Jerry Feather

Thanks Martin. I hope I have the post op instructions worked up into a usable format for now and will find out more next thursday at my first post-op session with the surgeon.

Jerry Feather

I had taken the previous mock-up apart and then started putting it back together more accurately. It looks like it is all going to fit as I intend. I have most of it back together and have the pattern pieces clamped in place. When I can figure out how to get it off the assembly stand I'll be able to make another pattern from what I have so far then use that for cutting holes in the final pieces of the plenum.

I also have a piece of 5 inch irrigation tube to use part of for the MAF tunnel at the bottom rear of the plenum. I'll need to figure just where to put it, but I can get it as high under the rear runners as three inches above the plenum base.

UpFixenDerPorsche

Wow Jerry - brilliant work.
(been out of circulation for a couple of months with health issues and on my return I find this).
Obviously very keen to see the working result.

Cheers
Upfixen

Jerry Feather

Hi Upfixen. Sorry to hear that you too have been under the weather, or, since your are "down under" already, does that put you above the weather? (Actually I don't know what it is that puts us at the top and you at the bottom.) Anyway, it is good that you must be on the mend.

There is way too much in this thread about my own health issues but they are improving also.

I am able to spend a few short periods of time on my feet out in the shop, and yesterday I changed the manner of holding some of the plenum patterning pieces together so I can take them off the mock-up and try to use them to make another one piece pattern for the tube holes on each side.

These fasteners I am using are called Clecos. Some are called side-grip and some are used by drilling a hole and slipping them through before releasing the spring pressure that holds them in place. The ones through the holes are much more accurate since they both squeeze the material together and hold it in shear.

Jerry Feather

I started making another pattern off the first. Here is a picture or two of my MAF tunnel.

Jerry Feather

I had measured and determined that I could make the MAF tunnel about 9 inches long, so I made it 10. Then I measured and found that at 3 inches tall it would fit under the runners, except that that is with the runners without the bell-mouths. So I am gong to go out and cut another one out of what was left from the first one cut and make it 2.5 inches tall and maybe even 11 inches long and that will be long enough to allow me to move it in and out to gain the clearances I will want without cutting off parts of any of the bell-mouths. Here I go.

UpFixenDerPorsche

Hey Jerry.

Sorry to hear that you've been in hospital as well. :-(

They certainly are clever little clamps. Couldn't work out what they were at first.

Re the bellmouths: I wouldn't be concerned about trimming the bellmouth where it meets the MAF tunnel, as the MAF tunnel 'roof' will take its place. Although it's not bellmouth shaped, it's 95% as good as over that short distance.

Will be back later Jerry. Not a lot of energy at the moment.

Cheers

John C.

Jerry Feather

Upfixen, that is a good thought. Actually I am not too sure where my MAF is going to want to end up so having some choices is good. I went ahead and cut another one 2 1/2 in tall and a bit longer; now either one can be reshaped quite a bit to fill the need.

I suspect that I am going to wait until I build the engine and put it in the modified car before I will be able to do much with the redesign of the filter air box. But, I did want to get the intake finished now so I can get it out of the way and start on some of the major body work.

My next major task is to try to refine my aluminum welding skills since that too is going to come in very handy when I get to the body work. I found my bag of aluminum scraps that I was intending to take to the recycle place, so now I have lots of pieces to practice on.

UpFixenDerPorsche

My account is in the post Jerry.

Jerry Feather

I took the clamped-together pattern off one side and then transferred the hole pattern locations to a single piece of sheet aluminum cut to the approximate size and shape of the part of the plenum side where they need to be and then cut them out in the mill with a small fly-cutter. Then I finished each one with a file until it would make a tight or snug fit onto the plenum base and with the tube runners through it in their near finished locations.

That took quite a bit of time, so it was a two or three part project with some rest off my feet in between. It came out much more accurate than I expected it would; so I think it is going to be very useful to locate the holes on the pre-formed sides of the finished plenum. I'll do the other side in the next day or two and then try to refine the locations on the finished pieces.

Jerry Feather

What I did first thing this morning was to take the multi-piece pattern off the B through H side of the intake and then use it as the pattern for the single piece pattern of the tube holes for that side of the plenum. I first did the front and back and then after resting for a while I did the middle two holes. I now have that pattern complete and clamped up on the assembly stand with the tubes in place. The pattern holes are getting more accurate as I go so I hope that when I transfer this pattern to the finished sides on the plenum they will be very close and tight enough to get clean looking welds.

I also remade the little welding mandrel I had made for the welder to use to line up the tube runner bellmouths with the tubes. The original one I made I had made out of tubing which is all I had handy but it is too thin and he had to beat it to death to get it out after the aluminum shrunk onto it. I made the new one out of a chunk of stainless bar that I found on eBay and I think that will work much better both since it will soak up more of the heat but also I'll make a little wooden rack that he can use to simply drop it on the bench top and have the mandrel fall out. Or, if I get to work on my own welding skills I'll be doing it myself.

Jerry Feather

I know that this thread, and my small project part of it, seems to have slipped into the past, but I haven't abandoned it at this point. Life, and now a death in the family, just seems to be getting in the way of most of my 928 stuff. I have been able to fab and ship some of my plastic parts, but dealing with the rest has held me up in working on my TIG welding and the rest of this fab. Don't give up on me on this one.

UpFixenDerPorsche

I understand only too well Jerry. Have wondered how your health issues were going. Sorry to hear of the death in your family. My condolences.

Best Wishes.
John C.

dr bob

Hi Jerry--

Sorry to hear about the death in the family. Just a reminder that family always comes first, and that the fun project pieces will be waiting patiently when your attention is again available.

----

I'm fascinated by the amount of pictures you are sharing, and hope that others get an idea of the amount of thought and then work that goes into a project like this.

As far as working on your TIG welding skills for the aluminum, can I gently suggest that you learn on something that has a lot less prep and fab time upstream of the welding? Like any skill, welding aluminum looks like something easy when you watch the folks who are good at it. Like driving at 11/10 or landing a helicopter without that annoying sound of rending metal, it looks easy until you try it yourself. I can't tell you how many melt-throughs and blowouts I managed as I was trying to just learn to join two plates. That was with an excellent teacher talking me through the process, with a good water-cooled torch. Learn on scrap pieces, working your way up to the various combinations of shapes and positions. Soft-drink cans are good fodder. Learning on production pieces will frustrate you as you damage and try to recover from mistakes as you learn.

Don't overlook that there are plenty of amazing UV-cure adhesives that can replace welding in these applications. Using adhesives solves a lot of warping issues during fabrication, saves from having to do stress-relief and Blanchard grinding on flange faces so pieces will mate with the heads, for instance. No need for gas purge during fabrication. It takes a little adjustment in design to make all the connections adhesive-friendly, but in the end it can dramatically ease a lot of challenges that welding brings to the process. Stupid stuff like how to get the end of the TIG torch into those tight corners suddenly go away too.

John Speake

I am in awe of your persistence with this great project ! Keep up the good work when other commitments are satisfied.

I really enjoy you excellent progress reports.