Hood vents / louvers

[fontleyroy]

Anybody add any hood vent louvers to their 68 - 70 Charger? I am thinking about it as there is not much room for heat to escape under the 70 hood. I do not over heat but I do not like looking at the temp gauge fluctuate from 200 - 215 on the highway - and the under hood bay gets HOT. Just wondering what they wood look like. Not hard to put back to factory just a pain to have to repaint the entire hood afterwards.

 

[davek]

No,I would not do that to my hood. I had a 69 440 6 pack charger and never had heat problems here is S Carolina. JMO put a 6 pack scoop on it if anything.

 

[Don67Satellite]

If your temps are going UP while highway cruising, you have other issues.

Stock fan or electrics? What kind of shroud? Anything blocking air flow to the rad? Rad in good shape?'

Oh, and asking if you should cut up a valuable Charger hood, well you must be trying to troll the members here.

If you need a hole in your hood, buy a fibreglass one.

 

[Black_Sheep]

I feel qualified to comment because I had 258 louvers stamped in the hood of my’58 Apache.

Louvers are forever, there is no “putting them back to factory “.

You will have to remove underhood bracing and strip the paint to bare metal on both sides of the hood in the area to be louvered.

They are a PITA to prime and sand.

If heat can get out, water can get in.

As previously stated, if your car is only running hot at highway speed there are other issues. My guess is an improper tune up or restricted coolant flow.

 

[fontleyroy]

I feel qualified to comment because I had 258 louvers stamped in the hood of my’58 Apache.

View attachment 1708589

Louvers are forever, there is no “putting them back to factory “.

You will have to remove underhood bracing and strip the paint to bare metal on both sides of the hood in the area to be louvered.

They are a PITA to prime and sand.

If heat can get out, water can get in.

As previously stated, if your car is only running hot at highway speed there are other issues. My guess is an improper tune up or restricted coolant flow.

I had a 59 Apache in the 80s 307 powerglide trans. I loved that truck and planned on taking it with me. My sister called a junk yard when I went to Parris Island - still a little pissed at her to this day.
The louvers I am looking at are about 5 x 15. I would have not trouble putting the metal back on the hood - much easier than doing the full quarters.
The 383 is running just perfect, (Get some flack at the shows because I have a GM HEI distributer) if you get into it too hard it will spin the tires when shifting to 2nd. I have dual electric fans. The headers are wrapped.
Like I said its not overheating just runs a little hot on the highway. I have recently added a spring to the lower hose as I was thinking that it may be collapsing a little. I just dont like seeing the gauge run up to almost 220 before coming down a little.
There is just no room for heat to escape from under the hood. Everything is too hot to touch.

 

[hunt2elk]

You have something going on with your cooling system if the temps are getting up to 220. Get that sorted and you will be fine. None of my cars ever go over 195. Don't cut up or add anything to the beautiful body lines of a second gen Charger....

 

[chargervert]

Yep! I had a damaged 71 Charger R/T hood,so I grafted it onto a 70 Charger hood.

 

[not so famous bob]

Anybody add any hood vent louvers to their 68 - 70 Charger? I am thinking about it as there is not much room for heat to escape under the 70 hood. I do not over heat but I do not like looking at the temp gauge fluctuate from 200 - 215 on the highway - and the under hood bay gets HOT. Just wondering what they wood look like. Not hard to put back to factory just a pain to have to repaint the entire hood afterwards.

View attachment 1708458

I had to run the entire gammit when trying to cool my 505'' 68 fastback supposedly 703 h.p. , alum rad. , hi flow pump , experimenting w/ pullies , coated headers , and chrome boat louvers in the fiberglass 6 pack hood , took all of it together to keep it under control , ave an aux. 14'' elec. fan in front of the rad . , mounted as far away as possible so as not to impede air flow ,
even closed off the area in front of the rad. (on top) , to force aor into the rad. , and not over it , like all new cars have now .
A home made chin spoiler helped too , never got around to replacing it with a pretty one , like Randys spoilers makes , out of Ark. ...
Also a scoop that's not sealed to the hood will often times pack the engine bay with air =impeding air flow thru the rad. ...

 

[1970RT]

Louvers can help relieve underhood heat, but you need a lot of them. Even then, they’re not extractors and their best function is as a high pressure release so hot air can normally flow from the radiator and down the transmission tunnel like normal.

I have 114 louvers in this hood, and it helps a lot at low speed and a little at highway speeds. Tall trucks tend to develop high pressure under them, so airflow across the cooler stack has a harder time making its way through. Louvers act like a pressure release to minimize that effect.

It’s also a massive amount of work, and while it looks cool and can work pretty good, I’d recommend chasing other things first. Better fan shroud sealing, new fan clutch and/or higher flow fans, cleaning the radiator, moving oil coolers out from in front of the radiator, and a fresh thermostat to name a few.

David

 

[Dave6T4]

I think it's the Chevy distributor that's doing it. It's so huge that it is restricting air flow around the engine. LOL.

 

[j-c-c-62]

This is what I use to locate my hood vents. Basically, one useful measurement in this context that helps in seeking the spot that has the maximum differential air pressure above and below the hood.

Series 2000-HA High Accuracy Magnehelic® Differential Pressure Gage - Dwyer

It has other useful information potential on a car, like finding brake duct inlet locations, etc.

 

[not so famous bob]

Louvers can help relieve underhood heat, but you need a lot of them. Even then, they’re not extractors and their best function is as a high pressure release so hot air can normally flow from the radiator and down the transmission tunnel like normal.

I have 114 louvers in this hood, and it helps a lot at low speed and a little at highway speeds. Tall trucks tend to develop high pressure under them, so airflow across the cooler stack has a harder time making its way through. Louvers act like a pressure release to minimize that effect.

