The Stovebolt Site Forums The Shop Area Engine Shop My 49 still getting hot

Every part of the cooling system has been replaced. Block flushed. Only thing we did against the advice of the brain trust was install an elec fan instead of the belt driven one. Fan has a full shroud but only moves about 800 cu. ft/min. We know we went against advice and will likely now change the water pump again and move it up to accommodate a bigger flex fan.

Is there any thing else that could be the problem? Timing is spot on. I'm at the end of my rope with this truck...and my money is getting pretty thin. The motor is a 235 out of a 57 car. Fenton headers and dual intake with two 2 bbls. from Langdon.

Is the fan full time or thermostatically controlled?
Does it overheat when idling for a while? At speeds under 40? Highway or under heavy loads?

If the electric fan is moving 800 CFM through the radiator full time, that is more air than the engine driven fan is moving at speeds under 3000 RPM's.

It idles at about 190...checked with heat gun, but overheats under load... Fan is controlled by a relay and temp sensor. Not sure of the setting on it though...

is the thermostat a 190 or 195? if so, why? have you considered checking/changing it?

Bill

It is 180 and opens right on the button...have tried a 160...same thing.

a thermostat sets the minimum temperature the engine can be, if it idles at 190 with a 180 stat, there's something wrong with the engine, timing maybe, or more likely you have poorly engineered it, a 235 should run right about the stat temp, with a 160 or 180

Bill

Is your radiator original? If the water level in the radiator isn't equal to or above the water jackets in the head there will be air trapped in the head. Is the water to anti freeze ratio correct? If too much anti freeze in the mix it will run hotter. Just my humble opinions and spelling.

Are you running the stock distributor? How do you have the vacuum advance connected? Your electric fan and shroud could be causing problems by blocking air flow thru radiator.

I know you probably bled the air out of the system, but sometimes it is just very difficult to get rid of it. One old trick is to drill a small "bleed" hole in the thermostat. Then after running it to temperature, make sure the coolant is at the proper level (after it cools a bit of course). I, and many others, have had the same problem, worked for me and them. Since you tried so many things, this may be something to consider trying.
don

Thanks to all. I have fwd this thread to my mechanic. Since the shroud is a full piece of sheet metal behind the radiator with the only hole for the 11" fan I think it makes sense that the air at speed is not sufficiently blowing THRU the rad..so less cooling effect.

http://s1276.photobucket.com/user/Dusty411/media/Radfan_zpscb7c53b6.jpg.html?sort=6&o=0

yes, I'd say the shroud is the problem, that flat configuration will only be cooling the portion of the rad directly in line with the fan, and is otherwise stopping the air flow, especially at speed .... a shroud normally stands off from the rad and tapers out to the fan so it can draw air across the entire rad fin area .... you'd do much better to go with a stock fan

Bill

Ok....today's update on this beast. He removed half the shroud and put a huge shop elec fan in front blowing tons of air thru the radiator...still heats up...and way fast for some reason. Said he's never seen a motor make this much heat this fast.

One thing I forgot to tell was that early last Fall we installed a Petronix elec ignition...dunno if that would make any difference. He has run it with timing set at different degrees...and spot on but it still is making heat. Radiator is NEW copper and brass from Jim Carter. Temp drop from bottom tank to top is about 22 degrees and plenty of water flow.

My mechanic will be on these forums as soon as the Mods clear him and he can answer questions on this thread then... He's a darn good guy and honest as can be...just stumped right now.

Just my 2 cents worth, but could you have a collapsed hose.? Pat

Also when I had the rad replaced on my truck I opened the heater and left it open for a while to make sure all trapped air was worked out of the system. Pat

Was all he did was install a Pertronix unit and it started running hot? Or was it running hot before the Pertronix was added?

Check the timing at idle, 1500, and 2200 rpm. If you do not see a change, there is your problem. Check vacuum advance while you are checking. @Where is the distributor vacuum hooked up? ported or manifold?

A really lean condition can make tons of heat, this goes back to the timing issue. How does it start? easy, struggle, spins easy, pulls starter down? How does the exhaust smell?

If you want to run your flat shroud, cut two large cut outs in the dead zone and put soft rubber flaps over them on the out side. Going down the road, the wind will blow them open. At idle, the fan wil not be able suck them open since they are on the outside of the opening and bigger then the hole.

Joe

The exhaust gas temp is the best indicator of a lean condition.
Aircraft engines monitor EGT all the time to set the mixture. You would be amazed how high it can get.
There is no place to put a sensor but an IR unit could check the exhaust pipe below the manifold (thinner than the manifold)

Running retarded will cause overheat.

Tell us about the block flush please. How was that done.

I ask because I did a block flush with an off the counter bottle of stuff ,, no apparent change .

Pulled the head and the block was very blocked with rusty goop, for nearly 2" deep in the lower water jacket area. It took a lot of scooping and scraping to clean out.

It took a while to get on here. My name is joe. I am the mechanic with the pleasure of working on thus truck. I want to start by saying thank you for helping with this problem. I will answer all questions to the best of my ability and always look forward to learning.

My phone is acting funny. Will post full write up and answer all input in morning. Thank you
Joe

Joe,
Glad you made it here. I talked to my VA friends tonight...all motor heads and to a man they said to look at a blown head gasket or cracked head......that's what they said cuz the motor is heating up sooo fast. So...if we (you) pull the head you can also see if Dusty ..above...is offering another solution...

