Is anyone running 1 7/8 tti headers on a small block? The unknown brand 1 5/8 headers that I took off when I started this project were awfully tight. Just wondering how they fit. I now have trickflow heads, not sure if that will effect things
1 7/8 headers on 69 dart?
- Thread starter PWdart
- Start date
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Locomotion
Well-Known Member
The rest of your combo can affect the optimum header size but, in most cases, I believe that 1 3/4" or 1 5/8"-1 3/4" step would Work better than 1 7/8". Just because you have better flowing heads doesn't guarantee that bigger headers will provide more performance.
As for fit, TTI are supposed to be good fitting headers. I was very happy with the TTI stepped on my 360 LAX head Dart Sport. But little things like factory production tolerances, tweaks in the frame/chassis over the years and/or motor mount design/wear can affect clearances. I don't know if there is any difference in the exhaust on your heads.
As for fit, TTI are supposed to be good fitting headers. I was very happy with the TTI stepped on my 360 LAX head Dart Sport. But little things like factory production tolerances, tweaks in the frame/chassis over the years and/or motor mount design/wear can affect clearances. I don't know if there is any difference in the exhaust on your heads.
I have their 1-7/8" full length headers and Trick Flow heads in my 72' Scamp. Fitment was tight but everything went together great. Helps to install them from underneath using a lift
The X-pipe is said to scavenge more exhaust and make slightly more power than an H-Pipe. The other reason I used an X is because I have electric cutouts and I wanted them tucked above the subframe connectors. With an H pipe, they would've been equal to the frame. Since this is a "street" car, I needed as much ground clearance as I could get.
Rat Bastid
Dunamis Metron
Can you post all your cam numbers and engine details?
Both H and X pipes, are used to equalize the exhaust pulsation between the cylinder banks. This usually tones down the lumpiness at idle to some degree. The equalization of pressure between the banks helps with cylinder scavenging on the port and can help contribute to better cylinder filling. Generally speaking an H pipe provides better low end torque, while X provides better mid range and top end. H pipe gives classic muscle sound while X pipe is a little raspier tuned sound. I run a 3" TTI X pipe on my W2 head 69 Swingers 408.
Oh comp ratio is 9.95
Rat Bastid
Dunamis Metron
What is the LSA on your cam? Your compression is low enough you could probably use a 2 inch tube.
110
No power steering. Engine is not in the car as of yet
My bad, Just Send it had posted the pictures.
Rat Bastid
Dunamis Metron
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.
As said above…. The H and X pipe help balance the pulses of the exhaust. In tests I have seen, the H & X are super close together as far as power is concerned with nether favoring ether side of the curve more than the other one to make a big or little difference on the street or track. They’re always within a few ft. lbs. or HP of each other.
For myself, I have found the H pile to deliver a more classic muscle thump and rumble where as the H pipe really whites down the exhaust note at idle. While under cruise as well but not a huge amount. Noticeable from what i have experienced. The one thing I have found with an X pipe is when your really turning out the rpm’s the car sounds like it’s spinning another 1,000 rpm’s and the vehicle is just screaming & it sounds like it’s shreaking!
Very awesome sound IMO. The H pipe doesn’t do this.
If you’re fabricating the exhaust yourself, the X pipe can be a PIA to do. The H pipe is much simpler to do.
Locomotion
Well-Known Member
This is open headers with 3" collectors vs 3" X-pipes ending with Dynomax Ultraflo or bullet mufflers ending at the rear axle.
In my particular 360 race only application, not only did it help ET/MPH a bit, but the now more efficient exhaust provided a bit more performance with jets 2 #'s leaner. I'm talking about hundredths. not tenths in ET. But it depends how close to optimum your jetting is to begin with. Weight was kept the same because the 55-60 lbs of X-pipe.muffler weight was removed from elsewhere in the car.
perfacar
Well-Known Member
on our 340 stocker, changed from 1 3/4 to 1 7/8 dropped 2 tenths and gained 2 mph, average to average , best to best, etc. friend of mine runs a 340 6 pac stocker, changed from 1 5/8 to 1 3/4 step headers to 1 7/8 with 3 1/2 collector, gained 35 hp. just food for thought. my son changed from 1 7/8 to 2 ' headers on his 440, gained over 3 tenths lower.
split63
Member
I put a set of 1 7/8 hooker headers on my 69 dart 340 with x heads back in 1971 and still have them on they are tight on the drive side but they fit
Do you have any pictures from the top? Not sure if you’re running power steering, but wondering about clearance.
split63
Member
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
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.
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