Shift linkage bushings are mostly complete

Yesterday I snuck over to my friend's place after leaving work early. I managed to knock out the rest of the work on the bushings for the shift linkage and shifter. Well, they aren't 100% done, but they are done with everything I need a lathe for.

I was so focused on things that I didn't bother with taking photos of the process, since I took photos the last time and most lathe work is really pretty similar. Turning, facing, drilling, reaming and parting. I'm not doing anything groudbreaking, here.

Anyway, here is the one pic I took of the mostly finished pieces:

The left bottom set is for the end of the shifter itself. The other two sets are for the yoke. There is one piece I didn't make, but I am going to see how well this works without that one piece and if it works then I won't bother having to make it right away, which is a good thing.

So if you recall, I left off with these:

 As you can see, those were not drilled and the outside of the shoulders were not faced to size. I hadn't even started the bushings for the shifter, as that was the lowest priority. My shift linkage was so bad at the yoke end, that was what I was needing to focus on, but thankfully I had the time to make them, too.

As far as the process, immediately after I showed up, I found a left hand tool holder and ground a facing tool. The tools I grind (I should take a photo of them sometime) are SHARP. This material seems to prefer a very sharp tool with almost no nose radius and not too much relief on any of the angles. Doing that and tweaking the feed speeds, I can get really decent surface finishes and take off a decent amount (at least for the size of the lathe I am using) per pass. A CNC machine could likely make all of these in the time it takes me to just face one of these things. LOL!

After I got the tool set, I faced the shoulders to size. This dimension isn't exactly precise as the yoke is thin sheetmetal that is pretty flexible. Within 5-10 thou is perfectly acceptable, though I manged to get both sides pretty close to the dimensions I calculated.

Looking at the time, I figured I could knock out the shifter bushings, so I slapped in the round stock, switched tools to the turning tool that I probably should have sharped up a bit but it worked well enough for the little bit of turning I had to do. I got the shafts turned to size, cut the bushings off the bar stock, slapped in the facing tool, faced both sides and then got read to drill and ream.

In production or at least time sensitive work, the thing that nearly always takes the most time is tool changes, so if you can eliminate as many tool changes as possible, especially if you only have one kind of tool holder for what you are doing, you can save a LOT of time. In this case, this basically meant that I center drilled all the pieces first. Dave only has one chuck, so changing the tools in the chuck takes a bunch of time. Granted, this isn't super critical work by any means, so changing the pieces out is perfectly acceptable and preferable to taking the time to mount a tool for every operation change.

So, yeah, I center drilled each piece. I then tried to drill one bushing to the just under the reamer size, but that didn't work too well at all. I read that with this bronze, it helps to grind the bit tip flatter than you would normally find on a general purpose split point bit, but since I didn't want to do that, I just pilot drilled them then got them drilled out to just under the .315" reamer size.

By all accounts, the reaming was supposed to be pretty gnarly, but, well, it wasn't. Dave helped by flooding the reamer with WD40 as we went along. We found a good, chatter free speed to turn the lathe (man, that VFD makes things so easy!) and we finished the holes to size.

In case you didn't know, reamers are for forming very precise and round holes. Drill bits actually don't make very precise or even round holes, usually with poor surface finish to boot. A reamer will make the hole very round and if you aren't rough with it, it will leave an very excellent surface finish for the hole.

We finished up and I had to skedaddle. I didn't get to chamfer the edges, which is slightly annoying but not the end of the world. I can take care of the burrs with a file. These don't have the prettiest finish, but, when these go into production on CNC machines (that's planned), they will be quite the handsome parts.

So that about sums it up for this wall of text. I hope you found some of it interesting, even with only one new picture for the whole post. heh

King Sandblaster Reigns! (Not Supreme, but reigns, nonetheless.)

I did some more sandblasting after work today. YAY! I finished the second FUCA (Front Upper Control Arm), then decided to see how well this thing handled crustier stuff. Enter my Hf manifold I've never cared a lick about aside from how it bolts in between the head and the turbo and usually directs exhaust gases into the turbo. 

This is how we started out:

 Typical trusty, crusty cast iron.

