VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 New to me 38 update

Michael,

Does the fuel gauge read empty when you turn off the ignition? If you disconnect the wire to the sending unit at the terminal on the gauge it should read full when the ignition is turned on. If you ground that terminal it should read empty.

Try to measure the resistance of the sending unit. If the float arm is stuck at the 1/2 point it should read about 15 ohms.

I do not know how you access the sending unit on your car. Another way to check would be to disconnect the wire that goes to the sending unit at the gauge post. The measure the resistance between that wire and a good ground.

Remember to disconnect the battery before you start messing with wires behind the dash.

Gauge does go to empty when ignition switch is off. Someone cut a hole in the middle of the trunk at what appears to be Gas tank contacts.

Hi Michael,

I thought I had heard that in that era sedan you needed to drop the gas tank to get to the sending unit. Obviously a previous owner for your car had other ideas about access. Which also raises a flag that things are probably not like they should be with the sending unit.

By using the special key (a pair of pliers) to open the custom access door you should be able to reach the sending unit. If you disconnect the lead at that unit the gauge should read full. If you ground that lead (make sure it is a good ground) the gauge should go to empty.

You should also be able to directly read the resistance of the sending unit. Connect one lead of the ohm meter to the terminal on the sending unit. Connect the other lead to a good ground.

Maybe so but the more shiny(Stainless), the more horsepower. I might even cap the oil filter lines but leave everything as a conversation piece after I clean and paint plus replace lines with fresh ones. I do appreciate the advice and references to originality but I will deviate from original on occasion.in most cases I can’t afford or will pay for original parts if I can get nice repops, bumper guards for example. A complete NOS set of 38-39 bumper guards went for $1900 on eBay, too rich for my blood when I can get repops for $125 each. Thank again for the references to authenticity

Quite an adventure today going for what I thought to be an uneventful drive. Knowing I have less than two gallons of gas(two gallon container to add gas to thirsty 38), i filled her up.
-After filling her up I noticed a stronger than normal gas smell in the cabin as I headed to the antique store looking for old Chevy memorabilia. After leaving the antique store I noticed the 38 smelled like gas as I walked around her and the smell was stronger from the trunk which has as big hole above tanks level sensor, I suspect. Surprisingly not much of a gas smell from the engine compartment.
-I notice she tends to bog at lower rpms in all gears especially first and even backfires a little.
-As I was nearing a amber light signal around 20 mph I realized I should stop but my 38 on bias plys didnt agree and slid about ten feet into the intersection, fortunately I was in the right lane so i slid into a right turn and kept going until i could make a u turn. My old 38 Master Deluxe seemed to be a bit more responsive vs the sluggishness of my Master Sport.
I have much work to do to track down the source of the gas smell and my brakes need adjusting as well as advanced planning everything I do will require advanced planning.

I started to adjust carburetor and discovered I have a Rochester B type carb

The fact that someone cut an access hole to the sender should be sending you at least 2 strong signals.

One is that someone has done work on the sending unit.

The other is that whoever did that work liked to take short cuts, does sloppy work, and is not necessarily concerned with the long term results.

It would not surprise me if that sending unit was re-installed without a gasket. That would allow gasoline to splash out the top of the tank.

Did you ever figure out if the sending unit or the gauge was defective?

I only see the car on weekends, just had time to put gas in

Ok, finally drained the oil and now have a list of things to do, had to remove the heater shutoff valve from its new position to remove the valve cover but now I need a reducer that I found on chevsofthe40s. I have decided to disconnect the oil filter but need to plug the block now there is a vacant hole there. I need to reposition the shutoff valve on the water pump, prior owner put heater shutoff where temp gauge goes into block requiring the hose routed over the valve cover. Motor mounts are shot too.

If you are going to order the motor mounts from The Filling Station I suggest that you order the reducer also from The Filling Station.
Make your shopping, list it will say you time and money in the long run.
Ordering from two different supplers will cost you dearly in freight.

Tim
VCCA 5049
Member since 1970.

There have been multiple posts lately about hose routings for heaters. That location on the block provides the hottest water to the heater.

I agree it is a pain when you want to remove the valve cover. I do run mine from the water pump and front of the block.

I did exactly that and a bit less expensive too
Thank you

Ok, started to clean engine and made some discoveries that might mean nothing. Some of the pushrods are straight and some are slightly bent. The sleeves where the pushrods run into the lower block are mostly flush but one sticks up more than others, I suspect it’s no issue. Do the lower pushrod openings or sleeves drain off into the oil pan. I drained the oil for gasket replacements including oil pan, I want to use isopropyl alcohol to clean everything thoroughly. Is that ok as there is grime in the pushrod sleeves
Thanks
Michael

Maybe I am missing something in the pictures. From what I can see the “sleeves” are really the valve lifters. The top of the lifter does come above the edge of the block during the opening cycle for that valve.