View attachment 1717240

It’s also a massive amount of work, and while it looks cool and can work pretty good, I’d recommend chasing other things first. Better fan shroud sealing, new fan clutch and/or higher flow fans, cleaning the radiator, moving oil coolers out from in front of the radiator, and a fresh thermostat to name a few.

David

the heat was so great under my hood "till I got it all figured out" , that it started melting the plastic chrome louvers on the pass side / still on the hood ...

 

[70chall440]

I think you are perhaps looking at the problem too narrowly; as you stated (correct me if I am wrong) you believe that the engine is getting hot just because the hot air cannot leave the engine bay. While this is 1 potential issue I personally would not focus on that since pretty much all cars of this era were similar and most remain that way without the issue you have.

So I would look at other potential issues, the lower rad hose is a good one which you have already addressed, so this leaves

Radiator issues (size, effectiveness, etc.): you didn't say but from the pictures it appears like its a GM style cross flow. It "might" be on the smallish side but hard to tell.

Timing (perhaps too advanced just a bit): You commented that the car runs great overall so this probably isn't an issue.

Lean condition: From the pictures it appears that you are running a carb so this probably isn't an issue however w/o a AFR gauge its hard to say. Personally I think every car should have one as it exceptionally helpful to understand what is happening.

Water passages (restrictions/debris): Although possible its not probable as it remains cool at low speeds and idle.

Fan (size, speed, CFM, etc): This is more times than not at least a significant contributing factor to this issue specifically. Clutch fans are designed to "engage and disengage" due to the temp of the thermal spring inside of them, this is a failure point. Flex fans are designed to flatten out at speed/RPM so as not to draw unnecessary HP as it is thought that at speed the air flow will be sufficient. Here again, this factor can be problematic as at idle/slow speed the flex fan is just barely hanging on but at speed it is not pulling enough air. Electric fans suffer primarily from using too small of fans for the application.

IME heating problems such as the OP is experience is not a 1 thing issue, normally it is a combination of issues which makes fixing it difficult.

As to putting louvers in the hood, thats your call as it is your car but I do not think it will have the effect you think it will. Yes it is hot under the hood but the engine doesn't care because it is using a sealed system, the ambient air temp under the hood generally is not significant as it relates to engine temp UNLESS it is significantly high like with huge HP, turbos, headers, etc.

 

[Tony Tee]

I had a 59 Apache in the 80s 307 powerglide trans. I loved that truck and planned on taking it with me. My sister called a junk yard when I went to Parris Island - still a little pissed at her to this day.
The louvers I am looking at are about 5 x 15. I would have not trouble putting the metal back on the hood - much easier than doing the full quarters.
The 383 is running just perfect, (Get some flack at the shows because I have a GM HEI distributer) if you get into it too hard it will spin the tires when shifting to 2nd. I have dual electric fans. The headers are wrapped.
Like I said its not overheating just runs a little hot on the highway. I have recently added a spring to the lower hose as I was thinking that it may be collapsing a little. I just dont like seeing the gauge run up to almost 220 before coming down a little.
There is just no room for heat to escape from under the hood. Everything is too hot to touch.

View attachment 1708956

View attachment 1708957

Yup! Had to separate the hood from the structure anyway to soak it in Molasses to remove the rust.
Built my own louver punch and die. And added baffles so the engine compartment stays dry plus more vents in the substructure to let the heat out.

 

[not so famous bob]

I think you are perhaps looking at the problem too narrowly; as you stated (correct me if I am wrong) you believe that the engine is getting hot just because the hot air cannot leave the engine bay. While this is 1 potential issue I personally would not focus on that since pretty much all cars of this era were similar and most remain that way without the issue you have.

So I would look at other potential issues, the lower rad hose is a good one which you have already addressed, so this leaves

Radiator issues (size, effectiveness, etc.): you didn't say but from the pictures it appears like its a GM style cross flow. It "might" be on the smallish side but hard to tell.

Timing (perhaps too advanced just a bit): You commented that the car runs great overall so this probably isn't an issue.

Lean condition: From the pictures it appears that you are running a carb so this probably isn't an issue however w/o a AFR gauge its hard to say. Personally I think every car should have one as it exceptionally helpful to understand what is happening.

Water passages (restrictions/debris): Although possible its not probable as it remains cool at low speeds and idle.

Fan (size, speed, CFM, etc): This is more times than not at least a significant contributing factor to this issue specifically. Clutch fans are designed to "engage and disengage" due to the temp of the thermal spring inside of them, this is a failure point. Flex fans are designed to flatten out at speed/RPM so as not to draw unnecessary HP as it is thought that at speed the air flow will be sufficient. Here again, this factor can be problematic as at idle/slow speed the flex fan is just barely hanging on but at speed it is not pulling enough air. Electric fans suffer primarily from using too small of fans for the application.

IME heating problems such as the OP is experience is not a 1 thing issue, normally it is a combination of issues which makes fixing it difficult.

As to putting louvers in the hood, thats your call as it is your car but I do not think it will have the effect you think it will. Yes it is hot under the hood but the engine doesn't care because it is using a sealed system, the ambient air temp under the hood generally is not significant as it relates to engine temp UNLESS it is significantly high like with huge HP, turbos, headers, etc.

this statement sure doesnt/didn't apply to my car , go way up in h.p. and see if things don't change ...

 

[70chall440]

this statement sure doesnt/didn't apply to my car , go way up in h.p. and see if things don't change ...

I think I covered your situation - "UNLESS it is significantly high like with huge HP, turbos, headers, etc."

 

[INTMD8]

I addressed cooling system airflow like modern cars. Building a duct to either block frontal airflow or force it through the radiator.

Even on the hottest days it runs just over the thermostat.

I would not alter the hood because I would not like the look.