CENTERMOUNT FAN SHROUD DUCTING INSERT

[VolksRodT]

FJCamper, PM sent.
Thanks.
Marcus...

[VolksRodT]

W/o trying to be particularly rude, how can I get FJCamper to respond? Appreciate all his informative threads n info, (gotta re-read 'em again, before asking Q's) & know he's really busy, but tried pm's in dec, posted here in jan & now. Want to buy a ctr-mount fan shroud duct insert, for a project, while I have a couple of bucks yet. If it's NLA, or there is another issue, that's ok, just want to know. Gotta know where to send coin if avail. Thread said PM. No luck yet. Help? TIA. Marcus...

[FJCamper]

Hi Marcus,

I apologize for not responding, but my work on government ID systems keeps me crazy busy. I don't have the time to appease or fight the mfg's of the shrouds. The plastics company no longer wants to make one or two at a time, as they are very labor intensive due to the arcing and securing of the internal vanes and guides in assembly.

The actual demand, including yours, for the center mount was so low (not even a full dozen) and the maker's price so high that we couldn't even get a minimum order of 25 guaranteed. The ones I had made I sold on to guys at costs. No complaints so far. And I wasn't about to take someone's payment in advance. We're a race shop, not a retailer or manufacturer.

This led me to develop an all plastic 36hp style fan housing, using the same vanes and venting design as the center-mount. The prototypes survives our on-track heat and vibration tests, but my efforts to get these made met the same result. Then the makers raised the price and would not agree to assembly, just material template cutting. The vanes have to be curved and precisely bonded to the interior, and that's too much hand labor for them.

I am now trying 3D printing to see if I can get the strength and thermal properties as before. It certainly makes the vanes easier.

FJC

[Ol'fogasaurus]

Interesting FJC!

Sounds like some of the same things we ran into where I worked. Some of the designs (of necessity) were of such small quantities that while we eventually did get what we wanted/needed the cost was proportional; aka $$$$. Labor, rightly so, can get expensive even when the cost of material needed wasn't that high, when dealing with small quantities. That doesn't even deal with the confusion that sometimes arises in some of these circumstances .

Lee

[VolksRodT]

Thanks for the reply, FJC. I get it. Was too late on the 1st run, because I didn't have the shroud n alt stand. Do now. Would you be interested/willing to sell a copy of the patterns to make the vanes & correct arcs & location(s) (sorta like a one-shot license deal?) for personal use - if the 3D printing deal doesn't work/falls thru? Just need one, don't want to produce, nor steal/copy your work. Willing to cut/bend/bond plastic or alum, my time = $0.00 for the fun part of the "hobby". (Love "adding lightness..."). This is a kinda long-term parts acquisition for a squishy mill. I like acvw, & having found the squishy (Endyn)tech, + was amazed at all the now-available stuff to get stupid power out of these acvw's, so eventually it goes into a VolksRodT (circa '67 R&C style). Hoping to scare myself silly - which might not take all that much in one of these... . 40+ years waiting... Please pencil me in on the list, I can wait for awhile. Hope I can afford it then. Also, if you do find a few minutes, check the PMs? If you can help, I'd appreciate it. If not, that's cool, I get it. TIA. Marcus...

[Piledriver]

I gave up on ordering the centermount due to cb not apparently making the required housing anymore, despite still listing it last time I looked.

[doc]

So this is disappointing news. Hope the project goes on. Please add my name to the purchase list if it helps at all.

[ProctorSilex]

I didn't jump on because all my VW plans are currently stymied. Even so, I'd buy one if there's likely to only be one run.

[Piledriver]

if this needs to be supplied as a kit that requires some assembly, I'm personally fine with that...
'm really good at following directions, and even better at figuring it out when none exist.

[dragvw2180]

That makes two of us .

[doc]

Sooooo - FJC - back to work!

[FJCamper]

The previous mfg cut everything from flat high-temp ABS stock on a big CNC machine you could lay a sheet of plywood down on.

The machine engraved in the slots for the vanes on the front and back outside panels, which were cut with the alternator holes. The actual assembly was to apply a special plastic welding glue to the engraved slots on the back outside panel, and hand-insert the bendable vanes in the slots, holding each one in place as the glue set. Then the front outer panel (also engraved) was glued to the vanes, to seal it up. A major "vane" that was actually the top cover was glued in place last.

It took two people an hour to assemble one fan housing once they knew what they were doing. Bending the vanes and holding them in place as they set is the struggle. The engraved slots are not deep.

My initial doubts was would the thermal ABS stand up to the heat off the cylinders, would the vanes warp, etc. Would the glue hold, whatever. But It all worked. My own insert has been through six events with no problems. The cooling is as good if not better (and I think better) than a steel fan housing.

The maker was proud of the durability, and told me he could make a fan housing that was not an insert. That's where the 36hp housing came from. And it worked. I can now say an-all plastic center-mount housing is possible.

Coming at this from a kit might change things. The only thing that might be tricky is the special glue. It's not hardware store grade stuff.

A kit might allow some design changes, such as small metal internal L-brackets to assist in assembly. I'll talk to the plastics guy soon.

FJC

[VolksRodT]

Hey, FJC;
I was also thinking (read: uh-oh...) that it may not be (as) hard to make the vanes out of Al strips(for an AL shroud), put ~ 1/2" lip on each side(like a 'Z' viewed from the side), & use a stretcher/shrinker to form the curves. Could use auto-body bonding glue, pop-rivets(which I hate), or hand hammered rivets(might be a challenge, but look oh-so-good), or as a gluten-for-punishment - use the MuggyWeld Al sticks. Would still need accurate pattern(full-size line drawing?) of curves, n placement of vanes in shroud in relation to fan. The plastic kit would be nice. I think I'd spend a little time to make wood (mdf?) patterns of the curves, & use cut-outs to hold/clamp the vanes in place while glue sets. Take longer, but wouldn't have to stand there the whole time &/or need those extra hands (which is just barely possible that the wife *may* not be happy about lending... ). However you come up w/a kit, I'll be happy, since like an idiot, I got the shroud n stand 1st. ;( . Actually ended up w/2 slightly different shrouds, one should work - somehow. Since I've also been thinking(uh-oh again...), I know you don't want to mfgr, maybe either I or someone might be willing to do a small run. Looking forward to what you figure out. Marcus...

[Piledriver]

Duro Plastic Welder is available everywhere, under a variety of brands (but all named plastic welder)
The consumer version is only raated for 200F, but the commercial stuff goes higher...

Its a methacrylic ester baed two part super adhesive, sticks to almost anything, has a small amount of flex, and has proven to be far more durable than jb weld, mostly do tio that tiny bit of flex///as to the aluminum vanes--- That would work if the vanes are flat sheet. I suspect a few are not.

[dragvw2180]

I used to weld plastic on my cracked snowmobile gas tanks and never had a failure , that was 30 years ago. I would suspect that if there are slots that the vanes are inserted into that they could be plastic welded .