Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

[Clem Z.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

hard running can turn the stock exhaust manifold cherry red. i have driven a 454 motorhone at night with the engine cover off and the exhaust manifolds got so transparent so you can see the exhaust port in the head as a dark spot. the later ones has a stainless steel flex joint in the exhaust manifolds to prevent cracking. the exhaust manifolds puts a lot of heat under the hood.

[Stuart F.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

My IFR data from over the years shows my exhaust manifolds checking in well above 500* after a run, with the right side being the highest probably due to the heat riser butterfly valve restriction. That was one thing that convinced me to go to an electric choke and do away with the hot air tube. I've never seen my manifolds cherry red, but I'll bet that choke tube in the manifold is lit up pretty good.

Stu Fox

[Michael M.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

Duke,

Thanks for the clarification. As best I can tell, the car does not detonate. The exhaust is kinda loud, but not overly loud as side exhausts go. Maybe I'm not hearing it? I would probably feel it. I'll have another go at it today or tomorrow using a bit more caution when shooting the temps. I don't know how accurate the IR device is, but I'll be more careful about what is behind the item I'm aiming at. I'll also shoot at some boiling water to see how close it is to 212.

Mike

[Stuart F.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

Sure would be nice to see some more data from other owners.

Stu fox

[Michael G.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

Another update:

63 L84, with fuel lines and filter insulated, all the way from under frame to fuel bowl inlet. Fuel pump not insulated

Cruised 60 miles in 92 ambient today, stopped half way for a coffee, for about fifteen minutes.

Fuel was a mixture of 15 gallons of 93 octane, 10% ethanol, leaded Mobil gas, with the five or so gallons of 110 racing fuel remaining in tank.

Car preformed well for entire ride. At half-way point, car was restated after fifteen minutes heat soak with hood closed. Car started a bit slowly, after a couple of turns, idle was rough for ten or fifteen seconds, then settled at 800 or so. This was the only performance difference I saw with the ethanol. This was much less severe performance degradation than I usually see with E10 ethanol gas. Car driven home and temps measured with car idling evenly at 800. Car was turned off and sat with hood closed for ten minutes, temps measured again.

Temps at idle (after drive) : fuel bowl: 152, engine: 185
Temps after heat soak: 159, 196

The fuel bowl got much hotter in this test, I don't know what caused this, as the route and ambient temp were the same as the last time. In my opinion, the ethanol could not have caused this.

I would say that the insulation made the car run much better than it previously did with ethanol and no insulation, though not quite a good as it did with no ethanol.

[Michael M.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

Hi guys,

Duke, I took my L79 for a drive again today. 1 hour stop and go and open road mixed. Temps @800 rpm idle / 5 minute heat soak, hood closed air cleaner back on. 81 degrees outside temp.

Temp gauge 170/180 est.
Exhaust manifold 553/312
Carb fr bowl 149/153
Carb r bowl 137/137
Thermo housing 178/182
Fuel line @ inlet 147/162
" " @ highest elbow 145/152
" " rubber 154/133
" " @ frame 144/137
Fuel pump 143/132
Intake below carb 190/185

I tried to take a little extra care as to what was behind what I was aiming at. IR gun read 209 into a pot of boiling water. Hope this is of value to you. Again, no detonation or other driving issues temp gauge sat at or near 160 the whole time. Cloudy and cooler than last time as well. But, obviously the engine makes it's own heat anyway. FWIW, pass side exhaust read "only" 547 degrees.

Mike

[Michael M.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

Sorry, I reversed the carb temp #'s above. front is 137/137 rear is 149/153.

Mike

[Joe V.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

Duke,

Here are some thermal images of my '65 L79 with the temperatures of the front bowl and at the base of the temp sending unit. I used a Fluke Ti25 Thermal Imager and the Smartview software to locate the temp readings. The readings are correct as the Imager was calibrated in June 2012. I drove the car for 10 miles to get the engine to temp and parkedin the garage to avoid any heat off the driveway. the ambiant was 88*F and the images were taken with the engine off. I hope this helps.

Joe

IR000017.jpgIR000023.jpgIR000031.jpg

[Duke W.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

Very interesting data, but you said you took the images with the engine off. How long after shutdown? Were they taken in quick succession, or over a period of time?

I'd like more time information given the differences in temperatures in the three images.

Duke

[Joe V.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

Duke,

I pulled the car in the garage, opened the hood and shot the pictures, that fast. The pictures are dated and time stamped, 8:29pm, 8:36pm and 8:42pm. I provided the picture in picture for reference, below are the same pictures in full infrared. Pick a point and I can get the temperature!

Joe







IR00002301.jpgIR00003101.jpgIR000017-01.jpg

[Clem Z.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

a lot of the temp you see in the induction system comes from the hot oil splashing around in the tappet chamber. the oil temp is most likely 20+ degrees hot than the coolant temp. also if you have a carb set up the exhaust heat crossover adds to the temp

[Stuart F.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

Wouldn't you say that 10 minutes of driving would elevate the oil temperature a whole lot, unless it was stop and go traffic or perhaps WOT.

Stu Fox

[Clem Z.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

Wouldn't you say that 10 minutes of driving would elevate the oil temperature a whole lot, unless it was stop and go traffic or perhaps WOT.

Stu Fox

all of my new corvettes that have a oil temp gauge show 20 + degrees higher than the coolant .

[Duke W.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

Duke,

I pulled the car in the garage, opened the hood and shot the pictures, that fast. The pictures are dated and time stamped, 8:29pm, 8:36pm and 8:42pm. I provided the picture in picture for reference, below are the same pictures in full infrared. Pick a point and I can get the temperature!

Joe

Thanks. I missed the date/time stamp first time around.

Duke

[Carl B.]

Re: Ethanol Laced Modern Gasoline -Carburetor and FI fuel meter temperatures

1966 L72 coupe /carb stock jets/power valves(4150/3247)full manifold vacuum adv.12 degrees initial adv./82 degrees /humid /37.6 miles
no hear riser
fuel pipe frame 167 /134
fuel line from pump 180 /196
ft. fuel bowl lower 182 /161
rear fuel bowl lower 187 /176
fuel pump 167 /149
thermo housing 204 /198
sending unit 192 /195
temp gauge just rt 210
little late hopes this helps