+1, I've seen too many rigs that had the thermostat removed run hot because the coolant didn't have time to transfer the heat from the block to the coolant and then from the coolant to the air through the radiator. I have done something similar to Coolbreeze 1340 in that when I tow I usually stick in the hulled out shell of the thermostat in the housing rather than take it completely out. Warmup is a bit slow but the rig maintains a pretty constant engine temp with no worries of a stuck theromostat. On the vehicle that is the subject of the thread: 1. It is now running a larger engine that also has a .060 overbore. That equals more heat produced. 2. Most likely it is puking coolant due to the radiator being filled to the top with no room left for expansion. It has to have some room in the tank for expansion if it doesn't have a proper overflow tank to catch and return the coolant. 3. The timing not being on the money can be a big contributor to the engine running hotter than expected. Set the timing. 4. The radiator just may not be up to cooling the new engine as well as it cooled the old engine.
Good thread. I am leaning toward timing to be the first thing to check, as leaner is hotter in most cases. And fluid level...
The thermostat is a part of a cooling system, and an important one. The system has a heating side ( engine ) and a cooling side ( radiator) , the tstat ties these two together. A proper system will have a radiator that is capable of cooling faster that the heating side can generate heat. There's some science there and plenty of research I won't go into. its easy to understand that it takes time to gain heat and to disipate heat. This heat transfer from the block into the coolant and then from the coolant into the radiator takes time. The engine was designed to run at a certain temperature. operating Below that temp causes issues and above that temp causes issues. The idea is to get up to temp as fast as possible and dont go over. Let's say that the radiator was sized perfectly and cooled at the EXACT same rate as the engine produced heat for all driving conditions. It is impossible but just pretend. Under this, without the t stat the engine would be below temp and experiencing accelerated wear the entire time until it reached operating temp which would be never ever. For the next pretend, let's say the radiatot was under sized by a small fraction of coolimg ability compaired to the engines heating ability. Without a tstat the warm up cycle would be very long and again with the wear issues. At some point the engine will be within operating temp but only for a short time. The heat generated is greater the the cooling and the coolant will progressively get hotter and hotter until the motor seized. Depending on the amount of under sized cooling maybe that takes 1 hr to warm up, and another 45 mins till overheat. That's almost 2 hrs and a substantial amount of time. Never the less, lots of wear. The t stsat has a 3/4 hole that's obstructed by a valve. That's clearly an obstructed opening, it will slow the water down. This opening feeds into a 1-1/4 or 1-1/2 hose to the radiator. There is never a chance that the flow will over power the hoses volume, ever when open. This insures the pump will always have pressure and never cavitate due to water surges, - never ever and always. Ok so with a tstat & it being closed, the cooling part of system is almost complety separated from the heating side. The heating side can get up to temp quickly until the t tstat needs to function. Once at temp the t stat opens allowing the pressure of the pump to push the hot water out then closes again. This only momentarily allows the both sides of the system together. The cycle repeats however the cooling side gets to work without being constantly being asked to move the water.
WOW...Breathe deep! Ok I give I'll put in the T-Stat! Worst part of puttin in the stat is that my dad will get to say he was right. Maybe I just won't tell him! I put on a catch can tonight, I'll be going to Jegs Tuesday and I'm going to buy a recirculating tank, unless my brother wants to weld one up for me before then! I'll be setting the timing tonight or tomorrow morning... Thanks again for the help!
Make one change at a time. The over flow can is needed and it can be done with the timing. I would wait on the hemostats until after a test run with good timing. Check the oil and make sure you do not have a head gasket problem.Check the radiator to make sure it is not blowing bubbles, which would indicate a head gasket problem. If you change all items at one time you will not know what the problem was.
Catch can, timing, air/fuel ratio, thermostat.... put in a mornings work and most of the time your issue will go away. You need to all the above anyways. Good luck and make sure you post your findings!!!
Here is probably more information than anyone want about how coolant flow can affect engine temperature but here it goes anyway. The question of how the flow rate affects engine temperature is very complex and depends to a great deal on the radiator. A higher flow rate will decrease engine temperature to a point and then will go the other way all being relative to the designed of the radiator and its low or high flow limit. Heat is conducted from the engine into the coolant, the coolant is pumped to the radiator, and the heat is transferred by convection to the air. In the low flow limit the coolant leaves the engine at thermal equilibrium and additional heat can only be removed by increased coolant flow (assuming constant engine temperature). Similarly with the radiator, in the low flow limit the coolant leaves the radiator at thermal equilibrium and additional heat can only be removed by increased coolant flow (assuming constant ambient temperature). In such a case the cooling can be described as flow-limited and increasing your flow rate will increase your cooling rate. If you increase your coolant flow you will eventually get to the point where your coolant is no longer at thermal equilibrium with your engine. In other words, the coolant is leaving the engine at a lower temperature than above. At that point the system is no longer flow limited and further increases in coolant flow will serve to further reduce the temperature of the coolant leaving the engine.If you still continue to increase your coolant flow you will eventually get to the point where your coolant is no longer at thermal equilibrium with your radiator. In other words, the coolant is leaving the radiator at a higher temperature than above. At that point the system is radiator limited and further increases in coolant flow will only serve to further increase the temperature of the coolant leaving the radiator. This would continue until the temperature of the coolant leaving the radiator was arbitrarily close to that of the coolant leaving the engine.
It could well be that the radiator that cooled a stock 283 isn't enough to cool a non stock 350. 200 is too hot for long engine life. Talk to your radiator guy if a thermostat doesn't cure it.
when you get overflow tank get Hi-Flow thermostat - has larger openings in body of thermostat. running a section of heater hose from heater outlet on intake manifold to inlet on water pump helps make sure no air bubbles build in engine and assists proper circulation of coolant. what mix of coolant/water using? a narrow aluminum overflow tanks look pretty but, can be hard to see where level of coolant is. best to get the larger diameter one or even a plastic one. transmission cooler mounted at front of radiator? engine stumble may not be timing setting. vacuum cannister on distributor good? and vacuum tube hooked up to correct carb port? where is hose from power brakes booster connected? multi-blade fan?
