Racingjunk Forums

Racingjunk Forums (https://www.racingjunk.com/forums/index.php)
-   Engine Tech (https://www.racingjunk.com/forums/forumdisplay.php?f=9)
-   -   To heat or not . . (https://www.racingjunk.com/forums/showthread.php?t=32425)

roadkill2 08-01-2012 08:48 AM

To heat or not . .
 
The boss (Bear4333) and I have had a running discussion about the heat in the BBC we're running . . I've always labored under the conception (or misconception) that Chevy's (both kinds) like to be "Toasty' up on the starting line . . somewhere between 180 and 195 . . The Boss disagrees and backs his 160-170 argument with quotes from Reher-Morrison and others . . not to mention, results . .

I'm beginning to believe that he's not only right but it should be almost dead cold (110) when you start it in the lanes . . And that goes for the Transgression too . . The converter seems to be a lot happier with cold fluid than when it's around 160-175 . . Leaves harder, more consistent and goes quicker . . (1.38 sixty fts, [email protected], 2825# iron Camaro in 9400' corrected air)

Is a "Warm Up" just wasting 116 octane? Discussion?

fast75vega 08-01-2012 12:03 PM

185-195 at the line is too hot in my opinion.... i like to be no more then 160 after the water box ..... im normally around 185-190 at the end of my run but this is with a SBC w/glide

itsabird 08-01-2012 05:06 PM


Originally Posted by fast75vega
185-195 at the line is too hot in my opinion.... i like to be no more then 160 after the water box ..... im normally around 185-190 at the end of my run but this is with a SBC w/glide

x2

mopar1968 08-01-2012 07:03 PM

x3

outlaw256 08-02-2012 05:51 AM

well make that x4. i dont care what so-called engine builders, tuners whatever say.from a metal mans own mouth 160 -170 is what metal prefers to do its work in.now ive run big blocks small blocks and almost no blocks lol and ive noticed that any car we have had seems to do its best when its 160-170.trans included. the cooler the trans =less friction.according to a guy whos built racing trans for 50 yrs.back in the mid 80s i had a 55 that i could not get to run consistant at all. my buddy who built engines for many more yrs than i told me to write down my temps at the launch and at the end on my timeslips.do that for a few weeks and bring them to him. he went over them and showed me that when my car launched at 150-170 i had alot better times.when it was runnin any hotter i realy dropped. sooooo. we made sure that little old car stayed cool.

roadkill2 08-02-2012 07:46 AM

Good discussion . . I'm pretty old school about a lot of stuff that has changed greatly over the last few years . . Add to that, For over 20 years I was tuning and tweaking a Blown Alky engine so just getting heat into it was sometimes a chore . .

And, it used to be, you could fatten up your car and go up to the lights dragging your feet a little, get the other guy a little hotter and his clutch/converter would hook up harder and quicker because his engine built more HP from being hotter . . Not a "Burn Down", but just part of the old racing strategies . . (done it, been done to)

Thus, one would tend to believe, a "toasty" motor is a powerful motor . . . maybe just an "Unpredictable one" instead?

I can tell you for a fact, heat "loosens" up a converter proportionally . . so if you want a predictable converter, the less heat the better (I think). Anyway, our results tend to bear out that theory.

jmarksdragster 08-02-2012 06:26 PM

Every engine need the oil to be warm to lower friction, however temperature that the rest of the the engine need doesn't need to be much, the cooler engine is the more thermally stable it is. The induction is a different issue, it need enough to add the appropriate heat or energy to the fuel to ensure even distribution without excessively sacrificing air density. The more efficient the carb and induction is the lower the temps can be, and the more power you can make because the air is denser. Next time you go to a national event ask the Pro Stock guys why they cool the water through the engine to 70 degrees or lower...

TheYellaBrick 08-02-2012 06:46 PM

Depends if the heads are iron or aluminum and what kind of fuel. Either way, you need enough heat in the heads for proper and complete combustion to take advantage of the cool intake charge.

TheRabbit 08-03-2012 10:38 AM

I put heat in my motor ,about 170 to 180*'s about 30 - 45 mins before I run then let it cool. I've never had a motor that liked to run under 155ish so I always stage at 160 to 170. With that being said I will not stage until I get it back down to 180. It only takes a second or two to go from 185 to 200 in most race cars. I use to worry about mine when it hit 200-210+ on the return road, but have had to do it a lot. NASCAR motors run at 240*'s all the time, but I'm not going to let mine get near that hot.

fast75vega 08-03-2012 02:24 PM


Originally Posted by TheRabbit
NASCAR motors run at 240*'s all the time

they also use other peoples money to build them.... we use are own..... lmao


All times are GMT -8. The time now is 10:56 PM.