My buds also said to check compression...which likely you have done

I must also add that before we did all this I once idled it with rad cap off...a lot of bubbles kept coming up to the top...dunno if that could indicate anything..

I'm surprised no one has mentioned this yet. If the head gasket is blown, that can heat up the water real fast. All it would take is one crack in the gasket near an exhaust valve, and the hot exhaust could be super heating the water in no time.

I doubt the fan is the problem. My '48 has an electric fan about that size, and the only time it gets above 180 is when it's really hot and I've got the air conditioning running full blast (in Texas 100+ heat). That will push it to 190 or even 200. And I don't have a shroud. The fan is blowing through the condenser and the radiator.

This may sound stupid, but make sure that fan is sucking air through the radiator, not blowing it through the radiator. Since you've got it mounted on the inside of the radiator, you want to pull cool air from the grill, not push hot air from the engine through it. If it is, mount it on the outside of the radiator so it blows the cold air through the radiator.

Pulling the head on the 235 is not very difficult. I would do that before you spend any more money on parts.

Wish you had mentioned the bubbles earlier. Classic indicator of a blown head gasket. Just my 2 cents.

You are correct about listing all symptoms in one place, but this has been a multi-post discussion (separated by trying different "solutions").

Bubbling was reported early in this multi-part, multi-"solution" saga.

Keep at it Mark and Joe.

I did not remember the bubbles until last night when one of my motor head friends asked if I'd ever seen such. It was a really long time ago...well, long to me anyway. I had been driving it, got home and wanted to check the water temp. I didn't have a heat gun yet. Took off the rad cap...very carefully !....and saw the bubbles...very tiny but constant. Used a meat thermometer (don't tell my wife) to ck water temp.

Things I would try: Dump the coolant for now run with just water, later go back to only miminum coolant. Make sure ALL air is out of system. Check timing using a vacuum gauge and set to peak reading. I'd put on a mechanical fan and use a pusher out front as a backup for hot days and in traffic. If all this fails try another radiator.
Best of luck
Jim

Jim,
Thanks for the input...the rad is brand new...

Doesn't auto part stores have a kit to check for exhaust gasses in the cooling system?

ok. i am back on a normal computer. Here is the run down, and then i will go and answer each question. There have been a couple posts so i will try to put all the information in one place.
When truck was brought to me it has a laundry list of issues. half way down the list was runs hot. we found the truck had the wrong radiator when the owner asked to install an electric fan. Wanting everything as correct as possible, I install new radiator support, new 4 row radiator, new short water pump, new thermostat, new hoses, and built a fan shroud with 900cfm electric puller fan, installed new temp gauge, thermostatic fan switch. Truck still runs hot. idles in shop at about 205. climbs to 220 driving. Stop before it gets any hotter. Only about 90deg. outside. So here is what I know."all temps taken with laser heat gun"
Radiator has 20-25deg. drop from top tank to bottom tank. that is with the electric fan on.
water pump flows what i would consider a normal amount of coolant when t-stat is open
tried 180, 160, 180 drilled, and no t-stat. all like results
added 1200cfm fan to front of radiator, same results
removed lower half of fan shroud to force more air through top, same results
tested coolant with block leak tester for leaking head gasket or head, so sign of hc in coolant.
ignition timing set to 5 deg., zero, 10 deg, no change.
closed chokes and ran engine to make sure it was not to lean,also checked for air leaks. same results
replaced belt checking for pump slip, same result

big red flags are jumping at me in a couple areas.
* engine heats real fast. about 2min from cold to 190
* temp sender at back of head reads 205 when front thermostat housing reads 180, but block reads 205 from front to back

is it possible that the head gasket is blocking some water ports? can they be installed backwards, or upside down? Could it be the wrong head? been years and years since i had one apart.

yes fan is set thermostatically, adjustable turns on right after thermostat opens about 185. gets hot at idle, about 205-215. heats about 220 driving, never let it over heat past that. just under normal driving conditions. never put under big load.

180 stat, 160 stat, 180 drilled, and no stat. all same results

aftermarket 4 row, water level about 6" above valve cover, water comes out of the temp sender at back of head when opened, dont think it has air?? 50/50 ratio on coolant.

well it's sounding like the bubbles are the clue, time for further investigation of the gasket/head

Bill

fan shroud is 3/4" off the cooling fins. tapers down to the edges of the radiator from the fan. i removed 6" from below the fan and resealed it. same results. i then removed the fan shroud and installed a huge pusher fan on the front with two shop blower fans forcing air into the radiator. all with the like results.

new hoses with metal wire inside. no kinks

no heater. ports have plugs blocking them off at the water pump.

ran hot before, but feels worse.after all other mods. dual carbs, ext....

vacuum advance is working. vacuum is coming from manifold not ported. starts and runs great. right at 5 btdc. i held the chokes on and cause a rich mixture. plugs were wet when i pulled them after this. results were the same. I agree with cutting the holes with flaps. my race car has the same set up. with the lower section of the fan shroud removed i don't think that is an issue???

exhaust temp at idle with heat gun are right around 500 deg at the collectors. 400 at each tube. again this is with a heat gun so.....

coolant was tested for head gasket/block leak. no sign of hc in the coolant. i tested it 3 times. Fans are going the correct direction. might have to pull head and examine.