Technical SBC 350 - How hot is too hot?

What about tap water?

Shoot, I apparently have made it difficult to approximate coolant ratio. When I drained the coolant in July, I drained the radiator and removed the lower hose. I filled with 50/50 mix. I didnt want to mess with drain plugs at the time (I forget why) and I don't know what was in it before.

Right now I drained the radiator and removed the lower hose. I wonder what filling with just water will give. Probably more like 40/60 which could be an ok start?

 

maybe something like that. Tap water will be fine....

you could also buy a hydrometer and see what the ratio really is.

 

Thanks again for the advice. I'm going to fill with tap water. Whatever is in the block is a mix from the older stuff (pre July) and 50/50 that got stirred up. Is that probably enough for lubrication and corrosion resistance? San Diego can get a little chilly (even mid to low 30s on the coldest of conditions) though it's really rare. Hmmmm...... however I wont be driving this to places where the weather is cold.. at least not right now.

I'll buy a hydrometer and thermometer but would be nice to drive this thing tomorrow.

 

MIT graduate combine your ratios
Would be nice if you new how many gallons you drained and added

Starting ratio- x
Second ratio x- .5x + 50/50
New ratio you want is back to x

 

That's the easy part... the problem is I have no idea what was in before I drained the coolant (from just the radiator) in July. If I knew what that was, it would be easy to guess what ratio coolant is in the block right now. The previous owner won't remember.

Worse comes to worse I can drain the block but with my luck something stupid will happen like a drain plug seizes or is stripped. It's been my luck all along. I want to drive tomorrow and I need to move the car easily next week as roommate wants to bring all the Christmas crap out from the garage.

I'm going to install the 180 deg stat and gasket now and let it dry.. I may walk to a parts store to buy the hydrometer.

 

Holly shit this thread is getting way to overdone ,thermostat in ,with a hole mix the juice in the container and add it to whats in the block and drive that sucker

 

just fill it up and don't worry about it.

If there is a forecast for freezing weather, then worry about it. But a hydrometer is cheap, and will let you know what's up.

 

Adjust you antifreeze to 15 degrees F and live with it . I run 50/50 mix all year long, when my car isn't in my shop (heated) it sits in cold storage that gets to 35-40 below zero F.

 

I say take the opportunity to flush it a few times to get all the crap out of it. Then start fresh. I still say go with close to a 50/50 mix, the increased boiling point offsets the reduced cooling efficiency. Coolant also contains additives to help prevent corrosion and erosion, and those additives work best in a 50/50 coolant/water mix. This is even more important if you run tap water, depending on how hard the tap water is in your area. Have you ever checked that?

http://www.qualitywatertreatment.com/city_water_guide.htm

San Diego area is "Very Hard". If you have access to softened water, use it. The minerals in the water form scale deposits in the cooling passages. Scale is a very effective insulator, and very thin layer of scale will prevent heat transfer from the walls of the coolant passages to the coolant, causing the engine to run hotter. Most people simply fail to grasp that.

Also, do you have an aluminum radiator? If so, better use a nitrite free coolant. Nitrites in the coolant breakdown into nitrates which attack aluminum. In any case I highly recommend using a nitrite free OAT type extended life antifreeze such as Peak Final Charge, which you may have to pick up at a heavy duty truck shop, but the effort is well worth it. Great stuff. And again, 50/50 is the proper ratio, it is what coolant manufacturers expect you to use, and they've designed the additive levels to work that way.

Again, there is a ton of information out there on all of this. I recommend again that you do some more research apart from this forum. You're getting a lot of information here that goes against the conventional wisdom of those in the coolant business and in the equipment maintenance industry. Google is your friend.

 

Thanks I bought a hydrometer. If I dilute the mix further what about using Brita filtered water? Haha.... I'm actually not kidding I don't feel like going to the store again tonight.

 

Alright some photos to summarize my day:

Sometimes I have to look at this picture to remember why the downtime is worth it.


Same applies to this picture. On a side note, I can't decide if I like running the fender skirts or not.

The coolant was to the very top of the radiator. I squeezed the upper radiator hose and it was full of coolant.


Bottom side of the 7psi cap.


Another view of the fan/radiator without any shroud.


While the coolant was draining I installed more looms to organize my spark plug wires a little better so there was absolutely no overlap on either sides. Note nothing touches or comes close the exhaust despite it looking that way because of the angle of the photo.


7psi pressure cap. The wetness is after I opened it. It does not leak when the motor runs.


The inside of the radiator.


Another blurry shot of the radiator.


This is when I took the radiator hose off and you can see the old thermostat in there. It didn't have any drilled holes in it.


Another shot of the thermostat.


Shot with the thermostat housing removed. I felt inside and no loose rust particles despite it looking like it in the photo.

Getting ready to put the new thermostat in and apply RTV to thermostat housing and both sides of gasket.


Drilled 1/16th inch hole in Mr Gasket 180 deg thermostat.


Thermostat installed and surface cleaned with razor blade for gasket.


Here's what came out of the radiator.


Another shot of what came out of the radiator.


With antifreeze tester the coolant that came out of the radiator read -20 deg F. Note in this photo it wasn't perfectly vertical but I tried with it vertical and it read the same.


Same thing here, photo taken with it not vertical and not filled all the way but the reading came out the same at 262 deg F.