Bottom line...(learned this about 30 years ago)... FIX WHAT YOU KNOW IS F'ED UP, AND THE UNKNOWN CAUSES/PROBLEMS WILL MOST LIKELY DISAPPEAR. A lot of guys surely have wasted a lot of time on this thread........
I'll get a high flow stat at jegs as well, I'm using 1 gal of antifreeze, and 2 1/2 gals of water. The oil is good no water, vapor, or discoloration. I'll be using a nice size re-circulating overflow, probably plastic, or my bro will make me one out of stainless, with a sight line. The trans cooler is infront of the rad but its about 8" in front of it. Dist vacume is good, and its coming out of the port Holley says to use, (I had a post about that last week) and the brake booster is ported on a T with the PCV valve in the intake behind the base of the carb! And I appreciate it! It kinda turned into a discussion forum as well as helping fix my problem!
need to get trans cooler moved away from radiator or rubber mounted directly to radiator. having it so far in front of only disrupts air flow to radiator. brake booster needs direct manifold port and PCV use carb port -do not use same T for both.
That one gallon of coolant to 2 1/2 gallons of water won't be of any help. The manufacturer's minimum is one to one. The 50% mixture will kick you up to a 265 degree boilover point. Use some distilled water, too.
It's puked from expansion, which is normal. It's running warmer than the 283 because a - it make more power b - timing is too far retarded 180 deg thermo is good
Because the old style downflow radiator does not have the strength of a modern crossflow radiator. Do not put a high pressure cap on an old style radiator - even a new one
I drove it about 30 miles or so round trip last night and the car never got above 180 till I got to the cruise in and let it sit, it inched up to about 190 before I shut it off! It ran below 180 all the way home in the cool air around 10:30. It still puked small amounts of water going there and coming home! The timing seems to be good now but I'm pretty sure I need to adjust the carb as well! I'm gonna check the timing again after tuning the carb when the engine is warm (as was suggested) because it did behave a little different after it was warm. I will do both of these things! I didn't think about the air flow thing, but that makes sense! Thanks again Ed, I was always told that water cooled better than antifreeze and its only purpose was to keep the water from freezing in the winter! When I add the T-stat this week I'll add in another gallon!
Put a reservoir on it! It "puked" because it is working, but you haven't finished the system! If you are going to continue to drive it, put any kind of container on the end of the overflow tube with the tube end immersed. When it is cool it only needs enough coolant in the tank to cover the tube. As it heats up the level will rise. When it cools off it will be pulled back in.
So far I have finished setting the timing, and adjusting the carb to get it away from the lean condition. Its running much better now so I think thats helping the temps. I took it out for 10-15 minutes of in town/country cruising, including a couple hole shots. When I got back it was a tick above 180 degrees. I still haven't put the thermostat in (but I do intend to). I got a catch can mounted and ran the overflow hose down to about an inch from the bottom of the tank, and put enough water in it to cover the bottom of the hose. I'm gonna get another alternator bracket next week at the swap meet so after that I'll pull the water neck back off and put the thermostat in then add a bottle of antifreeze to get the water mix to 50/50. Sunday I'm gonna drive the car a little farther to a cruise in so we'll see how it handles the heat then. Thanks again for all the help so far. If any of you have bothered to look at my history here on the HAMB you will realize I ask alot of these questions that may seem basic to you but this is how I'm learning every step of the way.
My .02 since most others have been covered.... 1) run a fan shroud! They help immensely!! 2) Ditch the flex fan, they are horrible IMO. Get a nice stock style 5 blade fan with a clutch. Good to go!
Both things I want to do SLCK64...I'll be making a shroud, and I hate flex fans! I'm hoping to get a fan at the swap meet too! Thanks again!
Have had multiple vehicles over the years that ran hotter with the t-stat out than when I reinstalled it.. so I come down on the side of wanting the thermostat in....
I did the unusual puke tank thing for a minute! I used a boy scouts canteen! I'll be making a nice one out of stainless some day!
The number 1 cylinder on a standard direction flow water pump engine always suffers the most wear because the water goes by it so fast it doesn't pull the heat off the cylinder. That's one of the reasons why they came out with the reverse flow system. I have always had luck running a medium size water neck restricter washer instead of a thermostat. Plus you never have to worry about a thermostat giving you any issues. But here in Florida I never have to worry about freezing my ass off in the winter either. I used to have a .040 over 400 sbc with air and I remember talking to Vintage Air about some cooling issues and they flat out told me there is no electric fan that will replace a 6 or 7 bladed steel fixed fan. They stated the reason why they came out with electric fans is for when engine room space is limited and no other fan configuration wil work. Also a thicker radiator is not always better,thicker the core,the more air has to travel through it at especially low speed. You can actually preheat your very inner flow tube,one closet to the fan. Two-three tubes should cool anything.
Without a t-stat the coolant will reverse direction when turned off and push out past the cap,every time.T-stat should be used for many reasons along with an overflow bottle.
What direction is the normal flow? The thermostats are open when the engine is first shut off after running for a long time. If the thermostat is open then it is like they are not there. I need to have you explain this theory?
Your theory about water flow is flawed. The flow of water is pretty much the same through the entire engine. The faster the water flows more heat is removed. A lot of people believe the water is not removing heat when the flow is fast which is not correct. They see the water temperature gauge is running cooler and do not realize the engine is cooler. If you measure the engine temperature it will be cooler. You theory is an old wife's tale.
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