Anyone know where I can get a 160 degree thermostat for a 1968 DeVille? The norm was 180. It's too hot down here and the car needs some help in backed up traffic.
Hi Mike,
You should be able to find a 160 degree thermostat at any auto parts store. I recommend a thermostat that is manufactured from stainless steel if at all possible. I believe Stant has these available. The stainless thermostats resist corrosion and are less prone to malfunction caused from electrolysis.
Terry
Yes, but will it fit in my 1968?
I just remembered, I have a NOS 180 deg one. I'll take that along to confirm the size.
I believe Stant calls them "Super Stant". I have one in most of my vehicles.
Terry
I agree with Terry about the Stant Thermostat. I had running too warm issues with my 63 for years using the parts house brands of thermostats. I put a top of their line Stant Premium thermostat in the car, problem solved. The car now consistently runs between 180 -190° where before it might get up to 230°.
A thermostat has about a 23° operating range from closed to fully open. If you have a 180° thermostat installed, it will be fully open around 203°, giving maximum flow. Is your car running at a temperature over 203°? If it is, a 160° thermostat will be fully open around 183° and will not necessarily cure the over heating situation but may slow the eventual rise to over heat condition. Is the radiator and cooling system in good clean condition? Fan clutch good and the radiator not plugged with bugs, etc?
It looks like a thermostat for a mid-70's Chevy Truck has similar dimensions, so you may be able to find a 160-deg unit on the shelf for one of those. I agree with David, though, make sure the rest of the cooling system works well. I think our 68 Calais has the standard thermostat in it, and the car has never spent any appreciable amount of time north of the Mason-Dixon line. Much of it's life has actually been in the Houston, Texas area, and we've never had an overheating issue with it.
The proper stat for the 472-500-425-368 has that extra disc at the bottom to close off the bypass passage when its fully open. Without that passage blocked there will always be a percentage of coolant flow that does not go through the radiator so in theory the total cooling capacity is slightly reduced.
John Deere apparently used the same stat on some of their equipment and supposedly still make a quality unit. I don't have the part numbers handy but I bet someone will.
There were also the 'balanced' stats that had the fairly large cup valve instead of the typical flat disc one. They were supposed to flow better too but apparently have not been made for the Cadillac / Deere app with that bottom disc for a long time. It may have been Robert Shaw that made those. They still make em for some apps like the common Chev and Ford ones. There was one in my 73 when I got it but it was stuck open. I tried to find another one but came up short.
You have to be careful going cooler especially on an engine that does not get regular driving. Lower temps tend to let a lot more 'crud' build up in the engine. Infrequent and short trips just make it that much worse. Like someone else said a lower stat is not going to help at all for running hot or overheating issues. Once its open its open no matter what the temp is and if the cooling system can't handle it it can't handle it.
The rest of the system is fine. The condenser is new, and it has protected the radiator from bugs, damage, etc. I had the original tanks re-cored to a 4 core in 2005 when I had the entire engine overhauled (and bored to .030 over). The radiator was rodded and cleaned in summer 2012 before I deployed the last time. Coolant was changed then and tests good. Fan clutch is new and working properly. Belts are new.
It works fine while driving, the gauge usually sits at the 1/4 mark. But this heat and the climate control put an extra load on it when stopped, and the traffic here can get very bad very quick. The gauge will then creep up - sometimes way up. Once I get moving it cools back down.
Some folks tell me that the boring out will cause it to heat up quicker than before, especially when stuck in traffic, don't know if that's true or not, or to what extent.
Thanks TJ, I probably need to pull the stat that is in the car and check it or just replace it.
The car gets regular use and warms up before I get out or my development. so I'm not concerned there.
Here is the one with the disc at the bottom. Doing a quick look all I can find that have that is 180 and 195's.
(https://forums.cadillaclasalle.club/proxy.php?request=http%3A%2F%2Fwww.mtscadparts.net%2Fmedia%2F00%2Fa20792914518e0f2f0b643_s.JPG&hash=d5606fc1c54045c98223a651586463eacc928b08)
Picture from www.500cid.com who does sell them (and other cool stuff) if you can't find the correct one anywhere else.
Another thing that may be worth doing is getting one of those IR temp guns and do some probing to see what the actual temps are. If it will heat up just sitting you can take readings and 'calibrate' the gauge so you know what the actual temps are at various readings. Factory gauges were never known to be that accurate or linear. I have had cars where if 200 was 1/4 3/4 was only like 220 which is still well within the operating range of a pressurized system. If everything is working as it should you should be able to get over 250 without boiling.