All put back together (except for stupid alternator tensioner bolt).


Another shot of the motor/fan and radiator with no shroud.


Another shot of the fan.


Stupid stupid stupid me. I stripped the tensioner bolt for the alternator/alternator bracket assembly. This bracket had to come out for the thermostat housing to come out. I had to go to Pep Boys and find a longer M8x1.25 and use a nylon locking nut on the back and tension with one hand while trying to tighten with a ratchet and hold a wrench on the backside nut. Fun!


That's all. I didn't fill it back up with water, or coolant or anything tonight. I will do it tomorrow, but filled my Brita water pitcher tonight and put it in the fridge just in case haha. Maybe filling half water and half of that drained coolant is fine. I'm too tired to think about ratios.

 

heh...nice pictures!

using RTV on cooling system gaskets is something I can't bring myself to do, but it is a pretty common practice. RTV is good for things that need RTV, such as the end seals on an intake manifold, or the corners of an oil pan gasket, but it's not really a gasket sealer. There are gasket sealers you can buy that are made for using on gaskets. Not something you need to worry about now (heaven knows, you can find enough to worry about!) but something to consider in future work.

Thermostats for chevy engines don't need holes in them, according to my old wife. your old wife's tale may tell a different story. There are thermostats for certain other engines that actually have a hole (with a little jiggle pin) in them, because they need a hole. google it one day when you're bored.


good to see some action shots!

 

Looking at your pictures..... appears that about 1/2 of the fan blade length is below the radiator.... or is that an illusion?

 

You mean the lowest part of the fan blade? It doesn't go below the radiator if that's what you are asking. It might look it from the photos.

 

Thanks that is a good point on the RTV.

 

I hear ya!
Another year in school and I wouldn't know anything.

 

Oh thank you for those plots. Looks like I can use the hydrometer data to better estimate the mixture ratio.

 

I forgot just about everything (all the advanced math stuff) I learnt in school, that was 12 years ago I finished.... but I still remember stuff I learned outside of school really well.

 

We're on the 6th page now and surely you're not going to just estimate the ratio.

 

why not? it doesn't really matter, he needs anywhere from 10% to 75% antifreeze in the cooling system.

 

When I drained the radiator in July I knew the exact ratio mixture I put in. What was left in the block is anyone's guess and it mixed with 50/50 that I put back in the radiator (I made this mix and took my time measuring). I should have drained the block at that point but I was moving out of a house I sold and had limited time to put the car up and get underneath, etc. If a hydrometer is reasonably accurate I don't see why ratio can't be determined from plots that give data on various coolant mixture properties.

My understanding is the only correct way to get an accurate reading is to buy more expensive equipment (I don't really want to do this) or drain the block and fill back up with a known mixture from scratch. I stripped the alternator tensioning hole yesterday and that was a new alternator from NAPA I bought in June. With my luck, should I do something stupid and strip a drain plug or even have a seized plug, the last thing I want is a nightmare job pulling a block out at least at this exact point in time. Roommate needs to get large Christmas stuff off racks in the garage, and the car cannot be pushed outside as the driveway is really steep upwards 3ft from the garage door opening. I know excuses excuses, but I rather not get in a jam at least right now if estimating coolant ratio will keep the car driveable.

 

Looking at freeze point, the back of the Peak hydrometer says use 50 percent water, 50 percent solution for -34 deg F protection and that correlates with the plots 31Vicky posted. The back of the hydrometer says 265 deg F protection for 50 percent antifreeze volume. That also checks out with the plot when 15psi pressure is considered (plots are for ambient pressure).

Using -20 deg F data point from the hydrometer, I should have a 46% antifreeze volume which is close to 50/50. The boiling point data needs to take pressure into consideration. I should have 45% antifreeze volume using the 262 deg F at 15psi reading (my system is 7psi but the hydrometer reading uses 15psi condition). On a side note according to the data at 7psi, 45% antifreeze volume should give 242 deg F boiling point.

If I drained the radiator in July and put 50/50 and the resulting mixture is 46% antifreeze, the previous owner likely put 50/50 but didn't measure accurately, or the the 46% is within the accuracy of the hydrometer. What doesn't make sense is the motor running a little hotter after draining the radiator and filling with new 50/50 (I did use Carlsbad city tap water which is hard stuff). I found no traces of air in the system when taking the thermostat out yesterday.

 

Look at the title of the thread. It's not too hot.

btw say hi to my sister Lynn when you see her, Carlsbad is a small town!

 

Filtered water is soft water, so yes it will be much better using the Brita.

Boiling point is raised much more by pressure, than coolant percentage.

Note: when you buy premix it's only available 50/50.

 

Well now that you've got that figured out, why not start a thread about the skirts and see how many pages that will go to .

 

This thread has now RE-INVENTED THE WHEEL AND SPLIT THE ATOM!

 

Nah, I'll just keep looking at pictures of the car with and without skirts daily from multiple angles so I can keep repeating the question to myself a million times.

 

Right. I don't want to try 15psi with my stock 53' Chevy radiator. It uses a 7psi cap.

I bought the Prestone concentrate and made my own 50/50 mix. I can't remember why I decided to go that route, maybe it was cheaper.

 

Disconnect your temp gauge but leave it there for looks, then hook up the IDIOT light and when it comes on then it's TOO HOT! Let's move on to the skirt thread please.