Intake manifold construction

[MysticZ]

Sean W Walsh wrote:
> 
> Can anyone give me a reason why I shouldn't construct an intake manifold using
> Glass Reinforced Plastics?
> 
> I have an older 4 cyl lancia engine with a dual throat single carby and 4 branch
> manifold. I'm converting this to EFI and want to create a port injection rampipe
> style intake with a small plenium etc. GRP lends itself to "backyard" techniques
> and since I have a bit of experience with boat construction I thought I'd give
> it a go myself rather than getting something fabricated.
> 
> What are the problems I'm likely to face : different temperature expansion rates
> of the inlet manifold (grp) and the head (alloy)?  fatigue from vibration? high
> temperatures breaking down the epoxy?  I know there are epoxy resins available
> that are rated to 150 degrees celsius so that should be enough (?) any other
> suggestions?

Yup. I use high temp epoxy resin for making carbon and kevlar exhaust
cans for bikes. One of these days I'll get around to making a carbon
header, too. Remember that you have to eliminate ALL porosity in the
layup or bad things happen. Best way to do it would probably be to carve
a foam plug to the shape of the inside of the ports, then attach that to
a very, very flat plate to form the flange that will attach to the head.
Might also be good to machine a 1/4" thick flange with bolt holes and
ports and actually bond it into the manifold. Same applies at the
throttle body end of the manifold. Vibration is a bad thing, so I would
make sure to support it at the end with brackets if it's very long.
-- 
Steve
97 Chevy Camaro Z28, Mystic teal, A4, not stock
90 Kawasaki EX500A4, black, M6, not even CLOSE to stock!
lt1_z28 at ev1.net  http://users.ev1.net/~lt1_z28
Aluminum, steel, carbon fiber, titanium, and two cast iron balls.
McMillan Motorsports- http://www.mmsbikes.com
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