headers
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Hi bigdadde
They won't fit, no.
It's a heat issue with the vans and why header manufacturers aren't going to be put in the legal loop for burning your van down to the ground "If" it does set something ablaze. Heat from steel (metal) Headers far exceed the cooling capabilities of an enclosed compartment where most will actually glow red when driven at high speeds.
This destroys electrical wiring that's anywhere near the headers which their are many around it with these vans. Another problem is design issues. Any header made for these vans won't give the performance they should because of the lack of space to tune them properly. The factory manifolds are actually a header type design with rounded ports not square.
Just my :2: for what it's worth, I'm sure others will chime in if they can.
They won't fit, no.
It's a heat issue with the vans and why header manufacturers aren't going to be put in the legal loop for burning your van down to the ground "If" it does set something ablaze. Heat from steel (metal) Headers far exceed the cooling capabilities of an enclosed compartment where most will actually glow red when driven at high speeds.
This destroys electrical wiring that's anywhere near the headers which their are many around it with these vans. Another problem is design issues. Any header made for these vans won't give the performance they should because of the lack of space to tune them properly. The factory manifolds are actually a header type design with rounded ports not square.
Just my :2: for what it's worth, I'm sure others will chime in if they can.
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Well, since the right headers flow so much better than exhaust manifolds, the heat is removed from the engine compartment more quickly. Now, do I have actual studies or articles to support this, no. Just two things I have noticed. First, my tailpipe is alot hotter in my astro than is ever was in my safari so some heat is being transferred. More importantly, when I tuning the engine, I do drive it around with the doghouse off. When I did that with the safari (stock 4.3L), the heat coming thru was incredible. When I do that with the astro, it is a lot cooler. Even with the cooling fans on, its not comparable to heat that I got off of the safari.Matrixx said:
But Matrixx is right about the headers that are made. It's all supply and demand. If suddenly millions of astro/safari owners wanted good headers for their vans, companies would make them. But since that is the case, no good headers are available.
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Hi bigdadde
I still stand by what I said BD. I have the highest respect astro355, but I have to politely disagree with the unlikely part of it (Yes I'm Paranoid. Hmm, Actaually, No, I'm careful).
Here's why:
-V6s are an odd ball firing engine, this odd ball firing order is what generates more heat than the V8s do with an even firing order which "internally" run cooler the V6s (being stock for both).
-Having said that, cast manifolds "hold" more heat than headers do and why you get the feeling of more heat from them. As for temperatures between the 2 (Cast Manifolds and Headers) the headers may not "hold" as much heat as the cast manifolds do, but they run at a "higher" temperature range than the cast manifolds.
That's why you can actually touch the cast manifolds when they are hot (If your quick and crazy enough of course) and not get burned as opposed to touching the headers where you will leave half your hand (skin) on the header pipe. It's this higher temperature range that the headers inherently run at that causes the heat issues mentioned above. The headers may not actually start a fire, but it will be responsible for it in one way or another (Ie: heat melting a wiring harness, Harness shorts out and the possibility of a fire starts from that, melted harness).
Headers are made of a much thinner material which in turn means it will heat faster and glow brighter than cast manifolds. Another thing to consider here with the later model vans (96+) is the size of the engine compartment as compared to the older style (95-) vans. Astro355s van has much more room at the bottom where the motor sits with his as what our vans have. If you can take a look at my gallery and his, you can actually see how much more room he has compared to ours. His sub-frame is smaller and the motor mounts and motor sit lower which in turn means better cooling or air flow over it compared to ours. Our motor and mounts sit up a bit higher and the compartment is smaller which in turn means less air flow over the engine for cooling (or more stationary heat).
I'm not trying to scare you here at all BD, I'm just trying to get you to see the whole picture when something like this is considered. The ultimate decision will be yours and Astro355 brought up a very good point about "Jet Coated"? or Ceramic Headers (maybe the same thing), that would be the best way to go for sure if you do decide to get headers made up. They run "much" cooler than stock metal headers.
I'm sure I have fired up a few people about this one, hehe. But that's my story and I'm sticking to it and the way the world is viewed from my eyes (always error on the side of caution).
Ramble Off.
