1948 Pontiac Streamliner 8

[r1lark]

Hi cevensky, good to see you posting, we have missed you!

[cevensky]

Happy to have some time to post! Here’s a video of the squeal, and I’ll try to capture one while I’m driving at my top speed. Looking at the picture I posted, there is a fair amount of caked on grease built up by the plug on the fluid torus. I’ll clean that off to see if it improves the vibration.

Have a trunk or treat to prepare for on Saturday. Hoping to get new front bearings in prior. 
Have a windshield to install and I’d like to find a shop to build me a new exhaust system. The ones online are expensive and I’d like to avoid having to clamp a bunch of pieces together.

It’s likely way past time to adjust valves, which I’ve never done but am excited to figure out. 

 

 

[Mike "Hubbie" Stearns]

Your squeezing sound like the belt imo. Mike

[Model56s]

Agree with Hubbie, fan belt

[Laughing Coyote]

I noticed in your video that the fuel line looks really close to the exhaust manifold. You may want to route it farther away from it. You wouldn't want to have a fire or cause the fuel to boil off. Does sound like the belt.

[Bloo]

That pic is quite confusing. I think the fuel line is really the one to the left of his hand.

[Model56s]

Proper concern Coyote (been following your Corvette refresh - thorough work!), but Bloo is correct. This is a Carter WCD with the fuel port on the left (unseen) in this picture. The vacuum line is what is running near the manifold. Over the last three weeks I’ve had to learn a lot about the WCD on my 49 Buick. Don’t ask me why.

[cevensky]

Indeed- appreciate the sharp eyes and concern! The fuel line is to the left of my hand and I bent it to take a course way out toward the fender and far from the engine. Vacuum lines are the only thing close to the manifold. I think the vacuum advance is next in line for a rebuild. 
 

Went on a drive to the gym and dinner tonight… it probably happened a good while ago, but my oil downdraft tube is gone! Oops! Guess I’ll need to source a new one. Windshield in this picture is really looking rough. 

[Model56s]

On 10/25/2023 at 10:23 PM, cevensky said:

Indeed- appreciate the sharp eyes and concern! The fuel line is to the left of my hand and I bent it to take a course way out toward the fender and far from the engine. Vacuum lines are the only thing close to the manifold. I think the vacuum advance is next in line for a rebuild. 
 

Went on a drive to the gym and dinner tonight… it probably happened a good while ago, but my oil downdraft tube is gone! Oops! Guess I’ll need to source a new one. Windshield in this picture is really looking rough. 

I always appreciate a lighted antique car dash at night! The good news about your windshield is it is 2 panes of flat safety glass, readily available, and a good glass shop can round corners using the originals as templates. Installing a split windshield can be a challenge though.

[pvfjr]

I'm so pleased to see some updates here, maybe it'll motivate me to work on my wife's '48 Streamliner!

+1 for the fan belt.  Do the rubber sides of it feel hard and glazed?  If the rubber isn't supple anymore, it can be hard to get enough tension on them.  

Do you have a tension gauge?  I recently "discovered" a clicker type belt tension gauge made by Gates that I really like (called the Krikit).  It takes the guess-work out of setting v-belt tension, which is critical in some applications.  I've got just a handful of rigs where there is a very fine line between tight enough and too tight. 
https://www.amazon.com/Gates-91107-Belt-Tension-Tester/dp/B000MUTAGS

[cevensky]

The belt is only 3-4 years old. It should tighten well. I will probably have to redo the universal type alternator mount to get proper tension. 
I have had the replacement windshield for a while… we will see how much longer it takes to go in. 

[Bloo]

On my 1936, I am using an industrial belt to get an old style wrapped belt. Gates does make a modern belt with an outer band and a notched bottom like modern car belts. In the industrial belts, I was using a "B" series belt, but found that after even a tiny bit of wear it was contacting the bottom of the pulley and causing slippage. I switched to a "C" series, and it appears to ride too high in some of the pulleys, but on closer inspection the pulleys may be designed for the belt to run like this. It's not been on long enough to know how it is working out. I would say though, if you are having slipping problems, look to be sure the belt is not bottoming in the pulleys.

 

Another thing I became aware of at an Early Times Chapter Flathead Reunion about 3 years ago was a possible problem with the belt angle. One presenter at the tech session, who I believe is a forum member here, passed around two flathead Pontiac water pump pulleys with different belt angles! The "wrong" one was causing slippage. I found no evidence of multiple belt angles on cars that far back, and cannot explain why that pulley exists, but it does exist. I held it in my hand and sighted the angle compared to a normal one.

