I've had the SBC running in the Cadirac for a few days & it seems that it's been running hot. I've got a mechanical "auto-gauge" brand temp gauge and it's reading 190 degrees at cruising speeds & 210+ in traffic. I'm running the stock radiator that's just back from the rad shop & a flex fan about 1 &1/2 away from the face of the radiator. Thermostat in it is 180 degree. I'm going to try to put a 160 deg. thermostat in it today and survey the results. It's still an open cooling system. Questions: Anyone running a radiator that's original to their car with a later model motor? Is that working? Anyone had a bum "auto gauge" brand gauge before? They're the cheap ****, so I'm not convinced that it isn't giving a faulty reading. Aren't sbc's supposed to run KOOL? Help or suggestions appreciated. -r
I'm running a stock 1940 radiator with a sbc in my 40 chevy and it runs around 180 to 190 in the Florida summers. I'm also running an electric fan in front, so I can turn it on in traffic if needed. I have found that you can play with the pulley size on the water pump and slow down and speed up the water flow thru the radiator and make as much as 30 degrees difference on the same motor and radiator. Also I do not use much anti-freeze as this removes water, which is the coolant for the engine.
Randy, I had a similar woe last summer with my SBC. It would run all day long around 190ish every day I owned it, with a 180 T-stat. Well, my first summer in Phoenix, the first day it was over 108 degrees oustide, it started running about 205ish. As the summer progressed, it would run 218 on the highway. This was in a 1983 Caprice with that car's stock radiator, 3 row. Some things to consider... Where is your temp gauge sender? In the intake manifold or in the head? Mine was in the head. If you are running headers, like I was, the consensus was that the heat from the headers could influence the temp. How do you have the distributor advanced, manifold vacuum or timed port? It sounds like you have it at the timed port, from the way it gets hot in traffic. Someone correct me if I'm wrong, but I think if you put it to manifold vacuum, it will advance the spark a smidge while idling and it might run a bit cooler. But you might have to reset the timing if you do that. Above all, remember that water boils at 212degrees. When it is under pressure it is higher. You also have a higher boiling point with the Antifreeze, so 210 shouldn't be anything to worry about. I'm guessing you are running a 7 psi radiator cap?
Thanks for the input. Deyo - Yup, dist. is advanced timed port. I'll mess with that today as well. I'm running the temp sender in the intake manifold so I dont think it has much to do with header temp. Also, I'm running a pretty big trans cooler in front of the rad, which may be restricting the air flow a smidge. I'm running a 13 psi rad cap. Bad idea? But... I just pulled the cap off of it & discovered that it is for a closed system rather than open - may have something to do with it. 160 deg thermostat - good idea? -r
Another idea is the cooling additives like Red Line 'Watter Wetter and Royal Purple "Purple Ice. They both will help the car run cooler. (maybe not the 30 degrees cooler that they claim but it works) At less than $10 a bottle, it is worth trying!
hey randy, you didn't say if your sbc was a new crate motor or a used motor with mounting milage. i have been running a very tired 305 4-barrell in the A for the past 2 years and it was a solid 180 all the time, even if i wanted to leave it idling in the drive for hours, that's with short water pump, a 180 thermostat and a new radiator, plus the fan is about 2" from the radiator but no shroud. this winter i installed a new crate 350 motor and a few weeks ago i got it running for it's initial 2 week trial run around town to see what kinds of bugs were going to rear their ugly heads. right away i noticed the motor ran hotter than the 305, reading around 190 while running at speed and up to 200-210 when i would get caught for a couple lights in a row at the same stop light, however the temperature would come down in the 190 range again when i got rolling. i questioned my mechanic friend and he told me the new crate motor was producing alot more friction than the old motor, hence the higher temps. makes sense to me so i'm going to keep an eye on it over the next few weeks and see what happens. if you have a new crate motor be prepared for the increased temperatures. not too many answers here but thought i let you know the problems i ran across, hope it helped man. mike
Stick with the 180º stat. It'll run too cold and foul plugs and get lousy mileage that cold. switch to Manifold vacuum on all SBCs unless it's drag race only, then do what gets the best time. You are running retaarded at low RPM. That's what makes it get hot. switch to manifold vacuum. If you are running a newer "smog" distributor the vacuum advance might be advancing too far for good initial timing and overal advance. The ones with MS stamped on them move too far, like 24º nd you only want 12º but you can stick a short piece of tubing (I use a cut off piece of brake hard line) over the rod to restrict it's movement in the slot. You have to take it off the dissy to do this. Set your timing with the vac. advance disconnected, probably around 10º-14º then hook up the vac advance. It'll quit overheating. Put a stock GM fan on it too, with the temp clutch if you have room. Flexifans are, I won't say it...
