Exhaust Wrap

[Buzzard13]

Trying to cut back on some of the heat build up under the hood. I think I could run it just to under the cab but there are at least three different types and I would need one that could repel or with stand mud , snow, water, the standard elements.

I got stock exhaust manifolds and stock pipes, I am rerouting the driver side one but I got nothing fancy here just need to cut back on the heat created on rolling slow.

 

[gandrimp]

I just use the Mr gasket brand.

 

[Cort]

Get the DEI brand and coat with their silicone sealant. Be forewarned that if you use any brand it will retain moisture and rot out your system.

 

[Cros]

Get the DEI brand and coat with their silicone sealant. Be forewarned that if you use any brand it will retain moisture and rot out your system.

This is a real concern. I usually wrap my motorcycle exhausts and it's just a matter of time until you have to replace parts. Would a hood scoop be an easier modification?


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[Cort]

What vehicle/engine/mods are you running and what are your underhood temps?

 

[Delete Me]

Jet-Hot !

 

[Cort]

I will vouch for jet hot, I've had multiple sets of headers done by them. Awesome company and product.

 

[Buzzard13]

What vehicle/engine/mods are you running and what are your underhood temps?

I run a 78 Dodge W200 with a 360, no mods. I have a aftermarket fan I am going to attach and I wanted a Trans cooler. should I invest in an oil cooler as well?
I have no idea what my under hood temps are, or engine temps are, I guess I should update the stock gauges, didn't want to.

 

[Cort]

I’d invest in some quality gauges before you spend money for solutions to problems that don’t exist. Your stock gauges are notoriously inaccurate anyway. I don’t like to add coolers unless they are needed, they are just additional things to fail.

If the fan is a thermostatically controlled electric I would mount the sensor as high as possible and wire in a manual on off switch at the dash so if you are in mud or fording water you can prevent damaging it by switching it off.

 

[ohiowrangler]

I'd second the gages upgrade. You need to what type of heat source you're chasing, it'll save you a lot of money on equipment you probably don't need. How old is the radiator? Do you run a fan shroud? I'm running a 350 sbc in a 90 jeep wrangler, I don't have an overheating issue. I added hood louvers to help with floor pan heat in high temps. I'd do the gages first. Ron

 

[Buzzard13]

Have a Fan shroud. The radiator is stock; the fan have now is the stock quad blade the new one is a five blade flex, so not electric. I don't necessarily have an over-heating issue I just want to drop the temp a bit to help in the long run. as for the exhaust I would be applying wrap or jet hot to extend the life of the part also.
I'll look into better gauges that will look similar to the old style.

 

[ohiowrangler]

When I first started looking for a solution I placed 1" spacers under the hood hinges, this provided an additional gap for the hot air to escape. It did look a little doppy at first, but it was cheaper than spending money on parts that didn't work, Ron

 

[Rorschach]

First, why do you think there is a cooling issue?
Second, stay away from flex fans if you're not going to run a clutch also. They rob power, mpg, and are noisy.

 

[Buzzard13]

How do Flex fans rob power and mpg? I do not have clutch fan.
There isn't a cooling issue or over-heating issue I just want to drop the temp a bit to help in the long run, maybe run better?

 

[Rorschach]

How do Flex fans rob power and mpg? I do not have clutch fan.
There isn't a cooling issue or over-heating issue I just want to drop the temp a bit to help in the long run, maybe run better?

It takes power to move a fan blade through the air. On a flex fan they have a drastic curve to the blade and as you go faster the blades start to "straighten" out to reduce drag but the resistance to the air is still there, (the cause of how loud they are,).

Think about a boat prop in the water. In this example that resistance moves the boat through the water.
By adding a clutch it allows the fan to freewheel above approximately 35mph. This reduces the load on the engine.

Manufacturers experimented with flex fans in the 70s and early 80s. They all ran clutches because of this. The best flex fan uses 10hp more than a clutch fan. Most manufacturers have gone to electric.

But clutch fans are not flawless. They are mechanically driven by the engine so they use up some hp too. Electrical fans are probably the best in this area but now you have added a load to the electrical system.

Now that I have caused total confusion, you might check out, "Fan Power Test" Car Craft May 2000.
It really depends how you use a vehicle. If you are a rock crawler a flex fan would be good due to the low rpms. If your off roader is also a daily driver, than the clutch would be better. Electrical is good all around unless you see a lot of water. They shut off when not needed as they monitor temperature.

Any questions, feel free to ask. This is kinda what I do for a living.

 

[Rorschach]

It takes power to move a fan blade through the air. On a flex fan they have a drastic curve to the blade and as you go faster the blades start to "straighten" out to reduce drag but the resistance to the air is still there, (the cause of how loud they are,).

Think about a boat prop in the water. In this example that resistance moves the boat through the water.
By adding a clutch it allows the fan to freewheel above approximately 35mph. This reduces the load on the engine.

Manufacturers experimented with flex fans in the 70s and early 80s. They all ran clutches because of this. The best flex fan uses 10hp more than a clutch fan. Most manufacturers have gone to electric.

But clutch fans are not flawless. They are mechanically driven by the engine so they use up some hp too. Electrical fans are probably the best in this area but now you have added a load to the electrical system.

Now that I have caused total confusion, you might check out, "Fan Power Test" Car Craft May 2000.
It really depends how you use a vehicle. If you are a rock crawler a flex fan would be good due to the low rpms. If your off roader is also a daily driver, than the clutch would be better. Electrical is good all around unless you see a lot of water. They shut off when not needed as they monitor temperature.

Any questions, feel free to ask. This is kinda what I do for a living.

Oh, and fan shrouds are important. They help with cooling. If you don't see one it may not have come with one, if it's an older car. On a newer vehicle it may have been left off, broken, but a person is fooling themselves if they think they don't need one.

 

[Cort]

Have a Fan shroud. The radiator is stock; the fan have now is the stock quad blade the new one is a five blade flex, so not electric. I don't necessarily have an over-heating issue I just want to drop the temp a bit to help in the long run. as for the exhaust I would be applying wrap or jet hot to extend the life of the part also.
I'll look into better gauges that will look similar to the old style.

Do you want to lower engine bay temps or the engine’s internal temp?

Wrap will significantly lower the life of the exhaust, jet hot can’t be added yourself. You buy jet hot coated headers. I’ve had really good luck with Eastwood ceramic exhaust coating. The key is the you have to coat the INSIDE of the exhaust to minimalize heat retention in the exhaust components. If you don’t have an overheat problem lowering the temps Underwood won’t really net any longer component life. Lowering the operation temps can hurt as much as help if it’s in spec. The engineers designed it to run a certain way.

Auto meter makes some awesome gauges that have a fairly stock look and they are good quality.

 

[Kevin108]

Be forewarned that if you use any brand it will retain moisture and rot out your system.

I was going to bring that up, but then I re-read the first post. Based on his listed location, I don't believe he will have any issues with that. Note the absence of green and blue in this region.

 

[Goldmarble]

Engine Masters did a very recent test of fans. Shows that flex fans....aren't great:

 

[srad2]

Be forewarned that if you use any brand it will retain moisture and rot out your system.

Second that. It will rot out a set of headers fast. Also, if you have an oil or trans fluid leak anywhere on the wrap it will retain the fluid and may cause a fire. Had it happen to my street legal drag car many years ago.