Cooler intake manifold

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Dan the man

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I was thinking about using exhaust heat crossover block off plate's and a lifter valley baffle, insulate the bottom of the intake manifold. The car will not be driven in the winter time. I've read that a cooler a/f mixture is good for power, is this true? Also would a carb spacer be beneficial, if so, how tall and what would be the best material for it to be made from? Best place to locate the air pick up for a cold air kit, and is there a kit available to insulate the duct work for the cold air kit? Are K&N air filters the best for a filter. I have to find ways to improve performance without breaking the bank account.
 
Cool air going into the engine will surely make a difference. A good, sealed hood scoop, or fresh air from the grill area is good but you will probably have to make your own set-up as far as that goes. K&N air filters are also very good but expensive at first, but worth it in the long run. Ducting cooler outside air to the carb should be a pretty well sealed set-up. (Under hood hot air, not nearly as good) I have heard of someone making a valley pan for a small block Mopar (non Magnum) from a 383- intake valley pan cut down to fit. Utawsome Performance makes one for Magnum engines. It bolts down to the 3 bosses that hold the roller lifter retainer in place. (I have used one on my Dakota) Keeping hot oil from splashing on the bottom of the intake is a help & like Brooks James said, a cool can for the fuel is also a great idea. Keeping your air & fuel cooler is always better, look at what adding Nitrous Oxide does when it cools the fuel being burned.
 
Dan the man said:
I was thinking about using exhaust heat crossover block off plate's and a lifter valley baffle, insulate the bottom of the intake manifold. The car will not be driven in the winter time. I've read that a cooler a/f mixture is good for power, is this true?
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It is true. The above ideas are a good start.
The lifter valley oil plate keeps the hot oil off the intake. That’s a plus 1.
The exhaust cross over blocked is a big one and that’s plus 2. Keep adding!

Also would a carb spacer be beneficial, if so, how tall and what would be the best material for it to be made from?
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Brook James nailed the material to use for keeping things cool. The height of the spacer can be an issue to the engines performance. This is more important than keep the carb/fuel cool. In order to keep the carb cool rod best performance, you would have to stick it above the hood in full to catch 100% of the moving outside air.

To this end, without dyno testing or track testing, I suggest (slightly blindly mind you) that a 4 hole spacer (a known torque provider) as high as the hood allows.

Best place to locate the air pick up for a cold air kit, and is there a kit available to insulate the duct work for the cold air kit?
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Try a search on a “Ram Air Box” air cleaner. There are air cleaners kits that have a single or dual (mostly seen) snorkel and ductwork that allows the air entrance to be placed advantageously where you need or want it.

OE equipment that use ductwork for the air cleaners tended to route the duct to behind the headlight, drivers side. Look for a picture of a Cordoba.

Are K&N air filters the best for a filter. I have to find ways to improve performance without breaking the bank account.
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I have seen test where a paper filter out flowing a K&N only when new with the efficiency dropping off rapidly as the filter gets dirty. I use K&N filters. There worth the expense.

The cool cam mention is a good one. However! Keeping the cam cool at all times with ice is a needless PIA. I rather suggest wrapping the fuel lines with insulation even though it isn’t a pretty sight. It is very effective.
Also, make use of a return line for the fuel. The constant introduction of cool fuel from the tank is a big plus and the (slightly) heated fuel will not increase the temp in the gas tank. The heated fuel from the return line will dissipate it’s heat Immediately and effectively.

The sealed from the heat and open to cool air idea above is also really good. That’s if your carb is going that high and can be easily sealed to the hood with fresh air available to it.

Run a colder thermostat.
 
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Cooler air is smaller air. Smaller air means more oxygen in the cylinder. Getting every molecule of oxygen you can get in there makes more power. We can always add more fuel to use it. (well almost). On an LA small block, the intake has coolant flowing through it. So it will be 180 degs? The air charge spends so little time in the intake tract in a running motor, there is probably zero heat transfer from the intake to the air stream. However, the fuel does spend significant time sitting in the bowl being warmed up. A good phenolic spacer, size will be trial and error. Reducing the fuel temp and the air supply temp will see the most gains. Outside of the engine compartment air supply.
 
You didn't say which intake you are using- if it's an Air Gap type or clone, it already has the exhaust crossover eliminated, and the runners and plenum isolated from the valley, making the valley baffle redundant. On a stock, LD340, Stealth or Performer style manifold the valley pan is a good idea, the crossover may or may not be present on the aftermarket manifolds, but would be a good idea on a factory one.
Cold air kits are great, lots of versions out there. What I like to do (I'm all about low cost) is use the air cleaner and ductwork from many ('89 ish?, and up) TBI and Magnum Dakotas, Rams, and vans. Takes a standard element and bolts right on to a 4bbl carb. The different applications use different length ducting, so measure and select the one you can make work in your application- or make your own with metal dryer vent hose. I'd be surprised if the whole thing cost you more than 10 or 15 bucks at the pick 'n pull. I've even cut and welded 2 housings together to make a dual-hose setup if you have the room.
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As far as carb spacers go, yes, the hardwood or phenolic spacers are the way to go; but if hood clearance is an issue, or tuning dictates a small or no spacer; consider a heat shield instead. Still reasonably effective, and not overly expensive. They're not tough to make yourself, either.
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Anything you can do to cool the incoming air fuel charge will help power output. heated air fuel charge has no place whatsoever in any type of performance engine, even a mild one, IMO. I've always thought that was one thing the factory got DEAD WRONG. It was all in the name of faster warmups and that's IT. There are no other benefits. If you have a choke that depends on exhaust heat, change it to electric, manual or go EFI.
 
..are you just driving your car on the street? A bit of manifold heat will atomize the fuel better, may improve mileage and burn cleaner.
 
