Jump to content
I Forge Iron

Modifying a 5.4L Ford Throttle Body for a forge valve.

Recommended Posts

This came up in a different thread and I thought I'd start a new one to document what I've done in case anyone else wants to try it. Basically I'm modifying a Throttle Body of of a 5.4L Ford engine found in various trucks in the early 2000's. This was selected for it's 3" hose attachment, and being the simplest available with the fewest sensors, valves, and passageways to deal with.


First you'll need to snag one off of the previously mentioned engines. There are cable operated and fly by wire types. You'll want the earlier cable type. Also be careful not to get one off of a v6 as they look the same, but are smaller.

Step one, unscrew and discard the throttle position sensor.

Next remove the two screws in the throttle shaft that hold the blade on.

Rotate the shaft so that you can pull the blade out of the shaft. It only comes out one way because of two stamped bosses in the blade itself. Make sure you not which way the blade is oriented with regards to the housing, it has beveled edges that are hard to see, but you want to put it back the same.

You should now be able to tap the shaft out of it's bore. You'll want to unhook the spring as you get it moving, it just clips onto the housing. Discard the spring.

Remove the O-rings from the throttle shaft.

Now clean everything. Good quality carb cleaner is a must to remove the carbon sludge, particulary inside the throttle bore.


Now that it's all clean, we can modify.

I chose to trim the end of the shaft back where the Throttle position sensor was. I just ground back the "blade" looking part that sticks out. This is optional.

There's a hunk of molded plastic on the other end of the shaft. You can remove it from the metal part with a wire wheel on a grinder. This should not hurt the steel bracket.

The bracket on the throttle shaft sticks out far enough that it will hit if you mount the valve on a flat surface. You can either: A, make a small riser block to go under the valve, or B, turn the valve shaft 180 degrees and cut most of it away. I chose B, see pics below.

I chose to drill out the one remaining hole for a 1/4" connector to bolt to. I'm going to use a rod linkage, but you may want to use a mower throttle cable / choke cable / PTO cable.


Re-assembly time.

Put new O-rings on the shaft and tap it back in.

Double check that you've got the shaft oriented where you want it, and slip the blade in place. A. Do not screw it down yet. B. double check that it's oriented correctly. It should be exactly the same as when you removed it, whether or not you rotated the shaft 180 degrees.

Now close the valve. That will line the blade up exactly on center. Install screws, and it's all locked in place.


I'll be making an adapter plate to get it bolted up to my forge, but you should know the bolt pattern on the TB casting is 3" x 2.6" and the holes are sized for 1/4" bolts. Once I've got that done, I'll get some more pictures up.



Link to comment
Share on other sites

I made an adapter from a piece of 5" diameter, 1" thick aluminum. I could just as easily have mounted it directly to the tuyere if I drilled holes in it's mounting flange. I didn't want to. I could also have made two flat steel plates and welded them to a piece of 3" pipe to make an adapter. I had aluminum, I used it.


I matched the through hole to the TB at 2.85" diameter and beveled the backside out to match the tuyere at 3.1". (Does NOT need to be that precise.) Then I messed up drilling hole patterns, and had to turn everything 90 degrees and redrill to the correct dimensions. Measure once, cut twice, ya know.


Mounted it up and started on the fan. I still need to build a rod to control the valve (push/pull style). I'll also need some friction on the rod so it doesn't just randomly move. But, that's tommorrow's problem.






Link to comment
Share on other sites

2 hours ago, ODaily said:

Measure once, cut twice, ya know.

That's why I trace whenever possible, sometimes the more I measure the farther off I get. 

Nice adapter, how does the forge work?

Frosty The Lucky.

Link to comment
Share on other sites

2 hours ago, Frosty said:

Nice adapter, who does the forge work?

Thanks! But.. Forge isn't working yet. The blower is attached by 3" silicone hose, and is seting on a scrap of wood.

Next step, mount the motor on a plate, move the control / switch to a more convenient location, and fabricate a control rod / lever for the valve. Then I can fire her up.

Also, I forgot to mention, I cut the adapter out of 5" round, but that's the absolute minimum that can be used with the bolt holes on the CF unit. It uses a 4" x 2-3/8" bolt pattern, assumably the same as the dayton blowers.

If I had a bridgeport, I could be more accurate. I guess I need a bridgeport.

Link to comment
Share on other sites

Good Morning,

Need = life necessity.  Want = Picture on a Poster.  Desire = Dreaming.  Could Use = More Practical. What was used = What was available within a reasonable distance.

The Machine doesn't create accuracy, the operator does!

If there is no Box to restrict your thinking, How is it possible for there to be a Box to contain your thinking?


Link to comment
Share on other sites

  • 3 weeks later...
On 5/9/2023 at 7:07 PM, Frosty said:

how does the forge work?

I needed to choke off the air intake. I used a shell of a mower muffler. The perforated holes let just the right amount of air in to put the valve in a useable range. By useable range, I mean from this is pretty hot to surface of the sun temps. Just flat wow. Everything I've learned to this point was on bitumenous with a handcrank. Anthracite with electric is a much different beast.

I really wish I would've built a diverter style valve. The blower is capable of insane for a newby heat, but can be ticklish to dial in as a result. Maybe I'll redo it at some point.

Anywho, pictures.



Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now
  • Create New...