The Stovebolt Site Forums The Shop Area Engine Shop CSB 327 question

Hi all. . . been a while since I've posted.
I've been working at work on the truck on the HOG and my marriage (not in that order )

Anyway - I know someone here will have an answer for me....

I have a SB 327 in my 3100 and my gauges are all new and senders as well. So I'm driving around town puttin her through her paces and I notice that the water temp just keeps climbing. . . 190 - 200 - 210 and then stops around 220. I've also changed the coolant and thermo (180).

Is 220 water temp right for this engine?

I've also got some tuning to do with the cold idle, choke (or something in this area). It's real choppy in the acceleration till it gets all wormed up (220).

Let me know if you need any more info - but the big question here is about the water temp.

Thank experts

220 is a bit warm but could be if you have a sealed system with overflow tank. Did you check the thermostat before installation? You might want to try a new radiator cap as well. An improperly tuned engine could run warmer than normal so double check your timing.

If it were mine, I would want it running close to the thermostat opening temperature.

Do you have a shroud for the fan?

Fried - thats what i was thinking - too warm.
I'll look into a new cap - good sugestion.

Trucker - I've done much research on the subject and thought the same as you. But I found out that it's not what your thermo is rated for that you should be at. It just allows the coolant to start flowing at 180 (or whatever your rated at).

LongBox - Yeah, no shroud. I also read that a shroud could/should drop the temp a bit too.

I'd still like to hear where others might warm up to. Perhaps someone out there with 350 or better still a 327.

Oh yeah, I removed my overflow tank too, to clean up the engine compartment. Perhaps there's just not enought coolant in the system to keep the temp down.

I guess this brings up another question - how much cooland shoule be in a SBC and do I need a overflow or a reserve tank?

Found the cooling system capacities. It's 17 quarts for 62-65 SB Chevys.

Heavy you have a problem temps to high. Did the truck originally have a 6cyl. radiator may be to small, plugged up? how close is the fan to the radiator? Really needs to be about 1 1/2 inch from it and have a shroud to cool it down. small block is a long way from the radiator. I have a .060 over 261 6cyl in mine and it steady as a rock at 180. new radiator no shroud.

The radiator capacities are the same on the '55-'59s regardless of engine, the only difference would be wheater or not it had a heater and the block capacity. However, the V8 engine will sit back from the rad. I beleive on the later TF trucks, they moved the rad back a bit to compensate for that, but also, V8 trucks used a fan shroud as well. I woudl stongly suggest a shroud, and possibly a fan spacer to get it closer to the rad. You may want to consider adding an overflow bottle, too, so that the system will reclaim any overflow rather than just dumping it out.

for every lb of pressure on your cap raises the boiling point of the water 3 degrees in your system. if you are running a 50-50 mix of antifreeze and water it raises the boiling point another 18 degrees
eg; 7lb cap raises it 21 degrees F. 212 + 21 + 18 a/f= 251 degrees before boiling
15lb cap = 45degrees F 212 + 45 + 18 a/F + 275 degrees F
before boiling
if you are running plain water with no pressure sap it will boil at 212 degrees F
ron
the above figures only work if your cap is working properly and if your cooling system can handle that pressure and is not leaking anywhere losing pressure

First thing to check is if your gauge is correct. An inferred thermometer is good for this. A cooking therm. will work. Then try another thermostat. I find about 1 in 5 are defective. Does it go right up that temp. & stay there or does it only get hot on a hard pull or slow traffic or hot weather?

the questions are
what pressure of a cap are you using
has the rad been rebuilt or replaced from original
what coolant mixture are you using
ron

Like Wrenchbender says, diagnose it first. If it's not boiling out of the radiator, which it should at 220, look at the accuracy of the guage first,
Scott

I'd put all of Scotts money on the lack of a shroud.

I'm running a 350 horse 350 in mine with a stock radiator and shroud and never run hot.

edit - by the way, nice truck.

A 15 lb. pressure cap will raise the boiling point to 257 degrees with plain water, slightly higher with a 50/50 antifreeze/water mixture (Not 18 degrees!) The only purpose a reservoir tank serves is to give the occasional puke somewhere to go to be recovered once the temperature goes down and a suction develops in the radiator. The puke can hose should always be submerged in the coolant in the reservoir so it can siphon the coolant back into the radiator on cool-down. It sounds like your radiator isn't doing its job; either it's too small, or dirty, or both. A fan shroud will also help to keep the air flowing through the radiator instead of around, or behind it. Position the shroud where the fan fits halfway into the opening for best efficiency- - - -the end of the shroud should cover only half the depth of the fan blades; it should not have the blade fully enclosed, nor stop ahead of the blade.
Jerry

220 is a bit high for that engine. I have a 327 in my chevelle, it's basicly stock other than it has a factory 350 horse cam in it . Mine usualy runs at 210, or just a tad under.
Im also willing to bet your radiator isnt doing its job.