It could be the transmission thats running hot. And you are SURE the fan is for beltdrive, serpentinedrive rotates the other way ou: my .02$
My personal view is that it is not a coincidence that Buick use the 455 and the "semi-enclosed" cooling system both in 1970. Are you using an overflow tank? The overflow tnak purges and draws as SOP in my car, using the stock (for a Skylark Custom w/350 cid engine) system which includes an overflow tank. If it cools at idle, I'd say your air flow thru the rad. Is fine...as is the t-stat temp...so extra fans are not needed, IMO
Larry, Timing is at 12 initial 34 total. I have played with using ported and unprted for the vacuum advance with no affect on the idle temp. Is there a better rebuilt water pump out there? Can any of you guys give me the diameter of the top and bottom pulleys that you are using? If I could find a larger crank pulley and or a smaller water pump, fan pulley it would definatley help with airflow and water flow. Thanks, James
James, do you use an overflow tank? What is the psi rating on your rad cap? Is the rad cap working correctly?
Chris, That is next to do! As I am testing it I havent seen it bubble any out, so I thought that it probably will not help the cause. Maybe I am thinking wrong? Anyone have a nice electric fan setup? cost and is it visible (stock looking) James
Well, I've said it before but: that overflow tank is sometimes thought to just hold "extra" coolant. It's not quite that simple. The radiator in my car is hooked up to the stock 1970 overflow tank. Buick called this a "semi-enclosed" system and I think it's not just a coincidence that the 455 used it. It seems to work very well. The tank allows the radiator to purge and to draw, all under system pressure. The overflow hose from the radiator is always under the level of coolant in the tank. If you have just an overflow line from the radiator, and your rad cap is not shutting properly, I can see a situation where the radiator needs to purge due to expansion, the rad cap opens, radiator purges, radiator stops purging, rad cap doesn't close all the way, atmospheric pressure enters the system because now the radiator is drawing outside air, lowering the boiling point of the system to ~212*F plus a few degrees from the glycol, from (if you have a 15psi cap) 247*F, and also drawing in air. With the overflow properly filled, you can never draw in atmospheric pressure, or air. It is worth trying a different radiator cap at the least, in my opinion. They are cheap.
For a 67-70 400-430-455, the A/C pulleys are p/n 1375143 (7 3/8") for the crank and p/n 1375146 (5 5/8") for the pump. The A/C water pump had 5 impellers that drive the coolant. The non A/C ones for a 400-430-455 are p/n 1375142 (6 1/4") for the crank and p/n 1375141 (6 3/4") for the pump. The non A/C pump has 6 impellers. The non A/C pump is getting hard to find and "most" pumps are the A/C ones. Using the non A/C pulleys will slow the water pump speed down. Check the size of your pullies and see what you have and try to match them to the same pump. Hope this gives you something to go on. Good Luck, Mark
My gauge starts out reading normal operating temps. As I get more run time on the motor in hot weather the temp gauge continues to creep upwards. No matter how slow I go or what ever I cannot pull enough heat out to make the gauge go the previous temp levels. I have decided that the thermal couple gauge builds up heat in the line and adds a false offset to the reading. Industrial gauges have cold junction compensation to prevent this from happening. I think having the line run over the intake manifold just makes the condition worse. I may try to isolate it from becoming so heat soaked.
