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My '47 Custom Clipper had a modern after market 6-blade flex fan when I bought the car. I changed it out for a stock Packard 5-blade fan to keep the car original looking. The fan installation I had was simple compared to the one described above. Four thick washers were placed between the flange and the fan. The washers were the thickness of the offset in the flange. This provided for a solid base to bolt the fan. The fan is self-centering with the diagonal slots for the four fastening bolts. It is an 18.25" diameter fan. Go to the Summit Racing site for various size fans.

(o{I}o)

There has to be 15 simpler ways than how i did it (or do anything) but this happened to be what was at hand and what fits the "look" of the new engine bay. It is, however, a very solid setup. No wiggling or play of any kind.

If you're willing to use the shallower cupped flex fans, or the ones that look like slightly bent stars, you could run a bigger diameter fan without hitting the belt or pulleys.

I used this style fan on my 5500 rpm pontiac and it's quiet and moves TONS of air. Quiet and efficient were my main two goals, looks third.

Also, found today that when i lifted the radiator up to install it with the bolts that the ledge would not be in the way with that size fan. I used spacers on the radiator anyway to move it forward some to be sure the anchors for the tranny coolers wouldn't be in the way of the fan coming around.

I noticed fans from 30's packards can look more modern and move more air than my stock stamped 4 blade fan. In a lot of ways, i think the 30's cars were better engineered.

Wow that sure is a bunch to absorb. Appreciate the feedback.
To answer the questions:

1. No the fan is not in backwards. Checked it many times.
2. The radiator is brand new. No clogs.
3. The block is clean looks like it was just boiled out.
4. The transfer tube appears brand new no rust etc.
5. Grill opening. Yeah that is rather tiny isn't it.
Don't know of anyway to work around that.
6. Had a second (new)guage on it and checked it with UV tester. Yes it is very hot and the stock gauge is accurate.
7. When temp goes over 300 degrees I shut it down. Yes it will keep going I would bet on it. Last thing I want is to warp the head.
8. Tranny overheat ? Nope just rebuilt by the best Packard mechanic in the states. You know who you are !
9. Water pump was rebuilt by the same. Got desperate so I mic'd it internally and the tolerances are very tight. No slop here.
10. Too much coolant. It overheats with pure water in it.
Even mixed 50/50 .. same.
11. Removed top hose from radiator put garden hose in the radiator top and ran it. Never overheated. Water came out clean.
12. Flex fan. Are you sure they work? I restore '60's+'70s vehicles and found that Chevys overheat with these flex fans. To really fix you need a hard big bite factory 5 bladed flex fan. The aftermarket flatten out too quickly.
The are sold for gas milage not addl cooling.
13. I put a big fan in front of the radiator and ran the engine. The addl airflow didn't matter it still overheated.
Wondering if the air flow is getting thru the radiator.

Observation. In idle with the radiator cap off and the engine hot. There is no ciculation noted in the cap until you rev the engine up. Guessing 2000+ rpm.

Anyone know of any replacement pulleys for this ? Would like to increase the waterpump rpm and the alternators also.
Yes I converted to 12v so I can put a big pusher fan on the front of the radiator. Yes desperate especially since the big floor fan didn't help.

Thanks
OTG

I had meant too much volume of coolant/water, not as much the mixture. If you have the system too full, it will blow the excess out when it expands and then be at the right full level cold. If you verified that the car is actually hot with thermometer and temp gauge, then you're not having this issue. That would be if the car doesn't seem hot at all but is blowing coolant out.

The grille opening is a bit small, but you'll notice the upper and lower sheet metal does a good job of shrouding the air right to the radiator so none is lost. Only shrouding issue is that we have no shroud around the fan. Those are nice to have, but if you had a fan in front of the car and it made no difference, then i doubt a little airflow efficiency increase by adding a shroud around the fan would make any difference.

