Tag Line

"Built Dam Strong!"

26 March 2012

An older, unfinished project, but still fun.

This is from 2008 and I don't have access to a lath or mill anymore, so I can't finish the project until I do. 

What happens when you have plenty of 2024 aluminum, bronze, stainless and machine tools? ITBs (Individual Throttle Bodies), that's what! 

First things first: flanges! You need to have flanges as a strong base for the entire project. Right now, I forget if this is 1/2" or 3/8" thick 2024 aluminum (the good stuff).

The single point flycutter (with a tool I ground myself after some trial and error) going to town on 4 pieces of material:


Notice the clamp on the overhanging material to reduce chatter s much as possible. It worked well enough, since the whole block of material was thick enough when clamped together to be pretty stiff.

After a few passes:


Once I got to that point (I ignored the small nicked spot from an oops with the band saw), I flipped the pieces over and leveled the other side. Gotta love the automatic feed! Set the speed and listen for any nasty noises that means your project is ruined and you have to start over. LOL!

Here's the other side: 


I had a Z6 intake manifold phenolic gasket sent to me and I used poor man's machinist dye (blue wide-point Sharpie!) for my layout. 

I don't have pics of the scribe lines, but . . . I hope you can picture the traced gasket on the chunk of metal. LOL! I determined by, measuring carefully and some math, that the bore spacing for the engine (Honda D16) is 84mm. Armed with that information, I made a bunch of these:

What are those? Pretty close tolerance bushings for the throttle plate butter fly shaft. (THANK YOU JANNE!)

You can see the start of the holes for them here:


I got the holes started then realized I should square up the sides better before installing things that are supposed to be fairly exactly parallel. LOL! 

I didn't take pics of drilling boring holes for them (because, well, the process of boring is . . . boring), but you can see how they fit here:



I used the mill vise to press the bushings in place, two at a time to balance the load:


After I got to that point, I started working on the mounting flanges again. Setting things up in a vise takes time. And though. And time. And measuring. And precision. And mostly time. heh

I didn't bother taking pics of the drilling of pilot holes, but the next few pics will give you a sense of what I was doing:





I left myself some room for final porting and shaping, but I think they turned out pretty well!



(I only had to remake one mounting plate because I oops when setting up the hole spacing . . . LOL)

Some of the other things I was working on while all that squaring up was going on was the actual runners themselves!

I totally forget the exact dimensions of this stuff, but, again, it's 2024 probably schedule 40 pipe.

 Each one needed a small lip turned. Yes, I messed one up. Sue me.


One of the hardest parts of this whole job was turning the butterfly shafts. I managed to keep the tolerances to within +/- .001", which is good enough for me!


I ended up making 12 runners because I could and also because I know I would screw something up in the future.


 Now, an astute observer will notice that I really having filled in the whole story yet! Where are the flanges with the bushings pressed in? Well, I am glad that you asked!

They were getting drilled then bored to size then counterbored!

Drilling the pilot hole:


Using the largest dang bit in the shop (1.25", IIRC):


And then the horrifically painful process of manual boring with a boring head. It would have gone a lot faster if we didn't only have the crappiest Chinese boring bars that fit the boring head. *sighs* It took days to size the holes correctly! (Working after hours during deployment (in Iraq) for sometimes 4-5 hours straight.)

Taking the biggest cuts I could at first to just get to near the correct size:


On size and good finish!


To compare, this is what I start from:

Then, after all that painful stuff, I had to counterbore the top of the plates like so:


 In order to fit the runners in place thusly:





I started making throttle plates, but found out too late that the plates need to have a 10-15" angle on the edge . . . and then we started packing up the equipment. Who knows when I am going to get to finish this stuff . . .