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Carbon Sumps

Radioflyer

Well Known Member
Just out of curiosity, any experience replacing the standard engine oil sump w one made from a carbon layup? The main interest would be to save weight and implement cold air induction. Some weight savings and other benefits could be gained by making the sump a smaller volume than the standard 8 qt or so capacity. Any RV's flying w carbon sumps?
 
Ask SAP (Superior Air Parts) how that worked out for them :eek:
Weren't those Magnesium? Been too long.

Doesn't matter. Designing for the nominal case, no problem.

As for the off-nominal? One good backfire or over-prime condition/gas in the inlet for whatever reason and the experiment is over. Save weight elsewhere.
 
Carbon can be very thermally conductive. I've had clients use it specifically for that attribute, as a heat conductor. If you design such a thing, it's something to consider. Its thermal deformation, though, is zero to slightly negative, so the sump-case joint will be affected by that, another design issue.

Magnesium is nearly the same density (it's slightly higher) so that might be a better material.

Dave
 
Weren't those Magnesium?

Ryton, an "engineering" plastic. Couldn't cope with the expansion forces involved in a back-fire. Carbon should be much better able to withstand those forces as the fibres carry the loads, but there are many other issues. A few years back Kitplanes carried a report on a carbon sump - took quite a bit of development work as I recall.
 
I still have one of these sumps for another project and have had plans to reinforce the intake with carbon and possibly add a pop off valve.
 
I still have one of these sumps for another project and have had plans to reinforce the intake with carbon and possibly add a pop off valve.

I designed and built a carbon fiber intake for my Pontiac GTO in the 90's. It has a 440 cu in plenum with a 3" dia blowoff valve in the bottom. A few times that has come in handy with backfires which make a pretty sizable BOOM and then smoke from the hood edge gaps as it dissipates.

Problem with an airplane application is the blowoff valve needs to be on the bottom most likely, which is where the fuel would puddle if someone hamfistedly overprimes the engine. A backfire would spray all that burning fuel into the lower cowl with probably bad consequences. I suppose you could connect a tube to the blowoff valve to duct the flaming mixture out the cowl outlet, but by then the assembly is so heavy that you've defeated the original purpose of having a composite manifold.

roar5.jpg roar4.jpg
 
Wow that’s a work of art! All carbon? How light was it? Seriously talented…

Thanks! It's been 25 years since I built that and at least 10 years since it's been off the engine, but it's around 10 lbs. It's not entirely carbon; it has 1/2" thick aluminum rails which bolt to the heads with the carbon bonded on top of those, and there's an aluminum ring embedded in the carbon to provide threaded holes to attach the throttle body (which I also made from billet 6061-T6 based on Chevy LT1 geometry). And the aluminum injector bosses bonded in.
 
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