If you are still uncomfortable with the temps, I would get a shorter spacer first. If that doesn't work for you, get either a larger crank pulley or a smaller water pump pulley.
water temps climb at idle
- Thread starter yellow wagon
- Start date
I've done lots of testing with water pump pulleys,IMO I would say its time to go to a 6 inch water pump pulley.Read this thread I've got many hours in testing.
http://www.348-409.com/forum/showthread.php?t=7396&highlight=water+pump+pulleys
http://www.348-409.com/forum/showthread.php?t=7396&highlight=water+pump+pulleys
Jim's research is a wealth of knowledge and information. I'd pull the fan back a bit like Brian recommended and is it possible to "try" a properly set up vacuum distributor before the serious expensive stuff. I think Jim had the proper specs on setting up a distributor, if not, I'm sure an observant member will provide the post. I don't feel your fan offcenter is as important than inserting depth. Good Luck
robert
robert
yea I haven't given up just yet on my current set-up. I still think I can get it to run a bit cooler with what I've got. I still think that a big part of the problem though is the radiator and it being corroded up inside 
I might play with my tune a bit too and reset my timing AGAIN as well as add a touch more fuel to the idle circuits in the carb. We'll see. She runs so nice I hate to mess with it. 
I might play with my tune a bit too and reset my timing AGAIN as well as add a touch more fuel to the idle circuits in the carb. We'll see. She runs so nice I hate to mess with it. 
I can't "burp" my upper hose cuz its one of those ribbed bendable hoses with the wire in it.
Get rid of that hose and put the correct hose on there. Those things are no good. That could be part your problem...
mac1
Well Known Member
IMO, Your 409 should run cool with the following changes.
Get rid of the clutch fan and install the flex fan posted earlier. The blades will flatten out at high RPM's, saving you a few ponies. (half in half out shroud)
install a four core brass or equivalent radiator
advance your timing as much as possible without encountering detonation
install only one gallon of antifreeze
install a 160 or 170 thermostat
install an aux electric fan
Adjust idle mixture screws for highest vacuum. (Edelbrock are usually 1 1/2 out)
Mac
Get rid of the clutch fan and install the flex fan posted earlier. The blades will flatten out at high RPM's, saving you a few ponies. (half in half out shroud)
install a four core brass or equivalent radiator
advance your timing as much as possible without encountering detonation
install only one gallon of antifreeze
install a 160 or 170 thermostat
install an aux electric fan
Adjust idle mixture screws for highest vacuum. (Edelbrock are usually 1 1/2 out)
Mac
I have a small block in my car but the same applies...a new radiator I think is what really would solve the problem. The tune is spot on. Holley 650 double pumper. Tuned for highest vacuum reading. 13 degrees timing at idle.
it runs nice when driving (airflow). But as soon as I try and sit for a few minutes on a hot day idling forward (no airflow) she gets hot. I didn't even boil over but she was hot.
It runs 190 on the money usually at cruise. Maybe 200 around town doing 30mph-ish. Maybe even a lil cooler than 190 on the freeway...like 185. Usually the temps will creep just a little bit sitting at a stoplight but then once moving again they come back down. Last friday night she hit 230 once I got into the show and parked.:
Like Phil said if your overheating running down the road then you have a radiator issue but if you are overheating at a stop then you have a airflow issue. JM2 cents.
One more VERY IMPORTANT item to consider when it comes to high temp. on the highway. I had a 454 Suburban that ran hot going down the road. I had recently 
installed a new 4 core rad. and all new hoses. I found the new lower hose did not have the SPRING in it. The the water pump would collapse the lower hose and restrict flow when hot. NO temp problems at idle or low speeds. My neighbor just got done with his 61 Buick convert with 401 nailhead and had the same problem on the highway. New hose was missing the spring. Come to think, when I did my 409 install I ordered new GM logo hoses from LATE GREAT CHEVY and the lower hose was missing the spring. This applies to the smooth style hoses. Easy to check. Give them the squeeze test. Leo
installed a new 4 core rad. and all new hoses. I found the new lower hose did not have the SPRING in it. The the water pump would collapse the lower hose and restrict flow when hot. NO temp problems at idle or low speeds. My neighbor just got done with his 61 Buick convert with 401 nailhead and had the same problem on the highway. New hose was missing the spring. Come to think, when I did my 409 install I ordered new GM logo hoses from LATE GREAT CHEVY and the lower hose was missing the spring. This applies to the smooth style hoses. Easy to check. Give them the squeeze test. Leo
good tip...my rubber hoses BOTH have a spring in them
Here's one for debate !!!
So I installed a new fan shroud with a 7 blade clutch fan. The fan was exactly 1/2 and 1/2 and the shroud fits the radiator like a factory installed (see pictures). She did run cooler at idle in the driveway. It was 100 degrees outside and she idled in the driveway for 20 min and never got over 200. That's the good news, if you've followed my posts over the past couple of years. The bad news is she ran at 200+ on the freeway at 65-70 degrees.
So I put the 6 blade flex-fan back on with the same fan shroud. Still fits like a glove 1/2 and 1/2. She still idled for 15 min and stayed around 200. The temps on the freeway dropped back down to 165-170 like they were before. So now I believe I have the best of both worlds. I'm going to get the seven blade flex-fan and try that to see if I can pull the idle temps down just a little more. Oh, and I'm getting the A/C hooked up again, tomorrow !!!!
