lbhsbZ Posted July 22, 2007 Share Posted July 22, 2007 I tied up some loose ends yesterday and towed the car out to Willow springs this morning for a track day....the first time the car has run anywhere but our warehouse parking lot. I was amazed at how well the car handles...even when I got it sideways, it was easy to recover, much better than I thought it would be. 3 laps into it, the water temp was at 230 and the oil temp about 280, so I came in....Idling with the fan on didn't seem to drop the temps at all. I went out for 1 more session....3 or 4 more laps and then pulled it on the trailer because everything was cooking again. Now the fun part: Diagnosis!!! Here's what I've got: 24x19 Aluminum Griffin Radiator Aluminum Cheapo water pump 165° t-stat 12x9 stacked-plate style oil cooler (10 quarts of oil in the system) 14" 3400 CFM electric fan (moves lots of air) Undersize crank pulley. Est. HP output: 520 crank. Willow springs is at about 3000 ft, so it probably wasn't making that much power. Mixture was 13.5-13.9:1 according to my AEM wideband AFR gauge, and the plugs looked good, so I wasn't running lean. I can understand if maybe the radiator is too small, or needs ducting, but in these cases, the temp would come down pretty quick idling with the fan on, and it didn't come down at all...so while ducting the radiator may be an issue, I don't think it will help out quite yet. I was thinking that maybe the undersize crank pulley is just driving the waterpump too slow, but I've never seen a case of that before so I don't know what symptoms are. I'm sure the thermostat is working...(if it didn't melt) because you can feel the temp change in the hoses when it opens. Any other ideas? Quote Link to comment Share on other sites More sharing options...
bjhines Posted July 22, 2007 Share Posted July 22, 2007 cheap water pump??? Try the factory pump and see what happens. Quote Link to comment Share on other sites More sharing options...
bschiltz Posted July 22, 2007 Share Posted July 22, 2007 Have you tried other t-stats, maybe 180*? Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted July 22, 2007 Author Share Posted July 22, 2007 I have not tried any other T-stats....I'm not sure how a hotter one would help, but I suppose it wouldn't hurt to try. As far as the waterpump...its a ProComp $65 unit. I'm going to pull it off tomorrow and yank the back plate to compare with an old used cast iron pump that I have. I haven't heard of any issues with the various aftermarket pumps out there though. Is anyone using restrictors in place of their thermostats? I still don't understand how the hell 10 1/2 quarts of oil with 2 filters and a decent sized cooler can go from cold to 285° in less than 4 minutes. After the first lap (about 1:30)...water temp was 210 and oil temp was 240, then things continued creeping from from there. I've never seen anything get that hot that fast. Quote Link to comment Share on other sites More sharing options...
bjhines Posted July 23, 2007 Share Posted July 23, 2007 Maybe it's just not broken in yet? Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 23, 2007 Share Posted July 23, 2007 Hotter t-stat helps because hot water in the radiator transfers it's heat away more quickly. ...I think....there is a thread here somewhere. Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted July 23, 2007 Author Share Posted July 23, 2007 Maybe it's just not broken in yet? How would that effect cooling? Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted July 23, 2007 Share Posted July 23, 2007 willow springs=hot.kind of like cooling an off road race car.i have run track time at thunderhill at 100+ degree temps ..i would suggest making sure you dont have a bumper in front and maybe a louvered hood.maybe study the results of the wind tunnel experiment.and the oil cooler should not be mounted in front in front of the radiator.my car might over heat on next track day because i mounted a big intercooler in front the radiator-and it has factory a/c.z is kind of short on front end space. Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted July 23, 2007 Author Share Posted July 23, 2007 willow springs=hot.kind of like cooling an off road race car.i have run track time at thunderhill at 100+ degree temps ..i would suggest making sure you dont have a bumper in front and maybe a louvered hood.maybe study the results of the wind tunnel experiment.and the oil cooler should not be mounted in front in front of the radiator.my car might over heat on next track day because i mounted a big intercooler in front the radiator-and it has factory a/c.z is kind of short on front end space. It wasn't to bad today.....kind of pleasant actually. It was about 90 with a nice breeze. Where should I mount the oil cooler? Quote Link to comment Share on other sites More sharing options...
