Daily Archives: July 20, 2022

Still thinking (it’s safe, no need to seek shelter)

I’ve been thinking of how I could build this intake manifold with the tools and materials I have access to here at Casa de El Poeta without having to purchase anything beyond the cloth and resin and molding materials like peel ply and mold release. I’m not coming up with much.

Part of the problem is making the molds for the runners that need to be used 8 times to build each manifold, probably more because some of the early parts probably won’t unmold without damage to either the part or the mold. One thing I have been thinking about is using 4 molds per runner and building the runner in 2 parts and then using the tape that will make the runners strong enough to support the plenums, throttle bodies, and the fuel rail and injectors, to also glue the halves together. I don’t have to be concerned about the surface finish of anything because the peel ply will give a textured finish as long as the molds aren’t too bad.

And as I was “rubber ducking” this into the blog post, I came up with a solution for building the outer mold for the runner by using the inner mold as a plug and using the sanding and polishing process on the inside surface of the outer mold to get the clearance between the inside and outside for the material to go. This will also ensure a high degree of compression in the composite. How to rubber duck a problem. If I had the vacuum pump that most composite molding systems use to remove air from the mold and part to use atmospheric pressure to force resin into the part and force excess resin out of the part I would not need the inner part of the mold, but by using an inner and outer mold I can get much higher pressure on the composite to distribute and squeeze out the resin to a much higher degree. Basically I can clamp the two parts of the mold together at much higher pressures than the roughly 15 psi I can get with a “perfect” vacuum. This is part of the “forged carbon” process that uses bits of carbon tow and chopped fiber much like the “chopper gun” method of making fiberglass parts, but with much less resin in the part.

I have been searching the web and the consensus seems to be that just about any resin that resists gas will work because of the limited exposure from the spray of fuel from the injector compared to the 24/7 soaking of fuel tanks. Basically any of the hard-curing gas tank liners will work for this application, but I will have to paint the finished part with a UV-resistant coating to sunscreen the resins and prevent UV degradation. I see this as a minimally problematic solution. Basically I will have to paint the manifold white after curing, instead of leaving the part natural. I won’t have the “cool” factor of a natural CF part finish, but the part will remain strong for a longer period of time, talking decades of use, compared to a couple of years without the sunscreen coating.

I’m still thinking about how to make the plenum, and whether to mold in the injector bungs or glue in aluminum bungs after molding the plenum. Molding has the potential to reduce the weight by a few ounces, but gluing the bungs has a higher degree of precision fit. Not to mention that molding the bungs requires a high degree of precision of the inner mold that I probably won’t get with what I have to work with. And I’m getting hungry and I need to make food to consume so I have to be away from the computer while I cook the food. It’s not so hot that I’m going to cook. It’s only 103°F and human flesh starts cooking at 145°.

Finally got Mrs. the Poet to go to the doctor

Since I haven’t been keeping you in the loop, Mrs. the Poet has been sick. Like not real sick, just kinda poopy and listless, and borderline dehydrated but even water tastes yucky. Well they don’t think she’s gonna die and her symptoms don’t come close to COVID, so that’s been ruled out. She has a mild fever, and I’m still as healthy as a horse, so at most she has some kind of allergy with maybe an opportunistic infection on top of that so the prescribed anti-nausea, anti-diarrheal, and something for the infection they aren’t sure she has but are pretty sure she might have. Like I said her whole diagnosis pivots on the point that I sleep with her and kiss her and I’m not showing any sign of her illness. I eat just about anything with no stomach problems even though I can barely chew because I don’t have many teeth. So whatever she has is presumed to not be communicable. So if she improves enough to travel she’s not going to be a plague rat spreading disease, either. Personally, I think she has allergies because her nose is also running and some of it is post-nasal drip down the back of her throat. This is probably the source of her digestive woes.

I finally got something to use to function test the lights I got, and I’m Not Happy with the results. The turn signal lights work as expected, low until the high is activated so I’ll just leave the low on all the time as DRL and connect the high to the turn signals. The headlights are a bigger problem, half don’t work at all and the other ones only have high beams. And the warrantee has expired on the headlights. So I’m at an impasse for my lights right now, and also I’m not 100% on those test leads working all the time or that I have the polarity right on the power supply output.

Late addendum: Mrs. the Poet has had 2 servings of applesauce since noon and everything is still where it’s supposed to be, no unfortunate discharges.