That could be so, but I have an aluminum intake that my gauge probe wire runs right beside, and I see the listed thermostat temp until I hit the highway. I don't know anything about your car, but in my mild 30 over 455, I'll see 200-210 on the highway, and as soon as I get off the highway, the temp comes back down, and within 10 minutes I'm on the t-stat temp again, if I'm doing about 35 mph or so. If I stop for gas, the temp gauge will go up to around 200 with the engine off, but when I turn it back on, it drops like a stone to 160*F. This seems normal to me- my fan clutch shouln't be doing much at high speed, and the engine sees approximately the same temp during a hot soak stop like that, and on the highway- fan clutch is doing pretty much the same thing- zip. I've used both the K- and J-type t/c's, with ceramic and with steel t/c probe bodies, never worried once about them adding a degree or two in industry (aerospace), up to around 500-600*F in custom built ovens. I know that I had to test an oven with J type t/cs that simply poked into the oven up to 600* for one half hour, no variance. Of course the engine runs longer than that and could get more hot spots than a smooth, new oven. Chart recorders and outside calibrating companies had to verify temps to satisfy Boeing...I don't think that the intake manifold gets much over 275*F or so. of course, that's my best guess, never actually tried to get a reading off the surface of the manifold. Isolating it can't hurt and I'd be interested to hear if it affected your gauge at all. I'm not trying to say you're wrong, I'm just giving some insight based on years of experience on a daily basis with industrial t/cs and ovens that ran 10 hours a day, 6 days a week that had probes not very dis-similar to the usual aftermerket mechanical temp gauges. We had very strict guidelines about over-temp conditions. Definitely something to look into, but if this were happening to equipment in my old shop, I'd say you're treating a symptom rather than a cause. Root-cause analysis isn't easy.
The single highest flowing electric fan you can get (research the Chevelle board) is the one from the Lincoln Mark VIII. Will flow 4000+ cfm and draws 40+ amps. Next best solution is the dual unit from a Windstar. Beware of the advertidsed cfm ratings from aftermarket companies, some are inflated. Current draw and cfm's are directly related, a good rule of thumb is 100 cfm per amp. In independant tests, only Spal and Derale have actually flowed close to their advertised cfm rating.
What about your pertronix system? Have you had any problems with it? Surprising that I went through a year of hell with overheating and misfiring and once I installed Dave's MSD system it runs cool and strong. On a day like today I would have overhaeated at idle in about 20 minutes and today I chugged along in hot traffic with the guage on "N". I still have not had my rad flushed or diluted the antifreeze mix which I plan to do this weekend. I've been told that a 75% water mix & wetting agent works really well for cooling but watch out for winter if you live in a cold climate. I know just how frustrating this is and I wish you good luck.
I've read this thread a couple of times and it just hit me. You state that it cools off idling in park but heats up idling in gear. This tends to lead me to the trany cooler. Do you have an external cooler? If you don't try putting one on and bypass the radiator completly. If this works you can try running it through the cooler and then back to the radiator if you run in any cold weather. Good luck
The 455 in my Apollo had the same problem until I swapped out the stock intake. The only chance I would have is when I ran a 205* thermostat, 160* and 180* stats would just climb until I shut the car off at a little over 210*. The 205* stat would run right around 200* driving, and would hit 205* at stop lights. I also had a huge hole cut in my hood for a cowl scoop, A/C waterpump with pulleys and a flex fan. Now I have a 160* stat and a TA intake and I run 160*. The worst thing a 205* stat can do to you is cost about $5 if you make sure to watch the temp gage. -Keith 1974 455 Apollo
james, i have the same problem with my skylark and it seems to be an issue with a lot of buicks in general. i have done eevrything these guys have mentioned, and nothing has worked. fan clutch is installed, new water pump, bigger fan moved closer to the radiator with a shroud, nothing works. it does not seem ton be an air flow issue, but it seems to be a water flow issue, or a crappy radiaotr, i am installing an aluminum radiator, the guys i talked too that had the same problem said the an aluminum radiator solved the same problem we have. try everything, but if you want the problem fixed permantly, the go teh an aluminum radiator from Summit ($169). sinclair
I hate to see anyone go to extra work without trying all the simple cures first. Why not do a complete flush and then use a 50/50 mix with a bottle of water wetter? Aside from proper ignition timing [this is a key point] this brought my beast down to running at 3/4 of where it ran before I did the flush. I used an acid based chemical and then a neutralizer and then 3 complete clean flushes by bringing the car to temperature before draining. I did put in a 160 thermostat. This has been our hottest summer on record and even after long drives in the heat and traffic I haven't had a single boil over, whereas before I had to carry extra mix in the trunk as it constantly overheated once coming off the highway or stuck in traffic. If that doesn't work you can at least save what is left of the mix to use again. Good luck and enjoy the challenge.