I still stand by what I said BD. I have the highest respect astro355, but I have to politely disagree with the unlikely part of it (Yes I'm Paranoid. Hmm, Actaually, No, I'm careful).
Here's why:
-V6s are an odd ball firing engine, this odd ball firing order is what generates more heat than the V8s do with an even firing order which "internally" run cooler the V6s (being stock for both).
-Having said that, cast manifolds "hold" more heat than headers do and why you get the feeling of more heat from them. As for temperatures between the 2 (Cast Manifolds and Headers) the headers may not "hold" as much heat as the cast manifolds do, but they run at a "higher" temperature range than the cast manifolds.
That's why you can actually touch the cast manifolds when they are hot (If your quick and crazy enough of course) and not get burned as opposed to touching the headers where you will leave half your hand (skin) on the header pipe. It's this higher temperature range that the headers inherently run at that causes the heat issues mentioned above. The headers may not actually start a fire, but it will be responsible for it in one way or another (Ie: heat melting a wiring harness, Harness shorts out and the possibility of a fire starts from that, melted harness).
Headers are made of a much thinner material which in turn means it will heat faster and glow brighter than cast manifolds. Another thing to consider here with the later model vans (96+) is the size of the engine compartment as compared to the older style (95-) vans. Astro355s van has much more room at the bottom where the motor sits with his as what our vans have. If you can take a look at my gallery and his, you can actually see how much more room he has compared to ours. His sub-frame is smaller and the motor mounts and motor sit lower which in turn means better cooling or air flow over it compared to ours. Our motor and mounts sit up a bit higher and the compartment is smaller which in turn means less air flow over the engine for cooling (or more stationary heat).
I'm not trying to scare you here at all BD, I'm just trying to get you to see the whole picture when something like this is considered. The ultimate decision will be yours and Astro355 brought up a very good point about "Jet Coated"? or Ceramic Headers (maybe the same thing), that would be the best way to go for sure if you do decide to get headers made up. They run "much" cooler than stock metal headers.
I'm sure I have fired up a few people about this one, hehe. But that's my story and I'm sticking to it and the way the world is viewed from my eyes (always error on the side of caution).
Ramble Off.
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MATRIXX!!!! :screaming: :screaming: :screaming:
No, just kidding.
I point I am trying to make here is that since the since the headers flow better than the exhaust manifolds, the heat (and more heat) is transferred out of the engine compartment faster. I understand that the headers pipes feel hotter than exhaust manifolds and your reasoning is correct there, but that heat isn't transferred as much into the engine compartment as you think it is.
I do a lot of work on 3rd gen (82-92) and 4th gen (93-02) Firebirds and Camaros. There is no room in either of those cars (4rd gen being worse) for any type of work. Putting headers into those cars cools down the engine compartment temperatures. You can feel the difference.
Jet coating is just an insulative coating that gets sprayed on the headers (inside and out). It gives it a chrome finish and you will not leave any melted skin on headers treated that way.
No, just kidding.
I point I am trying to make here is that since the since the headers flow better than the exhaust manifolds, the heat (and more heat) is transferred out of the engine compartment faster. I understand that the headers pipes feel hotter than exhaust manifolds and your reasoning is correct there, but that heat isn't transferred as much into the engine compartment as you think it is.
I do a lot of work on 3rd gen (82-92) and 4th gen (93-02) Firebirds and Camaros. There is no room in either of those cars (4rd gen being worse) for any type of work. Putting headers into those cars cools down the engine compartment temperatures. You can feel the difference.
Jet coating is just an insulative coating that gets sprayed on the headers (inside and out). It gives it a chrome finish and you will not leave any melted skin on headers treated that way.
i put an edelbrock set of headers (ceramic) on my 4.3 in my 90. i still have to close in my engine with a custom dash and engine cover. it only seems hot when i strart moving down the road because the wind blows thru the header onto my ankle. but i am concerned about the temp once its closed in. im going to put a hilborn type scoop on the carb so it will draw cooler air from the front of the compartment. i plan on rerouting any wiring close to the headers. i used the headers for an s 10 application of the same year. a blazer application might work also. the only problem with the fit was that i had to grind about a 1/2 in off the flywheel/bellhousing cover on both sides because it rubbed and i didnt want it making noise from motor vibration.