Historically I have not had cars with working AC so I usually removed the condensers. The last few years the AC has become more important to me so I have been fixing them. What I have found is that with the condenser there more crap seems to be getting stuck in the radiator than when I didn't have anything in front of em. I don't know why, maybe it being there lowers the air pressure so stuff does not just blow out? My Suburban was running hot this summer and I had had everything apart and clean when I got the AC working a couple years ago so I was not thinking it had a dirt issue, its not a daily driver. I was thinking of replacing the fan clutch while I had the air hose in my hand and for some reason decided to shoot some air at the fan. I was a amazed at the poof of dirt and stuff I saw come out the front so I took the upper shroud off and got the garden hose and long extension on the air hose. Running warm problem was solved.
A tip for cleaning that stuff is go buy a product called 'Bugs B Gone' and spray it in the front of the radiator and condenser, let it soak for a while, then hose it off. It breaks down organic stuff (like dead bugs) so they are more easily removed. Does not seem to hurt paint either, I have used it to clean dead bugs off the front of the hood and bumpers. Also works well on bird crap and grass stains if someone cuts wet grass near your car. Recently tried it on 'pet stains' and it seems to help there too, guessing due to the whole break down organic thing.
AFAIK there is no GM or aftermarket thermostat available for the 472/500/425/368 engine other than a 180 or 195. A Chevrolet thermostat will fit but will not function correctly. TJ posted a picture of the correct one below and any good parts store should have them. These cars cooled fine when new and if the cooling system is properly maintained and in good condition should do fine today. Putting a low temp thermostat in is only an attempt to band-aid a problem elsewhere. As TJ Hopland pointed out ---
"Like someone else said a lower stat is not going to help at all for running hot or overheating issues. Once its open its open no matter what the temp is and if the cooling system can't handle it it can't handle it."
I would change the thermostat (making sure it is the CORRECT thermostat for your 472) as it might be faulty and not opening fully, after that you can try an electric fan in front. But still, there is a reason for the overheating.
I have one of those Fluke IR temp guns, just need to find which box it is in. I packed up and sent home some 20 boxes while I was away and its' in one of them.
Rad is clean, I hose it off regularly. I'll check my NOS stat against that picture.
I've always had the climate control working, and that does put an additional strain on the system, especially here.
On the gauge, I completely understand. I'll definitely need to "calibrate" mine so I know what is what. If it's as you mentioned, then I have nothing to be concerned about.
I don't think a 160'F stat is really going help the car run cooler. Once it reaches 160'F or above any benefit is gone and the result would be the same as a 180'F stat which is what I run my 1970 Cadillac. Since the 1970 did not include a temp. gauge I installed a real good Autometer one and always know the temp. The temp typically runs between never hotter than 210'F in normal driving at 95'F and sunny. However, if in a traffic jam with a/c on and it sits idling for an hour it is going to keep up to 215, maybe 218'F or so. 220'F is the point where the factory idle speed up engaged to spin the fan faster and provide more cooling. I have driven it in 102'F weather no problem.
The car was designed to operate in hot weather with a/c on so you should be good. On my car I did change to a 4r radiator when original went bad and those dessert air radiators are also available for a 1968, but you have to be careful that the fan clears the thicker radiator. To add insult to injury the replacement fan clutches are deeper, pushing the fan closer to the radiator. Also, I changed my fan to the 7 blade commercial chassis type instead of the five blade. This does move more air but noticed it seemed to have a little effect on performance.
For your car be sure the fan blades are in proper planer alignment with fan shroud (clutch could be deeper), you may be able to use a shallower spacer. Be sure there is no place for air to go around radiator between sides/bottom/top of radiator and shroud housing. Be sure the rubber sheet at bottom is in place. Make sure timing is correct, even too advanced is no good, retarded is bad. If the water pump is old, it should be replaced. Consider a commercial chassis fan as it does move more air. Make sure fan clutch is good. Make sure idle is high enough and the idle speed up with climate control works too.
Usually I drive top down w/ac off unless it is below 50'F or raining. If you see my car driving top up on a hot sunny day, it has been stolen.
I read all of the posts and hesitated answering, but Scot hit the nail on the head - the purpose of the thermostat is to bring the operating temperature up to a certain level - be it 160, 180, 195, etc. Once that temperature is exceeded, the thermostat remains open and the cooling components take over - radiator, water pump, ambient air temperature. So, other than for winter driving when a 180 degree thermostat provides better heater heat than a 160, in summer driving replacing a 180 with a 160 really has no effect; especially if you are running 200+ degrees.
