Projects New Project: 1953 Oldsmobile

You may want to post a photo of your alternator so we can see what you have, the system that was posted is NOT for an external regulator.

 

Looks like you’re right, I was mistaken. But that leaves me with even more questions.

Here’s the alternator that’s on it:



Here’s the regulator I replaced with:




So as it is now, it’s working. How am I supposed to bypass it? Because when I tried this set up, the alternator burned up immediately;


Being confused when it works is just as obnoxious as being confused when it doesn’t work.


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Mad Mike, looks like you called it from the start. I’ll see about changing over for the internally regulated 3 wire.


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Mad Mike, just to make sure I understand: is this all you’re saying needs to be done on the regulator for the internally regulated alternator to function properly?


Thanks again for all the help.


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Also, I checked all the wiring. This is how it’s currently wired up (with the internally regulated alternator).



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Here’s what I want to try (per Mike’s recommendation):


Battery is disconnected. I won’t try it till I get a confirmation from someone.


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That 'looks' correct, however you still need to verify the wiring on the Alternator side.

Verify that the new 'T1' & 'T2' connections are correctly connected to what was the 'R' & 'F' terminals.

Your new wiring system will look like this electrically


As you've said there have been a few changes/add-on's so what is what needs to be verified before you hook up power.

And never run an alternator with the battery disconnected. This will overload the alternator and fry it.

For future, anyone converting from External to Internal regulated GM Alternators there are simple jumper kits available such as
American Autowire Alternator Conversion Plug Adapters 27555

 

NO regulator with that alternator, mad mike has the correct wiring, follow his plan and all will be right!

 

That’s what I was looking for. I’ve checked all the wiring and I know where everything is going now. Thanks again for the help.


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Ok, so jumped the wires. Everything looks great when I start out. Voltage is still bottoming out at stop lights. Anything I’m missing? I wouldn’t be so concerned if it had done it before, but this is a fairly new problem.


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I’m sure there’s a great reason why I shouldn’t get this, but I’d at least like to hear it. What if I change out the pulley for an overdrive?



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Nothing wrong with overdriving the Alt speed. GM did it in the 80's on 307 Oldsmobile powered cars. Engines could idle very low 450rpm in Drive, and with 2:14-2:41 rear gears plus OD was knocking engine rpm VERY low at highway cruise. Alternators were just not spinning quite fast enough too keep up with electrical loads.

What kind of voltage are you seeing at idle? Still 13V?
What is the voltage with the car in Drive(parking brake applied, wheels choked, headlights on, fan on, etc)?
If it is dipping below 13V then check your engines idle rpm. If it is ~450 or so bumping it up to 500 or 550 can dramatically increase the alternators output.

 

I just went to a local car show. Things gradually got worse all the way back.

Car started and idled at 14.5.
Going down the road it dropped to 14.0
Stop lights I was about 13.1

On the way home:
Started and idled at 12.7
Cruised at 13.5
Stoplights 12.5

I don’t think an overdrive pulley would help now. Revving won’t go past 13.5.

All I can come up with now is engine temperature. Under the hood still gets stupid hot. I could barely touch the regulator on the firewall when I got home. Maybe that toasted the previous alternators and this last battery.


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*cough*airdam*cough*

Heat will kill the regulator.

 

Heat will also increase the resistance of the electrical components, which in turn will reduce electrical performance and eventually start killing components.

I would REALLY suggest getting the underhood heat issue under control. A simple air dam under the radiator support as previously suggested will do wonders for cooling.

 

Thing is, nothing is safe under the hood. It all gets really hot. It looks like I have a stock style radiator. Maybe it’s just not enough to cool the 455?

Tomorrow once the engine is cool, I’ll try removing the electric fan and throwing in a mechanical like has been previously suggested to me. Might go ahead and swap the thermostat in case it’s stuck partially closed.

It seems like my primary goal is to get heat out from under the hood. For some reason it’s getting trapped. Which is crazy since the hood is louvered.

Here’s a side view of what it looks like right now:



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I can’t see a place where an air dam would be beneficial. I’ve read running a mechanical and an electric fan can work, but that only gets the engine a little cooler. I need to get all the heat out from under the hood.

Also, just guessing, I may not have the highest quality radiator...



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If the car was overheating all the time, then maybe. But the problem you have is unusual in that the car will overheat when on the freeway. This is a clear indication that there is not enough air flow pulling heat away from the engine bay. It just stagnates and gets hotter and hotter due to the air flow is going AROUND the car. You need the air flow to go THROUGH(or more correctly through the radiator) the car to extract the heat away from it. There needs to be a pressure differential to allow the air to go through the radiator and out and away from the engine bay. A simple 3-4" air dam under the radiator support would create this pressure differential.
Also the air flow that goes through the radiator cannot be allowed to recirculate back around to in front of the radiator. This will also cause overheating.

