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180 degree headers for sbc


fastzcars

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O.k. guys I know this will sound wierd but I got an itch to try to make some 180 degree headers, I.ve tried the search but couldn't find any info on what 4 cylinders to cross over to make them? Does anyone know or have pictures of 180 degree headers for a SBC?:D

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Explain to me what you mean by 180 degree headers? I bought a set of Stahl headers to use and cut them up to make headers for my tube chassi car, they might be what you are looking for. One header looks normal, the other looks like it crosses and go under the engine to the other side along with that side header. I think these were made for nascar.

 

John

 

O.k. guys I know this will sound wierd but I got an itch to try to make some 180 degree headers, I.ve tried the search but couldn't find any info on what 4 cylinders to cross over to make them? Does anyone know or have pictures of 180 degree headers for a SBC?:D
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Sorry, I read the post below and I do not think I have what you want. Also I have been busy trying to put my engine back together for SEZ. When I have time I will snap a few photos of what I have. Maybe this weekend.

 

Thanks John' date=' heres an OLD post on the subject, Maybe the header you have could be what I'm lookin for?

http://forums.hybridz.org/showthread.php?t=79112&highlight=180+degree+headers.

and a more recent post

http://forums.hybridz.org/showthread.php?t=110640&highlight=180+degree+headers.

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I found this thread that has pictures in it from a Porsche 928. Is that something like what you're thinking of doing?

http://www.lextreme.com/forums/showthread.php?t=3263

 

At first I had no idea how you would cross over, but now I see it's done just before the collectors. I bet that would cause some clearance problems.

 

There's also a couple of cool pic's of a GT40 replica with 180 degreee headers.

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I was just talking about this with my engine builder last week. The only way that I could see to do it on my Z was to run the headers under the sump. The engine builder said that it would then heat up your oil and negate any gains you made and if you were running the engine for a long time the heated oil would then be a bit of a problem. I think that properly spaced x pipe's will get you as much HP these days. I have given up on the idea.

 

Douglas

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ZROSSA I was just talking about this with my engine builder last week. The only way that I could see to do it on my Z was to run the headers under the sump. The engine builder said that it would then heat up your oil and negate any gains you made and if you were running the engine for a long time the heated oil would then be a bit of a problem. I think that properly spaced x pipe's will get you as much HP these days. I have given up on the idea.

 

Douglas

 

I was thinking the same way about routing the tubing . I had thought about using a semi wrap on the tubing and a metal sheild( kind of like a cat converter sheild) for the oil pan, in addition to a oil cooler. What do you think Douglas?

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O.k. guys I figured it out, Thanks to bartman for the link and to some pictures of a pantera's custom header and it's firing order I got over the net , the pairing's on the SBC are 1,4,6,7 and 2,3,5,8. the 2 inner tubes on one bank goes to the other sides outer tubes and vise versa. Now that I finally figures that out I have to see if it's even possable to make it? I just love that exotic sound! Thanks Guys.http://www.revsearch.com/sounds/dodge450.wav

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Could get the headers coated as well. I think they sound cool as well but i have to keep asking myself some questions such as, If tey work so well why dont we see them in more race cars? Drag racing cars have the room but you never see them on them. Lots of tube chassis race cars have room but dont run them. Speedway cars have room but dont run them. Racing jet boats have all the room in the world but dont run them. Now in a lot of classes they are banned which would lead you to belive that there was a gain to be had. Here in New Zealand the race engines that need as much torque as possable such as jet sprinting,tranzam and the speedway cars are using a system that finishes into a large single pipe.

What I am going to do is have an x-pipe after the collecters then run duals to the rear into a large single then into a muffler which I will make myself. Need it to match my rear undertray.

 

Douglas

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You have a point Zrossa. What don't other forms of motorsports use them. It could be the complexity of all the tubing criss-crossing and the ugly look of it all. But how much horse power are we talking about? Maybe 1 to 2 %. but what I'm after is the sound. I've actually had some positive comments on how my car sounds. I have block huggers to duel 2.5 inch to single 3.5 inch Y-conection to single borola muffler. But with the cam I have ,the lumpy sound is VERY pronounced. And it's ALMOST anoying to me. I kid you not, the windows of my house rattle when my car is idling in the garage, And it's a DETACHED garage 20 feet away! So I just want to even out the pulses.

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180 headers offer a performance advantage over 4:1 headers. Theory is the incoming exhaust pulse enters the collector 180 crank degrees from the previous cyl firing, so the negative reflection of the previous firing is at it's peak, and scavenging is improved. Because some tubes, the crossover ones, have to be longer than others, this means the tube length is very critical to match the pulse with the negative reflection. So it takes a ton of dyno work to get the tubes worked out to maximize the effect, and you have to do this in a package to fit the chassis in question.

 

Some 180 disadvantages:

 

-Because good ones are custom built, they are very expensive.

-The extra scavenging effect is only in a certain rpm range, not across the board.

-They create lots of plumbing/packaging/clearance problems.

-They are heavy.

-They can make previously routine maintenance a nightmare.

 

And a biggie- The top Nascar teams discovered a very well designed and built X pipe system is very, very, close to the performance of 180's, without all the above headaches.

 

180's were the standard for super speedway cars for a while, because the SS engines run in a very narrow rpm range. At Talladega the rpm will only vary a few hundred rpm around the track, so the 180's worked very well. They have fallen out of favor for the above reasons.

 

But, oh boy, they do sound wicked.

 

John

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Even if you're only after the 'sound', you probably won't be able to get the sound you want unless you can match the pulse with the negative reflection...not to mention other factors that contribute to the overall sound as well.

 

I'd hate to see you go to all the cost and trouble of creating a complete system to give you the sound you're after and then have it wind up sounding pretty similar to the way it does now.

 

I spent quite a bit of time and money to get mine to sound lumpy and I love it. Setting off alarms, making children cry, and rattling a few windows are just side benefits.:icon52:

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Great suggestions guys, keep them coming.:D I was thinking of a sudo x-pipe under the oil pan? What do you guys think of that route? Bartman , I know what you mean about " making children cry" . My kids go out and tell me that they get a headache from the 'thumping' that my car produces. It's actually pretty funny! :willy_nil

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I am with you on the sound! Still not past trying a set of 8 into 1's!!!

 

Grumpyvette once discribed that his system on his vette sounded like 4 cylinder on n2o. He had two x-pipes, one after the collecters and one before the diff.

 

I always wanted mine to sound like a ferrari 308 with balls. I dont think that the sbc will ever sound that way but maybe we can get closer and fool the masses.

 

I am probably about 4 to 6 months of getting mine ready to fire up so the sound tuning wont happen for a while. Dont want to give up any Hp However.

 

Douglas

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  • 11 months later...

I know this is an old subject, but I was searching for headers such as these to use on my project 240sx. Summit Racing sells these headers made by Howe Racing that will do exactly what you're searching for. Here's a link to Howe's website to have a look-see: http://www.howeracing.com/Exhaust/Index-180Degree.htm

 

Summit sells them for about $320. I think that price is more than reasonable to pay for these headers.

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