Fiberglass inlet manifold

[kingmick]

Yeah, but I'd wind up piling stuff on it, then it would get turned on and bad things would happen....

Bear in mind that I only do fiberglass work every few years - it takes me that long to forget how much I hate the stuff

heat gun or a bar heater! in winter we use a couple of bar heaters if im doing a bit of cold layup stuff. lol same as respraying 2 pak at 4am on a 1deg winter morning, because my driver wrote the car off and we rebuilt it overnight. hahaha a deep blue and it didnt go milky, but i left finger prints in it 4 hours later right before warmup!lol

[Ben Wilson]

Urgh - I can remember chasing epoxy around with a heat gun on a kevlar underbody protection panel because it was so cold the expoy wouldn't flow through the weave nicely. Canberra winters are pretty special

I might give the part a run in the patented "large cardboard box and a fan heater" oven to get the paint to set - I've seen temps over 80 degrees in there...

[takai]

Haha, yeah i remember that setup. I ended up using a similar one to do my cam covers last year.

[kingmick]

could go high tech and line the heater box with tin foil !lol

[Ben Wilson]

OK - The design.

As I can build pretty much anything here, there are a lot of possibilities going through my mind. I'm thinking about an oval plenum ending around 100mm from the end of the inlet runners with a central inlet between 2&3 facing back over the rocker cover (similar to my current steel one).

Any other suggestions?

[takai]

Since you can basically do rapid prototyping it would be interesting to see a taper at either end, over the 1 and 4 cyls. Theoretically the pressure wave reflections should push more air into those cyls preventing starvation.
At least that is what Helmholtz resonance modelling gave me when i modelled up my plenum designs.

[Ben Wilson]

OK - I finished the plug for the inlet runners off over the weekend (servicing at a rally gives you heaps of time for colour sanding). Hopefully next weekend, I'll get the parts I need to start on the fiberglass next weekend.

[Ben Wilson]

Having given it some serious consideration, I've decided that fiberglass is the devils work and I never want to speak of it again.

(yes it went that horribly wrong )

[ed]

so what happened? can we learn from your 'mistakes'

[Ben Wilson]

I was using a fine woven cloth, and apparently it was a bit too stiff to wrap around the trumpets nicely, the epoxy wasn't sticky enough to hold it in place and it kept lifting off and trapping air bubbles underneath.

The cloth was also fine enough that once it was wet with epoxy, I couldn't work the air bubbles through the surface. I think a fine chopped strand would have worked better for at least the first couple of layers, but as the shed is now showered with plaster dust and epoxy (I got that 'irritated' with it), it might be a while before I'm willing to try again.

[ed]

yeah, chopped mat wouldve been way better

what material did you make the plug out of?

[oldcorollas]

you could try with a more drapable fabric...
some fabric is not drapable at all and sucks even for simple curves.. some (like F1 carbon) can do very complex curves.....
sticky shit can be so frustrating.....

[Robbos_Toyotas]

I just yesterday bought a 95 AMG (mercedes HSV) and it has like a carbon fibre intake manifold...very tidy and light....something to look into...

[kingmick]

Having given it some serious consideration, I've decided that fiberglass is the devils work and I never want to speak of it again.

(yes it went that horribly wrong )

what happened? to cold?

[Ben Wilson]

you could try with a more drapable fabric...
some fabric is not drapable at all and sucks even for simple curves.. some (like F1 carbon) can do very complex curves.....
sticky shit can be so frustrating.....

The big difference is they use pre-preg and vac bags, so the cloth is mouldable and doesn't fray and lift like wet lay up. I might give it another go some time in the future, I just enjoy working with metal so much more