are there any practical things we can do with hot radiator water ? - Page 6 - Fuel Economy, Hypermiling, EcoModding News and Forum

Bicycle Bob · 02-22-2009, 04:09 PM

Smokey Yunick, one of the smarter mechanics in Daytona and Detroit, put a lot of time into an engine that even used preheated air to aid vaporization. It had a turbo, to help make up for the loss of density, but he called it the "homogenizer" for its role in mixing the mix. AFAIR, he got his intake temperature up to 400F with no problems over pre-ignition. Popular Science ran an article on a 150HP 2-cyl engine he was using in a test mule. This was separate from his adiabatic work.
The "Carburetor Heat" control is a standard safety precaution against carburetor icing on aircraft, and can definitely be noticed working some days. I wonder why icing is so seldom recognized in automobiles.

basslover911 · 02-22-2009, 04:58 PM

^^ Sure the super awesome hidden in mystery engines of Smokey.

I am going to install an oil temp gauge right before the fuel rail to check on stock fuel temps next week.

After, I plan on running some lines (1) through coolant (2) through the exhaust manifold.

Hopefully I can hit around 200 degrees (because remember fuel flows pretty fast through there so even if the exhaust is 20000000 degrees the fuel is only there for a fraction of a second and doesn't have time to heat up to that high.

Worst thing that can happen I imagine is the engine detecting knock (detonation) at which point I turn off the engine immediately! (And hopefully have no burnt pistons... but common its only 200 degrees even gas auto ignition temp is 500 of so degrees)..

I will let yall know how everything goes. ONE THING, dont try this if you have a return type fuel system because it will eventually superheat the whole gas tank and THAT can be very dangerous! We only want to heat up the gas that goes into burning seconds after!

brucepick · 02-22-2009, 06:14 PM

So, any thoughts re. preheating the intake air via the engine coolant, in a modern car with a stock (oem) engine management computer??

Would the stable water temperature be an asset, or would the resulting air temp drop at wider throttle - and would that be an issue?

gtkid2002 · 02-23-2009, 02:47 AM

First n00b post! Whee!

Has anybody thought about using the coolant heat to power a sterling engine, then hook that up to a generator? They've got a car based on this already, and it was on Hackaday (How I actually found this site!)

Dean Kamen’s Stirling engine car - Hack a Day

I know this wouldn't do much good for non-hybrid cars really, but for those that have a hybrid system, I ask you. Why not?

And sorry if this is a repeat post or something. I read through this thread, didn't see anything, and decided to give my two cents.

suspectnumber961 · 02-23-2009, 08:44 AM

Easiest thing is to heat the fuel...I managed an 8% gain with a carbed car and only raising the temp by 25-35F at cruise. Various methods from DIY to commercial fuel heaters/injectors.

bikin' Ed · 02-23-2009, 09:14 AM

you mounted a tank on the exhaust manifold, filled it with water(and alcohol during winter), and ran the fuel line thru it and air intake above it? The tank should have a low pressure relief valve on it and the released steam should be fed into the air intake.

The tank should be a small volumn, so as to heat up quickly. I have yet to figure out how to install a high volumn nurse tank and pump to refill on the fly. But, even if this whole system does go dry, you should still have a low efficiency heat exchanger operating.

At low rpm this should keep air intake and fuel both heated. At higher rpm the air won't be heating so long so a bit of extra power may be derived from the cooler air intake.

Daox · 02-23-2009, 10:03 AM

Quote:

Originally Posted by brucepick

So, any thoughts re. preheating the intake air via the engine coolant, in a modern car with a stock (oem) engine management computer??

Would the stable water temperature be an asset, or would the resulting air temp drop at wider throttle - and would that be an issue?

Well, first off you'd want the coolant loop that heats the intake air to be on the radiator size of the thermostat to maintain fast warm up. Second, your engine sucks so much air through it I don't think you'd see a ton of warming from running this extra loop. The exhaust is so much hotter, and its easier to pull heat off by running some ducting near it.

The stable water temps may be an asset if you run into pinging from too high of temps. It would be easier to control a steady temp with coolant versus exhaust heat I would think.