1 7/8 headers on 69 dart?

[Rat Bastid]

I have a similar displacement small block engine that was dynoed with both 1-7/8" and 1-5/8" TTi headers, because I already owned a 1-5/8" set, so I wanted to decide whether to spend the money on a set of 1-7/8". The difference was around 15 HP, with an Indy intake and Holley 1050.

Which header was better?

 

[Rat Bastid]

Which header was better?

Why the RED X? i was asking if the 15 HP again was with the small headers or the big headers.

 

[rumblefish360]

It’s gotta be ringer slip…. Move along, move along….

 

[360notch]

Which header was better?

!-7/8" was better. Both of them were the step design. TTi says the 1-7/8" step is recommended for above 500 HP, and the 1-7/8 long tube for over 550 HP. My engine maxed at 568 HP because I didn't want any pinging on 91 octane and I didn't want it to lope at idle. Ported Eddy heads flowed 308 at 0.500. Torque is over 500 ft-lbs from 3,000 to 6,000.

 

[360notch]

Why the RED X? i was asking if the 15 HP again was with the small headers or the big headers.

I appologize. I inadvertently hit the wron icon.

 

[273]

It is a 426 small block. The Dyno say 602 hp@5800 and 616tq@4500 with 1 7/8 Dyno headers. Cam is 408/258dur intake and 408/264 exh. @.050. 1.6 rockers

Impressive 1.44lbs-ft per cid

 

[rumblefish360]

Impressive 1.44lbs-ft per cid

That’s paying attention to not only to the rotating parts selected and good machining but it’s also showing a really good cam was selected.

I wonder what was done for the rest of the exhaust. Huge low end torque is always lost by common designs.

 

[Just Send It]

My bad, Just Send it had posted the pictures.

I have manual steering with a tubular k-member. It's a tight fit, but it fits. TTI makes good stuff. Masking tape is your friend to protect the ceramic coating when installing.

I did shim the motor upwards by 3/16" to give myself extra clearance. You can see it underneath the motor mount in the photo

 

[rumblefish360]

I leave the plastic bag for as long as possible when installing nicely nice headers.

 

[crackedback]

tti 1 7/8 headers are not the best header for making power in that tube size.

Unfortunately most of the better options don't fit as well or require a hole in the inner fender.

PS and 1 7/8 headers in an A body are almost always a no go. Tti being an exception.

 

[split63]

I am out of town but I will be back next week and send a picture but the car is automatic no power brakes or steering

 

[split63]

I leave the plastic bag for as long as possible when installing nicely nice headers.

View attachment 1716030242

 

[rumblefish360]

Well that might a slight problem with retaining the plastic shipping bag!

 

[B3422w5]

!-7/8" was better. Both of them were the step design. TTi says the 1-7/8" step is recommended for above 500 HP, and the 1-7/8 long tube for over 550 HP. My engine maxed at 568 HP because I didn't want any pinging on 91 octane and I didn't want it to lope at idle. Ported Eddy heads flowed 308 at 0.500. Torque is over 500 ft-lbs from 3,000 to 6,000.

I wasn’t aware TTI made a 1 7/8 step header.
I know they make 1 5/8 to 1 3/4 step
And they make a straight 1 7/8

 

[360notch]

I wasn’t aware TTI made a 1 7/8 step header.
I know they make 1 5/8 to 1 3/4 step
And they make a straight 1 7/8

You are absolutely correct. I plead temporary insanity. I have no excuse, because all I had to do was look at my 2 cars. My 426 small block (4.125 stroker) has a set of TTi 1-7/8" and my 414 has a set of TTi 1-5/8".

 

[Jim Kueneman]

Ok, IMO you are at least 4 degrees too wide on your LSA. At least. IMO you should be at 102. No wider than 104. Unless you are running EFI.

Plus you are low on compression ratio (again, my opinion) so adding that to that wide LSA you kill header function.

Since I’ve seen this a hundred times over the years I’m betting your Intake Center Line is 106, which also hurts header function.

Again, IMO you could probably just run 1.75 headers and it won’t make any difference.

Or you can use the 1.875 headers because like I said the engine will be numb to header tuning.

I have an article from a magazine where Billy Godbold (formerly of Comp Cams) talks about LSA, ICL and header function. If I can figure out how to copy it and post it here I will.

You have to read the whole article but he covers why sometimes headers don’t make any difference. IMO that’s where you are.

Did you figure out how to share this? I’m interested. I’m assuming it is because the valve timing is such the valve is not open when the scavenging pulse arrives?

 

[Rat Bastid]

Did you figure out how to share this? I’m interested. I’m assuming it is because the valve timing is such the valve is not open when the scavenging pulse arrives?

I’ve been out of town almost a week. I’ll see if I can get my wife to scan it tomorrow then I can post it up.

Of course, it’s always a trade off. She does the scan, I’ll have to do the dishes or vacuum or some crap like that.

So this will cost me bigly lol

 

[68cuda408]

I had the TTI long tubes with an HDK front end, 408"LA,727. The only issue I had was using a cable shifter. The #5 tube is directly in front of the shift lever. I made a 1:1 bellcrank at the "kickdown" lever pivot on the bellhousing to offset the cable and used a Heim ended link to the lever from the crank arm. GenIII 426 now, same K frame different block mounts.