Hooker Headers, good/bad/ugly

[Cobain03]

i believe if i switch out my patriot tri y's (been saying this forever) i can accomplish some obsticals i have with clearance.

how do they fit? hit the shock towers? not caring that much about ground clearance unless its ridiculous.

part number 6901 (ceremic or not, havent decided yet)

 

[ratio411]

Find out if Hooker still only coats the outside of the header.
Coated Hookers are cheaper from Jet Hot many times, and to add insult to injury, Jet Hot coats the ENTIRE header. Coated Hookers are known to rot from the inside out.
Unless they have changed, they don't coat the inside of the metal, and that is a far more harsh and corrosive environment than the outside.
Jet Hot buys the headers at a volume discount and sells them after coating them.


That said, I think coating is snake oil... If you want it though, might as well get the best you can.

6901s hang some, but they aren't ridiculous IMO.
They tend to have the best quality and fitment IMO.

Others opinions may vary.

 

[drk]

I've only heard good things from them. I hear they are one of the few headers that clears a 65-66 mustang with a t5 conversion.

 

[Cobain03]

jet hot sells their ceremic coated ones for CHEAPER then hooker ceremics lol so i think thats my route. my tri y's caused me to put a space on the engine mount to raise the engine so it would clear the shock towers. and its CLOSE to hitting the hood. SO... i cant change my intake to a better one cause of height lol.

Patriot should be shot.

 

[BullittStangV8]

I have Hooker super comps and they are great. I had to "reshape" one of the tubes slightly to work with a roller block and a z bar kit. However, they worked perfectly with my old 289 block, and they have not rotted in 8+ years at all.

 

[coolblue65]

I have Hooker super comps and they are great. I had to "reshape" one of the tubes slightly to work with a roller block and a z bar kit. However, they worked perfectly with my old 289 block, and they have not rotted in 8+ years at all.

Same experience except I have Hooker Comps, and I had them Jet-Hot coated- the coating definately cools the headers down much more quickly.

 

[Route666]

Coating is definitely not snake oil, it will slow energy transfer from the exhaust gas to the exhaust material, and thus slow energy loss altogether, resulting in better gas velocity (through less pressure loss from temp decrease). The percentage of difference is around the 10% mark though. I suspect coating the entire exhaust would yeild the best results as coating the headers just make the next uncoated section the biggest heat sink to suck energy / velocity out of the gas.

 

[ratio411]

Coating is definitely not snake oil, it will slow energy transfer from the exhaust gas to the exhaust material, and thus slow energy loss altogether, resulting in better gas velocity (through less pressure loss from temp decrease). The percentage of difference is around the 10% mark though. I suspect coating the entire exhaust would yeild the best results as coating the headers just make the next uncoated section the biggest heat sink to suck energy / velocity out of the gas.

Your exhaust will have a slightly higher velocity, therefore slightly more scavenging.
HOWEVER, if your headers are the right size, you have all the scavenging you need. That's why you pick the right tube diameters and lengths if you are serious.

You want the headers to act as a heat sink to get all the benefits they give.
The heat loss is where many of the benefits are vs cast iron manifolds.
If you want heat retention, you might as well port the iron and save money.

Heat loss at the header aids engine cooling, fights detonation, and shrinks the exhaust gasses so you can run smaller and lighter exhuast system behind the headers.

When the gasses come out hot behind the headers, you need to run bigger pipe/mufflers (more expensive) to handle the expanded gasses. This also adds weight which is effective HP loss!

So, if there really is a slight gain from scavenging, you lose it due to overloaded small exhaust, or heavier larger exhaust. Also from timing cut back to prevent detonation if you are running your fuel and/or compression on the edge. (Which it seems you would be thinking about all the dough you spent on coating!)

Edit:
Forgot about the mufflers...
They are meant to be located as far back from the headers as possible. The closer they are to the extreme heat, the shorter life they have. Heat kills most mufflers.
If you coat the headers and the high heat can't get out until later, you kill your mufflers quicker.
There are other things to consider I am forgetting to I am sure.
I have argued this before, but it has been a couple years.

