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thought alcohol motors were supposed to run cool???

Posted: Fri May 18, 2012 8:56 pm
by 71 chevy
i read about guys all the time doing away with their fans /radiators or running transmission coolers for radiators because they "cant get heat in the motor" on alcohol

so why is it that Im going from 100 to 190 in 3 min just idling on a little bitty stock compression, stock cam 364 cid lq4

AFR at idle is at 12.5:1 on the gas scale, so around 5.4:1
idle is set at 1000 rpms,
running a moroso water pump drive, scirocco radiator and single 12" fan with no shroud, so granted the cooling system is marginal but I thought on alcohol I would be able to even get rid of the radiator and fan altogether.

any one have any experience in this area?

PS. I Love alky. it smells awesome compared to e85 and picked up 300 rpms in stall so i know the engine is making some additional torque

Re: thought alcohol motors were supposed to run cool???

Posted: Sat May 19, 2012 2:42 pm
by apacheracing
Are you using a thermostat, or water restrictor? I you do not have one in, the water will not stay in the radiator long enough to cool.

Re: thought alcohol motors were supposed to run cool???

Posted: Sat May 19, 2012 6:24 pm
by 71 chevy
no, i am not. i think my problem may be the pump turning too slow as opposed to too fast

http://stewartcomponents.com/tech_tips/Tech_Tips_3.htm

Re: thought alcohol motors were supposed to run cool???

Posted: Sun May 20, 2012 1:55 pm
by clutchdude
It has to be super LEAN...

And yes alky can still run that lean (not safely), as well as fat enough to have fuel running out of the exhaust and still run.

Fatten it up at idle and see what it does, ignore your afr for now.

I am taking out my full sized radiator and putting in super small radiator...and am still considering no radiator and just circulating water in the block.

Re: thought alcohol motors were supposed to run cool???

Posted: Sun May 20, 2012 4:59 pm
by 71 chevy
clutchdude wrote:It has to be super LEAN...

And yes alky can still run that lean (not safely), as well as fat enough to have fuel running out of the exhaust and still run.

Fatten it up at idle and see what it does, ignore your afr for now.

I am taking out my full sized radiator and putting in super small radiator...and am still considering no radiator and just circulating water in the block.
OK,im going to try that. the afr was reading 12.5 to 1. i will add about 20% more fuel and see what happens. as it is now, it is gaining heat at exactly the same speed as when the car was on e85.


ill let you know what it does. what is your idle afr?

Re: thought alcohol motors were supposed to run cool???

Posted: Mon May 21, 2012 12:25 am
by clutchdude
I have only looked at afr at speed.

Is your car EFI? Did you put bigger injectors in it?

Re: thought alcohol motors were supposed to run cool???

Posted: Mon May 21, 2012 8:11 pm
by 71 chevy
clutchdude wrote:I have only looked at afr at speed.

Is your car EFI? Did you put bigger injectors in it?

hi, it is EFI. im running ford 160 lb injectors. they dont like to idle under 1.5 pulse width, but they work for what im needing.

can you tell me how quickly or slowly your car gains heat, say from 100 degs to 180

Re: thought alcohol motors were supposed to run cool???

Posted: Mon May 21, 2012 10:47 pm
by clutchdude
lol an hour, i have to pull the fuel shutoff half ways...to lean it out and even then it will take 10 mins to get to 160 degrees.

Re: thought alcohol motors were supposed to run cool???

Posted: Tue May 22, 2012 12:32 am
by 71 chevy
clutchdude wrote:lol an hour, i have to pull the fuel shutoff half ways...to lean it out and even then it will take 10 mins to get to 160 degrees.
wow, that would be perfect for me. i would like to stage at 150-160

do you have any problems milking the oil?

Re: thought alcohol motors were supposed to run cool???

Posted: Tue May 22, 2012 9:44 am
by clutchdude
Only at first when it was real fat and i could not get any heat in the motor, i could not even get it to 140.

With alcohol heat is a good indicator of your tuneup, like in your case it appears to be lean at idle. On a pass i would see a 10 degree increase in temp. and it will cool back down on the return road.

Re: thought alcohol motors were supposed to run cool???

Posted: Tue May 22, 2012 8:03 pm
by 71 chevy
clutchdude wrote:Only at first when it was real fat and i could not get any heat in the motor, i could not even get it to 140.

With alcohol heat is a good indicator of your tuneup, like in your case it appears to be lean at idle. On a pass i would see a 10 degree increase in temp. and it will cool back down on the return road.

Hey, thanks for your help on this I think I am finally making headway.

I added the fuel as you suggested, and it took a lot longer to climb in temp. with no fan on, it took 3 mins 40 secs to go from 100 to 160, and a total of 8 minutes to hit 200 degrees from 100, so Im super excited because this was with absolutely no fan on, just the water pump circulating.

the only other change I made was overspeeding the water pump by changing the pulley from a 35% drive ratio to 50%`

i think this is plenty of time to make a pass without overheating the motor. I plan to test it with the fan on and see how cool I can keep it

idle afr for this session was approx 4.5-4.6:1

Re: thought alcohol motors were supposed to run cool???

Posted: Tue May 22, 2012 10:11 pm
by 71 chevy
just tested it again with the small fan on. 134 to 170 degrees took almost 7 minutes. dayuuuuum!!!

im stoked. granted it was only 80 degrees or so in the garage but still im very impressed in how long it is taking to gain heat now.

afr was around 4.2 on this one

Re: thought alcohol motors were supposed to run cool???

Posted: Wed May 23, 2012 9:58 am
by clutchdude
I was just thinking about your setup... 160lb injectors on a stock motor are not going to work very well which is why your lean at idle. If i remember right those injectors are good for a 1000hp alcohol engine. And as you know you need a minimum duty cycle to get them to work reliably

Re: thought alcohol motors were supposed to run cool???

Posted: Wed May 23, 2012 6:49 pm
by 71 chevy
clutchdude wrote:I was just thinking about your setup... 160lb injectors on a stock motor are not going to work very well which is why your lean at idle. If i remember right those injectors are good for a 1000hp alcohol engine. And as you know you need a minimum duty cycle to get them to work reliably
yeah, i have the minimum pulse width set at 1.6 and it works good. anything below that and it surges badly at idle and alternates between normal and lean continously