is anyone running there small block without a thermostat? what temp does it get up to? my car runs around 200 to 210, the fan clutch is a little loose, I am going to change it. I live in south Louisiana where it is around 88-95 degrees all summer and the car has A/C

 

It's not a question of what temperature it gets to, it's a question of how much longer does it take to reach operating temperature. Which, without a thermostat, is going to be much longer.

 

Get clutch fixed first.

But I run a fixed 7 blade fan and no T-stat in Houston on my 540 with stock radiator and it does fine. It hangs right around 160-170 on highway and way under 200 in town. I quit messing with the T-stats and restrictors a few years ago.

It's warmed up by the time I get out of neighborhood...don't really drive it when it's that cold...so no T-stat isn't an issue.

You'll find that some cheaper T-stats don't open that wide. Sometimes the better Hi flow types will keep things cooler.

JIM

 

Get a Robert Shaw Hi Flo stat. Work great and if they fail, they fail open. Cheap thermostats don't make sense.

 

Hotrod,

I too live in Houston, my cooling system is giving me headaches! I think I'll try and just run without a T-stat for a few days and see what happens! I replaced the water pump with a high flow stewart and then went to a high flow thermostat, but things got worse. I am going to slay this dragon when I get back to town!

thanks

CC

 

Like 427Hot rod I don't run a thermostat and my car without any fan at all on the open road runs around 185. I turn one fan on in town and it stays about the same, never sees 200.
I tested time and agian with a thermostat, the next day no thermostat and found for me without was alot better.
I only drive in the nice weather.

 

I took the thermostat out of my '71 small block last month. It definitely takes a lot longer to warm-up...maybe 10 miles of driving.

On an average day (75 degrees in San Diego), the car tops out around 175 degrees while driving. If I'm stopped for a while, it goes up maybe 10-20 degrees.

My problem is that when I run the a/c, I add 30 degrees to the temp. My car is stock, so I'm guessing that maybe the radiator has lost some efficiency and might need a re-core.

 

Better fix that fan clutch before it takes out your water pump...Remember,they operate on the same shaft.....

 

not staying cooled properly.

SBC are one of a number of designs which REQUIRE the use of a thermostat or a restrictor to force water to back up to a high enough level to cover the tops of your head's cooling. This is super critical on aluminum heads.

The thermostat or restrictor plates act like a stop log in a pipe, causing the water level to back up considerably to the highest level in the heads before it's returned to the water pump or allowed to go out to the radiator. I don't know how much a rear Y pipe or one of the new intake manifold water return pipe setups like I have on this Edelbrock Air Gap might alter this.

Not all engines are like this - note many of these replies are from people with BBC's - and they may not require it, I simply don't know.

SB Mopars & 501 family Caddy's don't need one - I can't remember on SB Fords.

I have never believed the studies about as much as a thousandth's wear on cast iron in 2 hours of running at 140 degrees and such. I've had too many cars with way past a hundred K that ran as cool as I could get them - under that temperature for a lot of the winter. Since I live in a hot climate and most of my vehicles are pressed with cooling problems, I am always pursuing the strategy of slowing the time it takes before the thing heads for overheat! I want as much time as possible before having to pull over and shut down waiting for it to cool down... Sure, I want my oil temp to reach past boiling to get rid of water and know it runs best at an optimum temperature, but over the years I have been most concerned with one of the POS's making it to where I was going.

Use one of the restrictor packs (all of $15) - typically the middle sized one yeilds about the best temp, although I noticed with this new Victor pump it ran a small amount cooler (I think - it was by single degrees in anything but a careful controlled test) with the largest. Other than that, you can drill out the center guts of a thermostat or find an SS washer of the right size. To make sure your thermostat, if you choose to use one instead of a restrictor, does not get overcome by the pressure and get forced closed, get one of those equalized racing ones liek several have mentioned and/or drill a couple or three 1/8"ish holes on the flange to allow a little flow past it always to reduce that pressure.

When I found out the new Meziere 55+gpm water pumps greatly outflow even higher end mechanicals like my new Victor, I have wondered if they move enough water to overcome the flow loss effect of that vertical pipe straight to the upper radiator hose.

 

I totally agree with Wayne. I had a cooling problem after my engine mods and finally drilled three 1/8" holes in the thermostat. Now I have my restriction and a little gets by for additional cooling. Doesn't get past 180 even on the hottest days here in Maryland.

 

I just had my 383 out on Saturday after a complete rebuild and I have no cooling issues.

383 with aluminum TFS heads, 180 degree thermostat, Edelbrock aluminum water pump and a DeWitts aluminum radiator.

It was 100 degrees in the shade and it stayed solid at 180 degrees whether I was in town or crusing down the road.