My two NOS 180 stats look like the one TJ pictured, however one of them has a cracked cup that where the bottom disc clamps onto the main unit, so it's most likely no good.
as I have stated, the rest of the cooling system is fine. It only acts up in very hot weather (all the time here in FL) and when stuck in traffic (which was NEVER like this in then 60s)
You guys anywhere else don't know how hot the road surface can get here in FL on a sunny day. It can easily get over 130-140 degrees with air temps over 115-125 in stopped traffic. That's HOT. And all that Hot air is being pulled past the condenser first, then the radiator with more heat radiating up from the asphalt. Even in AZ & NM where it gets just as hot, that's Dry air, not this 95% humidity that we have in FL so that nothing cools unless a hurricane is blowing over it.
Took the car for a 30 mile drive this evening, gauge never went over 1/4. Outside Temp was around 91, but no sun load on the road, and no stuck traffic. It was a Nice drive.
I'm going to try and get that broken 180 replaced by the vendor and will check out my other one. I'll also try to "calibrate" the gauge so I know what the marks really mean.
I checked out MTS (500cid.com) and their stat price is reasonable, so I'll get one. They also show a new water pump that has a closed turbine style impeller. It looks just like the new ACDelco pump that I bought as a spare. It's supposed to have 25-30% more flow at idle, so that might be a good thing to install with a new stat. It can't hurt.
I am a year-round resident of Florida, and live just south of Melbourne on the east coast. My '73 472 runs cooler in summertime stop and go traffic, with the AC on, than it does at 75 MPH on I-95.
The water pump that MTS sells is a "Flow-Kooler", you might find Flow-Kooler's website interesting ---
http://www.flowkoolerwaterpumps.com/
I have a Flow-Kooler on both of my Cadillacs, the '73, and my 1935 472 powered Cadillac resto-mod sedan. I put them on both cars during their restoration because they both needed new pumps and I wanted to have what I thought would be the best. But I STILL say the stock pump and cooling system should do the job in Florida, or Arizona, or south Texas, etc.
Thanks for the link G. I'm checking it out.
Stop and go traffic is OK. Its the stop and stop here in Tampa that is not OK. You guys have a near constant sea breeze there. I'm some 30 miles in, and that's a big difference.
Looks like Flow Kooler sells the Robert Shaw stats, so I'll get one of those instead. I'll also check timing and the fan shroud &all the other air flow items.
As a note to two posts up, running at higher speeds does cause it to run hotter, the temp gauge goes part way to 1/2 above a steady 75MPS speed.
Yesterday, I ran it right up there to the 9th speedo quadrant, and sure enough it went to the 3/8 - 1/2 range. And even when I slowed down, with all the long traffic stops it stayed there until we got to the restaurant. But when we got out and went to a cafe, and later the long return trip, it stayed right at 1/4 all the way, even when stopped at 2 minute lights.
The hot daytime temps here are definitely driving me crazy.
Mike,
I have the stock water pump, but the seven blade commercial chassis fan and the 4 row radiator. Got stuck in traffic on way back from Boston GN for 3 hours traveling about 5 miles in 95'F temps with strong sun in the afternoon. Top was down and the car stayed around 210'F or so. Probably would have been 215'F with a/c on. Car does not like 230'F, so if I stay away from that I'm good.
I think it was pre-Christy "Bridge gate" and he did not get caught that time, because it seemed like traffic was stopped for no reason.
Please post on if that water pump is an improvement, would really like to know.
You should get a real good temp gauge that tells the real story and see what temps you are running. If 3/4 of the way corresponds to say 210'F then you should have no worries. Weird how the temp goes up so much at speed. At 80mph, mine never goes above 205'F during real hot weather - but my fan is also still working albeit at reduced capacity (no clutch - flattened blades). I bet you are Ok and gauge is leading you wrong a bit.
BTW if you ever get in trouble you can trick the climate control into full heat and it lowers temp about 10'F.
I got the flow kooler pump, 4 core (new) radiator, water wetter, "supposedly" cleaned out block and mine seems to run warm. Though I don't know what the water temp is though. I expected better from my set up, especially the flow kooler pump (advertises better flow at idle) and the water wetter (advertises 20 degrees less water temp). I'm still working on mine, though I haven't had time to actually "work" on it and start doing things. Work, yard work, house work and normal life are getting in the way. Soon, vacation will get in the way. Then starting a new job (same job, but new location-farther away). It's always something!
