CARBON FIBER OR COMPOSITE INTAKES! WHY NOT?

C

cameljockey

Well-known member
I did a cursory search for this subject in this part of the forum and saw that it hadn't been discussed (i.e. I searched for the words carbon fiber and nothing related to intakes came up if there is a post please share it here :) )
I haven't posted in a while so some inquiry for the sake of it will be refreshing :)
so:
Why or why not?
What benefits?
What Disadvantages

In my mind the benefits are:
1. good insulation from engine heat (composites are usually terrible conductors) (a heat shield would not be difficult to fab if you were concerned about fires or melting no?)
2. make ANY shape you want for relatively cheap and just add layers where you need EXTRA STRENGTH or Sealing surface and you could fit into tighter spaces if you needed the extra volume.
3. they're REALLY LIGHT! (well they are! :P )
4. they look WICKED COOL!

I wanna know the difficulties in Fabrication / Application For simplicity's sake let us limit the discussion to one particular composite say..... Carbon Fiber if we feel we can answer an issue with carbon fiber by using a different composite we can bring it up then

Keep Sixin'

Dan
 
With a non-crossflow I6 head, the intake runners would be snuggled between the extremely hot exhaust runners and I doubt a sufficient heat shield could be made. I would not predict a long and happy life
 
8) composite intakes are good in that they are light weight, and dont transfer heat to the intake charge. on the other hand though they are not as strong in terms of wear resistance as aluminum is. ford used a composite intake on the 4.6l V8 and they have issue with the alternator mount breaking on those engines.
 
Aye but isn't Ford's mod motor intake like injection molded? or is it a fiber composite layup? if it was fiber it would not break as easily IIRC the failure was a fatigue and creep where as failures in fiber layups are typically de-laminations.
 
The carbon fiber stuff doesn't bend very well, it breaks.
I suspect the alternator mounting points would be subject to high transient shock loads, whereas a typical manifold would not.
 
Just my thoughts,...Have to insure the resin could withstand long term exposure to gasoline.Could wrap the exhaust with that cloth heat shield material. What about the texture on the INSIDE of the manifold?Rough cast works pretty well for 'wicking' any gas that falls out of suspension, and tries to pool in the intake.What the inner surface of your carbon fiber intake is like would be pretty important.Maybe slice it in 1/2, so you could go in and texture the inside, OR, cast it in 2 halves, so you can use a mold to give you the texture you want, then laminate the 2 halves together?Jim
 
More thoughts. What kind of engine/ intake were you thinking of this for? What I'm getting at is, HOW are you going to make it. Have to form the carbon fiber/resin on or around something.Seems to me like you would have to cast 2 pieces, and then join them together.Could make a great way to experiment with different inside surfaces.Stock uses unsurfaced cast, cause its a bugger to get in there, and the rough surface works 'well enough'. If you made it in 2 pieces, you could make several. Carbon fibers expensive, but wouldn't need THAT much for an intake. Then you would have everything exactly the same, except you could put different finishes on the inside. Paint inside with a thin layer of resin, then coarse sand; similar to cast surface. Cut shallow closely spaced grooves, to promote boundary layer.Maybe a kind of 'pebbled' surface, larger than coarse sand?Anything else you can think of. Try each out and see what works best. Jim
 
so I haven't quite wrapped my head around the design just yet I imagined a light weight aluminum base that brings all the runners into a plate that would provide a good sealing surface and you could finish it any way you wanted to achieve the flow characteristics you wished. The Plenum then would be a simpler affair smooth on the inside to provide laminar flow all the way from the front to the back and would bolt or clamp down to the base. I understand this Idea is similar to a posting that Mike has made in the past but I would have no baffling inside to even out the flow and secondly I am only posing the question to see how one would go about making their own intake for the Classic Inlines head or any Aussie 250 ford head in general. But I also think the concepts would be applicable to any engine configuration even V-shaped engine configurations :)

The sealing surface would have to be as "simple" as possible so as to make for a good seal especially if one were to consider using this for a boosted application...

In a fuel injected application (assuming multi-point here) the injectors would be mounted either to the head (like tin the case of the CI Al head) or to the aluminum base of the intake thereby keeping fuel far enough away from the composite. but if there are resins that can withstand exhaust heat shouldn't that same resin be able to resist chemistry (I am not a chemist I got a C in Highskool chem and a C in college chem I HATE CHEMISTRY)

Long story short yes two halves would be the most practical but the complication of making runners out of composite is IMHO beyond the capability of the shade tree mechanic and so I propose casting, machining, or welding up and aluminum base to bring all the runners to a plate and laying up a plenum of any desired shape and volume that best suits your application.
 
was on the ENDINE site the other day, (they sell hi $- Hi perf. stuff), and they list a carbon fiber intake, so its certainly possible. I'm getting ready to start working with fiberglas and carbon fiber, right now. My first time, repairing the body; fender and roof.Did a little reading up on it, on the I-net, in preperation.Was just sharing my first thoughts.Could be real hot ticket.Yeah, I'm not too hot on chemistry, and even less so on aerodynamics, like "laminar flow". My eyes start glazing over, whenever I try to educate myself.
I was thinking take an existing manifold, like a Clifford for the vintage inlines, (cause thats what I have). Use it to make a 2 part mold.Then make it in carbon fiber.Would require some research, but seems doable. Carbon fibers expensive, but not talking a lot of material for an intake. And, it seems very amenable to back yard fabrication. Jim
 
Every CF intake I have heard of or seen has been dry flow, meaning direct port EFI. I haven't studied the thermal capacities of CF, but it is inherently flame proof and extremely stable, meaning little expansion and contraction due to temp change. I'd suspect it would survive pretty well on a common L6 as a direct EFI as long as peripheral components (throttle body, sensors, etc:) are supported independently of the intake. CF doesn't take structural load very well.

I don't know the porosity of CF, but would suspect it would not be advisable in a wet flow configuration unless you could eliminate the possibility of fuel puddling. That elimination seems difficult with the lateral port entry of the head.

Could be a great way to insure the coolest possible intake charge.

I have seen a user built, fiberglass, dual carb, tunnel ram intake on a BBF before. :shock: The builder swore no problems using the fiberglass in the (at the time) 2 years of use. This was also a trailer queen and occasional drag racer. I doubt it ever saw a real world temp cycle and certainly not everyday stress.
 
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