Here is a picture of the current set-up. There are others earlier in this tread.
So I installed a new fan shroud with a 7 blade clutch fan. The fan was exactly 1/2 and 1/2 and the shroud fits the radiator like a factory installed (see pictures). She did run cooler at idle in the driveway. It was 100 degrees outside and she idled in the driveway for 20 min and never got over 200. That's the good news, if you've followed my posts over the past couple of years. The bad news is she ran at 200+ on the freeway at 65-70 degrees.
So I put the 6 blade flex-fan back on with the same fan shroud. Still fits like a glove 1/2 and 1/2. She still idled for 15 min and stayed around 200. The temps on the freeway dropped back down to 165-170 like they were before. So now I believe I have the best of both worlds. I'm going to get the seven blade flex-fan and try that to see if I can pull the idle temps down just a little more. Oh, and I'm getting the A/C hooked up again, tomorrow !!!!
Here is a picture of the current set-up. There are others earlier in this tread.
Attachments
Hi NUTS, There can be an issue with fan clutches. They can apparently leak some of their viscous fluid and will slip at highway rpm. I have read and heard they a wear item. I have had used scrap yard fan & clutch assy. that would not run cool. Replaced clutch and everything went back to normal. You need to spend some money to get a quality clutch though. $75 to $100 for a heavy duty unit. Leo
7 blade fans were usually used on a/c cars that had a condenser in front of the radiator which reduced some of the airflow through the rad. Using it on a non a/c car might have the effect of blocking some of the airflow. It will have a lower blade angle (pitch) which will act more like a solid disc resisting airflow at higher driven speeds. A 5 blade fan would be typical on a non-a/c installation and should have a higher blade angle to move more air and not resist airlflow at higher driven speeds. Fan blade angle, or pitch makes a difference.JMHO
Clarifications !
Okay, so I do have an A/C car and the condenser is mounted in front of the radiator eventhough it isn't charged with fluid. The fan clutch is new, but I suppose it could be not working, there is that China syndrome. Anyway, the flex-fan seemed to fix the highway speed airflow problems. I would prefer the look of a stock fan and clutch, but I'll use what works for now...
Nuts
Okay, so I do have an A/C car and the condenser is mounted in front of the radiator eventhough it isn't charged with fluid. The fan clutch is new, but I suppose it could be not working, there is that China syndrome. Anyway, the flex-fan seemed to fix the highway speed airflow problems. I would prefer the look of a stock fan and clutch, but I'll use what works for now...
Nuts
Hummmm, With that post and link to the oil info I`m wondering is oil thickness leads to the heating issues?
http://www.348-409.com/forum/showthread.php?t=14387
http://www.348-409.com/forum/showthread.php?t=14387
UPDATE! Took the car out for a bit just awhile ago. 80 degrees-ish, not REAL humid today but warm in the sun for sure. Played around with the timing/carb before taking her out for a spin. Didn't touch ANYTHING else. Added 1/8th of a turn to the idle screws (a bit more fuel at idle) and made sure the timing was spot on...it was right around 12-ish at idle so I made sure it was at least 13 degrees at idle...36 all in. Got stuck at a LONG light 15 minutes into my cruise....temp never got over 190. It was veeerrrryyy slow to climb also. As soon as I was moving again (like 3 blocks of driving) the temp was coming back down slowly. This is GREAT progress.
So check those idle screws on the carb boys. I even verified when I got home that I was still seeing great vacuum and it was really good yet. Barely moved from the previous tune.
If anything, keep the idle mix on the side of a bit fat (not a lot). 
Lean is mean but not if you can't keep her cool
no1:
So check those idle screws on the carb boys. I even verified when I got home that I was still seeing great vacuum and it was really good yet. Barely moved from the previous tune.
If anything, keep the idle mix on the side of a bit fat (not a lot). Lean is mean but not if you can't keep her cool
no1:
My 62 327 ran fine all last summer in 110 degree stop and go traffic. Nothing has changed radiator is clean, same pullies as before, but twice in the last couple of months its overheated and boiled over, today I dove back from a cruise for about 40 miles 65-70 MPH no problems, as soon as I got off the freeway it boiled over big time. I Let it cool off, filled it with water and drove 20 miles back home through a mixture of freeway and stop and go with no problem. The problem I had last month was under similar conditions. I have a small MSD distirbutor and 600 Edelbrock carb, hoses look good from outside, 6 brade clutch fan. Seems like its related to long runs at freeway speeds that suddenly change to stop and go.
Any thoughts?
Finnally started my 409 with tri Power this week end, ran cam in with no problems the aftermarket bases on the outer carbs work great. Hope to have it on the road in a couple of months. larry
Any thoughts?
Finnally started my 409 with tri Power this week end, ran cam in with no problems the aftermarket bases on the outer carbs work great. Hope to have it on the road in a couple of months. larry
AZ409; As was already mentioned, it's possible your fan clutch, has bit the bullet. When they start to fail, they DO lose their viscious fluid, and then the fan slips, more than enough, to keep the engine kool. A few years ago, I replaced mine. It slipped so bad, I could hold the fan, while my wife started the car, and felt little resistance.:eek:
When they start to fail, they DO lose their viscious fluid, and then the fan slips, more than enough, to keep the engine kool. A few years ago, I replaced mine. It slipped so bad, I could hold the fan, while my wife started the car, and felt little resistance.:eek: