Overheating Issues, Perplexed

[elmariachi]

Originally Posted by Cobrabill

Yes.Now we're on the same page.Take an old NFG T-stat and cut the guts out of it.That should suffice.

Done. Now what will this accomplish that removing the thermostat will not?

[DAVID GAGNARD]

EL;

I would definelty put on a smaller diameter water pump pulley,the water pump pulley should be at least one inch diameter less than the crank pulley.... I have expiremented with this for a year on my Mustang.... March and other pulley makers as well as the makers of water pumps will tell you the same......look at your wife's car and see the difference is pulley size, you'll be suprised!!!!!!!

As for the water puking out of the tank, dat don't look good!!!!I've seen this when all the air was not purged from a system...... I would try removing the thermostat altogether and put a water restrictor. You can buy the kit for a few bucks from any dirt track racing outlet....It looks like a very large washer with a hole in the middle, usually you get three, with varouis size holes.... see how that does along with a pulley change.

http://store.summitracing.com/partde...0&autoview=sku

I think you have enough radiator and cooling fan capacity, maybe a radiator flush just to be on the safe side....In all my vehicles I run a gollon of anti-freeze and fill it with water, usually about 2 to 3 gallons of water, never had any problems and thats about 25% to 35% anti-freeze, that's all you need.....

When I was testing different pulley sizes on the Mustang, I would leave the radiator cap off and start the car and let it get up to temp and watch the coolant flow thru the radiator, with the same size pulleys, the flow at idle was suprisingly low, the water would come out the tubes maybe a half inch, rev the motor to 1500 rpms and it would come out 2 inches and that is with a high flow,top dollar aluminum water pump!!!!!!!!!!!

I'm guessing slow water pump speed and possibly air in the system....

Are you sure the fan is turning in the correct direction?? (puller or pusher)(puller works better than a pusher)?? Some fans will turn either way depending on which wire is hooked to the hot and ground... If it runs hot on the highway, but you can keep it cool with a garden hose at idle, that points to a fan that is running backwards from what it needs to be.... I've done this before myself and have seen it done a number of times... check the easy stuff and double check it all.....

David

[LMH]

Just a thought but while sitting still, when it starts to overheat, raise the RPM up a little and see if the temp comes down. That might tell you if it's a coolant flow issue.
Larry

[elmariachi]

Originally Posted by DAVID GAGNARD

EL; I would definelty put on a smaller diameter water pump pulley,the water pump pulley should be at least one inch diameter less than the crank pulley....

That's one of the things we were discussing last night with a few other owners at the car show. It can't hurt anything to drive the water pump a little quicker.

Electric Fan is cranking in the right direction, it blows air out the back on the driveway and will suck a paper towel in the nose up against the radiator.

Originally Posted by LMH

Just a thought but while sitting still, when it starts to overheat, raise the RPM up a little and see if the temp comes down. That might tell you if it's a coolant flow issue.Larry

It will cool 3-5 degrees briefly by revving the idle. Then it continues to climb. One thing to note about the flow. Let's say I heat it up to 100C, then shut it off but leave the electric fan on. After about 3 minutes of the fan cooling the radiator if I start it, it immediately drops down 10* as it sucks the cooler water in out of the radiator. I can kill it, wait a couple minutes and do it again, and I can get from 100* down to 80* in 5-7 minutes like this. So I think that suggests I am getting good flow, no?

[PaulProe]

Jim
Are you sure your engine builder put the head gasket on the correct direction? FE gaskets can be installed backwards. The engine will run ok but it will overheat quickly.

You should be able to see a little tab on the front of the engine, at the head/block mating point, near the exhaust. If you don't see any gasket there, be suspect

You might want to do some pressure tests on the sytem and cylinders. The video of the car running and coolant puking isn't right. You might have a cylinder leak.

The Hurricane radiators were built by PRC

Paul

[acmjg]

I had similar issues. I have the hole in the t-stat, etc. I fill my system via the heater hose fitting on the top of the intake. Put a piece of hose on a funnel and raise it above the engine and fill until it comes out of the expansion tank. Also if you have a heater make sure it is on and all the air is purged from it also.
Anthony

[olddog]

I had a problem getting all the air burped out of my car. I had air pockets in the top of the heads. The engine would gurgle when you shut it off. I finally backed it over a steep bank and got another 1/3 of a gallon in it. It may not be your problem, but make certain it is not.

Just for the record, water has a higher heat capacity than glycol. I'm not sure what the GM coolent is, but you will get more cooling with water than glycol.

[olddog]

I re-read your first post. Origonally it ran cool down the road, but got hot at an idle. This would mean that at an idle you are either not getting enough liquid flow or not enough air flow.

If the problem is not enough liquid flow and you have plenty of air flow, then you should be able to rev the engine up to highway rpm and the engine temp would drop to normal. If it gets hotter, then the problem is lack of air flow.

[Mastiff107]

I don't have any connection with the stuff other than I researched it some. Heck, you take a turd and call it "new" and I'll buy it. Anyway, after being confused by the fact that you measured your engine displacement in inches and your temperature in centegrade...I have found one thing that worked for me. I run a mixture of 50/50 which all research I have done is supposed to be the best (water transferes (releases) heat much more efficiently than antifreeze).. I was normally running 180-200 (F) on my 289 (up to 210 on a hot day). I added one bottle of RMI-25 Cooling System Treatment (8 Fl. ozs) or 236.6ML. Anyway, on the hottest day now it runs consistently 15 degrees (F) cooler and I mean ALWAYS. This stuff really works. I run Evans Coolant (100%) in my hotrod which will heat the same but can not boil over. Good luck

[CHANMADD]

From what is happening in your header tank ,you either have air in the system or a blown head gasket! As far as I have ever read it is never good to run 100% glycol ,it actually does not work as well as a 50/50 mix. Also never run without the thermostat...ever!!

John

[Cobrabill]

Originally Posted by elmariachi

Done. Now what will this accomplish that removing the thermostat will not?

It'll slow the flow down a bit.A restrictor is to a T-stat like a "Test-tube" used to be to a catalytic converter...sort of.An open housing/water neck(what ever you want to call it )flows way to much.On my SCCA car,i run a restricter all the time.It just happened that the cooling system/motor liked the flow of the restricter better than a T-stat

[Rick Parker]

If the gaskets were on incorrectly it would continue to heat up even more at road speed, regardless of airflow. Olddog made a good point about purging the air, you need to be sure there are no retained air pockets. If there are any threaded plugs in the water passages of the manifold you could fill there until is runs out, cap it and then continue filling at the surge tank. I'm betting on the water pump drive ratio.

[elmariachi]

Originally Posted by Rick Parker

If the gaskets were on incorrectly it would continue to heat up even more at road speed, regardless of airflow. Olddog made a good point about purging the air, you need to be sure there are no retained air pockets. If there are any threaded plugs in the water passages of the manifold you could fill there until is runs out, cap it and then continue filling at the surge tank. I'm betting on the water pump drive ratio.

Thanks for all the replies guys. One thing is for sure, I do not expect it to be one item that solves this. Rick your idea of the pulleys makes a lot of sense. If anyone know what the stock diameters were, or at least of the water pump pulley is supposed to be smaller than the balancer, please chime in here.

The head gaskets are Cometic and they are on correctly, I was there when we mounted them. If this is a head gasket issue I will be more surprised than seeing Elvis, the engine DID NOT heat up going down the road before the shroud. From the dyno day until yesterday, the engine has never broken 80-85*C going down the road. For those of you that can't convert metric on the fly, that's 175-185 F. And prior to the shroud, it would not rapidly heat up at slow speeds or coming to a stop. Once you stop, it would slowly start creeping up. This has been the MO until last weekend when it was suggested that I needed to run a shroud to assist while stopped.

I just finished draining all the coolant out, removed both hoses and ran the garden hose through the radiator. When blocking the lower exit with my hand, it filled up pretty quick also but discharges very quickly when I remove my hand. My guess, it holds 2 gallons at best, which isn't much. Doesn't seem obstructed, but this is not valid test by any means. I refilled with distilled water only and jacked the nose up to the moon and burped it again. I also realized I had installed the heater control valve when I last had the expansion tank off for soldering and I never did open the valve. So I know I had air in there. As of sunset, the volcanic action is gone with straight water at ahalf-full level in the expansion tank, but I ran out of daylight as it approached 90C/195F and I shut her down for the night.

While I had it apart I also did a little t-stat comparison on the stove top. I'll add those pics to this thread shortly with details. Interesting findings.

