Thread: SBC Running HOT

Tweet

Hey guys. I have a question.

I have a SBC 350. It is the HO engine GM offered a couple of years ago (non-vortec heads). It is installed in my '67 Camaro and was the result of an engine swap from a 230 inline 6.

The engine runs hot when the temp is above 75 and I am sitting at idle. Once I get going again, the temp come down again and things are OK.

I have a brand new four core radiator, fixed fan w/appropriate shrowd for a SBC camaro.

I am running a little less than 50/50 mix on antifreeze/water...bias towards the water.

This is not a wild engine and I thought I addressed all of the basics. Any suggestions? This is getting really frustrating.

How hot is hot, over 210?

What temp. Thermostat does it have in it? Was the engine rebuilt before it was reinstalled? Or is it new? Timing O.K.? If it runs cool when moving ... radiator must be o.k. Maybe water pump? You said it had the correct shroud? Maybe different fan like a clutch fan? Just thinkin' out loud.

try a product called water wetter...........scooter

or get an electric fan or do what i did get a washer the same size as the thermostat housing and put on there it still will provide some restriction but also constant flow. gotta let it warm up a bit though if you use the washer....scooter

I second the 160 stat, the best I know / use is a milodon #16400 HIGH FLOW, none better imho

Thanks for all of the help guys! In answer of a few questions

1 - Temp is getting to 210 and higher at long lights
2 - 10 degrees initial timing with vacuum advance hooked up above the throttle plate.

3 - Already have a 160 thermostate...was the first thing I tried
4 - Have water wetter as well.
5 - Engine was brand new from GM when I bought it.

210 is not hot. My Olds 260 ran 220 on a average day. Thats the reccomended temp too. 10 is a bit high timing for a SBC, bring it down to about 6, after unhooking the vacuum advance.

If your vacuum advance is hooked up above the throtle plate, that means it only advances while driving. That is not what you want. You want vacuum advance during idle and light acceleration. Hook up the vacuum advance to manifold vacuum, then set your idle again, and try it.

Other than that, it would seem to me that you need more air cause it is only at idle that it heats up,.... so I would install a clutch fan with more blades on it.

are you using under-drive pulleys? what kind of pulleys are you runing ont he crank and water pump.

I agree 210 is not running hot, as for the water wetter I don't use it but I seem to remember that it works MUCH better in straight water, have you double checked your temp with another gauge ?

One of my buddies has one of those slick laser heat guns....unfortunately...the gauge is right...I can also feel a difference in idle quality when the heat comes up.

you may also have an air bubble in the cooling system take the cap off and bring it up to operating temp so it can purge that air bubble..........scooter

there are so many opinions on cooling, i too was kinda paranoid when i started hitting over 190, but as far as i understand the new cars are running in at about 227, and i have a fairly potent 350 in the rear of a porsche 930, it was about 90 here today i idleing in the garage it was bumping 205 after a drive around, i was told optimum temp for zero wear was around 200 deg. i do know i have to burp the system as it is new and sure i have some air in it, but it seems to just want to set in and run 195-200, that is with a gauge mounted on the water port of the intake manifold #2 piston area, i have a restricter to slow the water down in the system to give it more time in the radiator.think ill have my fans kick on earler maybe...any other suggestions would help.

Plenty of airflow into the engine area while driving with the gt 3 wing, has small scoops on each side to funnel the air in, think ill just relabel the gauge...yeah thats the ticket, by the way how do you get your car photo in under your name on the left?