Scot, where do you hide your temp gauge, and how is it hooked up (where is the sender located? I really do need to get mi gauge "calibrated. I'll do that when I change the pump (or earlier). We'll just sit there with the IR gun and get actual temp readings at 1/4, 3/8, 1/2, 5/8, and 3/4 (that's as high as i will let it get!). That should shed some light on this.
I'm going to call those FlowKooler folks tomorrow. I have a new ACDelco pump, and it has a similar, if not identical impeller, but it costs half what the FlowKooler one costs ($56 vs $119). I do like the robert shaw stats though, so I'm definitely getting one one of those.
Chris, I put water wetter in mine too, and do not notice any advantage. Maybe for hot racing applications with no thermostat, but not our cars, i guess.
If the water wetter is really lowering the temps, the stat will just partially close to allow the coolant temp to get hotter. It will still eventually settle on what the stat is calibrated for.
Mike,
Not hidden, removable. Unplug, one bolt and gone - good for shows. There is a tach in the glove box. The gauge is way better than the IR gun. The sensor is under compressor and I lose the warning light - who cares, plus still have the hot block light.
I used to think who cares about the stock lights too but then I had to re rebuild my engine after the oil pump failed and I always wondered what if I caught it sooner? Now I have gauges and the lights. I figure it can't hurt to have both.
On my gauge cluster still have the oil pressure light, but not temp light. There is a hot block light, and that I still have.
The hot temp light is not a great value, it basically informs you when there is an extreme situation only. This is true because when you shut car off on super hot day with a/c running and come back to it in 20 minutes, the temp is past 230'F which means that the warning light probably does not illuminate until say 250'F or so.
The oil press light is probably the same, a real low press situation indicative of a leak.
The gauges help you prevent a future problem. My volt gauge is the best because it saved me on a bad regulator and a bad alternator - two times it saved me from a possible break down.
It is nice that the Cads have the metal temp lights. If I am really feeling like not paying attention my gauge system has a very loud alarm that can be enabled. I turned it on once, no way you could miss it. I think its intended for RV's where you may not be near the gauges.
My water light seems to start to glow in the 230 range. Sometimes I will see it slightly glow just before a hot restart. Its not the original sender, its one I picked out of a catalog. I don't remember what the set point was supposed to be, I was not expecting 230 but I am happy with that.
If you can find an old school parts store that still has older books you can just page through various sensors and pretty much pick the set points you want. Some industrial engines have oil pressure switches in the teens vs the car stuff that is more like 5.
Here's my gauge set up.
Chris,
I'm going to make a wild guess that you don't spend a lot of time looking at the tach.
Greg Surfas
Only after I get done sending a text!!
>:D
It's nice look down and see how many revs it is. I no longer need "shift points", as I have become an old man! It's more for monitoring...........
chris.
Those are both nice setups.
My tach is in glove box. Use it to set idle, set timing, and monitor occasionally. It is also useful impressing my friends who wonder what rpms it requires to reach 70mph.
Well, I got the FlowKooler pump and RobertShaw stat in.
The Impeller looks like it will move more liquid than even the new ACDelco unit, which also has a round impeller but with shallower vanes and only 6 vanes compared to 10 on the FlowKooler pump. The Delco unt will by my road trip spare. The stat is a unique construction. I'll try to remember to take a couple of pics tomorrow in the daylight before installing it.
We'll try to get it flushed out and installed tomorrow. I'm replacing the upper and lower radiator hoses as well and any suspect looking heater lines. The rad itself is fine as is the heater core. I also have a 1960-70 overflow tank installed. That has really helped the past few years, by preventing coolant loss to the ground.
Well, the FlowKooler Water Pump and Robert Shaw Thermostat were both installed and while driving back that night all was fine. The next day in blistering 100 plus heat, during a 17 mile traffic jam, it went to 3/4 and a bit over (but didn't boil) and stayed there until I got to my house. It was like a 1,000 car procession, every light required waiting for 2 or 3 cycles to get through, and the light ahead was already red before I got through the one i was on. That was really rough.
When I finally got home, I drove it for about 10 more miles at 55-65 MPH around the development and it cooled right back down to 1/4. An hour later I drew off some coolant to look at the radiator and it looks like the coolant is flowing nicely through the radiator. It also idled for over 30 minutes without going over the 1/4 mark.
We checked the temps across the radiator and there is a steady progression from about 195 on the upper hose to 180, 170, 160, 150, 140, etc until just before the return tank and then Wham! 185 degrees F. WTF??