I am running a 48 rediator with SBC. I run a 12" electric fan. Last year I had the same problem. I put a hi flow water pump on and some water weter in. No more problems. I also have the same gauge you have. She gets up there sometimes but not much. Only on the high way (411's with a 3 speed and 26" tall tires) Setting still in trafic is no problem anymore.
Huh. The motor is not a crate, but a rebuild. It has MAYBE 100 miles on it right now. Anyone else heard of Thirtycoup is referring to? Sounds reasonable. I'm going to play with the timing & see what that yields before I get REALLY serious. I've heard of that "water wetter" stuff, but never tried it. I'd like to solve the problem mechanically if I can w/ additives being a last resort. Fan shroud is a possibility, but I'm going to try the other options first as I'd hafta fab one to fit. The ol' '56 didn't have one stock. Thanks fellas. -r
[ QUOTE ] If you are running a newer "smog" distributor the vacuum advance might be advancing too far for good initial timing and overal advance. Put a stock GM fan on it too, with the temp clutch if you have room. Flexifans are, I won't say it... [/ QUOTE ] I'm running an MSD "Pro-Billet"(shut-up, I know) distributor on it. No smog stuff there. Flexifans ****, huh? I'd never heard that. Actually I'd never heard anything at all about 'em, they just seem to be everywhere. Not being a smart-***, but why? No room for a clutch fan unfortunately - it's a pretty tight fight as is. -r
Flex fans don't ****. They take a little more power than the clutch fans though, but still a big advance over any stock fans. Is this a built engine? I have a fairly built 355 with a 57 6cyl rad in it and it runs 185 on the road and about 195 in traffic. Where is your sender? There are a few places to put them. The more common place seems to be by the thermostat, that way you get a reading just after it goes through the radiator. The other place is on the side of the block and that can read much higher. Especially if you have headers. Is your guage mechanical or electrical? If its electrical it probably won't be affected by hedders.
A friend once told me those low end gauges can be 10 to 15 degrees off. He used an infra red temp device and measured the temp at the sensor, compared that to the gauge. I know, not much help, the car could be running even hotter My SBC used to go over 200 alot sitting in traffic. But on the first real hot summer day it started climbing to 210, then 220, then 230. I got out on open road and it eventually cooled down. That was the start of the process. I next installed an extra electric fan in front, to use for those few occasions I was in traffic. Eventually I went to a larger radiator just to be safe. In answer to your question, I know alot of Merc owners still running the original Merc radiator with SBC or SBF motors. It's more a matter of radiator capacity (size of the core exposed to air) than whether a radiator is older than the motor. If you can make one complete p*** at Paso on the Friday nite cruise without boiling over, you've p***ed the test.
OCP, straighten up in that chair and pay attention, boy...He said his sender was in the manifold! Anywho, for the record, when my SBC, mentioned in my post above, would hit 218 degrees on the highway, this was with a fan shroud. For what it's worth.
Mike, I'll have to wait for the TEST until May. Until then I'll see about getting the motor better timed & the spark sufficiently advanced. Thanks. -r
I have a stock 1940 Ford radiator in my 40 Ford coupe. 40 Fords are supposed to be difficult to cool . The SBC is fresh and bored .060 over. I have a mechanical belt driven fan and nothing else special. I run a 192 themostat and the coupe shows 190.......old Stewart Warner gauge. I believe that the 192 themostat holds the water in the radiator LONGER allowing the coolant to cool down while it is getting back to 190 in the engine. IF it is already going 190...what do you have to lose..try it..... I run my MSD small HEI (8361) on full time port at the carb. I run just enough anti freeze to keep the motor from freezing (in the Southland....about 20 above ) which is barely green. I have stock 57 Chevrolet (1/2 ton pickup) water pump pulleys.
