So after having the idea from Madjack of using the Pacesetter header, lopping off the collector, and attaching one without the restrictive ball-joint connection, I started looking at different collectors.
The first one I found that conveniently comes with the correct primary piping size of 1.5" is the
Flowmaster Scavenger-Series, however, it would pretty much make the 4:1 into a 4:2:1, which I'm not sure I like. On the up side, it is cheap ($160 is for a pair) and fits the needs of most OHV owners right off the bat.
Then I happened across this:
Dynatech Headers' Merge Collector
These have encountered increasing use in professional racecars, and I also caught a
review that a Carcraft did where they gained 15 hp on the engine dyno just by changing between a straight collector and the dynatech merge collector. Problem is, they don't make it in 1.5" primary and 2.5" outlet. And from my measurements of the exhaust ports on the 2200 head, going any bigger than that on the primary piping size would be pretty much useless.
Burns Stainless will custom make one, even computer modeled to the engine and cam specs, but, its looking like $350+ just to get started, and since the Pacesetter is mild steel, I'm not too keen on welding it to stainless, and thats really all Burns will make these with. There's always the full custom header idea, but I'd prefer off-the-shelf as I'd want this build to be about making an NA motor that anyone on here could duplicate with 3/4 of a brain, a blue-collar wallet, and a decent machine shop.
So does anyone have any clue where to find one in mild steel and 1.5" primary tubing? I'm not particularly concerned about the cost, as long as its not REALLY ridiculous. Also open to other input from those that are more well versed on the topic than I.
Arrival Blue 04 LS Sport
Eco
Turbo
Megasquirt
'Nuff said
Thanks John, but what I meant was a collector that merges like the Dynatech does... Smaller initial merge that expands to pipe size afterward.
Arrival Blue 04 LS Sport
Eco
Turbo
Megasquirt
'Nuff said
Depending on your final OD size, if you were to expand the pipe after the initial collection, it seems like it would have the same effect.....although with a 2.5" outlet, i think you are looking to bottle neck it right after the collector...right? That seems to be what the dynatech ones are.
I suppose it would be hard to get the correct angle to help flow instead of hurt. I found a couple in stainless ranging from the same price as the dynatech to $650 starting out....
but that too, is not what you are looking for.
Ever think to drop dynatech a line to see if they'll make you one, and at what cost?
Yeah they say they don't do any custom orders... they did recommend a fab shop to me but as said, I prefer to get something off the shelf for the duplication aspect.
Arrival Blue 04 LS Sport
Eco
Turbo
Megasquirt
'Nuff said
so would this be just to further help flow of a header or just redesign one to work better for our engines?
alot of people pay alot of money for merge collectors , that do less than the ball socket does
if you really wanna waste the money , just cut ball end off and fully weld their flange to the header , and use another 2 bolt 3" flange to make a down pipe with
you are not going to get anything different in the same location as they have it already , the collector is angled and short
Luis Marroquin wrote:so would this be just to further help flow of a header or just redesign one to work better for our engines?
Basically its intended to help the flow of any header because it scavenges better than a straight-through collector. Although even dynatech says its possible to "overscavenge", but my thinking here is that, for someone looking to push the OHV to over 6500 rpm, it might be worth it as thats the area where the head will prove most restrictive, even after porting. Just an idea though which is why I'm looking to open discussion a little.
Arrival Blue 04 LS Sport
Eco
Turbo
Megasquirt
'Nuff said
oh ok well good to know, i guess i will add this page to my bookmarks on useful information!
Well i have a ECO and i spent the bokoo $$$ for a custom built header. A local racer recomended SPD Exaust. With a little help from my dyno guy he said a step header 1 3/4 to 1 7/8 then a merge collector 3" to a 4" megaphone. So i spent aprox $650 for all the piping and such. Then i told my racing buddy to build it to our specs, he charged me $600. All im going to say that its tuned to 9500 rpm peak. I have a magnaflow muffer 3.5" in/out, WOW is that sumbitch LOUD!
Dyno day it was rainy and windy, with the new exaust and 2.4 eco manifold, car did low 170's whp with mid 140's tq. then first test and tune session car went best mph ever 104.95 and backed with 104.77. my thoughts money well spent, we will be in the 200whp by the end of the season
hope that helps
-Ben
You could also try Al's Headers. They're really popular with the LN2 guys on the S-truck board I subscribe to (In addition to here).
Go beyond the "bolt-on".
