Thread: Ideal temperture thermostat for SBC?

Tweet

It looks like this thread is wrapped up and Rodger wants me to start a new thread. I have his directions to start a new thread but this is the SBC Forum and I have almost the same question. Just last Thursday I got my engine started after YEARS of messing around. It is a '76 2-bolt 350 bored 0.030 0ver with a nominal rebuild, mild cam, cleaned exhaust ports in 882 heads and heads milled to give 9:! compression ratio. Several years ago I was advised on this site to get a Zip water pump riser and I have searched this site for further information on the Zip Riser but found most information in the Technical section on the H.A.M.B. I admit making several mistakes but my expert help from Progressive Performance (Ashland, Va) and I ran in the cam for about 10 minutes at 2000 rpm but shut it off when the temp. reached 220 F. I know I made at least three mistakes:

1. I used straight Prestone, no water.
2. I had no fan shroud, although a 17" flex fan.
3. I did not purge the air bubble out of the Zip manifold with a 160 F thermostat.

I have spent the last few days adding a shroud (lots of fun!) and I have added a 3/16" hole in the 160 F thermostat. I have also drained the radiator and diluted the Prestone to about 55/45 with water. I also discovered the air bleed on the top of the Zip manifold and I will bleed it after I add the Preston/water back in the radiator and seal it with a dab of RTV. The Zip instructions specify a 160 F thermostat, maybe because the Chevy-6 water pump does not have equal flow rate to the SBC V8 pump it replaced? Anyhow if folks here think 190 F is optimum I will be glad to run at 170 F with the 3/16 hole in the thermostat. If it runs too cold with the hole in the 160 F stat I will be glad to run with a 180 stat also with a 3/16" hole. Just to keep this thread going I will report the results of this setup in a day or two. A complication is that I will have to modify one of the lines to the trans cooler at the bottom of the Walker Cobra radiator since the old line position conflicts with the bulge of the shroud at the bottom and I may have to bend a new line around the bottom of the shroud. Stay tuned, I am amazed that several of you as well as the H.A.M.B. examples run cool but I have made three change/improvements and I hope it will run cool with these changes. I will welcome any and all suggestions as to what I might do more.

Don Shillady
Retired Scientist/Teen Rodder

Don, as you already know, straight anti-freeze is less than desireable, no shroud and not bleeding out the air was probably your deal breaker but a flex fan also leaves a lot of uncertainty. Many guys have not had much success with that fan. But, try it out anyway. Maybe you'll be okay.

Originally Posted by Don Shillady

It looks like this thread is wrapped up and Rodger wants me to start a new thread. I have his directions to start a new thread but this is the SBC Forum and I have almost the same question.....
Don Shillady
Retired Scientist/Teen Rodder

Don,
I suggested that starting a new thread is in your best interest so that people will know from the topic listing that it is your question, and also so that anyone who might be looking for "...that question Don had..." can find it by doing a search on "Threads Started" by you. As it is the thread is one that some people may see as "...old news..." and ignore. In some cases the originator of a thread may not be too happy to have someone "hijack" their thread, or they may feel less inclined to come back and provide feedback on how they dealt with their issue. For example, in this thread Joe (curmudgeon) last posted that he was going with a 180 degree stat, hole drilled, etc. He could come back to tell us, "Hey guys, it worked great!!", or some other feedback, but finding a new subject engaged he might turn away and say he doesn't want to confuse people since his thread has now been taken into a new discussion area, similar, but someone else's problem.

I hope that explains my thoughts on why it would be best for you to start new threads if you have a new question or comment. I don't really care if you start a new thread or not - I'm just glad to see you back and posting here!! I was simply trying to point out to you that you will improve your chances of engaging people in dialog if you do. Hope your cooling problem is solved. I won't mention new threads to you again, and hope that you'll continue to post often.