Bracket Talk
Cool down/ turn around time
May 10, 2020, 08:07 AM
JPoseyCool down/ turn around time
What would be a normal coolant cool down time/ turn around time for a dragster from say 200 degrees to 140? Mine warms up properly I feel like, but it does not shed heat as quickly as I feel it should. Thanks
May 10, 2020, 08:27 AM
Mike RietowDepends on the transmission temp. Common sense. No transmission temp guage, no telling.
May 10, 2020, 08:46 AM
1320racerI don’t recall either of my cars ever returning to my pit at 200 degrees. That said, 185-190 on the hottest days and 15 minutes later the water temp is less than 120 cooled with nothing but straight water. Trans temp is not a concern until round robin, then the Jones trans pump goes to work.
May 10, 2020, 08:58 AM
Mike RietowOn methanol, you're working to have it 200 when it's shut down. Spragless converters aid methanol combo's in this regard.
200 shut it down and walk away. No fan, no water pump, no battery charger, no generator needed.
Fact.
May 10, 2020, 09:14 AM
Mike RietowFrom 200 my Nova will cool the water from 200 to 160 in seven to ten minutes, running the fan and water pump.
If the fan isn't cooling the circulated water in the radiator fast enough, with the engine not running. Slow down the water circulation through the radiator, so the fan has more time to work on it.
May 10, 2020, 09:19 AM
AlaskaracerOn alky, the only thing I get concerned about is if there is a lot lag between rounds...my car will be dead cold and I'll have to warm it....I don't even concern myself with turnaround time anymore, other than fueling the car and getting something to drink......
Mark Goulette
Owner/Driver of the Livin' The Dream Racing dragster
www.livinthedreamracing.com"Speed kills but it's better than going slow!"
Authorized Amsoil Retailer
May 10, 2020, 09:21 AM
Mike Rietowquote:
Originally posted by Coloradoracer:
On alky, the only thing I get concerned about is if there is a lot lag between rounds...my car will be dead cold and I'll have to warm it....I don't even concern myself with turnaround time anymore, other than fueling the car and getting something to drink......
That's a early round issue. Posey has late round issue's, with heat. Big difference.

May 10, 2020, 09:45 AM
27KeithWhere is your radiator mounted ? and what size lines are coming out of it ? You could have too much flow, too little flow, or no air passing thru the radiator.
4 X Track Champion ( 2 & 2 )
2 X Run off Winner
May 10, 2020, 10:01 AM
JPoseyDang based on your numbers I have some work to do. Mike I do have a message sent to Patrick James on swapping my good PS gas carb to alcohol. Ed I see you have a rear mounted radiator. Do you happen know what P.N. and brand Undercover used behind the driver. Saldala, Afco, and Ron Davis seem the current go to on dragsters based on my internet search ok current dragster builders. I haven’t called anyone yet. Thought I would run this by you guys first. Currently have a Griffin with a CSI pump, all older stuff.
May 10, 2020, 10:50 AM
1320racerRon Davis #1Z-UC2010 14 1/2” x 17” x 2” thick
May 10, 2020, 11:08 AM
Alaskaracerquote:
Originally posted by Mike Rietow:
That's a early round issue. Posey has late round issue's, with heat. Big difference.
If I round robin the car, I just give it more fuel when not on the track.....it will cool quickly....or turn on my fan....
I couldn't keep my car cool on gas....one of the main reasons I switched to alky......I have to work to build temp now. Fourth run last night, temp was 175 coming off the track, was less than 160 by the time I got to my pit....about 50 yds from the timing booth and about 150 yds from where I turned off the track. There weren't many cars in the second race, about 15-20 minutes before my next pass. I did nothing to cool the car. shut water pump off...fueled car, downed a bottle of water, and got ready. Car was already down to 120*....I had to build heat before I made the run....
Mark Goulette
Owner/Driver of the Livin' The Dream Racing dragster
www.livinthedreamracing.com"Speed kills but it's better than going slow!"
Authorized Amsoil Retailer
May 10, 2020, 11:12 AM
Alaskaracerquote:
Originally posted by Mike Rietow:
Slow down the water circulation through the radiator, so the fan has more time to work on it.
Gotta call you on this one...it's a myth that's been busted about a million years ago....slowing the flow down through the radiator will not cool better, as it allow the coolant in the block to get hotter...best thing is to speed up flow overall. Straight water is best, as it absorbs and rejects heat better than any coolant mixture. It's about taking the heat from one area and transferring it to another....
Better do some more homework on this one Mike, you are wrong.....
Mark Goulette
Owner/Driver of the Livin' The Dream Racing dragster
www.livinthedreamracing.com"Speed kills but it's better than going slow!"
Authorized Amsoil Retailer
May 10, 2020, 11:17 AM
Mike Rietowquote:
Originally posted by Coloradoracer:
quote:
Originally posted by Mike Rietow:
That's a early round issue. Posey has late round issue's, with heat. Big difference.
If I round robin the car, I just give it more fuel when not on the track.....it will cool quickly....or turn on my fan....
