I have been running alcohol for 5+ years, I love it and have no plan to switch. My car burns a crazy amount of fuel warming up, approx 4 gallons, sunday I was in and out of the car for the first start up so wasn’t watching the temp and lean out the whole time but at 160 degrees I ran the 5 gallon cell out of fuel. When I originally set the car up I ran 3/8 fitting and line for the lean out. I know most use a 1/2” line and I know I need to upgrade to that but my question is will the 3/8 to 1/2 make a large difference? My lean out only raises the rpm approx 200 rpm when pulled.

Also, I have someone trying to tell me a thermostat changed their fuel warm up dramatically, to me with a manual water pump there would be no need for a thermostat. Does anyone have experience with and without a thermostat while warming an alcohol car?

Thanks guys!

We have 1/2" I.D. hose on our lean-out system, it works ok for most of the season. The addition of Two core plug heaters and an oil pan heat pad made a world of difference on warm up time for us...

Upper mid-west/great lakes area temps are challenging early in the season then again later in the year. These heaters have helped a great deal...


Dan

Carb or injection?

if injection just pull fuel shut off till it idles up some. You can also use nitrous solenoid with jet to bypass fuel back to tank.This is all assuming bv is set correctly.

If its carb,beats hell out of me.

4150 carb

If you are using a mechanical pump, the 3 way shut off from Good Vibrations works awesome. That is what we use.

I tried a link, but it would not work.

Go to goodvibesracing.com and go to 3-way shut off valves

You don't have the water pump on the whole time do you?

No I toggle the water pump on and off but I make sure I run the water pump when the lean out is on. I normally will pull the leanout for 60 seconds than turn it of for 60 seconds or 2 mins, I had an engine builder tell me never pull the leanout for more than 60 seconds

It's probably dumping raw fuel out the boosters the entire time your warming it up. Have you ever watched the boosters while the car is running/warming up? I have an alcohol carb on my sbc, no thermostat and the car doesn't use one gallon of alcohol from the trailer, down the track and back to the trailer.

I've always just pulled the lean out and run it with the water pump off until the gauge starts to move (130-140) then toggle the pump on and off til I get to 180ish then let it cool back down on it's own. If running them more than 60 seconds is bad ive been doing it wrong for a long time with a bunch of different rides.

If you are using that much fuel you probably need to tune it a little better. Yes use a lean out valve but you also need to lean your idle mixture WAY down. The only thing is when you lean the idle down you must be careful if the air gets much better you may have to fatten it just a little or it will stumble.
Adjust the idle to where it idles clean and builds heat as it idles. Then you may also have to tune some with squirters/nozzles.
When your carb is right you may only use about 3 quarts of alcohol for one 1/8 mile pass driving it to the lanes and back to your pit.
I use an electric water pump and lean it down and toggle water pump off and on until temp is where I want it. I am currently running a thermostat but I did drill some 1/8 inch holes in it to allow some flow all the time. Also I started running alcohol in 1998 and most of that time I did not run a thermostat. It will not hurt to run a thermostat but you really need to address the real problem why it is so fat and not building heat.

I have mine open all the time. I burn maybe gallon to warm to 160. 3/8 line on leanout. 4150 APD or Rupert depending on what's on it. I drive to the lanes with the leanout open and the water pump off a lot of the times in cooler weather.

One other thing I do when it is cool outside I have a few movers blankets and I throw them over the motor when I get back to my pit. Try to help keep the heat in the motor. Often I will lean it out after the pass on the drive back to my pit to help put more heat in it.

Thanks for the replies! The carb was just freshened, this was the first warm up since rebuild but this has been a consistent issue since I have had it, I have played with mixture screws multiple times but the results have no changed much, normally between 3-4 gallons to get to 180. The car is going to the chassis dyno this week at the carb builders shop so hopefully he can find some adjustments.

Do you guys think going from the 3/8 to the 1/2 lean out will make a large difference? I have to pull the manifold to redrill it and with the season starting if I can avoid that it would be nice to leave it for a break in the season

-Team’s post. With the lean out open it will raise the rpm when booster activates. Train your ear to hear activation/look at egt.
-having manifold drilled on one side will drastically effect the cylinders closest, if a cylinder is in the right condition with methanol something could get too hot. Distribute the leak proportionally. Makes a difference and piece of mind it’s done right.

Most carb builders have idle circuit WAY too fat so it will work even in good air.
I would lean it way down with idle mixture screws until it starts working right.
Also I would blow out your air bleeds every now and then, when they get clogged the carb acts stupid.

I think when you get idle mixture right the lean out valve you have now should work better. It should not take that much fuel to reach temps which most likely means it is too fat.

quote:

Originally posted by Scott Creed:
I have mine open all the time. I burn maybe gallon to warm to 160. 3/8 line on leanout. 4150 APD or Rupert depending on what's on it. I drive to the lanes with the leanout open and the water pump off a lot of the times in cooler weather.

X2

Getting to 160 depends on the ambient temp, but everything else is pretty much the same.

quote:

It's probably dumping raw fuel out the boosters the entire time your warming it up. Have you ever watched the boosters while the car is running/warming up?

I had the same problem with a 4150 on our 454. Burned a shyt load of fuel for warm up and anything past 1600 would dump fuel. Had a 3/8" leanout valve and it did squat.

Put a dominator on it and problem solved, warmed up nice and very fuel efficient. Go figure ..........

Do you have a mechanical fuel shut off valve? I open my lean out & partially close the shut off. I try not to make it a habit of going too lean on warm up, but between the 2 I can get my motor so lean it will barely run.

I would change the idle air bleeds. Sounds like it's way to fat at idle.