Projects Cooling problems, here's what I'm going to do, any other ideas?

OK, so I've taken a couple of days off working on the Fordillac for relaxation, and I'm going to spend tommorow doing what I hope will fix it's wanting to run too hot. For those not following my too hot hot rod problem, the Cad 472 runs at about 210 when the air temps are 65 or so, and a little over 230 when it's in the mid 80's. Not wanting only to drive the car only in the cool of the evening or early mornings, something has to be done.

It's got a '66 Mustang V8 3 row copper radiator, new. 185 T'stat, 13 lb cap and a 14" 2000 CFM (supposedly) fan. The radiator, by neccessity, sits right behind the 2x3" rect. tube front crossmember, which blocks the bottom 1/4 of the radiators airflow. I have a catch can, which holds about a quart. It doesn't push coolant out of that nor blow the cap.

I'm going to cut holes in the crossmember with a holesaw to open up airflow to the blocked portion of the core. It's almost a quarter of the cores surface area. Since there's a 1 1/4 DOM tube crossmember at the very front of the rails, and another 2x3 crossmember at the rear of the engine, where the rear spring hangers are, I think this'll be OK chassis strength wise.

The Caddy engine has only 1 heater hose port, just below the t'stat housing. I'm going to pull the radiator and have a 5/8 hose outlet added to the lower tank (as the Caddy system used in '68), and use a large heater core I have as an auxilliary radiator, mounted under the floor at the rear of the car, with it's own fan. I thought perhaps running copper tubing to that might help shed some heat as well.

I'm planning using the current 14" fan, of dubious CFM rating for that, and replace it at the radiator with a new 16" fan. The aux. fan I'll wire hot to the switch, so it'll run whenever the ign is on. The fan is, and will be, behind the radiator as a puller. I have a 180 degree fan control and relay which works well, and will keep that but may wire it to a constant hot source so that it can run after the engine is shut down.

It's been suggested by several people that I replace the 180 'stat with a 190 or 195, in order to slow the coolant flow down thru the radiator, and replace the 13 lb cap with a 15 or 17. I'm also running 50/50 antifreeze mix with a wetting agent, but I'm willing to cut that to a 70/30 mix. I'm in MI, and I'm NOT going any lower than that.

The radiator has a trans cooler in the lower tank, no other aux. cooler at this time. Might it help to put a cooler ahead of that?

I've already made a (really pretty nice looking) air dam at the lower part of the grill of aluminum, and one at the top of the grill, under the hood, to direct all the air flow thru the grill thru the radiator core. I also made side panels of aluminum to fill the opening at the side of the grill to the crossmember (it's a fenderless car), to keep air from escaping out there ahead of the radiator, so I can't get any more air thru the radiator core.

I wondered about wrapping the exhaust pipes with header tape as well, in order to get as much heat as possible away from the engine compartment, and out from under the car. This would also seem to help keep exhaust heat away from the starter, it does have a little hot start/starter dragging issue. New 2KW high torque starter, BTW.

Any other ideas or suggestions are welcome. I'd be perfectly comfortable with it running at around 210 in traffic on a warm day, but it wants to get hotter and hotter while going down the road at speed, which leads me to think my problem is airflow. 230 to 240 is just too hot, I think. Admittedly, my chassis design is a problem now, but by opening up the crossmember and adding a little extra radiator capacity, I'm thinking I may be able to help with these things.

Brian

 

I also run a seperate trans cooler, I didnt want to put any more heat in the radiator than I had to.

Edited.....I just saw the problem is at freeway speed.

 

Brian, For once there's a cooling thread where the basics are covered. You are thinking the right way. I don't know that the aux radiator should be necessary, but it won't hurt.

I think your biggest concern right now is that dubious fan. Put something in there that you KNOW moves air effectively. I stopped buying aftermarket fans years ago and started grabbing OE fans from the salvage yard. LT1 Camaros and such used 2 fans (maybe 14"?) pulling. One was on the temp sensor thru the ECU and the other was a slave to the A/C relay. I ran just one a V8 S-10 for years in all kinds of heat. It ran right at 210-220 with the 195 t-stat every day. It was a TBI motor and this is right where they run in OE fit. I like a 16 lb cap and don't sweat anything under 240. I might get nervous if I saw 230-240 routinely in moderate conditions.

The only thing I would ask, if you get out on the highway and stay there, does the heat creep up? That would indicate an airflow problem or a BTU capacity issue. If no, you have a fan problem down low. If both, start with the airflow before being concerned with low speed operations.

 

Definitely sounds like an air flow problem. Does the radiator have a shroud? That can make a major difference in air flow. As for slowing down the water flow, forget it. That just doesn't work or make sense. Have you tried running without the thermostats (just to see if it makes a difference) not recommending you don't uses stats, especially in Mich. Let us know how you make out.

 

Ok
your concerns are noted
now

accuratly check the coolant temp? .. Gauge , senders and such may vary 10-15 degrees

50-50 mix af is best .. Do not alter

waterpump flow / stat restriction.. If circulation is to fast watertemp increases cuz heat is not drawn out thru transfer into metal of radiator... Used radiator specific paint right?

A race car ..adjustable electric water pump may control your flow beter

radiator hose not collapsing? Lower must have wire coil insert

push or pull fan .. Is it on the rightway? Spiinin the right way?

Timing not too advanced .. This causes excess heat

a sealed overflow tank system with proper (non lever)cap so no air will be in the system ... Purge air out at highest point of system which may not be the cap!THIS WILL HELP DROP THE BOILING POINT QUITE A BIT

Separate trans fluid cooler ?... Beware as some trans need the heat from the water as well


having the rear heater may help .. Adding more water capacity ...but the routing and bleedoff of heat may not be noticed ... So adding enlarged tanks to the rad top may work the same way


air flow .... Means little if the air cannot escape the engine compartment ...short of a wind tunnel a smoke bomb (dunno how? ) will tell ya at speed or sitting where the air is going.. Good luck with this part

hood louvers vs fans and shrouds maybe the radiator need angling a bit for direct flow ..


Gosh if it were me and it ain't puked or vapor locked i'd put tape over the gauge and go for a drive

 

I just got rid of my cheap 2500 cfm fan and replaced it with a lesser rated 14" SPAL. Night and day difference! I live in the desert, 103 today and it didnt seem that bad, drive all day long at 185-190. 185 therm, SBC w/10.5 to 1, timing at 36 total advance (it does make a difference) stock water pump, mustang 3 row rad, fan switch in the head (becool). I learned my lesson!

 

seems as though, if heat builds up on hiway,.. air flow is NOT the concern, usually 60 m.p.h. air is alot more than your fan will produce..usually, if heat continues to build up at highway speeds, usually,radiator is too small(not enuff cooling capacity) or the engine is LEAN.. the ignition timing needs to be checked also,(retarded = hot)
what carb. do ya have? easy test, back idle screws out three+ turns and drive it, ...it will run like crap, but if it cools your engine down, you know it's becasue of a lean condition.. : ).... oldest trick in the book..

 

Those radiators werent even big enough for the engines they were built for anyway, let alone a 472. You would be well off to find a crossflow radiator like you would find in a gm, possibly a 4 core if you can stuff it in there.

 

I've got a472 in my 57 cad. with a 2 row alum. radiator. drove it to cali. last year with worn out engine idled for an hour with air on in awards line , 180 deg. came home rebuilt engine now that sucker runs 220 and gets to 250 if you set more then 2 mins. have shroud, clutch fan , everything is the same excpet new engine. drove it too austin, detroit, and all over ks. you would think it would be broke in. any ideas?

 

Get a thermometer (laser/infrared is preferable). Take temperature readings from all around the radiator. If there are any spots that are distinctly colder than everywhere else, you could have a blockage in your radiator. You can also use it on your engine to check if your gauge is accurate.

Checking to see if your hoses are collapsing as stated earlier is also a good idea. Lots of good ideas here, good luck!

 

You can put the head gaskets on backwards on the big caddys. This will not let sufficiant flow of collant the the back of the engine and cause it to run hot in the range you said, over 230... Also try using a possitive gauge " one that does not use power to work"

Big engines need big radiators and lots of liquid to work right.
Cooling systems are not just a prt here and a part there. They are an engineered system just like brakes. Any one that hits it right the first time with zero thought involved has dumb luck. You have to figure the btu output of an engine and the btu capacity of the radiator and the needed air flow, how fast the coolant is moving in the system. A thermostat is a regulator of flow! keeping the water in the radiator longer when needed and in the engine as needed. If you have taken one out, you need to put one back in as this is designed in the system and needs to be there to work right.
take it or leave it. Brian.