[cobraman428]

First of all, if the car does not overheat at road speeds but does at idle it is simply an "air flow" issue and not anything with the coolant/water pump speed or pully speed. With the radiator cap off, there will be some bubbling due to pump pressure and everything expanding as it heats up. The tank should only be about 1/2 to 3/4 full when the engine is cool. You MUST run a thermostat. Repeat, you must run a thermostat. On my 428 I knocked out the center spring and it leaves approx a 5/8" hole. Takes alittle longer to warm up but big deal. You definetly need to run a thermostat to create a restriction or backpressure on the waterpump. I went through all this on my freshly 400 hp FE 428 and worrying about overheating and determined my electrical temp guage was giving me crap readings so I went with a mechanical guage that cannot lie. I also went with customized fan and shroud. e-mail me if you want pictures. Wanta check your air flow or lack of it at idle, turn on your engine fan with car at idle. If it begins to overheat, go inside your house and get your floor fan or oscillation fan that you have to blow on you while watching tv and place it in front of your car. borrow your neighbors if you have to but keep adding fans and you'll soon realize your electric engine fan is undersized. You need near 4000 cfm on a 427 or 428 on a 90 degree day at idle. Also, the electric fan is best when the blades are about a 1/2 inch from the radiator fins. You want to avoid air cavitation but want too achieve 100% draw. My 428 can idle forever on a 95 degree day now and stay at 180 degrees. Also dont be alarmed if it consistently runs at 200 degrees especially, If you have an all steel engine block and heads, 200-205 degrees is no big deal. At those temps your getting better fuel combustion. Sorry, ...enough rambling.

[elmariachi]

Decided to throw three 180* t-stats into hot water. Lower right is a NAPA FE t-stat that was in the engine when it was built and on dyno day. Upper right is a NAPA replacement I installed about 10 days ago when I tested the lower right and decided it was opening late (~190*). Gold t-stat is the new Cobra Velly hi-flow. It is the one that has been in the engine since last weekend when I added the new fan and final repaired/painted/pressure tested expansion tank.

The gold one and the upper one started opening around 185F, and the lower right at 190 as stated before. All were wide open as you see here by 200*. The hi-flow will pass a LOT more water than either of the NAPA units. The lower right unit is much more restricted than the upper right, though both are NAPA models for FE. Its interesting that on cool down, the lower right one went closed first at 190 (which makes me think its mis-labeled) and the upper right closed at about 175-180*. But the hi-flow stayed open all the way down to 150*. Again, I know this is not my entire problem, but it could be contributing. If the hi-flow is opening and staying open, then the coolant in the radiator doesn't have time to cool it just races on through. Not sure its the best one for the job.

P.S. Yes, they all 3 have 1/8" holes in them.

[elmariachi]

Originally Posted by cobraman428

First of all, if the car does not overheat at road speeds but does at idle it is simply an "air flow" issue and not anything with the coolant/water pump speed or pully speed. With the radiator cap off, there will be some bubbling due to pump pressure and everything expanding as it heats up. The tank should only be about 1/2 to 3/4 full when the engine is cool. You MUST run a thermostat. Repeat, you must run a thermostat. On my 428 I knocked out the center spring and it leaves approx a 5/8" hole. Takes alittle longer to warm up but big deal. You definetly need to run a thermostat to create a restriction or backpressure on the waterpump. I went through all this on my freshly 400 hp FE 428 and worrying about overheating and determined my electrical temp guage was giving me crap readings so I went with a mechanical guage that cannot lie. I also went with customized fan and shroud. e-mail me if you want pictures. Wanta check your air flow or lack of it at idle, turn on your engine fan with car at idle. If it begins to overheat, go inside your house and get your floor fan or oscillation fan that you have to blow on you while watching tv and place it in front of your car. borrow your neighbors if you have to but keep adding fans and you'll soon realize your electric engine fan is undersized. You need near 4000 cfm on a 427 or 428 on a 90 degree day at idle. Also, the electric fan is best when the blades are about a 1/2 inch from the radiator fins. You want to avoid air cavitation and 100% draw. My 428 can idle forever on a 95 degree day now and stay at 180 degrees. Also dont be alarmed if it consistently runs at 200 degrees especially, If you have an all steel engine block and heads, 200-205 degrees is no big deal. At those temps your getting better fuel combustion. Sorry, ...enough rambling. cobra428bigblock@yahoo.com

I was previously running the expansion tank half full until just before that video. We thought that the extra half-gallon might help. Your idea about the fans is good, I can make that happen tomorrow. Regarding the shroud, it 100% sealed around the edges and where the fan meets the shroud. In front of the radiator I have a couple of small openings in the bottom corners as I am running a false floor in the nose until I have time to install an oil cooler. But why would the shroud make things worse? This 3600 cfm fan is sucking a HUGE amount of air through it. Its mounted 1/2" away from the core face. I would be fine with 200-205 at idle, but I am suddenly at 215-220 at idle now since adding the shroud, and 205-210 down the road with ambient temps at 92*.

