier.

Besides, nothing heavier than SAE 20 was recommended in 1946, and I know many trucks around here never ran anything heavier than 10W.

And 0W-16 runs about half way between the two when hot.

The truck doesn't use much oil, it doesn't leak any more than my other Chevs 🙂, and my oil pressure is right up where it should be.

If I were loading it up and driving it hard, I would switch to 0W-20.

PS

With the 0W-16 I never hear any knocks taps or clicks at start up.

Even at the first start up in the spring (it sits idle all winter) it sounds like it was just parked and shut off.