 

Yes, it gets hotter and hotter on the highway at steady speeds of 60-65. When ambient temps are around 65 (as in, on the way to work at 0600) it's OK at 210, and at 80-85 (in the afternoon on the way home) it seems to just keep on climbing. It's a 35 minute drive to work, by the time I got home the other night, temp gauge was at 240. I think perhaps the fan itself, a cheapo one, is blocking airflow at speed.

I did unhook the original Ford gauge, which only read to 210 and was suspect anyway, with a new mech. gauge, so I THINK the temp readings are accurate. The radiator cap is the highest point in the system, so I don't believe there's air entrapment (I had that problem intially with the LT1 in my '48).

There is absolutely NO room for any larger radiator than the Mustang I have, so the system I know is crippled in that regard, but there's no changing that. The '36 grill shell is sets in is only so wide, and so high, the engine sets where it does, less than 3" from water pump pulley to radiator core. Using heater cores as aux. radiators is a bandaid I know, but I'm an RN in an ICU, and not afraid of bandages!

I have considered simply pulling the hood sides, but the car looks wrong without them. I built it with a specific style in mind, and it's gotta look how it's gotta look.

Carb is stock Quadrajet, rebuilt. New 180 degree stat, known to be good, tested in a suace pan and boiling water with a candy thermometer. New hoses, wire supported lower, not collapsed.

The car is down for a couple of days while I wait for new front brake hoses (the left front collapsed and that brake hung up), so this the perfect opportunity to try to increase the airflow, add the heater core, better fan, and see if that helps. If not, I guess the hood sides come off, I only drive at night, or tape over the gauge...

Brian

 

is the eng. setting higher than the rad. Make sure you have water thru out the eng. some times air will get cought at the back of the eng. on fill up. Drill 3 1/8 holes in the stat and jack the front of the car up and fill it up.

 

Hmm, I may be answering my own question here, but I just searched "Ford tractor radiators" and came up with dozens and dozens of heavy duty, up to 5 row core radiators that'll fit in '36's sectioned grill shell, with trans coolers and without. Seems a radiator that'll cool a diesel tractor under extreme conditions, may be better than a 3 row automotive one. More fins per inch, two more rows of core, same size, same hose dia. and location. Maybe this is the answer...

Brian

 

Your radiator capacity is inadequate.

 

When I was a broke kid and couldn't afford a new radiator we used to turn on the heater for a little extra engine cooling, it made the inside of the car hot but would drop the engine temp 5-10 degrees. Maybe you could rig some BIG car heater cores somewhere and help your situation out.

 

Brian, if you put a 460 in a mustang would you expect the stock small block radiator to be sufficient? As an off topic street machiner, I'd never even consider it.

Definitely ditch any fan that's defined as "dubious". But in order to have a truly robust cooling system I see only one solution, and that's an aluminum mustang radiator with much higher heat exchange abilities.

Good luck, hope you get to enjoy that car soon!

 

These overheating problems can be a pain-in-the-ass to chase around. All of the advise given here is valid and informative. Everyone that builds cars runs into this at least once, usually more though.
A friend just dumped a couple of grand into his BBC powered car trying to cure his overheating problem. Eventually they put a larger pulley on the water pump to slow down the circulation and that cured his situation.
I am a gauge watcher to a fault and it makes the drive stressful at times. As a result,when I built my Buick powered Model A, I put the gauge on the engine and a 240 degree light on the dash. Then, if I needed to know what the temp was, I had to pull over and get out to find out. This would not be a recommended as a cure for real problems.

 

LOL, tell me something I don't already know! The space available for a radiator is 20x22. With the three row core radiator I have, there's a whopping 2 3/4" between the core and the water pump pully. The Mustang radiator is 20x21. I'm there.

 

A 20x20 aluminum radiator with 16" electric fan and shroud will cool a healthy 440 mopar.

 

A 1/8" hole in the thermostat flange is sufficient to avoid an air lock when topping off the cooling system.
Two 1/8" holes will not let the engine warm up for quite a ways in wnter weather.
(One mile vs four miles in 16* F weather.)

The 32 has the radiator cap (7#) at the high point of the cooling system, but I still got an air lock.
Only once, but that was enough to convince me to drill the thermostat.

Motors Manuals used to have a table in either the back of the book or in each section (by make - Caddy, Olds etc.) that listed coolant quantity's in quarts.

I believe you've been through the timing stuff by now.

