14point7 Spartan 2 install, Holley 4150 tuning, & exhaustcapades

LILCBRA

I wish I didn't have all of these balls in the air
15 Year Member
Dec 6, 2005
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Marietta, Ga
As I said in the BS thread, here is my thread on installing the A/F setup and gauge to try and tune my carburetor. As many of you know, I swapped manifolds a while back and replaced the Offenhauser 360 with a cheap Edelbrock Performer RPM Airgap knockoff a couple years ago and during that process I took the carburetor back to off the shelf specs. I didn't do much to it after that, hell I've hardly driven the car! I've been too preoccupied with other things in life, but now things are starting to fall into place (other than this COVID-19 mess we're going through right now....) and I'd really like to get my car back into shape. As I posted late last year I took it to a show that offered Dyno pulls and I decided to give it a shot. And, as you could see in the video I took, it's running EXTREMELY rich. I changed the oil a few days ago and as you'd expect it was somewhat diluted with fuel. So, on a whim, I decided to jet the primaries AND secondaries down substantially. I also installed a new Autogage tach at the same time, so I started the car just to confirm the tach works, and that's as far as I've gone. Oh, and a couple years ago when I took the carb apart I took a vacuum reading and installed a more appropriate power valve, but I now question if THAT'S part of the problem, so I'll be going through that process with all of this too.

Here is a pic of the gauge, O2 sensor, wiring, and instructions that were sent as well as my vacuum gauge. And who doesn't listen to tunes while they're working on their car?!?! Gotta have THAT!!! :D

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Ok, it's time to go get things done! I'll update later.....
 
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Initial carb jetting and what I haphazardly took it to. Going to triple check my Holley guide to make sure, but these should've been the original the jet sizes before I took them down.
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I confirmed the power valve size. 5.5 should be correct, but I think as insurance I may pick up another 5.5 PV when I pick up the sensor bung from the parts store.

Edit: The more I think about it I think I'll pick up a 4.5. I think I should err to the lower side with this, and since it was somewhere in the 10-11 inch range for vacuum, I'm going to go with 10 which would require a 4.5 power valve. Since they don't carry a 4.5 PV, I guess I'm at a standstill with actually going farther with the carb once I get the gauge installed. So this escapade will continue for at least a few days.....

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I present my exhaust for your viewing pleasure. As you can see, I've had an oil leak for some time, I'm hoping that the damper repair sleeve takes care of that issue. But these are the same pipes I've had on my car since the 90s. :)

You should also be able to see where I marked the location for the O2 sensor. Next up is drilling a hole, welding the bung, and installing the sensor. Directions call for the sensor to be installed 2 feet from the exhaust ports for an N/A engine. I have long tubes, so I figured shortly after the collector should be the right location. But if I go any further back I'll run into my transmission cross member, then the sensor would definitely be farther than 2 feet away. Any closer and I think I'd be too close to the primaries.

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great progress! Do you have over axle pipes or is it "dumped" in front of the rear axle?!

They're dumped at the axle.

Ugly welds, but whatcha gonna do with a 120v flux core welder? Tried preheating everything with a propane torch. It IS solid - hopefully it's air tight.

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On an unrelated note, I think I said something not long ago about finding a pinhole in my rocker - I pressed on it with my pinky, here it is now.

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Bums me out.....
 
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Ended up tearing a collector gasket, so this pic is basically a mock-up, but it shows the position of the sensor compared to the cross member. And I think this is where I'm going to call it a day. Going to have to order collector gaskets as well as the 4.5 power valve before I can get too much farther. I'm also waiting on the gauge pod so I can relocate the 2 gauges I already run and keep them with the new gauge.....

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Oh man I'm excited to see air/fuel adjustment based on the gauge!
Always wanted to try this after doing old school way for ever
( sitting side of road after high speed blast looking at plugs, guessing at color )
 
NICE! Especially to see that you use mufflers from the company I'm working for. :cool:
And about the weld: with the right tools everyone can do it...

I'm not too bad of a welder really, but I'm not too great with this welder if it's not thin. It welded everything on those pipes. Once I was able to get everything warmed up it wasn't too bad, but since the bung and the pipe are both different thicknesses and the heat dissipates differently between the 2, the welds just look like crap. One of these lifetimes I'll pick up a better welder, but this one was the right price years ago so it does most everything I ask of it except make good looking welds. It IS convertible to gas, just never done it....

Oh man I'm excited to see air/fuel adjustment based on the gauge!
Always wanted to try this after doing old school way for ever
( sitting side of road after high speed blast looking at plugs, guessing at color )

Me too! It's gonna be nice to not have to play that guessing game all the time. I have a distinct feeling this way will take less time in the long run, just gotta get it all installed.
 
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Whoo Hoo! Take it off! Take it all off!

Wait! put it back on, drive it around. All the way around!

Either way it looks short and sweet(read loud).

Oh, and it IS loud. I'd really like to quiet it down some. I've toyed with the idea of welding in some kind of resonator before the mufflers but I'm not sure what to try or how it'll affect the sound, other than quieting it down. If I were to drive it to Mustang Week in Myrtle Beach again quieter would be MUCH better. I already have tinitus from years of working around stamping presses and loud cars, it'd be nice to NOT do any more damage than what's already been done.
 
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Oh, and it IS loud. I'd really like to quiet it down some.

I feel your pain, my other mustang is loud, wait I mean LOUD!, setting off car alarms and scaring women and children loud.
Like the resonator idea.

I said something not long ago about finding a pinhole in my rocker -


Old Mustangs rust...Alot!
Fix it or wait till worse... just keep driving it!!