The transmission cooler is in that tank, and sure enough when the car has been driven, those lines get quite hot - and they are taking away all the cooling done across the radiator. Normal THM400 operating temp is 170, but these lines were 180-185. Hmmmmmm...
The radiator cap was also suspect so I changed it. Not sure what that will do, since it has not boiled over at all, and I have had a 1969-70 coolant recovery tank installed since 2005.
Went to Ocala (approx 75 mi each way) on Sunday, it warmed up to 1/4 (approx 180 deg) and only rose after it got very hot outside to about 3/8 way. Going home at night it never went over 1/4.
Had the transmission fluid flushed and filter changed. It seemes to run a little cooler. Gauge was slightly Below 1/4 while driving, but still crept to 3/8 while stopped for any length of time.
I'm looking at two last items. First timing; Ineed to make sure base timing is 5 deg BTDC with no vacuum input. Second I need to make sure that the Distributor Vacuum Switch is working. Of course that switch isn't supposed to shift vacuum unless coolant gets to 230F, and that's almost pegged on the gauge. This is the 3 port vacuum switch that is near the distributor (4 ports on 69 & later) and supplies either carburetor or manifold vacuum to the distributor. Again, it is only supposed to switch to MT when the coolant temp gets to 230F, so maybe it hasn't gotten that far yet?? Who knows.
Maybe the car isn't operating out of design parameters. The owner of the shop that flushed the lines, said the car didn't want to overheat, and the extreme traffic is an abnormality. It's just very unnerving with all the money spent on the overhaul, i don't want to burn any bearings.
If the above doesn't help further, then I'm looking at an aux transmission cooler and an engine oil cooler mounted up front. These should both take a load off the regular cooling system.
I've looked at Hayden and Derale. Does anyone have any experience or opinion on either of these brands? They seem similar and both have light, medium and heavy duty applications.
Mike,
The oil cooler is a great idea. So is the independent trans cooler. If possible do not make those in series with air flow thru radiator. If I lived in South FL or TX, probably would do this. Also you can do a fuel cooler too. One of the lesser discussed purposes of oil is to cool engine too.
Have not heard from you much about the fan that draws air across a/c cond and radiator. The fan from commercial chassis is superior air flow than the one for standard chassis. Try and get one of those. I did that on my 1970, 5 blade standard (no clutch), 7 blade commercial. Also, do you have the fan shroud and radiator sealed well so that air drawn by fan cannot by pass radiator? That rubber sheet piece on the bottom of radiator really helps cooling on a 1970 Cadillac.
Yes check the timing! That can make a huge difference. You can tell also a little if your car shifts hard between 1-2 and 2-3, timing may be too retarded.
Keep in mind that the 0.030 inches over bores do tend to run hotter than factory (mine is bored thirty over too, so it is a 478)
My car never gets tested like you described because if it is sunny and 100'F my top is down and a/c is off. If it rains (usually does at the end of a sunny 100'F day) top goes up and a/c on, so less strain on cooling system.
I got stuck in a 3 hour sit and idle never go more than 5mph trip home form GN 2013 in sunny afternoon, 95'F in NJ. Top was down, enjoyed talking with neighboring stranded car occupants. Temp never crossed 215'F, but a/c was off.
Enjoy your Cadillac,
Scot
Scott said "Temp never crossed 215'F, but a/c was off.".
With the Air conditioning on, on a ,say 95 degree day, in slow moving traffic, the air going through the condenser will exit the condenser and enter the radiator at somewhere around 130 degrees. If you are driving at say 65 MPH, there is enough air flow to lower both the condensing temperature and the resulting air flow to the radiator temperature.
The Flow-Kooler pump increases the water flow at low speeds, up to (I believe) 2500 RPM, and the 7 Bladed All steel factory HD Cooling fan increases the low speed airflow. With these two devices and a correctly running engine and non clogged radiator, a 472/500 motor will stay well within the design temperature the engineers designed it for. The motors do not stay at an exact temperature but of course vary as the load and conditions change. That was clearly understood and devices were incorporated to change timing settings when required. Chasing a numerical "ghost" was the reason that I removed the water temperature gauge from my Eldo decades ago. If there is an actual problem the "water" light will alert me. In spite of my car b eing subjected to some of the most demanding conditions from 110 degree phoenix traffic to constant 100+ MPH across the CA desert, the only time the water light stayed lit (it often came on for a moment when the car was re started after a hot weather "heat soak" was when I blew a hot water heating valve. These cars were meant to be driven by people that had absolutely no knowledge or interest in how they worked mechanically, so ALL systems and devices were designed to be indestructible as long as all fluids, belts and hoses were correct.