One thing you may want to look at is your harmonic dampener.
Is it marked with true TDC?
Stock dampeners on old engines will many times allow the outer ring to slip and things will look right under a tming light, but be off by quite a ways in some cases.

I suspect this is what's happened to my 462" Buick engine in the roadster.

I gave it 4* additional - at 12* now - initial timing and kept the all-in timing at 32* which is what most recommend for stock and modified 455 series Buick engines.
Seems a little stronger, no ping and no mpg figures yet.

It's running a couple degrees cooler on the highway and around town.

And checking true TDC is on the list.

It's easy to get fooled with a light car/big engine combo.

Even out of tune they'll still haul ass, but in tune?

Good stuff....

 

Try a dirt track aluminum radiator. They come in a variety of sizes to fit all kinds of aplications. I have used two of them now with an aux fan and have had great success. Also, they are alot less expensive than you would think.

 

I'd look at a 4-core Mustang radiator from a 390 application. It will do a lot more cooling than what you have.

For the bottom, you can make a duct to catch some air similar to what saturday night stock car racers do. You can recess it somewhat for looks, but put a screen it it to keep the big pieces that it'll tend to snag from the road.

Bob

 

Good advice. I THINK I have the timing question sorted out, but you're right; 400+ hp, 2,000lb car=who cares if it's tune or not! It'd be a rocket if only 4 or 5 cyl's were firing!

While I'm tinkering, I'm going to see if TDC is where I think it is. It's been a head scratcher, but I'm learning stuff and I'm sure it'll get handled. I'm getting closer! If it was easy, anybody could do this, right?

Brian

 

One of the guys in another post is right. Look at the spal brand fan. They have a more honest cfm rating. Be sure you run the electrics on a relay. Could you run two smaller fans and get more coverage of the radiator core ?? $0.02

 

Fwiw - and I know you have space problems - a Hayden 18" mechanical six blade fan with fat stainless blades has an airflow capacity rating of 6000 cfm.

 

Well, here's what I did, so far. I took the entire center of the crossmember out, leaving about 3/8" lip. The radiator sets directly behind this, with an inch of the core below the bottom edge. In effect, I'd blocked the lower 1/4 of the radiator from any meaningful airflow. While this looks pretty scarey strength wise, remember there's a 1 1/4" DOM front spreader/crossmember, and a 2x3 rect. tube at the rear of the engine, just in back of the rear spring hangers, as well.

There is a lot of room under the floor at the rear of the car, enough actually for a small radiator if I can get one wiggled up around the exhaust and trailing arms. There's a 21x20 unrestricted space, with about 6" clearance at the tightest point over the driveshaft and 3rd member. The exhaust is below the axle, so there should be enough airflow of relatively cooler air to push thru either a radiator, or perhaps 2 large heater cores. It's worth a shot, before I buy another radiator.

At least at this time I have as much unrestricted airflow as I can get to whatever radiator I end up using. The Ford tractor rads turn out to be about 2" too tall to fit under the hood and not hit the front axle.

The core of the Mustang radiators are about 18x18. A 16" fan will cover most of the core, and seems it'd be better than 2 small ones. I have the system on a 180 degree temp switch and relay, so I'm all set in that regard. I have to be careful of clearance between the fan and water pump pully, an 18" fan would have to be centered, and would interfere with the w/p pulley. A 16 thinline fan I can drop to the bottom of the core, get centered side to side, and still (barely) clear the w/p pulley bolts.

 

Brian, before you go to the ends of the earth with trickery, just put an aluminum radiator in it. Paint it to camoflage the touch of modern tech.

Seriously. Everything else is a baby step when you need a leap. You might get it under control now but will still be so close to the line that heavy useage will cause you to have to manage the heat with driving style and route choice. That's a suckass way to enjoy a car. Buy the aluminum radiator.

 

Shifty, I've kinda given up on camoflaging the modern stuff at this point! Electric fans, relays, dual chamber master cyl, etc. etc. I'll see where I get with the increased airflow. At least with the crossmember opened up, I can put it back together and see where things stand, be able to drive the car a little, and order up a new radiator if I have to buy one. It's a couple hour job to R&R the hood and radiator to swap. No big deal.

 

I am a fan of the tractor radiators have one in my sedan and can drive down the road without a fan.With a mech. fan as soon as the tstat opens the temp drops back to about 150 in traffic on a 100 deg. day.I am running a very healthy small block but have friends running them on big blocks with the same results.