The Stovebolt Site Forums The Shop Area Engine Shop 216 being picky about temp

Ok so my 41 with the 216 has been running really since the other day when I had to get through the thermostat problem. Except it gets hot at a certain time, I can drive it on the back roads around 40 mph and it runs about 180, when I get on the four lane and I speed up and it's working harder it runs around 190 and then when I stop and get back on back roads or just run slower it gets up to abou 200 and sometimes goes down a little but runs about 200 after that, and when I shut it off it shoots over to 212 and pukes out the overflow a bit and if I start it back up it goes back down to 200.
It has 160 stat with the hole, new water Pump and system is clean, does anyone know how to make it run cooler?

Did you have the radiator cleaned, flushed and flow tested?

Do you have an 1/8" bleeder hole drilled in the T-stat?

Are you leaving room in the top tank for the coolant to expand when filling?

Is your timing set correctly?

Mike B

Raidiator clean
Hole in stat drilled
Only filled till water was just over the fins in radiator

How does timing affect temperature?

Retarded ignition timing increases water temperature. Expect hotter if your vacuum spark is not working.

Was the radiator hot tanked at a radiator shop and flow tested?

Mike B

Radiator didn't need hot tanked it was clear and I've been keeping it clear with a water hose, I did take the radiator to a shop to see if it did need hot tanked but the man said it was fine.

Try a new stat there are a lot of bad ones out there.

Pete

Pull the draincock in the driver's side of the block. I'm wagering you'll find a lot of rusty crud. If that's the case you'll have some work ahead of you. Proper coolant contains rust inhibitors that help keep the metal parts of the engine from rusting. In the day a lot of folks didn't change the coolant or even ran just water so, over time, the block & radiator fill full of rust. Rust doesn't transfer heat well plus it blocks the proper flow of the coolant.

See I know it's not the stat cause I just put a new one and I know it's opening cause I took it out while it was hot after driving and it was wide open and my cooling system is clean cause the rust was a problem but I cleaned it out for quite a while. I had rust desolver soak the block, took freeze plugs out, and everything and everything is flowing fine.

Other than cooling system related stuff what else could it be

Have you ceonsidered a fan shroud? You want all the air your fan is pulling to go through the radiator. Take a look at just about any souped up motor and it will have one.

You can have clear water and still have crud restricting some of the radiator tubes. I don't know of a way other than having a radiator shop flow testing it as Mike suggested. You might be able to feel a cool spot on the radiator as it is warming up. Sounds like you did most of the stuff so you probably changed hoses. Otherwise, you could consider a collapsing hose.

Dennis

Dennis,
I wandered about what you said about the radiator and I did what you said about feeling cool spots last night but I didn't feel and, I've had the radiator out of the truck a lot and it seems to be letting plenty of water through.

A couple guys said timing, should that have anything to do with it?

Yes, if the timing is slow it will cause it to heat up. The reason is when the gas mixture explodes the piston is further down in the cylinder than it should be and so more of the cylinder wall is exposed to the heat.

If the vacuum advance is not bringing the timing up as the engine rpm is going up it might cause the same problem. The mechanical advance should bring the timing up if the vacuum is not, so might check the mechanical advance to make sure it is free to work. It is inside the distributor under the breaker plate.

Check the basic timing at idle to make sure it is correct.

While idling the engine you can reach down and slightly turn the distributor to see if the engine rpms go up slightly. If they do and the engine runs smooth then the timing needs to be checked to make sure it is not slightly slow.

if it was too fast the engine would make a rattling sound as you open the throttle under a load.

I turned the distributor like you said and it revved up and smoothed out quite a bit. On to check the rest of what you said.

If and when I have overheating problems I am going to use my laser digital thermometer to help diagnose the problem. In general, the more power you are using the more waste heat there is to get rid of. So your problem seems to be that the ability to ramp up the heat removal is limited. This may seem like a trivial comment but often the problems come with a specific condition like it won't cool when idling, etc.

One thing you need to be aware of is that the timing specs back then were set for lower octane fuel. You can advance the timing quite a bit past what the manual calls for. I don't even use a timing light on my '38. I time to the best idle. Each to their own and everyone has their own formula that works for them. Just know that the spec in the manual isn't set in stone.

Ok thanks for the advice, Tiny can you walk me throught the steps you take to time yours? I've never done it and I'm trying to figure out how

Pretty simple on mine. I start it & let it warm up then loosen the clamp on the distributor & adjust to the best (fastest/smoothest) idle with the octane selector set on 0. Lock the clamp then reset the idle if necessary & drive it. If by chance it pings under load I can fine tune using the octane selector to retard until the ping stops. Info Chevy put out in '36 (I think) about using the octane selector. You can see from that, that these vehicles were timed to much lower octane than today's fuels.

I GOT IT!

I loosened the clamp on the distributor and moved it like an eighth of a turn and it changed my truck, she ran a good temp the whole way, she started so quick and easy and sounds so smooth and quiet, it's amazing, I pulled hills in 4th like it was nothing and even accelerated up them and shifting was so much smoother. That changed my truck.

I have all of you to thank for this, Tiny, Roy Rogers, truckernix, Mike b,
And everyone else thank you so so much!!!

yep, that is why there has always been such emphasis on the "TUNE UP" setting timing and dwell. It really does matter.

My 1950 216 used to run hot. I noticed a stream of bubbles in the radiator when the cap was off and was afraid of a crack in a casting somewhere. I changed the head gasket and it runs pretty much a constant 180 degrees and no more bubbles in the coolant.