* I see its 240 deg but how hot is it running at idle in traffic and when at cruise?
NOTE,did you verify tem gauge by using an auto type ac type hand held temp thermomter placed in hot coolent thru rad filler nech or a new type hand hel themal electronic tem gun to ensure its really at 240 deg?
* Is temp sender in head by ex port or in the intake that runs approx 10 deg cooler on avg then with temp sender in head by the localized hot spot by ex port & ex manifold/header? But take 10 deg away from 240 and 230 if still too hotto be running on a nornmal basis with a hiperf sbc,not a 2009 moroe designed to run no problem at 210-220 deg all day long.
* what gear?
* if auto trans are you running an extrenal cooler mounted in front of rad partially blooking airflow thru the rad which can also increase temps with marginall cooling system or when other tuning issues are present that cause the motor to run hotter? If yes move ext trans cooler away from front of rad and use small elec trans cooler fan to do that job,airflow is key to better cooling i traffic and at lower cruise speeds.
* what water pump?
* what type radiator,3-4 core stock type copper brass or al with 2 lrg tubes?
* with motor hot and t-stat open or with open restrictor plate in place of t-stat can you see ample coolent flow thru radiator tubes with rad cap off and looking into filler neck of rad with motor at approx 2k-2500 rpms? Coolent should be comming out of rad tbes pretty good at that point and if not rad may be blokced,collent passegaes in block may be blocked, and or w-pump may have issues.
* is bottom hose collasing or being sucked closed if there is no spring in it which would stop or slow collent flow?
* are you running a fan shroud?
* what type fan,fixed,7 blade clutch fan wit hd fan clutch,elec fan/s?
* are you running enough octane? If need more try kemco supreme 130 real lead booster,can mix to over 10 octane with 93 fuel.see kemco site for details,its much cheaper then race fuel.
* excessively lean fuel calibration (or vac leak )esp at idle and at lower rpm cruise speed will also casue a motor to run hotter
* (this is a must check )are you running at least 18 if not 20 deg base timing with the hot cam your running to get 600-650hp with 43oish cubed sbc ? Retarded base timing makes motors run a ot hotter on street in traffic and at lower engine speeds before mech adv/total is fully in.
Note 1,when setting base timing ensure if=dle is low like 600rpms toensure mech adv in dist isnt partially activated which will srew up base timing adj making it considerably more retarded then you think it is becasue the mech adv would be additing some timing to the base timing when setting base timing at too high of an idle with mech adv partially activated.
Note 2,when set timing for total only that often leaves base timing retarded which is a mistake many dyno perf shops/people overlook for s street applaication,they are only interested in max power on the dyno ,not dirveability in traffic. For example,if total is set to 36 deg some heis can have as much as 28-30 deg mech adv. So in that case 36 total - 28 deg = 6 deg base timing when your hot cam needs approx 18-20 deg base timing for street use. That leave base timing horribly retarded by 12-14 deg which is huge. But for stip use only or other racing its not an issue at all because of not much idle time like on street in traffic and or in slow 25-30mph traffic .
* also,for street a vac adv can also help it to run even cooler esp at idle and or low speed due to the additonal timing it adds to help a motor with hot perf cam idle better. But if your running the proper 18-20 deg base timing and motor is tuned properly you can get away without vac adv on street with hot setup.
I bet you have more then one (at least 2,3,maybe even 4) of the above items going on with you motor collectively all tat the same time adding up to make it run hoter then it should. So chk all those things out esp the base timing, vac adv which are often overlooked items with hot setups like yours.
Good luck.
Scott