Mike,
chasing the temperature gauge can drive you nuts without gaining a thing. If you have the "water" light installed and operating it will warn you in plenty of time if there is something wrong.
Greg Surfas
Greg has got to be right and a point we forget about, my Grandmother (she enjoyed a 64, 67 and 73 Caddy SDV) turned on the climate control and drove her Cadillacs everywhere without regard for temp gauge setting. Never has my caddy run rough or noticed any difference no matter what temp gauge reads. My light never even glowed before it was disconnected on a heat oak after running on a hot day and restarting after 20 minutes.
Sometimes when people ride with me and it is 95'F, sunny and top down they complain at the stop light and I turn the a/c on for them, it helps a little. It does drive the temp gauge up about 5'F after ten minutes at idle. Conversely, I put manifold vacuum on power servo to drive heater on as an experiment during 90'F day just to see what it will do and it lowers temp gauge about 8'-10'F. Provide the car is above 180'F on temp gauge to as hot a it ever has gotten, it runs the same when in proper tune.
"Mike,
chasing the temperature gauge can drive you nuts without gaining a thing. If you have the "water" light installed and operating it will warn you in plenty of time if there is something wrong.
Greg Surfas"
Hear! Hear! Been there done that.
Quote from: Scot Minesinger on September 27, 2014, 11:47:37 AM
Mike,
The oil cooler is a great idea. So is the independent trans cooler. If possible do not make those in series with air flow thru radiator. If I lived in South FL or TX, probably would do this. Also you can do a fuel cooler too. One of the lesser discussed purposes of oil is to cool engine too.
The mfs all prefer that you run the trans cooler in series with the in-radiator cooler, but they say the tank cooler can be bypassed (they recommend the next larger size cooler though). I have this under serious consideration and will use either Hayden or Derale, and will use their top tier lines. No cheap-a$$ tube & fin coolers for me. The engine oil cooler being a new addition could only help.
Quote from: Scot Minesinger on September 27, 2014, 11:47:37 AMHave not heard from you much about the fan that draws air across a/c cond and radiator. The fan from commercial chassis is superior air flow than the one for standard chassis. Try and get one of those. I did that on my 1970, 5 blade standard (no clutch), 7 blade commercial. Also, do you have the fan shroud and radiator sealed well so that air drawn by fan cannot by pass radiator? That rubber sheet piece on the bottom of radiator really helps cooling on a 1970 Cadillac.
I believe my shroud is pretty much airtight, and I have all the splash guards in place (new ones) including the all important one under the radiator. The fan is a 7 blade with clutch as specified for All AC equipped cars for 1968. There is very good fan draw across the condenser and radiator and good cooling from 195 to 140 or so across the radiator at idle. I also have a 1970 7 blade no-clutch fan, that I might consider, but I think that won't be needed.
Quote from: Scot Minesinger on September 27, 2014, 11:47:37 AMYes check the timing! That can make a huge difference. You can tell also a little if your car shifts hard between 1-2 and 2-3, timing may be too retarded.
I'll check the timing, the Distributor Vacuum switch, and the idle speed up & fast idle this week. I need to find my spring kit from the Crane Cams adjustable vacuum advance kit to reduce the high RPM mechanical advance (needed for the crappy modern fuel). The transmission has always been fine. I don't think it got over 230 from reading the manual.
Quote from: Scot Minesinger on September 27, 2014, 11:47:37 AMKeep in mind that the 0.030 inches over bores do tend to run hotter than factory (mine is bored thirty over too, so it is a 478).
Yes, this whole thing might be just the result of the boring out for the overhaul. It did seem to run a little cooler yesterday, but I was in a downpour. I need to get out on another hot afternoon.
Quote from: Scot Minesinger on September 27, 2014, 11:47:37 AMMy car never gets tested like you described because if it is sunny and 100'F my top is down and a/c is off. If it rains (usually does at the end of a sunny 100'F day) top goes up and a/c on, so less strain on cooling system.
I got stuck in a 3 hour sit and idle never go more than 5mph trip home form GN 2013 in sunny afternoon, 95'F in NJ. Top was down, enjoyed talking with neighboring stranded car occupants. Temp never crossed 215'F, but a/c was off.
Enjoy your Cadillac,
Scot
The sun here is oppressive, and I had the top up & AC on last week in that jam.