 

[ratio411]

Now that I consider it, I realize something!

When you coat your header, you are effectively decreasing the primary diameter...
Think about it.
The exhaust gasses can't shrink from cooling, so you have more resistance.
Might as well save money and use the next size smaller header!
That is all the effect you are having.

Going from coated 1.625" primary to uncoated 1.5" would give you the same velocity, AND you would keep all the benefits of the headers being a heat sink! Best of both worlds.

I wouldn't do it. If the 1.5" works better, then I would have planned for it and they would be on the car already!

 

[BullittStangV8]

Ratio,
You are forgeting however, that cooler, denser gas flows slower. Higher gas temperater (higher kinetic and potential energy), woud allow for higher exaust flow speeds, if that is what your point is. Also, by keeping the heat inside of the header, you are decreasing engine bay temperature, leading to a cooler inlet temperature (more hp).

 

[mikethebike]

I've only heard good things from them. I hear they are one of the few headers that clears a 65-66 mustang with a t5 conversion.

I have a T-5 and the clearence problems were not with the transmission. I just removed the Super-Comps from the '65 due to interference with the clutch linkage, power steering AND spring towers. After looking at all the cable coversions and hydraulic systems I decided to use Kevlar lined Teflon impregnated sphrical rod ends at all the pivot points on the linkage and went back to hi-pi manifolds with a cross-over pipe and 2.5" exhausts.

Only problem was they are after-market manifolds and they interfere with the plugs! I had to modify a socket by grinding a slot in it. Next time the manifolds are off I'll borrow or buy an old head and mount and grind the manifold for clearance.
Just one of many problems when you work on a car that is just too damn small in the engine compartment.

After all these years fighting this type stuff on this car I may just get one of those 1400 Lb. Mamba Lotus-23's with the 220 H.P. 4-valve Ford out back. That would be some kind of fun. Or maybe one of those tube frame 550 Spyders from Vintage.

 

[mikethebike]

Your exhaust will have a slightly higher velocity, therefore slightly more scavenging.
HOWEVER, if your headers are the right size, you have all the scavenging you need. That's why you pick the right tube diameters and lengths if you are serious.

You want the headers to act as a heat sink to get all the benefits they give.
The heat loss is where many of the benefits are vs cast iron manifolds.
If you want heat retention, you might as well port the iron and save money.

Heat loss at the header aids engine cooling, fights detonation, and shrinks the exhaust gasses so you can run smaller and lighter exhuast system behind the headers.

When the gasses come out hot behind the headers, you need to run bigger pipe/mufflers (more expensive) to handle the expanded gasses. This also adds weight which is effective HP loss!

So, if there really is a slight gain from scavenging, you lose it due to overloaded small exhaust, or heavier larger exhaust. Also from timing cut back to prevent detonation if you are running your fuel and/or compression on the edge. (Which it seems you would be thinking about all the dough you spent on coating!)

Edit:
Forgot about the mufflers...
They are meant to be located as far back from the headers as possible. The closer they are to the extreme heat, the shorter life they have. Heat kills most mufflers.
If you coat the headers and the high heat can't get out until later, you kill your mufflers quicker.
There are other things to consider I am forgetting to I am sure.
I have argued this before, but it has been a couple years.

Has anyone ever seen a dyno comparision...and not one of those ones done by a magazine that sets it up so you can't really tell which is better. Theroize all you want. Until you test the same engine on the same day with both type headers you won't know. And I would prefer a mass-air fuel injected engine so you don't have to contend with carb tuning.

 

[ratio411]

Ratio,
You are forgeting however, that cooler, denser gas flows slower. Higher gas temperater (higher kinetic and potential energy), woud allow for higher exaust flow speeds, if that is what your point is. Also, by keeping the heat inside of the header, you are decreasing engine bay temperature, leading to a cooler inlet temperature (more hp).

Higher exhaust gas temps do cause the velocity to increase.
But the gasses also displace more area because they are expanded.
So, without larger exhaust pipe, you will cause increased flow restriction.
My point is that even though you gain positives in one area, there are 10 others that are all effected negatively.