Flex fans are not a fuel saving device at all. OEM clutch fans are more fuel efficient, as they only spin at a percentage of the water pump speed when cool, and even when engaged at 80-90, always slipping some. A HD clutch will spin at a closer to water pump speed rpm than a regular duty clutch. Hayden makes good clutches and has tons of info on their site. Flex/mechanical fans spin at 100% of the rpm of the water pump all the time, even at high rpm and when the motor is cool, wasting hp to drive the fan when it isn't needed. The flex fans are however cheaper, lighter, and do flatten a bit to help at sustained high rpms. Even in high performance setups, many professional builders recommend a HD fan clutch and 7 blade OEM fan like that would come on an A/C or towing package equipped car.

It's a moot point for us Packard people anyways, as all of our fans are pretty much flex fan direct drive 1:1 mechanical fans. We can choose factory stamped or some variety of flexfan.

Blade flex, count, and pitch determine how much air is moved. Few are worse than the narrow pitch 4 blade steel stock fan, although it should be adequate given everything else in the car is working well. It did when new right?

It'd be hard for a Packard straight eight to get enough rpms to flatten out a flex fan. Even a SBC would have trouble flattening it out too much. Reach under the hood and rev the engine to 4500 rpm on a sbc and feel how much air that fan moves Most heating problems are due to other factors anyway, and people want fans to band aid them.


SOME (or most) flex fans are literally crap and don't move any air at all compared to OEM. I have about 10-15 different flex fans and have found the best for quietness and cooling. I have a dozen different spacers around and tons of diameters of the same fan models to check and test differences. I did a whole study on them for my Pontiac motor last year. (Run a hayden hd clutch and a decent 5-7 blade OEM fan, not aftermarket, aftermarkets don't usually have the uneven blade spacing that helps eliminate noise at higher rpms.)

Attached are 3 pics of great flex fans, and 3 pics after of ones that suck. You can tell the difference between them easily: good ones have more pitch, more blade surface area, and usually more blades. (the flexalite 1818 blue 7 blade fan looks odd, but it moves some air and quiet as a church mouse, one of my favorite direct drive fans)

You can also get direct drive non-flex fans that look just like an OEM clutch fan with blades that don't move at all but bolt to the water pump instead of a clutch, but i'd have my doubts about getting one into the tight space of the front of our Packards. I could be wrong though, never tried one. I just figured if i wanted that type and style i would go OEM clutch for the fuel/sound savings:

summitracing.com/parts/DER-17417/


All that fan science aside, i'm wondering why yours runs so hot after you've done so much to make sure the system does well. With everything clean, it should idle cool with the plain jane stock fan.

The fact that you ran cool off of hose water won't point to much, that's like a boat with a steady supply of 60 degree water. The pressure will help circulation though. I might be wrong, but i thought like 230 or 240 was hot and 300 would be well past cooking. I'd have to look it up, but i aim for 200-205 in almost all my (gm v8) cars for best fuel efficiency without being too hot.

I have a clear inline filter on my upper hose, when it's warm and running i see coolant rushing through it, and mine isn't the cleanest setup in the block side.

Have you thought maybe too small exhaust (doubt it since it does it at idle) or maybe the carb is running things too lean or you have a massive air leak somewhere like a manifold gasket leaning out the mixture? If it does it only at idle, i'd start to wonder if there was a problem where you're running really lean on the idle circuit. Any coolant loss pointing to head gasket issues?




Like i was saying, i see my coolant moving at idle. I can't give you an RPM and be sure my idle isn't high because i just got it back together and i don't have the 6v tach here yet to tune it with. Doesn't seem like maybe more than 1000 rpm though?

Perhaps the radiator paint is too thick and blocking heat transfer and airflow? Others have talked about this somewhere on the board before.

Leave it in neutral and idle for a few? Maybe the tranny is slightly in gear in park or the selector linkage is off and the car is working itself trying to move some forward.


I know how much heat issues can ruin the fun of car, and i try to do everything i can to help someone enjoy their classic more. There has to be a cause that it's not running cool the way it is. If we go down the list and check everything, something will turn up. You've already covered most of the hard to check or change items on the list.

Could the dist tube be in upside down? Don't know if it will even fit that way, but that would put the holes in it spraying on the motor instead of towards the exhaust valves to cool them first, correct?