Quote from: "Cadillac Kid" Greg Surfas 15364 on September 27, 2014, 12:56:42 PMThe Flow-Kooler pump increases the water flow at low speeds, up to (I believe) 2500 RPM, and the 7 Bladed All steel factory HD Cooling fan increases the low speed airflow. With these two devices and a correctly running engine and non clogged radiator, a 472/500 motor will stay well within the design temperature the engineers designed it for...
...If there is an actual problem the "water" light will alert me... ...ALL systems and devices were designed to be indestructible as long as all fluids, belts and hoses were correct.
Mike,
chasing the temperature gauge can drive you nuts without gaining a thing. If you have the "water" light installed and operating it will warn you in plenty of time if there is something wrong.
Greg Surfas
I'm sort of getting to be in agreement.
I don't have the water temp light, the 68s still had the gauge, but from the owners manual, maybe I'm getting too concerned over what is considered normal function. I do have the engine metal temp buzzer and that does work. It activated once in 2005, fortunately i was just stopping the car anyway.
1968 Owners Manual P 10:
"Normally, The gauge pointer will more gradually from the extreme left when the engine is cold to approximately the one-quarter mark.
Do not be alarmed if the the pointer registers above the center range in heavy traffic or on long drives during warm weather. The pressure controlled radiator overflow will normally prevent coolant losses up to 259 deg F"
This is exactly what it does - it just seems to be too often for me, but it
is very hot here in the summer (and on sunny days in the winter too!). I never lost coolant and have the 69-70 closed system in use. Even with the older RC27 cap, it never blew out the overflow tank.
"The temperature gauge can sometimes register "H" (Hot) under severe operating conditions. However, this is not necessarily cause for alarm
unless the the red warning light (the engine metal temp light)
is on, and the warning buzzer sounds.
Hmmmm...
The warning buzzer only sounded once, and that was back in 2005, before I had the 4 core radiator put in. The buzzer goes off, and the temp gauge pegs the H. Even in that long traffic jam, while the gauge did indeed get pretty close to the H, the buzzer never went off, and it cooled right back down once I got to a 2-3 mile open road.
I pretty much replaced or serviced the entire cooling system by now. No leaks, radiator flow is fine, fan & clutch are good, new condenser with no blocked / dented fins, good cooling progression across the radiator from upper hose to the other side, new cap & hoses, and now a cleaned out transmission with fresh oil. No vacuum leaks that we can detect (I went through that the past 6 months with the climate control).
I do have two things working against me:
First, the block is bored .030. This makes a difference, but how much???
Second I do have a mild Comp Cams cam in the car. This is not supposed to affect idle quality, but it might be, and it might be dropping carb vacuum at idle a little thus retarding timing a little. This as I have come to find out can cause the engine to run hotter, so I'll check that when I re-set the timing next week.
I just scored a couple NOS GM ported vacuum switches (in case mine had gone bad), so that'll be covered,
Mike,
It seems you are satisfied with the car's performance. Can we close this topic?
Greg Surfas
If a moderator wants to lock it, fine.
I'd really be satisfied if the gauge never went past 1/4, but that's not going to be the case. I just want to be sure I'm not damaging bearings. I spun a bearing in my old 1970 way back. I didn't know what happened, and in a couple minutes it broke the connecting rod. You don't ever want that to happen. A couple years prior to that, I blew out a freeze plug on the interstate at night, and that's where I probably caused the bearing damage.
I don't want that happening with this car.
After I verify timing is correct and the Distributor Vacuum switch & idle speed up are working correctly, and (IF) I put the coolers in, I'll post those results. There won't be any more postings from me until I make further changes to the car.
Mike,
The reason the trans cooler independent of the radiator install instructions is to be in series with radiator is that it does not have a fan more than likely and relies on the car radiator fan for air flow. This is the same almost as having it integral to the radiator in that ultimately the engine coolant also cools the trans as is the case now. The trans cooler I probably intended for radiators without a trans cooler.
You can buy an inexpensive 12V fan from Summit racing and attach it to the trans cooler with a stat powered by ignition on only power source. Then it will not need to be in series with radiator fan. This will accomplish your goal of not having the engine coolant absorb the trans heat too. Make sure you have a high capacity trans cooler, because by your account the trans was a significant source of heat.
BTW same with oil cooler, independent fan too. The oil does not get cooled otherwise, so anything you add will be a help, contrary to trans were you need to at least equal what the radiator capacity is.
