SS Headers tuning

[slimjimandtherats]

I had to replace the stock log style exhaust due to cracks on the 170cid, and i opted for the Stainless steel set of headers; the price was right, and i like the option of swapping them over to a 200ci if i choose to do that swap in the future. I'm assuming some sort of carb tuning will be in order. The gentleman before me replaced the stock carb, with a rochester 2jet. Looking forward to playing around with that guy a lil as soon as the exhaust gets fabricated. Should i expect much difference in jetting between the stock log style exhuast manifold and new ss headers?? Cheers

 

[BCOWANWHEELS]

PUT THEM ON AND DONT WORRY. it will be fine

 

[powerband]

... here we go with the "backpressure/scavenging " discussion: Either you are sure small exhaust pipes out the back will help performance with 'backpressure' helping the 'scavenging ' of gasses or you are sure the evidence proves pipes have no effect past the collectors . I believe both and will argue the points of both beliefs - endlessly ...

have fun
.

.

 

[BCOWANWHEELS]

every engine except wot engines need back pressure

 

[slimjimandtherats]

Yeah, I'm gonna build me a nice set of dual exhaust, and see how she sounds with it being straight piped. More than likely, ill get a set of thrush glasspacks and toss em on. Any suggestions on exhaust? I love the sound of the straight 6. Sounds sooooo good!! https://www.youtube.com/watch?v=PcVk981 ... tml5=False

 

[Ironhorse302]

Awright, guys....don't jump down my throat yet...I just wanna know how a set of headers that are "optimized for 170/200 engines" will work on the 250.
That's an additional 50 to 80 cubes pushing through, isn't that just a wee bit too much backpressure? I'm willing to go with it if it will work; but if there's
a better choice for the 250, I'd like to hear from you all. Also, what say you about a crossover (x-pipe) if I use the dual outlet pipes? I'm definitely going
with dual outlets at the back (well, actually side dumps).

 

[RichCreations]

Awright, guys....don't jump down my throat yet...I just wanna know how a set of headers that are "optimized for 170/200 engines" will work on the 250.
That's an additional 50 to 80 cubes pushing through, isn't that just a wee bit too much backpressure? I'm willing to go with it if it will work; but if there's
a better choice for the 250, I'd like to hear from you all. Also, what say you about a crossover (x-pipe) if I use the dual outlet pipes? I'm definitely going
with dual outlets at the back (well, actually side dumps).

Well, considering they use the same head/exhaust ports... The header is not the "bottleneck" either way...

 

[chad]

does any 1 have the Vizzer (or Vissard or what ever his name is) article, that would help get em up to speed…

2X -
"…David Vizard has some excellent articles…"
what he said…

 

[Soldmy66]

every engine except wot engines need back pressure

This is not actually correct.

What is correct is that each engine must have sufficient exhaust gas velocity. For most practical purposes, exhaust gas velocity is positively correlated with exhaust scavaging.

It is also correct that too large of pipe diameter will reduce exhaust gas velocity.

Because too large of exhaust pipe diameter reduces exhaust gas velocity, it is commonly stated that some "backpressure" is necessary. Again, for so long as there is sufficient exhaust gas velocity, no backpressure is necessary nor beneficial.

It is possible to build an exhaust system with zero back pressure (or no loss of horsepower as a result of running a full exhaust system).

David Vizard has some excellent articles on this.

I hope this came across in the well intended and respectful manner with which it was intended.