Unless you already have the mechanical bits laying around, I would suggest making a simple air dam.
Such as...


Pretty simple. A piece of sheetmetal can easily be fabbed up for an air dam. The one above is angled as the application has limited space but helps direct the air up. As a temp air dam you can also use tape around edges to help seal any gaps that may occur from the bottom of the rad support not being perfectly flat.

Currently your car is like this...


Air, like anything else, will find the path of least resistance. It will go around the smooth body rather than try and go through the small grille opening. And air that does go through the grille has no reason to continue to flow out as there is no pressure differntial.

What you want the air do do is this...


Air can't go under the car, so it has to either go around or through the engine bay.
Since there is also now a pressure differntial of lower pressure behind the air dam(vacuum) the air is going to go through the radiator and continue out and under/away from the car.

NOTE: I do not suggest making an air dam under the bumper, just one under the rad/rad support to direct air up and through the radiator.

Those louvers might actually be hindering your air flow.
Remember cowl induction fed cars use the high pressure built up at the base of the windshield in the cowl area to help force air into the air cleaner/scoop.
If there is more air pressure above the hood than below, the air will be forced down into the engine bay, not out. This will cause the engine bay to be a high pressure area. Not good when you are trying to pull air through the radiator.
Some simple tuft testing, 2-3" lengths of yarn taped near the opening of the louvers will show you at speed where the air flow is going. If the tufts stay going back as being blown from the wind, then there is air being pulled out of the engine bay. If the tufts get sucked into the louvers then the air is going into the engine bay. You can seal those up temporarily with some masking tape on the underside. Drive again and see if any of the other louvers change airflow direction. This alone may aid in your cooling issues. Block off the harmful louvers, leave the extracting ones open.

Ideally the leading edge of the radiator/rad support should act as a wall. Only letting the air to flow through the radiator into the engine bay. If there are any louver that are in front of the radiator, seal those off. They are going to be bleeding off high pressure cooling air, rather than pushing it through the rad.

 

What isn't made overseas anymore?

As long as it holds pressure and is not leaking I wouldn't question the radiator. Just make sure the fins are clear of dirt and debris.

 

This has explain a lot. So, a couple more questions.

Currently, there’s no place to add the airdam under the radiator, the floor is solid:


Does this mean I have to bust out the saw? I’m not a fan of the idea, but I’m willing to do it to get this thing cursing properly.

Also, in the engine bay, there’s really no where else for the air to go other than down and out besides the louvers. How can I fix that? Or is that the whole reason for a dam?

I did have a mechanical fan around, but it was an older dented flex fan. I already ordered a steel fixed blade fan from summit.



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Your photo shows the area in front of the radiator. You need to rig up a deflector of some sort just behind the radiator to kick up a bit of cool air directly into the engine compartment. Any air passing thru the radiator and trans cooler is going to pick up a lot of heat on it's journey.

 

No need to start cutting just yet. I did forget that these cars, including my own 210, sealed up and are 'front feeders'.

However...

Bingo.

You want to create a wall that diverts the air away from under the car. Create a low pressure area in the engine bay behind the air dam.
The area in front of the air dam will be a high pressure area, this 'bubble' of air will spill around the air dam. Getting pushed to the sides and away from under the engine. This can also cause air to stay forward and push up and into the front of the car and into the rad/grille opening. Rather than going under the car.

If the radiator support has any holes that do nothing(removed vent tubes, etc) block those off as well. Any air in front of the radiator needs to get around the rad by going through it.

The area behind the air dam will be the desired low pressure area.
Air will want to flow to the low pressure area.
High pressure in front of the radiator > passes through radiator > dives down into the low pressure area behind/below the radiator. As you drive forward the hot air will now be moving away from the engine bay and radiator.

The only question now is what are those louvers going to do to your air flow?
If they allow high pressure into the engine bay and pressurize the engine bay then there will not be sufficient airflow through the radiator as there is no pressure differential across(through) the radiator.

What you are doing is creating ducting to get the air to go through the radiator.
It may not look like ducting, but that is the idea, to divert air where you want it.

I would suggest picking up a few rolls of blue painters tape and some yarn for tuft testing of your hood louvers. Block of the ones allowing air INTO the engine bay at speed. Because even with an airdam there will be some louvers that are detrimental to desired airflow. I'd suggest taping from the bottom of the hood horizontally.

Louvers can be helpful in cooling, but if they were arbitrarily installed then they can be doing more harm than good.

Originally with the unlouvered hood it acted as a seal to the engine bay. Air would only go through the rad and out the bottom. It was a 'closed' system but with the louvers it is now 'open'. You can try sealing these off with tape and seeing if this improves cooling. The tuft testing would be more telling.

