The Forums Home | Tech Tips | Gallery | FAQ | Events | Features | Search
Take time to remember ...

Memorial Day 2023

Click for the BIG image

Visit a spell at ...

The Legion Hall

Searching the Site

Get info about how to search the entire Stovebolt site here. To do a search for just the forums, get those details in the IT Shortbus fourm.
2023 Old Truck Calendars
Second one
Sweet-looking old Stovebolts

2023 Stovebolt Calendars

Check for details!

Who's Online Now
11 members (52Carl, EdPruss, 1953 Forever, CuzzFuzz, 2 invisible), 188 guests, and 3 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Most Online1,229
Jan 21st, 2020
Step-by-step instructions for pictures in the forums
Previous Thread
Next Thread
Print Thread
Page 2 of 3 1 2 3
Tramp #1458952 Sat Jul 16 2022 03:35 PM
Joined: Feb 2004
Posts: 26,303
Kettle Custodian (pot stirrer)
Look at the blade angle on your fan. It's supposed to PULL air through the radiator as it turns, not push it. A reverse rotation water pump will try to flow coolant the wrong direction if the serpentine belt is mis-routed, also, even if the fan blades happen to be angled correctly. I have an idea the direction of rotation of your fan and/or water pump is the problem.

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!"
Abraham Lincoln

Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!

There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self.
Ernest Hemingway

Love your enemies and drive 'em nuts!
Tramp #1458954 Sat Jul 16 2022 03:44 PM
Joined: Apr 2005
Posts: 11,554
“Grease Monkey” “Former herder of cats”
“4 1/2” from the radiator “ is not good for optimal cooling. You also may have a air bubble in the system. Coolant should be only about 1/2 inch above the fins in the radiator. As HRL said, find out if your water pump is rotating the right way. Fill the system properly and add a properly spaced fan shroud. Start the engine and hold a piece of tissue paper to the front of the radiator. If it sucks tight to the radiator when the engine is reved up the fan (not necessarily the water pump) is rotating correctly. Good luck.

'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne 4dr 230 I-6 one owner (I’m #2) “Emily”
‘39 Dodge Businessmans Coupe “Clarence”

"I fought the law and the law won" now I are a retired one!
Support those brave men/women who stand the "Thin Blue Line"! Hug a cop!
USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)

Hotrod Lincoln #1458973 Sat Jul 16 2022 05:53 PM
Joined: Feb 2007
Posts: 470
Tramp Offline OP
Howdy Rowdy,
The fan is pulling air through the core and back towards the firewall.
I'll have to do some homework to find out what's going on with the water pump. I appreciate all the help, and will let you know what happens.

dj durant

1964 Chevrolet C-10 Pickup Truck
In the Stovebolt Gallery
More pix on Flickr
Tramp #1459017 Sun Jul 17 2022 02:01 AM
Joined: Jan 2019
Posts: 955
Herder of Cats, Goats, and Sheep (moderator)
Your comment about the serpentine belt system gives me pause.

V-belt drives have the crank and water pump (all of the pulleys, actually) turning the same direction. As a general rule, serpentine belt systems will have the crank and water pump turn opposite directions to get more wrap on the crank due to the added force on the belt.

If you didn't change the water pump for the serpentine drive, that could be your problem right there.

From the Rocky Mountains?
Check in with the RM Bolters!

HiPo Forum Moderator

1958 Apache, long bed Fleetside, V8 w/SM420
Driveable but the rear axle needs work.
Tramp #1459019 Sun Jul 17 2022 02:06 AM
Joined: May 2005
Posts: 288
Tramp, that symptom of repeated spiking temperature then dropping seems exactly like mine before I added the external bypass to the water pump. The stat opens then allows a batch of cold water to enter the motor then it closes and repeats. When it closes without the bypass, hot spots develop before the stat opens again causing the temp gage to show the spike of temperature. You have to have an external bypass if the passenger side cylinder head does not have it built in. If your water pump was rotating the wrong direction I don't think the temperature would drop back to 180 when it over heats.


Tramp #1459023 Sun Jul 17 2022 02:58 AM
Joined: May 2015
Posts: 7,328
Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
A water pump rotating backwards will severely restrict circulation, but won't make it flow backwards. A centrifugal pump like water pumps will still pump in the right direction, but flowrate will be WAY reduced. And if the vanes are straight and radial to the shaft, they can run either direction and won't restrict the flow as much as angled vanes.

Newest Project - 51 Chevy 3100 work truck. Photos []
#2 - '29 Ford pickup restored from the ground up.
First car '29 Ford Special Coupe
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Tramp #1459038 Sun Jul 17 2022 12:03 PM
Joined: Dec 2018
Posts: 2,475
Tramp Seems like with that much space ahead of your fan that the aluminum radiator people could produce a core thick enough to solve your problem. Once on a 421 Pontiac we just barely caught the fact that mice had put a nest in the block water jacket mostly over a weekend !! Any chance that could be your trouble ??

59 fleet #1459068 Sun Jul 17 2022 05:31 PM
Joined: Feb 2007
Posts: 470
Tramp Offline OP
I've done some homework, and found that the water pump is turning in the right direction.
If I were to have a new radiator built, there is definitely enough room to make it plenty thicker, thereby increasing the coolant capacity.
59 talks about adding an external bypass to the water pump, and I'll have to do some more homework to better understand that possibility. What he said is how it's acting.
Also, all of the sites that talk about coolant capacity say the 350 needs 17 quarts, which would include the block and heater core to fill. The 348 and 409 call for 23 quarts. I'm thinking of draining the coolant that is in the truck now and measuring to make sure just how much coolant it does have. I know when I flushed and refilled it this last time, it took one gallon of antifreeze and just over another gallon of distilled water to bring it up about an inch above the core. I also installed a new pressure cap 13#.
Having a new radiator built can be done here locally, but it would cost me $800 or more.
Again, I appreciate all the help. You can be certain I'll be doing the happy dance in my skivvies in front of the post office, and take an hour to draw a crowd when this gets straightened out.

dj durant

1964 Chevrolet C-10 Pickup Truck
In the Stovebolt Gallery
More pix on Flickr
Tramp #1459082 Sun Jul 17 2022 07:37 PM
Joined: Oct 2005
Posts: 3,888
"Hey! I sound like Darth Vader!!
Instead of having a custom one built, try one of these? Champion Radiators []

Also, the bypass is that 90* hose that goes from the top of your water pump to a port below the thermostat.

Attached Images
Chevy Water Flow.gif (56.72 KB, 130 downloads)
MNSmith #1459131 Mon Jul 18 2022 12:24 AM
Joined: May 2005
Posts: 288
If you think that bypass might be the problem, try driving with the heater on max heat. You don't need the fan on, just coolant flowing through the heater. The heater circuit will act as a bypass and if your temp is more stable, then you have found the problem.


Page 2 of 3 1 2 3

Moderated by  Fibonachu, KCMongo 

Link Copied to Clipboard
Home | FAQ | Gallery | Tech Tips | Events | Features | Search | Hoo-Ya Shop
Powered by UBB.threads™ PHP Forum Software 7.7.5