Are you one of those convertible top up guys when it is not raining and gets a little hot? When I was a kid my Dad would only lower the top on 1970 Oldsmobile convertible when it was 72'F, sunny and no humidity and the car did not have a/c! I thought he used bad judgment operating the car. We set out sometime to not repeat our parent's perceived errors when we were kids. If it is over 50'F and not raining the top goes down. In 2009GN at LV rented a Mustang convertible and the top was down at mid day 105'F and I loved it. Just messing around here, but when it is hot and sunny, the solution to your engine running hot issue is drop the top and turn off the a/c. If a ran my car in 100'F + temps with a/c on in stop and go traffic for hours, I might have started this thread.
Scot,
There is no engine oil cooler in the 1968s so anything I add can only help. It will have to go in front of the condenser, so it will get airflow even at idle. anything that gets to oil outside of the block for any length of time helps, and adding a cooler should add about 1-1.5 quarts of capacity making it a 6 quart or greater oil system and that also helps.
NorthStars have a 7.5 quart oil system in a 4.6L engine.
I'm going to get the largest trans cooler that will fit up front on the passenger side of the condenser, and see how that does.
I'm a top down guy, and will drive it in anywhere from 45 to 105 with the top down, as long as its not raining. I've also been caught in the rain more times than I can remember, the most recent being last week on sat night. I stopped and we got the top up just before it started to downpour. Last few days here it's been awful, with rain most of the day, but today its looking good. Good for a country drive.
When I had the top op that time was to test out the changes made to the cooling system.
Mike,
You should be all set. If you don't drive with top and a/c on when sunny and hot you should be good. The fact that you made it thru a 3 hr top up a/c on ordeal during 100'F is good and an unlikely future event.
You are right since oil cooler was not available in 1968, anything you do will be an improvement. The trans cooler I disagree if you install it in front of radiator or condenser, the heat rejected is essentially transferred back to the radiator engine coolant (not all of course, but some), just like it is right now.
Modern cars seem to all have that oil cooler and that may be why they go 200k miles no problem. My 1995 Fleetwood had an oil cooler in the radiator, and it ran superb even at 254k miles.
The GM diesels of the 80's and 90's had engine oil coolers. In the 90's GM also really seemed to be in love with them, just about all the 'truck' based stuff had em which as Scott mentioned included the D bodies. For the most part I found them just to be a major source of leaks and ended up removing them in most cases. I was not towing regular or heavy with any of them and other than stopping the leaks I didn't notice any difference.
I have a friend that is an engineer that designs various heat exchangers and over the years have talked to him about automotive cooling systems. Things like coolant flowing too fast and external coolers in front of the radiator vs in the radiator. For the most part his answers have always been that it all makes very little difference because from his view point a typical automotive cooling system is fairly crude. I have not asked him or showed him anything from the 2000's so maybe they have got a little more high tech but I did show him more than one system from the 70's and 80's and all that impressed him is how well they apparently work for being a fairly crude design. The stuff he designs and builds are not mass produced so its a totally different ball game than what the auto engineers have to deal with but the principals are still the same.
I really have not noticed them on newer stuff but I have not really worked on a lot of them and since they have so many wires and hoses jammed into a fairly small space I may have just not looked hard enough.
Being an engineer myself, this coolant flowing too fast through the radiator is not valid. Actually turbulent flow produces better heat transfer than laminar flow (slow and smooth, coolant does not get mixed up)
I'm with Scot on this, quick flow through the radiator (or relatively quick, since we are not talking about fire hose volumes here) is better since it also means the coolant is not sitting in the block too long either. At least that's what the FlowKooler ads say. ;)
The 1994-96 Fleetwoods (with extra capacity or heavy duty cooling options) have both engine oil and transmission coolers, and while the one in my 1996 developed an oil leak, it only had to have the lines replaced. The 1995 never leaked. The transmission cooler looks like a mini heater core, and I think it does not have a radiator tank cooler (I'll check the svc manuals). I like this setup because I do tow occasionally.
There is an in-tank trans cooler in the right tank, so these Fleetwoods have two oil coolers in their tanks, and they never overheat. I checked mine a few times this summer (set the Climate Control diag pointer to # 24 and that is coolant temp in deg C), and it stays between 95 and 100C, usually 96-98C.
Yes these are crude compared to precisely calibrated systems, but they are more than adequate for their requirements, especially with multiple variable speed cooling fans.
I spoke too soon about the weather, it's been raining all afternoon & evening.
Still raining here in FL...