As for the engine bay... heat in the bay means that it is not in the engine.
It's a good thing.
Hood scoops have always been used to overcome bay heat.

Like I said, smaller tubes assure higher velocity if that is what you need.

 

[Route666]

Higher exhaust gas temps do cause the velocity to increase.
But the gasses also displace more area because they are expanded.
So, without larger exhaust pipe, you will cause increased flow restriction.
My point is that even though you gain positives in one area, there are 10 others that are all effected negatively.

As for the engine bay... heat in the bay means that it is not in the engine.
It's a good thing.
Hood scoops have always been used to overcome bay heat.

Like I said, smaller tubes assure higher velocity if that is what you need.

I agree, if you have headers that flow at the limit when they're uncoated they could "become" a little small when coated because of the higher pressure gas. However if you know the optimal size headers you need when uncoated - you could get coated ones with slightly bigger pipes for an increase in flow, while maintaining the velocity. You would probably need to go from (for example) 1-3/4 to 1-7/8 pipe though, going from 1-3/4 to 2 is probably too big of a step.

EDIT: I notice that you said basically the same thing a couple of posts earlier!

 

[Cobain03]

either way guys, i have a secondary tube (two singles into one thats a little bigger) thats almost complelty bent in half cause of my pitman arm. i dont think the inner coat of ceremic is gonna affect it THAT much

 

[ratio411]

either way guys, i have a secondary tube (two singles into one thats a little bigger) thats almost complelty bent in half cause of my pitman arm. i dont think the inner coat of ceremic is gonna affect it THAT much

I was speaking coated vs non-coated.
The inner coat deal I brought up because if you are going to pay for coating, might as well get a thorough job.

Also, I know it's a bit of a hijacking of the thread, but it's a good discussion to have.

 

[Route666]

Yeh the inner one is the one to have if any - provides the best insulation to the header metal - protects it the most and would provide equal if not better heat transfer reduction.

In mild builds I don't think it is really worthwhile money-wise, however if you want nice silvery (or different colours really) headers that cool to touch quickly and won't rust anywhere near as easily - get it.

 

[Helmantel]

Don't forget that you're still pushing the same mass through the exhaust pipes, regardless of temperature. The critical gas velocity (=speed of sound) goes up with temperature, so a pipe of a certain diameter isn't necessarily more restrictive to a hot gas than it is to a cold gas, as long as the mass flow in both cases is the same.

All in all, I think that the main contribution of coated headers to performance is due to lower underhood temperatures.

 

[ratio411]

Don't forget that you're still pushing the same mass through the exhaust pipes, regardless of temperature. The critical gas velocity (=speed of sound) goes up with temperature, so a pipe of a certain diameter isn't necessarily more restrictive to a hot gas than it is to a cold gas, as long as the mass flow in both cases is the same.

Mass is not the issue. Mass is a measure of weight.
I would think that mass is not affected by heat.
However, volume is affected by heat, and the gasses displace more volume the hotter they are. So you are creating restriction by increasing heat in the same pipe. The pipe is the constant value of volume capability. The gas varies in volume depending on temperature.
That is why I said that you can have the heat wicking of the headers, which is a big benefit, while having higher backpressure and velocity, just by using smaller uncoated primary pipes.
Heat in the engine bay is good. It is not in the engine if it is in the bay.
Think about it.

Heat wicked from the heads allows lower octane fuel, OR more timing and compression for performance... depending on your particular needs.
All this is why hood scoops are used in the first place. The only thing heat in the bay hurts is if your air cleaner is not exposed to incoming cool air.

 

[65ShelbyClone]

I have Hooker super comps and they are great. I had to "reshape" one of the tubes slightly to work with a roller block and a z bar kit. However, they worked perfectly with my old 289 block, and they have not rotted in 8+ years at all.

+1. I had Hooker Comps in a '65 notchback with a 289 and Toploader and the headers didn't need any hammer work at all. It also have manual steering, though. I put them in my '68 with a roller 302, Toploader, and Z-bar adapter bracket and had to put a few dents in a primary or two. I also converted the '68 to manual steering, so the ram wasn't an issue. On PS-equipped cars, it will be.