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Headers are only apart of a package combo where as the cam,heads,intake system,rpm range,all take part.The smaller primary tubed ones work better on street driven trucks,vans,cars.Some headers start having a effect about 1800 to 2000 rpm,but that is only the starting point and many start at 3000 rpm and those are all related to the combo of what exhaust system is beyond the headers too.Those rpm ranges are not primary to street driven trucks,vans,cars.So my answer is two fold.Do headers them self's add alot to output-no.Do headers on street driving stuff add to primary driven rpm ranges-no.
The other thing to consider it headers on street stuff has always had a history of leaking and rusting out or cracking or burning out.Working as a dyno tech at a chevy engine plant I saw a number of different brands of headers and Headmen headers always lasted the longest.
The other thing to consider it headers on street stuff has always had a history of leaking and rusting out or cracking or burning out.Working as a dyno tech at a chevy engine plant I saw a number of different brands of headers and Headmen headers always lasted the longest.
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In order to be able to correctly choose headers you need to know something about them.This link is a good read and may not completely share my views,but it does cover a lot of areas about headers.I suggest you read the article to find items you find useful for you.
http://www.superchevy.com/technical/eng ... index.html
Of course two articles are better than one.
http://www.carcraft.com/techarticles/he ... index.html
http://www.superchevy.com/technical/eng ... index.html
Of course two articles are better than one.
http://www.carcraft.com/techarticles/he ... index.html
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54 Posts
For perspective, I've been running Hedman tube headers that RaceCrafters supplied with their V8 AWD conversion (AWD is different from 2WD) kits since 2001. Driven almost daily except for when gasoline was $4 bucks plus. Driving it again now. This is in a 94 Astro with an LT4. I wrapped the starter wiring in aluminum heat protection. The starter wiring, plug wires and head temp sensors are the only wiring that is close to headers. Never had a heat related failure. My major concern is that the headers will rust out and I won't be able to find a replacement set. They don't fit the LT4 "D" ports well, but I've never seen anything else available for that application. An Astro has no more heat-trapping than a Camaro or Vette. An Astro has good quality heat resistant material in the engine cover and the the underside of the driver and pax floors.
Installed a new set of plug wires in '04 (GM OEM 'Vette) and have not had any problems with plug wires either. I had to drop the subframe to do this. Had an odd miss and thought the plug wires were at fault. The problem wasn't the plug wires. Eventually found the TPS was causing the problem. MAJOR bummer. TPS is a 15 minute job. Still running perfectly with the OEM '96 Optispark too.....for now. Cool huh?
I just drove the van on a 300 mile ride the other day at interstae speeds. I've done this off and on for years. I don't believe that heat is going to be a problem for most owners.
It is assumed that most wiring and engine plumbing (especially fuel lines) are installed using OEM heat sheilds and installed in a workmanlike manner. Any headers (tube headers or OEM) and contact with combustibles is a fire waiting to happen. I will agree that tube headers will glow red at highway speeds...but so will cast iron headers.
Anyone know if RaceCrafters still in business? If so, gotta link?
FWIW, JR
Installed a new set of plug wires in '04 (GM OEM 'Vette) and have not had any problems with plug wires either. I had to drop the subframe to do this. Had an odd miss and thought the plug wires were at fault. The problem wasn't the plug wires. Eventually found the TPS was causing the problem. MAJOR bummer. TPS is a 15 minute job. Still running perfectly with the OEM '96 Optispark too.....for now. Cool huh?
I just drove the van on a 300 mile ride the other day at interstae speeds. I've done this off and on for years. I don't believe that heat is going to be a problem for most owners.
It is assumed that most wiring and engine plumbing (especially fuel lines) are installed using OEM heat sheilds and installed in a workmanlike manner. Any headers (tube headers or OEM) and contact with combustibles is a fire waiting to happen. I will agree that tube headers will glow red at highway speeds...but so will cast iron headers.
Anyone know if RaceCrafters still in business? If so, gotta link?
FWIW, JR
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Astro355: bscene-buttmoon:
I always wanted to try that one out, hehe, Ah just kidding 55.