 

No.
This will create a high pressure area in the engine bay.
We want a low pressure area in the engine bay so cool air will travel through the radiator and down and away from under the car.

 

I’ll play around with the louvers tomorrow and see what I can come up with.

I’m still not understanding where a dam should go on this setup. I can’t see a good play to get from below the car to go through the radiator.

Now, there is a lot of air that passes through the front that I haven’t thought about before:


I know it’s supposed to bring cooler air into the car, but they’ve never done that properly. It’s always hot. Should I just block these off? There are also 1” gaps on the side of the radiator. I can block these off and see what happens.


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The air dam does not need to feed air into the radiator directly, and is not the sole purpose of the air dam.

Airdams main purpose is to create a low pressure area(vacuum) behind it, this does two things on a modern front engine vehicle.

Diverts air (directly/indirectly) away from under the car. This promotes stability at higher speeds. The vacuum 'sucks' the car to the ground as shown in the drawing above. It removes the 'float' when getting up past 80MPH especially in brick shaped vehicles air getting under the front of a vehicle creates an air cushion, a poor mans half-ass hover craft. Which can cause aerodynamic drag on the car.

With this low pressure area created, it can offset the high pressure area in front of the car. This pressure differential can be used to a vehicles advantage by placing heat exchangers(radiators) in an opening between the different pressure areas. High pressure wants to flow to low pressure.

There are three types of vehicles on the road, 'bottom feeders' any kind of vehicle that doesn't have a grille opening on the front, they pickup air from behind or under the bumper, 80's Camaro/Firebird or Corvette.

Other vehicles will be 'front feeders', basically any car with a massive grille, trucks, classics, that kind. And there is a combination of both, 80's up cars may have a smaller grille to maintain looks/styling and have cooling from both the front and bottom. 80's Malibu/Cutlass/Mustang.

I forgot our cars are 'front feeders', but this will not diminish the usefulness or aerodynamic benefit of the air dam.
Placing the air dam under the radiator support, even on a 'front feeder', will create a low pressure area behind the air dam. Air will either have to go around the sides of it or find another route. With the lower pressure behind the air dam, air in the engine bay will want to pulled down into this area. A properly sealed engine bay(or one that is designed with louvers/vents/scoops) will then only allow air from the radiator opening to enter the engine bay. This cool high pressure air flows through the rad, pulls heat out of the rad, and then drops down and away from the radiator into the low pressure area, eventually dispersing as the car drives over and past.
The closer the air dam is to being in line with the imaginary 'wall' of the radiator/radiator support the more effective and stronger the low pressure area will be behind the radiator. An air dam under the front bumper will still create a low pressure area, but not where we want it for better cooling.

It's more indirectly getting the airflow where you want it. Not using a fan or blower onto the radiator to push air through. At speed air flow going through the radiator should be sufficient to cool. At lower speeds where there is no/low air flow that is where the fan is used.

I was referencing any unused holes, or non factory holes cut out by previous owners that allow air to bleed around the radiator. Not the vents.

No. they are vent tubes and even warm air moving is better than stagnant hot air in the car. Part of the reason the air is hot is due to the air underhood that is not properly cooling is radiating heat off anywhere it can, which includes heating up the vent tubes and air inside. The vents themselves will not affect the cooling of the car, they are not bleeding off needed air for engine cooling.

Sealing the gap around the radiator will aid in keeping the low pressure area behind the radiator a lower pressure area. We want whatever cooler air there is to flow through the radiator to pull the heat off the radiator and then dump down into the low pressure area(created by the air dam) and then flow under the car.


I looked back on the pictures of the louvers.
That's a lot of louvers.
I would suggest, as the easiest/cheapest/non permanent mod would be to get some 2" painters tape, and close up all those louvers. Four long strips of tape.
Change nothing else.
Go for a drive, get her up to speed and watch what the temp gauge does.

These cars stock didn't overheat, and granted the 455 is probably pumping out twice the power(heat) at highway cruise it's still going to only use 30 or so HP that the original Rocket used. My current belief is the louvers are affecting the original cooling capabilities by bleeding off the low pressure area underhood.

 

what a stunner, I love these beauties. A buddy had a 53 with a 57 j-2 in it. Hot summer nights deciding what girls to let ride in it.

 

Air dams always worked on stock cars. Plus they looked mean... Have you tried a drive with the hood OFF? Just to see what it does with all that heat allowed out.

 

I wanted to mention, there is an upper cover for the radiator that mimics the shape of the hood.



I went for another drive this morning, fairly long. About 30 minutes to my destination, then 30 back. I kept an eye on engine temp and voltage to see how closely they were related.

