Making custom headers, which cylinders to pair up together 4-2-1's.
11-21-2004, 01:24 AM
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Making custom headers, which cylinders to pair up together 4-2-1's. I am just making up my own 4-2-1 headers for my LS1 retro swap and one RHS I plan on pair up cylinder 2-8 & 4-6 as its a better fit.
With the LS1 is it vital which cylinders you pair up or theres no optimal combo?
What do most header companies pair together?
With the LS1 is it vital which cylinders you pair up or theres no optimal combo?
What do most header companies pair together?
11-21-2004, 12:37 PM
#3
Won't most power be created by keeping the exhaust gases from each cylinder seperate longer? Then join them together all at once with equal-length tubes? Thats what I thought made the most power... 4-2-1 is essentially how a stock manifold is designed.
11-21-2004, 02:04 PM
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Thanks quick time, looks like your pair 2-4, 6-8, 1-3. 5-7.
I have a set of aftermarket pipes like yours that pair 2-4, 6-8, 1-5, 3-7 so there not identical on opposite sides.
I just have more room pairing 2-8, 4-6, 1-7, 3-5.
Anyone see any problems with pairing them this way?
BTW 4-2-1 is the only option I have as 2 go on each side of steering column.
I have a set of aftermarket pipes like yours that pair 2-4, 6-8, 1-5, 3-7 so there not identical on opposite sides.
I just have more room pairing 2-8, 4-6, 1-7, 3-5.
Anyone see any problems with pairing them this way?
BTW 4-2-1 is the only option I have as 2 go on each side of steering column.
11-21-2004, 02:53 PM
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Originally Posted by GTS346
I just have more room pairing 2-8, 4-6, 1-7, 3-5.
BTW 4-2-1 is the only option I have as 2 go on each side of steering column.
I would have staggered them according to the firing order, which is exactly what you have there.
1-8-7-2-6-5-4-3
11-21-2004, 11:52 PM
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QTP has them paired a certain way for a certain reason. You're separating and pairing them that way for scavanging reasons. Any other way and you could cause problems. You don't want two cylinders paired that fire @ nearly the same time as you will over-fill that section of the collector (per its size), causing a pwr loss. You want to do the exact oposite for optimum results. You may just have to get creative with the routing. Try to keep the primary lengths as close to one another as possible. That will also help with scavanging. Good luck! 
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11-22-2004, 02:08 AM
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The cam is a 220 cam so pretty much there would be 20 degrees when both exhaust valves in the pair are open together "both pipes dumping gasses for 20 degrees", would this hurt or improve bottom end/top end?
