Big tube header vs small tube header on a stroker

-

B3422w5

Well-Known Member
Joined
Feb 9, 2017
Messages
3,697
Reaction score
4,571
Location
Portage michigan
Gonna run 1 5/8 headers(Dougs), at least for a season, on my new stroker motor with eddies. Primarily because i have them, and they fit nice.
Wonder how much doing so will cost compared to a 1 7/8 header?
 
Gonna run 1 5/8 headers(Dougs), at least for a season, on my new stroker motor with eddies. Primarily because i have them, and they fit nice.
Wonder how much doing so will cost compared to a 1 7/8 header?

are asking about cost? Or ET?
 
Cool. Will be nice to find out . I have been wondering if the 1-5/8 headers on my Dakota are holding me back if any. The only thing that sucks for me is, the 1-5/8 header is the biggest hooker makes for my Dakota
 
I would imagine that would depend on cubic inch and Rpm out the back along with the length of your header extension

on my 390 (630hp) I changed from 1 7/8 with 3 collectors to 2 inch with 3 1/2 collectors and I didn’t see any improvement on the dyno until 6800rpm to 7500. And it wasn’t much.
 
Last edited:
I've always said for racing, run as big a primary tube as will FIT.
 
I would imagine that would depend on cubic inch and Rpm out the back along with the length of your header extension

on my 390 (630hp) I changed from 1 7/8 with 3 collectors to 2 inch with 3 1/2 collectors and I didn’t see any improvement on the dyno until 6800rpm to 7500. And it wasn’t much.

I dont doubt you wouldnt see a difference with the above factors.1 7/8 headers are plenty for anything Indy head on down
I put a 3.5 inch collector on a 700 horse W5 motor and saw nothing compared to a 3 inch collector( 1 7/8 headers). Ran 140 mph@3220


my motor will be a 12 to 1 418 with decent eddie heads and a flat tapper cam. I race a lot. The 1 5/8 headers were on my stock stroke 360
 
I would imagine that would depend on cubic inch and Rpm out the back along with the length of your header extension

on my 390 (630hp) I changed from 1 7/8 with 3 collectors to 2 inch with 3 1/2 collectors and I didn’t see any improvement on the dyno until 6800rpm to 7500. And it wasn’t much.
I went from 10.80 with 1 3/4" 5204 hookers to 10.29 with 1 7/8" hedmans 75140
 
At 7000ft last year 1 5/8 headers and running dangerously lean the best run was 11.72@114

This year with tti 1 7/8 and not lean, 11.27@119.5 7000ft da... same everything else.

I'm sure the lean condition didn't help... but almost 6mph and 5 tenths... I dunno.
 
Maybe talk with someone who runs or makes a lot of consistent pulls on a dyno (west tech in California). They makes hundreds of hits a week, from street to race oriented engines.

While it’s not a hit on a track they might be able to discuss if the hp/tq shifted rpm wise along with any improvement in hp/tq
 
Last edited:
At 7000ft last year 1 5/8 headers and running dangerously lean the best run was 11.72@114

This year with tti 1 7/8 and not lean, 11.27@119.5 7000ft da... same everything else.

I'm sure the lean condition didn't help... but almost 6mph and 5 tenths... I dunno.


I can believe that too.
 
I have never, ever seen a 340 lose power with an 1.75 header. Ever. If you are over an honest 10.75:1 compression and have a cam that isn’t totally wrong for the application, a 1.875 header on a 340 will NOT lose power or low end.

I’m going to dyno at least 1.750 and 1.875 headers on the dyno next late spring. May do 1.625 too if I can find a set, but I’ve done that enough to know on a 340 it’s a power loser.

I can’t think of any 400 plus CID engine that can’t benefit from a 1.875 header.

BTW, when using a split pattern cam with an *** load of exhaust duration and a wider than it should have LSA the small header will be damn near equal to any other header because the cam timing is wrong.

And changing the header won’t fix that. But, if you fix the cam timing and then try the small header it will kill power everywhere. But put the big headers on it and it will gain everywhere.

When I hear a big tube header lost power the first thing I look at is cam timing.

The only exception to this rule is building headers like Calvin Elston does it, and that requires rethinking everything from the induction side to the end of the collector.

And, when a bigger collector doesn’t do anything or slows down the car, it’s most likely too short. In fact, most collectors are significantly too short.
 
I asked my wife. "I said Hun What do you like more? The 2 inch we are using or would you want to go 1 5/8 ?"


She wanted the 1 5/8 they were cheaper.

The car wanted the more expensive 2 inch tubes.

DSCN1684.jpg


DSCN1685.jpg
 
Last edited:
So the wife wanted smaller? Man, you don't hear that too often. :)
If I were racing you and saw that motor, I'd walk away and keep my money! :thumbsup:
 
I asked my wife. "I said Hun What do you like more? The 2 inch we are using or would you want to go 1 5/8 ?" She wanted the 1 5/8 they were cheaper.

The car wanted the more expensive 2 inch tubes. The car will always Win! This way if anyone ever asks. Did the car ever win? Your not lying when you say Yes!

View attachment 1715630628

View attachment 1715630629
Y




Old Man, Those are some nice looking valve covers, mind sharing where did you get them ?
 
My son had my firend laser cut a flange out using a gasket for a pattern. He then fitted them to the heads around the pushrods. Then he welded them up with the air filter to match.

The covers are just blanks he ordered and fitted to our motor using the flange he made. The breather bungs were welded in by us . Its hard to find covers with out the holes and then they are left breather in the front , And the right breather in the back.

Because we wanted both breathers in the front for the evac-system we had to make the covers ourselves

Here is a picture of the bottom of the valve cover flange getting fitted to the push rods and intake, He also milled and fitted up a aluminum timing cover. Most all of the fabbed parts on the car were made in house.

He is making some cool parts for the new car he and I are building.

Steve 046.JPG


Steve 065.JPG
 
Last edited:
I am looking at the 4 bolt per tube header flange are those older W5 or aluminum Batten heads ?
 
Old Man, what brand headers are you running on your Bad *** Duster, looks like one tube wraps around the frame rail, any interference with the tire turning ?
 
Wow... 70 or 80 horse probably

my guess was it might cost me 15-20 horse using 1 5/8 compared to 1 7/8

Don, IIRC several years ago Ryan Johnson told me that 1 7/8" Hedmans were worth 15-20hp over 1 7/8" TTI's on a engine similar to my 408. I'd think they'd worth close to 2X as much over a 1 5/8" header.

I run the 1 7/8" Hedmans with a 3 1/2" collector and have considered finding a pair of 2" with the W2 flanges to try. Honestly I don't think it would be worth the $$ but it would be a interesting test.
 
Don, IIRC several years ago Ryan Johnson told me that 1 7/8" Hedmans were worth 15-20hp over 1 7/8" TTI's on a engine similar to my 408. I'd think they'd worth close to 2X as much over a 1 5/8" header.

I run the 1 7/8" Hedmans with a 3 1/2" collector and have considered finding a pair of 2" with the W2 flanges to try. Honestly I don't think it would be worth the $$ but it would be a interesting test.

Remember that.
Think that info originated from Brian @ IMM
 
Gonna run 1 5/8 headers(Dougs), at least for a season, on my new stroker motor with eddies. Primarily because i have them, and they fit nice.
Wonder how much doing so will cost compared to a 1 7/8 header?
Not sure if this helps you at all, but my car currently has 1 3/4" Headman Hustlers on it. I've been curious for years if stepping up to 1 7/8 would be worth the trouble.
 
-
Back
Top