Projects 1949 Buick Sedanette Mild Custom Build

Thanx guthriesmith, appreciate the comment. The '48 is a "slow" build, I've owned the car for over 20 years and work on it when I get a free minnit or two...and, FWIW, I had the '55 Cad in Salina for the first and only time in 2011...11 years ago. It's still my most popular build (and HAMB thread...!!!).

No, rockable, I haven't done a thread on the '48...I've written some of it and have plenty of pix but just haven't gotten around to it...
R-

 

Dang! If you had told me back in February that I wouldn't be road tripping this car in July, I would have bet you anything. However. Big Bertha has been a real PITA to get right. After finally getting the tire situation and the cam situation (hopefully) resolved, I've been fighting cooling problems.

After changing thermostats, hoses, pumps, etc., it was still not cooling right. I drove it into the driveway one day at 210 with the AC running. I opened the hood and it immediately cooled down. The CCI fan and Walker Radiator were doing their job. What could be wrong? Then, it hit me. The fan was drawing hot air from the engine compartment over the radiator and recirculating it. The temp would just go higher and higher.

So, I got to work this week and fabricated a fence to seal off the engine compartment from the fan. This was tedious work but I got a good fit on the hood and it won't look too bad once it's painted or powder coated. Cadillac owners don't have this problem, as the hood hinges in the rear and Cadillac sealed up the area in front of the radiator. I couldn't do that due to the tilt forward hinge system I built, so the fence was the best solution. These old Buicks were not known to run cool in factory trim, from what I gather.

I can't test it until Wednesday, due to waiting on some piddling little parts but I should know something then because it's supposed to be hot. I feel pretty confident that I've got it covered now.

 

Nice panels.

 

Thanks! It was a lot of fun making the templates with the engine in place. Not!

 

Well, that didn't solve the problem. The beat goes on.....

 

Damn, that sucks, hate to ask, but is she spinning the right direction?

 

The fan was drawing hot air from the engine compartment over the radiator and recirculating it. The temp would just go higher and higher.

This may be a dumb questions, but which way is the fan turning ?

 

It's pulling. I guess the problem is the hot air is not getting out from under the hood. After consulting with 3 deuces (long time hot rod builder) he suggested I may have to modify my inner fenders. I may have done too good of a job fitting them. Dang!

 

On June 8 you did a 150 mile drive with no mention of cooling problems.
What has changed? I know it's warmer now, but thermostat should largely control the temp.
Is the electric fan set up to run all the time, or with a temp switch?
What happens when the fan is wired to run all the time?

 

It was pretty cool that weekend, for June, and it was virtually all interstate driving. Fan is operating properly. Trust me.

 

210 in town, stop and go, in the hottest part of summer may not be that bad.
However, the CC fan should be able to reduce the temp some.
Again, what happens if the fan is wired to run constantly, bypass the temp sensor by grounding the sensor wire?

 

As a test can you prop the hood up in the back to vent the compartment and run a test to see if the hot air exits without causing any damage?
I followed another thread where there was the same issue but with a big Olds. It was thought that there was a vortex setting up in the engine bay holding the hot air in. It was recommended to add an air dam under and in front of the radiator to break the vortex. Just a thought fwiw.

 

I am trying this test today. I already added an air dam and that didnt help.

 

Nothing happens. It cuts on at 205 and runs continuously. I also jumpered it once. I have already covered this (and almost everything else) without posting. Thanks but in order for the fan to move air across the radiator, there has to be a pressure differential across the core. Apparently the air is dammed up inside. So, the hot air must be pushed or drawn out of the engine compartment. I am down to solving that last part of the problem, I believe.

 

Have you considered punching louvers in the hood?

 

Man, I can't believe I haven't checked in on this thread in so long. What an amazing build. I love everything about this car.

It sucks it's been fighting you, but I have no doubt you'll get it figured out soon and you'll be out cruising. Can't wait to see this one in person

 

What is the thermostat open rating temp?
Your fan switches on at 205, at what temp is it rated to turn off?

If the fan doesn't go on until 205 and temp tops out at 210, the fan isn't providing much cooling.

At 210, and moving slowly, the fan is not able to lower the temperature? Just want to be sure I understand the problem.

 

The other thing I've read about creating a pressure differential to pull hot air out of engine compartment and exit under floor is:
Install an air dam below the radiator.

Look at your daily driver. They all have the air dam (until careless drivers rip them off parking too close to the curb).

Remember, there is no way to create a pressure differential when you are still or moving slowly, other than the fan.

 

Maybe adding some inner fender louvers would help.

https://www.jalopyjournal.com/forum/threads/inner-fender-louvers.855838

 

Drop a Kleenex between radiator and motor to see how much air movement you have. Also use a point and shoot thermometer to determine hot spots.

 

I tried making some openings towards the rear of my inner fenders. It helped but wasn't the silver bullet I was looking for.

Despite the fact that my electric fan would hold a folded handkerchief on the condenser, I proved I had an airflow problem and not a radiator problem today. I had room to bolt a mechanical flex fan onto the water pump. Voila! The temps went down to thermostat setting. So, I will be build a shroud this weekend that uses the mechanical fan.

The electric fan is not capable of pulling enough air through the condenser, 4 row radiator and pushing it out of the engine compartment. Bottom line. Thankfully, I can see some light in this tunnel.

 

Every cooling problem in a new build I have had, so far, has been air flow related. I'm learning.

 

That has been my experience as well. Nothing has ever cooled as well for me as a big ass, steel, multiple blade fan with no clutch. I had problems like you're having years ago with my Ford. A 7 blade steel fan off a 500 Cadillac with a shroud is what did the trick. Now I just default to that option. I'd gladly sacrifice some horsepower for a car that I don't have to drive crosseyed looking at a temperature gauge.

 

My experience is that nothing works better than an engine driven fan with a shroud around it. Electrics are only used as a last resort when there is no room for an engine driven fan.

 

One custom fan shroud made! Unfortunately, it will be later in the week before I can get the fan to test it with. Meanwhile, I am confident enough to go ahead and get it powder coated. I don't want to install it but once since I have to drain some coolantto disconnect the top hose.

 

Looks great, should solve your heating issues.

 

I will let you know soon.

 

Well, I am gaining on it. My new fan and shroud are working like a champ.....as long as I am moving. The temperature didn't go over 195 at speeds of 40-50 mph, which it would never do before and it was a hot humid 91 here today.

The bad news is that at idle, there is not enough air movement. I immediately thought of adding a pusher fan but that was going to be difficult with my forward tilt hood. So, in brainstorming it with my friend Richard, he suggested putting 2 small electric puller fans in the upper corners of the shroud. This is the hottest area plus it would give airflow over the top of the engine compartment where heat is collecting. The parts are on order. Stay tuned.

The bottom line in this situation is the 4 row Walker Radiator plus condensor are hard to get enough air through. Especially, given my engine bay.

Meanwhile, the shroud and fan turned out nice, I think.

 

Since your problem is not enough air movement at stand still , have you thought about a smaller fan pulley?

 

Looks like you could go 1" larger diameter of a fan and go into the shroud by 1/2".