As an answer to the pulley question, no, i haven't found any smaller pulleys, but i only looked around with minimal effort. Maybe another brand pulley will be smaller and line up with a packard setup?

I have a converted gm 6volt pos ground alternator with the wider pulley for my 50 belt, it always did great even at idle. I'd have to guess and say it's 4" in diameter? About the same as a regular alt pulley.

Maybe missing the upper or lower sheet metal that guides air after the grille to the radiator?

Don't go pusher fan yet, if a fan in front of the car didn't help, it won't much and could also block air at higher speeds vs just a wide open front setup.

You checked tight belt right? Also, you're using the correct belt, not an "industrial belt" off a store shelf? Someone mentioned they're not exactly the same and will bottom out in the pulley and have some slippage vs the correct one seating against the V properly and driving the pump/gen properly.

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Dear otgdy:

Wow! The 288 motor should not run hot. It is Packard's best all around straight 8. I drove some originals that had plenty of power and ran great on the freeway even without OD.

Obviously something is wrong. Take out the thermostat for starters. If the condition goes away replace the unit and drill a few 1/8 inch holes in the plate of the new one which is available from NAPA. I don't have the number handy.

Next, I guess you had the radiator out and with the water pump off shoved a steel rod to the end of the distribution tube. Sometimes motor rebuilders forget to put those things back in the motor which causes huge overheating.
Also, I have seen cases where mice got into the cooling system and the nest clogged the tube.

I assume the motor is in good shape. I coped with a 1911 that ran hotter than a cinder because of a vacuum leak and too slow burn rate. Is the timing chain and compression good?

Does the lower radiator outlet still have the intake pipe or has it been replaced with a single hose? I have had to make up the intake pipes to cure overheating caused by collapsed hoses.

Has the cylinder head been off? I dealt with a V-12 that was junked in 1956 because the aftermarket cast iron heads were not drilled on the left bank.

To be sure, when new these cars ran without overheating, however, as they age the metal itself starts loosing its transfer properties. But that won't cause it to boil like a volcano.

Are any exhaust vapors coming out of the radiator cap? I worked on an 11th series car that people said had a cracked block. I bought a carbon monoxide tester from McMaster Carr and tested for exhaust in the radiator. Nothing. So the problem boiled down to the overflow tube being too high in the radiator.

Good luck and I'm sure this problem can be figured out.

A restrictive exhaust can also cause an overheat problem as well.

Good point on the exhaust. Had forgot about a local 51 some years back that had severe overheating issues including burned exhaust valves because the heat riser valve was not opening. Don't remember if the valve was stuck of if the spring had been installed wrong but took the owner quite some time before it was sorted out. I think his overheating was more consistent though, not just when idling.

Could it be trapped air? I don't know if that was ever an issue on straight 8's but I have had a few cars over the years that would overheat because of air trapped in the cooling system.

I wouldn't trust the results of a test without a thermostat. I've had vehicles personally that, without a thermostat would run SUPER hot because the coolant didn't stay long enough in the radiator to cool down (theory why anyway) and another that wouldn't get above 100, no kidding, driving it all day. Had NO heat, not even luke warm, without a thermostat in it. Depending on flow rate and how efficient the cooling system is, it could overheat or it could run super cool and you wouldn't learn much.

The best trick seems to be thermostat in a pan of water and see what temp it opens at.

I have experienced the following causes for overheating on various cars (not my Packard.)

1. Timing retarded - car starts fine and overheats
2. Someone removed sheet metal shrouds directing flow through the radiator
3. Cracked head allowing exhaust gas to enter the water

The 288 in my 1950 Series 23 Packard cools fine and I have not devoted all the effort you have on your car. I have a rebuilt radiator, new (not rebuilt) water pump, stock fan, new stock thermostat, new stock radiator cap, new fan belt. I have not touched the block or the distribution tube. I put in a new water temp gage under the dash with numbers on it so I can know what is really going on. The car runs between 150 and 200 degrees.