I'll send you an email, I am grateful for whatever you have.

[Michael C Henry]

The deal with the head gaskets is there is a tear drop coolant passage hole at one end of each head gasket and the outline around the blocked passage at the other end of the head gasket. The heads are interchangeable and have the matching tear drop passages at both ends. The gaskets block coolant flow at front of engine. Coolant is supposed to be forced into the front of the block on both sides. The major Coolant flow is supposed to flow to the rear in the block then rise into the heads throughthe open coolant passage in the head gaskets and come forward in the heads. The coolant is then goes to the thermostat in the intake manifold. The small tubes and short connecting hose to the back of the coolant pump and intake manifold is the only circulation of coolant untill the thermostat opens. I perfer a Chrysler thermostat. It fits the T-stat pocket in the housing and has a larger valve area than a OEM Ford T-stat. I use a good grade of thermostat at 180° with a small hole that I locate at the top. I have had problem with that Dexcool coolant ,it clotted and blocked a new radiator in a Toyota Land Cruiser radiator. Radiator shop rodded it out to fix the problem.
If fluid level climbs when engine revs . more than likely it isn't flowing through the radiator. Remember coolant is supposed to fall through the radiator.
There are so many points you need to be sure of . A presure tester would be a great help when checking things out. With the system caped at the usual surge tank,, you can watch the pressure gauge in the tester . Start the engine and watch the presure gauge. If it climbs too fast ( faster than normal heat expansion) that would indicate a cylinder( combustion ) pressure leak into the coolant passages. Another check is to remove the cap on the surge tank and make sure the fluid level is high enough to watch for bubbles rising throuh the fluid . With the engine stoped the fluid should be still. Once the engine is started and running, if bubbles strat rising up through the coolant fluid. the bubbles would be combustion gasses escaping into the coolant (not supposed to happen). Cylinder pressure leak could be a bad head gasket seal, or a crack in the cylinder wall, or a crack in the cylinder head, there are many more variations of this possible. I presonally like the idea that the Dexcool has plugged your radiator and not enough fluid can move through it. Thats a remove radiator - Take the radiator to shop have them test and repair it.

[elmariachi]

Originally Posted by Michael C Henry

I have had problem with that Dexcool coolant ,it clotted and blocked a new radiator in a Toyota Land Cruiser radiator. Radiator shop rodded it out to fix the problem.

There are so many points you need to be sure of . A presure tester would be a great help when checking things out. I presonally like the idea that the Dexcool has plugged your radiator and not enough fluid can move through it. Thats a remove radiator - Take the radiator to shop have them test and repair it.

The pressure tester is on my list of to-do's tomorrow. Just for the record on the Dexcool subject, I currently have 170k miles on my 9th Toyota Land Cruiser since 1994 and the last 6 of them have had Dexcool with not one single issue. And we aren't talking Mall Cruisers, see below. The DexCool has only been in the radiator for 258 miles/2 weeks and its all drained out as of tonight just to remove that from the argument. I just ran fresh water through the radiator tonight for 10 minutes and if its plugged, it's sure passing a lot of clean water very quickly. But removing it and having it tested is rapidly moving up my priority list.

Jim

[elmariachi]

I'm going to pressure test the system tomorrow, run the traps on the pulley dimensions, and try and sort out whether it should be 100% coolant or 100% water, as both have been recommended in this thread thus far. I will burp it yet again and try jamming more air into the nose. Unless I see a breakthrough, I am removing the shroud and digressing back to where it was running cool while moving. Then I can at least safely drive it to the radiator shop for further eval.

Thanks for all the replies, I'll post again tomorrow.

Jim

[Rick Yeager]

What should the difference in temperature readings with an Infra Red Thermometer when the termperature from the lower hose is subtracted from the the temperature of the upper hose on a good running radiator? I read one place that it should be above 40 degree F but this seems a little small to me. If this were known, one could readily know if the radiator was the major problem after the engine was warmed up and the fan running. What do you all think?

Thanks, Rick