Engine cooling

[yokebutt]

Allright, here's a looney thought I'm sure you guys can tear to shreds like a pack of piranhas. I was just thinking the other day that incorporating a cooling circuit for the engine into a trim-tab (like a closed-circuit keel-cooler) might have some merit, what sayeth you? Is it merely a bad idea or a REALLY bad idea?

Yokebutt.

[marshmat]

Heinkel tried something a bit like this on the HE-100 fighter planes back in 1939. They ditched the radiator and ran coolant loops around the plane's wings. It was a promising development but they never got it working right before the project became outdated.

I don't see anything particularly wrong with your suggestion.... then again, I don't see a huge advantage either. Is the idea to keep corrosive saltwater out of the engine? A closed-cooling loop via heat exchanger can do that.... what benefits do you see in it?

[yokebutt]

No particular reason, just one of those random thoughts that may or may not have benefits, here's another one; would high-temp silicone be heat-resistant enough to be used for an exhaust elbow? or perhaps fiberglass with a high-temp matrix?

Yokebutt.

[marshmat]

you mean sealing the elbow, or the elbow itself?
silicone? maybe; isn't there some special orange goop that's used for that? fibreglass? too rigid i would think. but I've seen carbon-fibre/epoxy exhausts on Formula1 cars.

[yokebutt]

I was thinking of cornering the market on exhaust elbows that won't corrode away in a couple of years.

Yokebutt.

[stevel]

I have seen a lot of stright sections made of some kind of GRP. Obviously, the corner would take a lot more abuse, so it isn't necessarily an easy leap from straight to elbows.

The high-temp (silicone?) hoses used on some turbocharger applications lead me to believe that material will handle the heat, it would just need something to give it a bit of support. Maybe a fiberglass shell around the silicone?

I'm intrigued. I'd certainly like to have an alternative that holds up and is reasonably affordable.

[Danielsan]

I know there are some rocket lounchers for anti tank use that are made off grp it shurely needs to handle pressure and high temp for a short period of time

[yokebutt]

Maybe fiberglass with a silicone resin? What's that automotive exhaust-pipe repair tape made from, anyway? anybody know?

Yokebutt.

[PowerTech]

we make a line of exhauste elbows that are a 1/4" thick stainles steal inside and out for john deere motors that are not failing at all.most coustom elbows are made out of thin stainles or cast iron ther fail often.cat had a elbow out af bronze that hardly failed also.you don't want to fuss with werd stuff on a boat just keep it simple.And the exhoust gets up 1500 deg and that ain't nothing to fool with.If you want to go exotic and have the bucks I think titaineum would be the way to go.

[FAST FRED]

AS the elbow , where the hot sea water and exhaust gasses react is the problem , just do it differently.

Keep the cool elbow but dump the water in further down the exhaust system.

Use something so cheap you can replace it annually at little cost.

Galv 4 or 5 inch pipe with a boss welded on to allow the cooling water to dump in comes to mind ,

but a really nice heavy duty brass pipe with brinze nipple brazed might last "forever".AS would a 4 inch bronze reducing T , 4X1X4

FAST FRED

[yokebutt]

Maybe just using 400 series stainless is as good as it'll get, oh well.....but how about ceramic then?

Yokebutt.

[mackid068]

Ceramic is nice. I think its probably one of the few space shuttle components that's not entirely bad.