Best place to pick up cool air is the front of the hood. The lower the air pickup is, the hotter the air is from the road. The farther back a hood scoop is the less air will get in it.
 
niceolddart said:
............ Keeping your air & fuel cooler is always better, look at what adding Nitrous Oxide does when it cools the fuel being burned.
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Sorry, but this statement is very misleading. Nitrous oxide actually takes part in the combustion reaction, it is not just cooling (although that is an added benefit at about -127°F). I forget the exact temp, but somewhere around 570°F the nitrous molecule breaks down, releasing the oxygen (i.e. when the air fuel mixture is compressed and lit). This oxygen can now take part in the combustion of fuel making it possible to burn more fuel; thus, you are able to make more power by burning more fuel.

I don't have time to correct all the weird stuff in this thread....but, to the OP, in the end, finding a way to get cooler air into the engine will give you a little more power, and the most bang for your buck. The cool can thing won't do much for you unless you are having vapor locking issues. The fuel needs to atomize, so heat is not a bad thing...however, you still want cooler air if possible because cooler air is more dense (not smaller as someone stated in this thread...I can explain that later if needed.)....in other words, you can fit more cold air in the same space.

High flow air filter, Good.
Cool air into carb, also Good.
 
ir3333 said:
..are you just driving your car on the street? A bit of manifold heat will atomize the fuel better, may improve mileage and burn cleaner.
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BINGO. If you are going to run a cold manifold you need to understand what happens if you don’t get the fuel atomized well enough leaving the booster. If the manifold is too cold, you’ll lose power and burn a bunch more fuel if you don’t the fuel atomized at the booster.
 
Street drivers? They love these types of boosters!

Annular

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I have seen this type of fresh air setup done on Mopars before, using a dual snorkel air cleaner. The air from the vent box at the base of the windshield is supposedly under more pressure. Yes I know it’s a Chevy.
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Upto a few weeks back I've been daily driving my '62 NY wagon (413ci) with blocked heatriser port in the intake. Temps were around 40-45F.
The car would start to run and idle rough and stall at slow speeds after a few minutes of driving... Why? The carb's idle-circuit was freezing up. Frost was visible on the outside front of the carb.
The issue was worse with higher air humidities.
 
Rat Bastid said:
BINGO. If you are going to run a cold manifold you need to understand what happens if you don’t get the fuel atomized well enough leaving the booster. If the manifold is too cold, you’ll lose power and burn a bunch more fuel if you don’t the fuel atomized at the booster.
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You guys have given me a lot of good information about this. I think that I'm not going to insulate the intake manifold. What thermostat would be better to use, a 160* or a 180*.
 
In the cool can add salt to the water, it will reduce the temp dramatically, water will still be a liquid till -21 degrees C
Experiment with the amount of salt needed
To plunge the temp
Remember the rock salt on ice in the ice cream maker?
 
Brooks James said:
In the cool can add salt to the water, it will reduce the temp dramatically, water will still be a liquid till -21 degrees C
Experiment with the amount of salt needed
To plunge the temp
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This is a daily driver so I probably wouldn't use a cool can. But thanks for the tip as I didn't know that about cool cans
 
Dan the man said:
You guys have given me a lot of good information about this. I think that I'm not going to insulate the intake manifold. What thermostat would be better to use, a 160* or a 180*.
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It depends. The 160 will make more power and let you run more cylinder pressure, but with the coolant that cool, it’s hard to vaporize the fuel so booster choice becomes that much more critical.

Any air gap style manifold or tunnel ram is already pretty cold. Dropping the coolant temp makes them cooler yet. If you can get the fuel atomized so it can then vaporize you can make more power. And be more detonation resistant.

You just have to be careful about car/booster selection.
 
diymirage said:
this is how i run mine

View attachment 1715859811
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Noticed your fuel line moves away from the hot motor block as soon as it can. Then the lines stay as far away on the inner fender and frame. Also can catch airflow in engine compartment. Good way to avoid vapor lock.

Stock fuel line run between the block, heads, alternator. Basically encased with heat sources and heat retainers (large hunks of metal).
 
autoxcuda said:
Noticed your fuel line moves away from the hot motor block as soon as it can. Then the lines stay as far away on the inner fender and frame. Also can catch airflow in engine compartment. Good way to avoid vapor lock.

Stock fuel line run between the block, heads, alternator. Basically encased with heat sources and heat retainers (large hunks of metal).
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And that is an old picture
In the mean time I've added a new 3/8 fuel line and converted the old line to a return

Even less worry about vapor lock now
 
Brooks James said:
In the cool can add salt to the water, it will reduce the temp dramatically, water will still be a liquid till -21 degrees C
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This is incorrect and outright wrong but he is on the right thinking track. Here’s why!

Salt, in itself, does nothing, I repeat, NOTHING to lower the temperature of any liquid, PERIOD.

What salt does allow is the ability to change the boiling or freezing point of water.

What this means, IF you can accomplish this, is the ability to get the cool can’s water below the freezing mark. This is a minor Benefit at best because the now colder than 32*F - 0*C water surrounds the fuel line for sure.

On the issue of how cold gasoline can be before it becomes frozen or even a slushy mix, I don’t know. Also, more food for thought, how dense can fuel get from chilling? A smart *** says, to the point where it starts to freeze, but is it any denser where a measurable gain is seen? AKA - Is it worth the effort?
 
Rat Bastid said:
BINGO. If you are going to run a cold manifold you need to understand what happens if you don’t get the fuel atomized well enough leaving the booster. If the manifold is too cold, you’ll lose power and burn a bunch more fuel if you don’t the fuel atomized at the booster.
Click to expand...
But by the time the engine warms up to operating temp it no longer matters.
 
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