Thread: headers

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For you engine guru's:

I am in the "mock up" stage on the Ranchero, one of the next challenges I am going to be starting on will be the headers. Was curious what you guys had for thoughts on tube size and length. The engine will be the 501 stroker, heads will be aluminum with some port work, single Dominator carb. Leaning towards the Edelbrock Victor heads unless someone convinces me otherwise.)

I used a set of merge collectors, the 4 into 2 into 1 variety on a stroker Windsor in a Fairmont body a number of years back and was very pleased with the result. I will probably be incorporating a set of these collectors into the Ranchero headers and wondered what you guys had for input on cylinders, and which cylinders should be paired in the collector as it makes the 4 into 2 transition.

Oh yeah, my major empahsis on this engine is low end torque. I am aiming for the highest possible torque number, and would like the torque to be "all in" by 5200-5800 RPM. Trasnsmission will be a vintage full comp Doug Nash 5 speed, with a steel flywheel and an 11" clutch. (or maybe a dual disc clutch). This car (truck?) will be 75% track usage and an occasional late night venture onto the street to play with the other kids....

Thanks in advance.

2 1/8 to 2 1/4 primaries 36 long if you use the blue thunder or a heads that use this type of flange ?heads with the big block chevy header flange ?if not the you may want the 2 1/8 it as alot to do with what size ex you are running to. if it will be small 3 inch
then you will went to go down on the primaries size but if it more than 3 say 3 1/2 or 4 run the bigger primaries tube

Thanks Pat. I will be running 4" exhaust, outsiders quite similar to the '66 Ford Cobras for the occasional street use. The collector for racing will be a 4" "tuned" to length by the old match the plug reading to the reading on the white chalk inside the collector method. I believe the Edelbrock Victor heads are the Ford port arrangement, don't hold me to that, though. I know the John Kasse designed head is a BBC flange. Have you ever used the merge collectors on a big block??? I know on a Windsor they build quite a bit of extra low end into the motor????

yes the merge collectors seam to be the way to go . no i have not made a set by the time i get all the tubes fitting i am burnt out and it seams no one want to pay more for them any ways. but i was thinking of making a set for my goat it shure dose not need any more low end .but i could test them to know if they are worth it. your primaries may be longer then 36 if you are going out side of the car so this may help lowend .and if you have the room go to 2 1/4 is can get tuff to do .you want a nice flow out of the headers so you may have to dump two thru the inner fender and make them slip fits .i use a old piece of tub and hold it to the head to see were thing may get in the way and see if the first bend will not get bent to bad and i try to keep a way from the steel donuts they have a supper tigth radii on the for 2 1/4 it would be on 2 1/4 you may need to use some but it can get verry $$. i hope is helps

If I'm getting you right Dave sounds like you want to do what we used to call Tri-Y headers. Good for torque, best for street, somewhat easier to route, and typically reduce exhaust noise (which may or may not be an advantage with your side pipe setup depending on how much noise you want)

Here's one article that deals with Tri-y's; http://superchevy.com/technical/engi...r/index1.html. As they mentioned, Doug Thorley loves these things so you might get some info from his site, or a conversation. I did a quick Google and there're some other articles discussing this design you may want to sift through.

try y i have made.i made manny sets of headers and have made one set of try y and they were step tube to they are on my 50 chevy. i do not think you want them if you are running them out side of the car if you are going for the cobra look but they do work good if you do not have not much room .you will need a set of big tube headers for big engine. have built a lot of them and never see a set of my headers on any customer car run slower

Similar to an old Tri-y, Bob. It pairs up two cylinders on each head into 1 collector, then merges both of these collectors into the large 4" collector. The logic behind this, as it was explained to me, is to better scavenge the cylinder in essence making the engine think it has a higher velocity on the exhaust gasses???? I'm really not much of an engine guy, but on a 408 stroker motor I had in a Maverick we played a bit on the dyno with conventional headers, step headers, and big tube headers with the merge collectors and found the big tubes with merge collectors developed another 18 foot pound of torque above what the conventional header developed. As I've said, my main goal for this engine will be to build lots of torque, and get in in at the lowest possible RPM. Hope this explains it a little better.