Deuce, You live next to old fort Jackson huh? That place is *****in & very well preserved. You know a guy named Joe Blunt? Maybe Greg Starbuck? They both worked there at one time. Thanks for the advice. -r
For what it's worth. I'm running a 305 and it runs steady at 180 to 190 with a 180 thermostat. To me it is running at the temp I would expect. It does seem to get much warmer than 205 when it's hot. The trick I've learn when in traffic or at a light is to kick it out of gear. This takes the load off and kicks the RPMs up a bit and cools it off some. To me it sounds like you have a motor running just fine. Aren't they supposed to warm up a bit? Cheers.
[ QUOTE ] The trick I've learn when in traffic or at a light is to kick it out of gear. [/ QUOTE ] Which advances the timing enough to not overheat from it running retarded at lower RPM.... Whatever ya gotta do to get around 24º of advance at idle, is what is needed for a SBC to stay cool. Manifold vacuum on the vacuum advance is the easiest way. It's how the Chevy factory does it.
damn this post was great timing. i am having the same problem with my 56 chevy with a well built 383 in it. thanks guys for all the info. i will be trying some these suggestions on my car. diego
Hey home chicken I'll go search through Old Scabbys pile of super secret Caddy parts as I may still have a fan shroud from the dear departed 64 laying around. Also doing a junk yard run this week and will keep an eye out for one. Is you rcarb set up right? And like everyone else said timing too. Carb to lean, motor run hot!! Timing off, motor run hot, ****py cheap *** gauge, motor run hot (but not really gauge just LIE to you ).......
and its been hotter n hell the last few days since you got it on the street! One thing I hadn't seen mentioned...Randy, you said it was a rebuild with only 100 or so miles on it? May well be running a little warm till everything settles in.... Just a thought... dave
[ QUOTE ] [ QUOTE ] The trick I've learn when in traffic or at a light is to kick it out of gear. [/ QUOTE ] Which advances the timing enough to not overheat from it running retarded at lower RPM.... Whatever ya gotta do to get around 24º of advance at idle, is what is needed for a SBC to stay cool. Manifold vacuum on the vacuum advance is the easiest way. It's how the Chevy factory does it. [/ QUOTE ] chevy hooks them to the carb at ported vacuum. the advance it to help cover the "lag" between idle and when the centrifigal (sp?) advance kicks in (it feels like a accel pump going bad). if you hook to manifold vacuum it defeats the vacuum advance (which in turn the dist becomes more of a mechanical advance dist). i do agree with the retarded timing makeing the motor run hotter.
Vacuum advance should be on manifold anyway, unlike what a lot of far more knowledgable people say It'll give you maybe 40 degrees advance at idle and very small throttle openings, which is exactly what a motor wants for economy, emissions and COOL runnings. Course, if you're racing, toss the whole vaccuum advance thing in the trunk. And fit a decent shroud to your radiator, so that the fan actually ****s 100% through the rad, instead of just circulating air round the outside of its own blades. You will see the difference immediately, in traffic.
64 chevy truck, year old 4-core stock recore, 180 degree stat, 327, adjustable vacuum advanced hei hooked to intake vacuum, 70 % antifreeze, 17 inch electric fan that is stuck on whenever the ignition is on... I cruise at 190 on a hot day, even in stop-an-go... but I think my gauge is off by ten degrees... I already forgot my initial timing, I set it and literally forgot about it, i think it was 8-12. yeah, and I dont ping on 87 either... Dr.J may be nuts, but I followed his recipe and it runs great, and cool, consistantly.
You know, I never had my vacuum advance hooked up at all. It had a hesitation when you'd come to a stop. Just for a second. It never stalled but it tried to. I bet that was most of my problem. A guy back east said not to worry about it, I don't think he knew that it would be in 118 degree heat someday.
I've got a pretty hopped up AL headed 406 SBC (notorious for running hot), with a CSI electric water pump, 160 deg thermostat, Griffin AL radiator, and dual 12" electric fans (with a shroud),and 38 degrees TOTAL timing (with NO vacuum advance). It's 178 Degrees when moving, (with the fans OFF!), and 180 degrees in traffic. Even in HEAVY traffic (like idling down woodward for 5 hours!!!)
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