Has anyone here ever done such a thing? They do exist mainly for tuner cars though I've read some pretty interesting things about molds that are water soluble(will dissolve in water) Yeah, I'm dreaming here. You could create a 18 Degree Tpi Type intake with runners between 9" and 11". If you made the plenum a little wider and angled the runner slightly with a sharper turn, in conjuction with a high/closer parallel angle injector bung so the rails would clear the sharper runner turn. The 18 degree heads have a shorter intake runner than the 23s anyway.

Anyone up for some pottery?

 

What can you do with a water soluble mold that you cant' do with a dissolvable plug sand casting?

 

probably easier to make in your garage than a sand casting

 

The dissolving stuff can be shaped, fine tuned like silly putty if you will. Sand wouldn't be a good plug for carbon fiber aka high strength fiberglass. The mold would have to be smooth and coated with release agent. Has anyone tried such a thing?

 

I was implying that in an industrial sense it does not allow for more extreme shapes than one could get casting aluminum. I can't name one off hand but there are plenty of petroleum based clay agents out there that melt above the cure temperature, but not above the breakdown temperature of high temp epoxy resins.

 

Its possible. And it can be done. Why hasnt it been done yet? Carbon Fiber work is a PITA, and its expensive. And the mold is the easy part, if youre only making one part.

Also, making a TPI intake, with all the bends and turns and flanges would be very hard. Its not like the straight shot of most inline 4 cyl. engines. A cover would be alot easier. Alot of parts claiming to be "real carbon fiber" are mostley either fiberglass with a layer of CF, or a plastic/CF or fiberglass/CF hybrid.

 

It's not fiberglass; fiberglass is is material made from extremely fine fibers of glass. Where as carbon fiber is material consisting of extremely thin fibers about 0.005–0.010 mm in diameter and composed mostly of carbon atoms. Also if you can mock one up out of whatever you have I can make you one.

 

You meant intake runners for a tpi set up with what it takes to make those you need alot of equipment and alot of money. Also, you really have to know what your doing. I asked a guy at elan technologies how long it took to make the one for their they said they had a few hundred hours in it.

 

Matt,

Do you think an LSX style is possible with an upper and lower with internal tubes? I could use PVC and carve out the rest as a mold.

 

I looked into making a carbon fiber cold air intake for my Trans Am. The price was around $300 and I believe I would have to make the mold. Doing an Intake manifold would be another ballgame. Can't imagine what that would cost.

 

I know it's not fiberglass but the mat is almost identical to fiberglass. If you formed a mold you could wet it with resin and lay down the fiber with a paint brush, then thicken it up. Let it cure and you're done, dissolve the mold.

 

You can lay on carbon fiber in wet lay up but it is only in cunstruction. You need to use pre preg carbon fiber. With pre preg it has to be put in an autoclave to make the part.

 

Its really not that easy. We are making simple instrument shrouds at work. A simple thing really, and its a PITA. The resin was melting the styrofoam, and deforming the part. So we went with a slower cure time resin, and had to move the mold into a climate controlled office over the weekend. And it still melted the mold, not to a point that the part deformed, but enough to make the mold unusable next time. You wont want any deformation in an intake runner. And we have thousands of dollars in equipment, resin and weaves including research, and testing in this thing, and its only our second one. We have a scrap one that was cut wrong, and we probably have $3k in it. And we still cant get the outside to look like we want. Remember, with fiberglass, you are going to paint it, so touch ups, and filler work wont show. The reason you use carbon fiber in most cases is for looks. It has to be right, when it comes out of the mold. Seams, edges, and any mating surfaces can have a little work done, but it will show.

Im sure there is a foam of some sort that can be sculpted into a complex shape, then dissolved out. And if you are just hell bent on making one, do it. Its not impossibl, and I think it would be cool as hell. Its going to cost alot more than you think, and if you get it right the first time, Ill be suprised.

 

If you have alot of money to put in it you could cut one out of this stuff that is like body filler, but you make it into a block put it in a fives axis machine and cut it out. And pull a mold off, and lay carbon in that.

 

Yep. But what does time on a 5 axis machine cost? Ive recently been quoted, for just a 3 axis, about $45 an hour. Thats with me providing the CAD, and all the engineering for the part. And billable time started when he started transferring my numbers into a program for his machine.

I know its possible. There are guys making full bodies, fender, bumpers and hoods. I want a custom hood. But from a cost perspective, its not worth it. But if you have the money to buy time on a 5 axis, and pay an engineer to make the models, then money isnt going to stop you. Just dont be suprised if that manifold costs you more than the rest of the car.

 

You only need pre peg and an autoclave if you want the true strength and weight of CF.

While I agree honeycomb/pre peg/etc are are great cores for structure pieces seem for what he wants to do Its not needed.

To the OP :

Good link if you want to learn alot about making one off custom parts
http://forums.corral.net/forums/showthread.php?t=660756

 

$45 an hour is actually a really good price for a 3-axis. Around here it starts closer to $70/hr, although that is at shops with several military certifications. They have a pile of 5-axis machines there, but I've never asked what they cost to use. They are several times larger than a 3-axis machine with a comparable working area, and it wouldn't surprise me if the cost is on a similar scale.
Drummerdad, in my experience with resin and foams there are two causes for the foam to be eaten: cure heat and chemical incompatibility. If it is a chemical incompatibility issue then the slower cure resin will make the issue worse. However, adding a few layers of glass to the mold usually fixes the issue, and increases the mold life.

 

Thats the point I'm trying to make, if it isn't on the market their is prob the reason why and that is cost.

 

When I go back to school in a few weeks I'll take a picture of the intake for the panoz P1 car from the american la mans series.