 

Edited October 31, 2023 by Bloo (see edit history)

[Sir Gonzo]

@cevensky I've really enjoyed reading through this thread and I'm very impressed with the work that you did to bring your $1,500 project car back to life. Amazing job! I've also have a '48 Streamliner, straight-8, automatic transmission that seems to have the same perplexing overheating problem that you described even though my engine was recently rebuilt before I bought it a year ago and the radiator had been recored. I have been at my wits end trying to figure out why the car overheats so easily when it sits too long at idle or in slow moving traffic even on cold evenings. Did you ever resolve the overheating problem on your car and what did you do to fix it?

[cevensky]

@Sir Gonzo thanks for the kind words.

First things first: check that your gauge is accurate-ish. Are you boiling? If not your gauge could be off. Using a laser thermometer can help you discern the temp difference between top and bottom of the radiator (i.e. is it cooling). Make sure everything is clean. Rebuilt doesn’t always mean the water jacket is clean. Similarly, it doesn’t mean your recored rad didn’t get junk run into it. 
Flush it, see what happens.

Water pump rebuilt?

Hose not collapsing? My rebuilt water pump in combo with junk in rad and block caused suction and collapse of the bottom hose. 
Ensure the thermostat works. 
Timing. Full tune up.

Junked up carburetor contributed in my case. 
Do you have the water jacket distribution tube?

I think first place to start is with a good thermometer. See if you have hot spots and if radiator is working. 
 

[Model56s]

35 minutes ago, cevensky said:

@Sir Gonzo thanks for the kind words.

First things first: check that your gauge is accurate-ish. Are you boiling? If not your gauge could be off. Using a laser thermometer can help you discern the temp difference between top and bottom of the radiator (i.e. is it cooling). Make sure everything is clean. Rebuilt doesn’t always mean the water jacket is clean. Similarly, it doesn’t mean your recored rad didn’t get junk run into it. 
Flush it, see what happens.

Water pump rebuilt?

Hose not collapsing? My rebuilt water pump in combo with junk in rad and block caused suction and collapse of the bottom hose. 
Ensure the thermostat works. 
Timing. Full tune up.

Junked up carburetor contributed in my case. 
Do you have the water jacket distribution tube?

I think first place to start is with a good thermometer. See if you have hot spots and if radiator is working. 
 

Good advice. I had a cooling issue with my Chevrolet panel truck 235 six (clean water jacket, new radiator, fan shroud, verified that the water pump was working &c.). I solved the problem by running without a thermostat and 1/2 of the radiator covered, it runs at 165 degrees and no more than 180 during an extended idle. In hot weather I’ll remove the radiator cover.

 

But I recommend following Gonzo’s advice first.

 

BTW Gonzo, anything new on the Pontiac? Love the car!

[Bloo]

These Pontiac engines do have a water distribution tube inside the block that can rust out if it is made of steel, and it usually is. While checking things with a laser thermometer, the difference in temperature between the front and the back of the block can be a clue about the condition of the water tube.

 

 

[Sir Gonzo]

6 hours ago, cevensky said:

@Sir Gonzo thanks for the kind words.

First things first: check that your gauge is accurate-ish. Are you boiling? If not your gauge could be off. Using a laser thermometer can help you discern the temp difference between top and bottom of the radiator (i.e. is it cooling). Make sure everything is clean. Rebuilt doesn’t always mean the water jacket is clean. Similarly, it doesn’t mean your recored rad didn’t get junk run into it. 
Flush it, see what happens.

Water pump rebuilt?

Hose not collapsing? My rebuilt water pump in combo with junk in rad and block caused suction and collapse of the bottom hose. 
Ensure the thermostat works. 
Timing. Full tune up.

Junked up carburetor contributed in my case. 
Do you have the water jacket distribution tube?

I think first place to start is with a good thermometer. See if you have hot spots and if radiator is working. 
 

@cevensky Oh yeah, it's boiling alright. Since the engine was rebuilt before I bought the car I can't vouch for everything, but everything looks good, it runs GREAT when it's not overheating, supposedly the carburetor was rebuilt. It did not have a thermostat so I put one in, but that didn't resolve the problem. When it's overheated I have not checked the hoses, so I will if/when it happens again. I do have another new/rebuilt water pump so I'll probably flush the system and put the new water pump on. I sure as heck hope it has the water jacket distribution tube and that it's in good shape. I'd hate to have to start tearing into that. But first I'll get the thermometer to try to narrow down the problem. Thanks for the advice.

[Sir Gonzo]

2 hours ago, Bloo said:

These Pontiac engines do have a water distribution tube inside the block that can rust out if it is made of steel, and it usually is. While checking things with a laser thermometer, the difference in temperature between the front and the back of the block can be a clue about the condition of the water tube.

 

 

Thanks @Bloo I will check that!