bschiltz Posted July 23, 2007 Share Posted July 23, 2007 Hotter t-stat helps because hot water in the radiator transfers it's heat away more quickly. ...I think....there is a thread here somewhere. Yeah, if the thermostat open too low it won't ever close and the engine will just keep getting hotter, almost like running no t-stat. I don't know if it would effect the temps that fast, though? Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted July 23, 2007 Author Share Posted July 23, 2007 OK, I played with it a bit tonight....I might be on to something. When I first fired the engine a month ago, I had a problem with a few of the headstuds leaking water past the threads....I pulled each stud out 1 at a time, cleaned, resealed, and reinstalled. During this process, some oil got into the cooling system while changing the studs under the valve covers. It was pretty obvious, because there were little oil droplets floating on the water under the radiator cap. So I squirted in a bunch of Dawn dish soap and ran it around for few days at work, then drained it, and refilled with clear water....which is still clear, so it led me to beleive that I had gotten all of the oil out. I stuck my finger in the radiator and felt a oily film all over the inside of the tank.....So I imaging that this same film may be on the insides of the radiator tubes, and the block and head castings....which would explain why nothing can transfer heat like it should......I think. Any Idea's to clean this? I have a pretty stiff degreaser called OilEaters that I was thinking of mixing up 50/50 with water and pouring that in, then run it around and get it hot a couple times with no thermostat, and then drain and flush it a couple times. I also ordered a set of the Moroso water neck restrictors and a stock sized crank pulley to try out. I'll pull the water pump tomorrow and compare the impeller to a stock pump....if it turns out to be a POS, I'll order a better pump too. I'm trying to cover all the bases, because I only have 1 more test day before the next race. Quote Link to comment Share on other sites More sharing options...
johnc Posted July 23, 2007 Share Posted July 23, 2007 Are you measuring your oil temps before or after the cooler? Given the horsepower numbers and size of the oil cooler you're running, 285 going into the cooler isn't bad if it stabilizes there. A bigger cooler would help. I ran a 12 x 12 stacked plate oil cooler on my L6 when it made around 300hp and the oil temps would stabilize around 250 running at WSIR. Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted July 23, 2007 Author Share Posted July 23, 2007 ...or maybe I should just trade in my 300° oil temp gauge for a 250° gauge....that would solve the oil temp problem .....If only they made a 180° water temp gauge Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted July 23, 2007 Author Share Posted July 23, 2007 Are you measuring your oil temps before or after the cooler? Given the horsepower numbers and size of the oil cooler you're running, 285 going into the cooler isn't bad if it stabilizes there. A bigger cooler would help. I ran a 12 x 12 stacked plate oil cooler on my L6 when it made around 300hp and the oil temps would stabilize around 250 running at WSIR. John, The sender is in the oil coming out of the engine, so that explains the high oil temps. Maybe I'll look into a bigger cooler anyway, or at least move the temp sender so I don't feel so bad when I look at the gauge Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted July 23, 2007 Share Posted July 23, 2007 How would that effect cooling? Engines that are newely rebuilt are tight and will run warmer then normal until properly borken in. But if you have a couple hundred miles on it then it shouldn't matter. Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted July 23, 2007 Author Share Posted July 23, 2007 Mine is pretty well broken in, Its had a hard life so far. Quote Link to comment Share on other sites More sharing options...
TONY C Posted July 23, 2007 Share Posted July 23, 2007 what engine are you running? i know that some gm v8 had 2 different water pumps. they look identicle on the outside but the impeller is made right or left. meaning that maybe your pump is actually spinning backwards. I have seen this once. maybe. peace Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted July 23, 2007 Author Share Posted July 23, 2007 It is supposed to be the old style pump....although, seeing as how it's both cheap and chinese, it might be wrong. I'm not really sure how I'd tell unless I disassemble it, which should happen tomorrow. Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted July 23, 2007 Share Posted July 23, 2007 i think there is a good american made pump with a new style of impeller that is more efficient.also make sure it is a v-belt pump-some cars with serpentine belts turn the pump backwards. Quote Link to comment Share on other sites More sharing options...
jt1 Posted July 23, 2007 Share Posted July 23, 2007 Make certain that the radiator is sealed to the rad support, the support is sealed to the hood, and that the bottom of the support is COMPLETELY sealed to the air dam or valence, what ever you're running. Wash the system out a couple of more times. Leave a little soap in it or run some water wetter. 13.5 is pretty lean for a circle track or road race motor. Watch your plugs closely. jt Quote Link to comment Share on other sites More sharing options...
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