intake manifold design?
 

Lately I have been toying with the idea of making a plastic, large plenium intake manifold.

I got the idea down at my buddys machine shop and they were making parts out of ABS black plastic and this other stuff that had strands of fiberglass in it that was even better. I wanna design and test a manifold using this type of material because its been proven to work on many stock vehicles, but for those that dont know plastic and composites will dissapate the heat and not absorb the heat from the head as much as an aluminum manifold will.. if anyone is familiar with the hondata intake manifold gasket these use the same principal

I Have plans of turbo and the only fear with a plastic manifold and turbocharging is that when the manifold heats up and is under boost it will balloon, to solve this problem i have the proposed idea od layering a single layer of carbon fibre over the whole thing, not enough to make the manifold retain any large amount of heat, but enough to hopefully keep the manifold from balooning, of course i would have to use a high heat epoxy when i impgrenate the carbon and what not but i will figure those details out when i actually start purchessing materials

I drew up some pictures of a design i made for it on Rhino 3D, dont mind the randon square thing in the picture, it just showed up when i renenderd the photo

Whats everyone think about this idea? pros? cons?

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Re: intake manifold design?
 

you should make it with velocity stacks in the plenum for each runner. Hmm this might work except i would make sure the plastic will withstand probably at least 250 degrees? Maybe more? Underhood temps can get pretty hot, especially on a boosted car. You also have to make sure the flanges will be thick enough not to crack and seal evenly, and plus youll have to find a way to mount injectors and the throttle body. Sounds like a lot of work but i think itd be pretty cool if you tried this. Any particular engine you wanna try this on?

Re: intake manifold design?
 

the other thing to consider is how it will affect intake temps... it could end up dissipating heat worse than aluminum. i wouldnt know either way but its something to look into.

Re: intake manifold design?
 

The LS1 uses a plastic intake manifold. I think if you added some velocity stacks, that ---- would be hot.

Re: intake manifold design?
 

yeah I'm working on changing teh plenium design a bit right now so i will take a thick wall pipe cut a side channel out of one side and use flat 3/4 inch thick and machine the holes for each runner, maybe add velocity stacks and what not

I am not sure but I have heard around the machine shop that this stuff i'm looking at is rated full structural integrity to 295 degrees, more than enough, especially since from what i have researched an aluminum intake manifold on a boosted engine runs anywhere from 150 degrees to 200

For the head flange part I am planning on hacking off a stock manifold, weld on some short aluminum pipes just long snough to clear the injectors before having some type of mating between teh plastic composite and the aluminum

also i have heard that heat wont transfer from teh head to the intake as much through plastic as it does with aluminum, hence the concept of hondata's headgasket? correct me i'f i'm wrong here, I am open to any sudjestions

My test engine I want to run it on is the b18 i'm building for my 95 sedan, turbo'd...... but this motor wont be in teh car untill middle of next winter, I think I may run it on the stock D for testing and use what i learn from that to creat a better bulletproof manifold for teh B

Anybody have any other concerns or comments on this project, I expect at least a little flamming from the quality personalitys at HMT ;) but honestly any sudjestions to connect the plastic composite to the aluminum would be prime, I have figured JB weld and window weld may be solutions but I'm sure someone has a genious idea of how i could do it

Re: intake manifold design?
 

yeah the plastic intake manifold will conduct FAR less heat than an aluminum one will. 295 degrees should work fine. The hondata intake gasket is designed to prevent the head from heating up the intake manifold from the heat transfer. Velocity stacks i think will help alot

Re: intake manifold design?
 

Get Minor Threat to post up the links I gave him in re thermoplastic welding/forming/deformation temps/chemical resistance. If you use any old plastic laying around chances are it will come apart on you.

Re: intake manifold design?
 

If it wasn't Good Friday tomorrow, I would be at Homeboy Depot buying ABS pipe..

Re: intake manifold design?
 

WTF does good friday have to do with you not going to home depot????

Re: intake manifold design?
 

Everything around here is closed, it's a holiday.