I strongly recommend replacing the bent pushrods. That situation never gets better. Typically a bent pushrod means that the valve has or is sticking and will not open properly.

You should watch the valve opening action for all valves as someone cranks the engine by hand. Removing the spark plugs makes that a lot easier.

Also, plan on removing the rocker arm shafts and taking all that apart to clean it. You need to confirm that the rocker arm assembly is getting adequate oil flow and that the rocker arms have not scored the bottom of the shafts.

To test if pushrods are bent, with the removed from the engine place each end of the rod on flat surface and roll them if the centre oscilates they are bent but if the centre stays level there is no bend. If there is a bend it will only get worse when the engine is running.
Tony

Congratulations, you still have the original lifters and pushrods. As Rusty noted the "sleeves" are your lifters. They are shaped like a cup. The longer pushrods that are used with those lifters are notorious for bending. I believe Egge sells the longer pushrods but don't know that to be fact. When I first got my 38 I bent several by inadvertently sticking the intake valves closed. At that time I was unable to find the longer pushrods and ended up using later model "milk can" lifters and shorter pushrods. You might consider that route. If you decide to stay with the cup lifters and longer pushrods I kept my old ones and there are a few that are still straight if you need them.

Thank you gents for the sound advice and patience with my lack of knowledge. Tiny, I will be keeping the engine stock as far as I know not wanting to make things worse by trying to modify it. I am interested in your pushrods if you think they will work for me. I assumed the pushrods would be readily available with so many stovebolts on the road. In regard to bent rods. I rotated them in place and saw some wobble. I now have to learn how to replace pushrods and adjust valves, not what an impatient person was hoping for. I pray for patience on occasion so I guess the Lord is teaching me through the 38, LOL. I’ll be reading my 38 service manual and watching YouTube videos. Keep you all posted

I'd recommend buying new ones if available. I checked Egge and this is what they list. You'll need to measure on of yours to make sure it's the correct length. https://egge.com/part/nos-1330-838409os/

There are folks who recommend setting your valves loose cold then resetting at full operating temperature. My experience is different. If you check the graph on the repair manual the lash is the same cold and fully hot. I set to spec cold then re-check when hot and I've never had to readjust. To be honest I don't even re-check any longer. I just set to spec cold and go with it. Never had a problem. You'll hear that the lash gets tighter as the engine warms, that's why you need to set them loose. Just the opposite happens. The block gets hot and grows before the pushrods are warmed by the oil so the lash actually get looser rather than tighter. As I said above, when it's full hot it all returns to the same lash as cold. That's been my experience.

Replacing pushrods and lifter is pretty easy with the rocker arms removed. Which I already recommended you do.

I agree with getting new pushrods if possible. Tiny is heading you in the right direction.

I also agree with Tiny’s experience regarding setting valve clearances. There have been multiple posts about hot or cold. In one of those threads I even noted that the thermal expansion rate of the cast iron in the block and head was very close to the same as the steel in the pushrods, lifters, and valves. So everything “grows” uniformly with heat. The only guidance I offer is to only set them either with everything at ambient temperature or after everything is uniformly hot after a long drive. I prefer cold because you can take your time and do not have to worry about things cooling down.

Now a question for the experts. Hopefully Gene is checking on us! On my ”˜37 there is an additional set of lighter load springs that fit between the top of the lifter and a slip-on retainer that fits into a groove in the pushrod. Were those eliminated in ”˜38?

So I basically remove rocker arms and rods simply come out? Adjusting valves cold is fine with me and more convenient. I can do everything while pans are removed and spark plugs are out. This is fun.

Push rods and lifters for a 1938 may be difficolt to find.
I would recomed using the 1940 and up push rods and lifters
The lifters are taller and push rods shorter which prevents the from flexing.

If I were to take the layer model lifter and pushrod, who is a good source to purchase an entire set? I can look myself but trust all of you with experience.
Thank you

not neceasary to replace all.

If you are using any of the original lifters put them back in the original hole (or location)

Is this the consensus view that I follow Chev nuts advice and go with taller rockers and shorter rods? This makes sense to me but will cost a bit more. I do plan on putting a larger engine in my 38 to accommodate ac as we might be moving to the Houston area. I might go in the cheap knowing I will swap engine. I suspect this engine is long in the tooth and would require an overhaul even if I decided to keep it. Thoughts?

push rods are easy to straighten