I'm glad I sparked a good debate on this subject and some good points have been brought up on both sides for sure. Overall (personally speaking of course) I think if you look at the amount spent, to what is gained and what is lost, their just not worth the expense for a stock 4.3. As for Cameros and Firebirds I don't recall changing plugs from the fender wells or from underneath the vehicle like we have to with our vans which in turn means less space and more heat.
My initial comments to BD were to just to get him to see the overall picture. The final decision will be his anyways.
bscene-buttmoon:I always wanted to try that one out, hehe, Ah just kidding 55.
I'm glad I sparked a good debate on this subject and some good points have been brought up on both sides for sure. Overall (personally speaking of course) I think if you look at the amount spent, to what is gained and what is lost, their just not worth the expense for a stock 4.3. As for Cameros and Firebirds I don't recall changing plugs from the fender wells or from underneath the vehicle like we have to with our vans which in turn means less space and more heat.
My initial comments to BD were to just to get him to see the overall picture. The final decision will be his anyways.
first, i would like to say thank you guys for helping me didint think any 1 would help but is there a way to cool it all down like a ram air hood or something like that i i dnt know what to do maybe i will just get it coated and see what happens. i want to put a trubo on the v6 tol i get the v8
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Header tubes on turbo's have to run hot in order to work correctly and the intake charge is where a inter-cooler comes into play.Wrapped tubes collect condensation therefor rust out faster.(hot/cold cycles)Some of the things to consider with a turbo and the tight compartment in these vans. :think:
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Oh, you're killing me!Matrixx said:Astro355:
I always wanted to try that one out, hehe, Ah just kidding 55.
I'm glad I sparked a good debate on this subject and some good points have been brought up on both sides for sure. Overall (personally speaking of course) I think if you look at the amount spent, to what is gained and what is lost, their just not worth the expense for a stock 4.3. As for Cameros and Firebirds I don't recall changing plugs from the fender wells or from underneath the vehicle like we have to with our vans which in turn means less space and more heat.
My initial comments to BD were to just to get him to see the overall picture. The final decision will be his anyways.
Camaros and Firebirds don't have access from the wheelwells or underneath because they have a hood that complete covers the engine, unlike our vans. Accessibility to our engines because of the lack of a full hood is why we have to go the wheel wells or under the van. Really, firebirds and camaros have less space available around the exhaust than our vans do.
But has as already been stated, proper installation will go a long way in getting everything to work right.
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I hope I'm not killing you to badly 55, hehe.
I see every ones point here for sure, But the point I was trying to make with space in our vans wasn't the height but the width. there is no way on gods green earth I can even consider sliding my hand down the side of the exhaust manifold from the inside compartment. As for Cameros and Firebirds (at least the ones I have worked on) you can, and that's the point I was just trying to make.
I think we need to take in consideration the differences between the old style and new style vans as well. With the larger sub-frame and the higher sitting motor mounts with the new Gen. astro/safari vans, it really restricts access as compared to the old Gen astro/safaris, I found this out the hard way with my engine re&re, but I'm glad I cut the rad support anyways, it gave much better access to the front of the motor.
With your van 55, I couldn't believe how much room you had when you showed us the picture with your front end apart. Ours (Gen-2) is no where near that much room and maybe why were looking at things a bit differently (Maybe),hehe.
I think I will leave it at that and what ever BD wants to do after this "Great Debate", then that will be entirely up to him.
I see every ones point here for sure, But the point I was trying to make with space in our vans wasn't the height but the width. there is no way on gods green earth I can even consider sliding my hand down the side of the exhaust manifold from the inside compartment. As for Cameros and Firebirds (at least the ones I have worked on) you can, and that's the point I was just trying to make.
I think we need to take in consideration the differences between the old style and new style vans as well. With the larger sub-frame and the higher sitting motor mounts with the new Gen. astro/safari vans, it really restricts access as compared to the old Gen astro/safaris, I found this out the hard way with my engine re&re, but I'm glad I cut the rad support anyways, it gave much better access to the front of the motor.
With your van 55, I couldn't believe how much room you had when you showed us the picture with your front end apart. Ours (Gen-2) is no where near that much room and maybe why were looking at things a bit differently (Maybe),hehe.
I think I will leave it at that and what ever BD wants to do after this "Great Debate", then that will be entirely up to him.
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