I couldn't keep my car cool on gas....one of the main reasons I switched to alky......I have to work to build temp now. Fourth run last night, temp was 175 coming off the track, was less than 160 by the time I got to my pit....about 50 yds from the timing booth and about 150 yds from where I turned off the track. There weren't many cars in the second race, about 15-20 minutes before my next pass. I did nothing to cool the car. shut water pump off...fueled car, downed a bottle of water, and got ready. Car was already down to 120*....I had to build heat before I made the run....
I know, you really need it 190-200 when you get back to your pit, it'll use a lot less fuel. That thing use a 55 gallon drum every time out, or what? (sarcasm)
I could win a 7 round race with 10 gallons of methanol with my sbc, w/ one time run. It's one of the reasons I switched from a BBC.
2 jugs sbc
3 jugs BBC
May 10, 2020, 11:25 AM
Alaskaracerquote:
Originally posted by Mike Rietow:
I know, you really need it 190-200 when you get back to your pit, it'll use a lot less fuel. That thing use a 55 gallon drum every time out, or what? (sarcasm)
I could win a 7 round race with 10 gallons of methanol with my sbc, w/ one time run. It's one of the reasons I switched from a BBC.
2 jugs sbc
3 jugs BBC
Yeah, it's got a healthy appetite for alky, I can't deny that...I won't tell you how much I went through last night....except that had I gone more rounds, I'd have been buying fuel at the track...but also I was solo, so had to drive the car to the lanes and back...that burns a ton too.....oh well, is what it is....
Mark Goulette
Owner/Driver of the Livin' The Dream Racing dragster
www.livinthedreamracing.com"Speed kills but it's better than going slow!"
Authorized Amsoil Retailer
May 10, 2020, 10:07 PM
Mike Rietowquote:
Originally posted by Coloradoracer:
quote:
Originally posted by Mike Rietow:
I know, you really need it 190-200 when you get back to your pit, it'll use a lot less fuel. That thing use a 55 gallon drum every time out, or what? (sarcasm)
I could win a 7 round race with 10 gallons of methanol with my sbc, w/ one time run. It's one of the reasons I switched from a BBC.
2 jugs sbc
3 jugs BBC
Yeah, it's got a healthy appetite for alky, I can't deny that...I won't tell you how much I went through last night....except that had I gone more rounds, I'd have been buying fuel at the track...but also I was solo, so had to drive the car to the lanes and back...that burns a ton too.....oh well, is what it is....
LoL. Atleast you have a good sense for humor about it. I've been there myself, I get it.
May 10, 2020, 10:23 PM
Mike Rietowquote:
Originally posted by Coloradoracer:
quote:
Originally posted by Mike Rietow:
Slow down the water circulation through the radiator, so the fan has more time to work on it.
Gotta call you on this one...it's a myth that's been busted about a million years ago....slowing the flow down through the radiator will not cool better, as it allow the coolant in the block to get hotter...best thing is to speed up flow overall. Straight water is best, as it absorbs and rejects heat better than any coolant mixture. It's about taking the heat from one area and transferring it to another....
Better do some more homework on this one Mike, you are wrong.....
I don't mind being wrong, but let me ask ya this before we decide I'm wrong.
What if I was referring to the topic of the thread, turnaround time? Like when the engine is shutdown and Posey is trying to cool it down quickly, in preparation for the next round? Am I still wrong?

May 11, 2020, 05:01 AM
Alaskaracerquote:
Originally posted by Mike Rietow:
Slow down the water circulation through the radiator, so the fan has more time to work on it.
I don't mind being wrong, but let me ask ya this before we decide I'm wrong.
What if I was referring to the topic of the thread, turnaround time? Like when the engine is shutdown and Posey is trying to cool it down quickly, in preparation for the next round? Am I still wrong?
Yes, physics doesn't change because engine is shut off....water still absorbs the heat, heat still has to be rejected to the atmosphere....what he can do is what I used to do...maybe not the best solution but it worked:
Take a sprayer bottle and fill it with ice water. Spray down the radiator with it...the cold water will speed up the heat transfer thus causing the water in the radiator to cool quicker....leading to a cooler engine....
Mark Goulette
Owner/Driver of the Livin' The Dream Racing dragster
www.livinthedreamracing.com"Speed kills but it's better than going slow!"
Authorized Amsoil Retailer
May 11, 2020, 05:46 AM
BJs Wild RidePretty sure the water restricter is about cavitation. Years ago people found that the system would cool better with a restricter. This is because the restricter prevented the pump from cavitation, thus the restricter actually INCREASEd flow rate in that system vs not running one. I was trying to think of an easy way to measure flow rate on the closed system but I haven’t come up with anything reasonable.
May 11, 2020, 06:29 AM
AlaskaracerA restrictor does not increase flow. It does exactly what it says it will do, restrict flow...the faster you can flow the water through the engine, the better it will cool. A water pump will only cavitate if the suction side supply cannot keep up with the flow demand from the pump. The block itself is the restriction, take a look at the head gaskets...the holes on certain passages are not fully open. This is not by accident....T-stats and restrictors came about to keep heat in the block, not to remove it......that's why you have a heater in your daily.....
Mark Goulette
Owner/Driver of the Livin' The Dream Racing dragster
www.livinthedreamracing.com"Speed kills but it's better than going slow!"
Authorized Amsoil Retailer
May 11, 2020, 06:44 AM
1320raceragreed, another 20th century hot rodding myth