I started out slow. Kept the car 45 and below. Engine temp would voice between 180 and 190. It’s hit 190 and almost immediately cool back down (does that mean a 190 thermostat?). Along with these temps, voltage stayed at 14.3 while driving, dipping to 13.7 when stopped. I’m totally cool with that.

On the way back, by now, heat has built up under the hood. Mostly ran 190-200. I had a small jump on the highway where temps ran up to 210, but then slowed back down and stayed at the 190-200 range, no matter what speed I slowed to. Voltage maxed at about 13.8, and would dip to 12.9/13 at stops.

Coming home last night, I cruised 65ish most of the way home, temps ran around 210/220 and that’s when the voltage sucked the most.


Ok, here’s the current plan I may go with. Mike, free to jump in and correct any bad ideas.

I want to make two smaller cuts so the air dam will help blow into the radiator.


From there, the metal can bend down, and I can add to it from under the car to make it a much larger dam.

I have the mechanical fan ordered, I feel like I might as well use it. At the same time, I don’t see a reason I can’t put the electric fan on the front side of the radiator to assist.

Now, here are two other ideas I’m not sure about:

what about some ducting that runs straight to the alternator to cool it off? I know mike said to get all of the air through the radiator, so I didn’t know if this would counter that effect.

Also, should I put some kind of block off plate on the underside between the bottom of the radiator and the engine crossmember? Here:


I haven’t tried taping off the louvers yet, though I did buy tape. I can’t think of any way to block those off long term that wouldn’t trap water. I may try the tape just for the sake of knowing what I’m up against.

Anyway, help welcomed as alway. And again, a huge thanks to Mad Mike for all the help so far.

I actually thought about taking the hood off, but I’ll never get it back on properly. Haha



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I'm sure the engine would run cooler as the engine bay air would evacuate easily, but it would not be practical and not show us any useful airflow data.

That cowling is fine. If anything it is helping direct are towards the radiator, rather than letting it spill up and over.

I see how there is a massive gap on the side of the radiator. That would allow usable cooling air to bleed into the engine bay, which in turn would also prevent building up air pressure.

Looking at original '53s...


your radiator is forward the stock position and is now cut into the cowling rather than behind it.
Was this to clear the 455?
Those gaps at the radiator sides need to be blocked off to prevent the needed cooling air from bleeding around the radiator. Air needs to go through the rad, not around it.

We need to build that wall.
Make cooling great again.

Thermostat will stabilize the temp. Allow an engine to warm up and the thermostat will gradually open til it reaches operating temp, and from then on will gradually open/close to maintain a given temp.
If you see an instant drop in temps that is more likely to do with a fan, or a fan turning on. With an electric fan it would kick on/off at two temp set points.

Sounds really good. Anything above 13.5 is preferred.

Yup the alternator is getting heat soaked. Increase in heat will reduce voltage output. And increased ambient temps of the wiring will cause them to have higher resistance and cause voltage drop as well.

No cutting!

Not yet anyway.

Currently we are in a research and diagnostic phase. Any modifications for testing need to be done in a non permanent way. Lot easier to undo a modification that makes the problem worse if it is just tape or bolted on. Cutting and welding are a bit harder to undo. Besides there are plenty of things to fix before we begin modification.

Yes, I know you are itching to DO something, but you need to do things that will move your progress forward, not back.

What we know is at lower speeds there is adequate airflow to keep the engine bay at a normal operating temperature. At higher speeds the air is not flowing where we want it to cool.

Those massive gaps on either side of the radiator prevents cool air from going through the radiator. Those gaps are also huge leaks which prevents a proper pressure differential from building across the rad support which would allow the air to be pulled through the radiator, out and down to cool.
We have to get there first.

Fan isn't going to do much if air is not getting directed through the radiator.
Adding a pusher fan to the front of the rad will impede air flow as well.
Fix the air flow problem first.
Need to create that pressure differential.
Need to create a low pressure area behind(engine side) the radiator. All those open gaps are not allowing that to happen.

Getting the air to flow through the rad, proper, will reduce underhood temps overall and improve the charging system.
The deficiencies of the charging system are related to the excessive underhood heat temps, which is a product of the faulty air cooling.

NOOOO!!!
That is exactly where, with an air dam, the low pressure area would be created. That is where the hot air would get pulled down away from the radiator and out of the engine bay
Engine bay is already cocooned enough and marinating in stagnate heat.

Tape off the louvers and, if you can, tape off the massive air gaps on either side of the radiator. And go for a test drive.

 

Sounds good. I’ll tape off stuff and go for another test drive this evening. I’ll dig around in my scrap metal and see if I’ve got something to make an airdam with (I can’t tell you how many times I’ve typed “airdamn” in this thread on accident ).


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