After a couple of minutes playing around:

 I then realized I was burning daylight and had better things to do with my time, related to my front suspension. Enter one of the hubs, clean for your consideration:

 The front side is clean, at least. I have to finish the backside.

Notice the tape around the hub stub:

 I don't want to blast the precision machined surface that fits into the bearing. It is already very clean and doesn't need the tolerances changed a bit.

I've been tweaking the setup of the cabinet as I've gone along. Having eliminated all the leaks I can without getting really retarded (and I do need a new hose as the hose is leaking, too, darnit), the only problem I have with blasting continuously is keeping the end of the media feed tube buried.

To that end, and since I nearly always am holding the piece I am blasting closer to the cloudy, sand/dust covered plastic "viewing" shield, I took out the grate:

 This let me use my hands in the gloves to scoop the media over the end of the media feed tube much more easily, and this made blasting a heck of a lot faster.

I am wondering if grounding the cover would help at all. I am pretty sure that most of the issue is static cling.

Finally, this is a for reference shot of the other hub which is about as crusty as the other hub started out:

I totally <3 sandblasting.

Mr. Clean ain't got nothin' on MY magic eraser!

So at the end of last year, I bought this:

That is a small sandblasting cabinet. It is sold by all the cheap tool stores. I figured that as long as it worked halfway correctly, I'd be better off using it than wasting blasting media all over the back yard at the house. So, yesterday after work, I got it set up and tried it out with my two small/too small compressors and had at one of my front upper control arms. 

Ok, first I actually finished off this dust ring:

As you can see, it worked. I've got the cabinet filled with HF aluminum oxide media. You'll also observe that the box does leak some around the corners, but honestly not much and not the horrific amount that claimed by many online reviewers. 

So, what do I mean by two too small compressors? 

That is the area removed with one charge from one of the compressors. Is it slow going? Yes, but it works! 

I'll get more pics of the process and progress I make over the next few days if weather permits. 

Perspective, or how taking the time to look at something changes everything.

Yesterday I took apart a B-series head. Looks all honky dory, right? 

Here's #3:

All the bits and pieces:

People who don't pull engines apart regularly would likely not believe how much junk gets chucked around when something goes wrong. Case in point: Aluminum shavings on another cylinders intake valves:

So, why am I messing with this? The owner of the head is letting me have it for mock-up purposes. Mocking up what? That remains to be seen . . . heh heh heh 

DYNO RESULTS OF MY CUSTOM HEADER!

I spent this evening using the power of the interwebs to remotely dyno tune the car that has my custom header. This was the first time I had done this. It was exciting and annoying at the same time. I couldn't see everything in exactly real time, but, it was a huge step up from just getting a datalog file sent via email. I could see where the engine was in the timing and fuel maps in semi-real-time. This was a huge help to get my brain wrapped around what needed to be changed. At the end of the evening, we ended up extracting over 10WHP on an already potent package that had been tuned via feedback and datalog. Given my familiarity with this engine, the final timing curve was only off from my guess by at most 2* at WOT.

Here is what I can say about the engine:
It is a DOHC D-series. It has my custom header on it. (See THIS LINK for more info, and also search around for more pics of the thing and design theory.) I tuned it. The engine has more power to gain, especially if it is revved higher. The engine is extremely easy to tune with no stupid peaks, no issues. The AFRs are extremely consistent and it pulls very cleanly through the RPM.

Rather than focus on the numbers, look at how darned flat the torque curve is and how close to linear the power curve is:

YES it is a crappy copy. No, I can't an won't post more of the chart. 

The scaling of the torque curve is also wrong, due to an issue with the dyno coming out of sync with the RPM. The dyno computer thought the car was revving to 9200RPM when the team was doing pulls from 2500-7500ish RPM.

Also, this was done on a Dyno Dynamics dynamometer. I mention that for the people who know about them. Those that don't and obsess about numbers, you can make fun of the WHP, but I will take this as a huge validation of the general design of my own headers. I will take feedback from this team and improve on what I can do and make things better than before. 

I have been smiling with this success the whole evening, eager to share the results with people who have known about this project, and now I share with you!