How hot?!!
Thread Starter
|
Junior User
Joined: Jun 2002
Posts: 62
Likes: 0
From: Mid-Eastern US
How hot?!!
I have a 390 with a C6 tranny and a Holley 670cfm carb which I believe is too big for my motor and may be part of my problem but anyway, what is too hot for my truck to be running and what is normal? The engine was built from a 360 and has had some slight mods like a bigger lift and a valve job with a high volume oil pump but not far from stock. Engine does not have a noticeable lope. I have a new 3 core radiator and run a 180 thermostat with a 50/50 mixture. The fan is one of those five blade plastic super fans that is really supposed to pull the air. The only thing I am missing is a fan shroud. Could it make that much difference in temp? Engine gets up to about 220 to 230 idling in the driveway. Do not know how it does while driving as the truck is not yet road worthy. Sorry to be so lengthy. Thanks to all for help.
Post Fiend
Joined: Feb 2000
Posts: 5,130
Likes: 8
From: Brea CA
How hot?!!
Yes you need a shroud, there is no air going through the rad and the fan is just flapping around there. Also a rebuilt motor will generate a lot of heat while it's breaking in, don't overheat it.
Barry
Barry
Senior User
Joined: Aug 2003
Posts: 152
Likes: 0
From: Maple Ridge BC Canada
How hot?!!
You could have a slight vacuum leak or it could be jetted lean, If your idle is set too low the water pump cant push enough water thru the rad to properly cool it. 230 is plenty warm especally for a fresh motor
. The carb is just about perfect for a 390, I run a 750 on mine.....d44hd
. The carb is just about perfect for a 390, I run a 750 on mine.....d44hd
Thread Starter
|
Junior User
Joined: Jun 2002
Posts: 62
Likes: 0
From: Mid-Eastern US
How hot?!!
Ok, but no one is telling me how hot? I appreciate the help, don't get me wrong but, while I am running this thing breaking it in or for whatever reason, at what temp should I start getting concerned? What do your trucks run at normally? Thanks.
Trending Topics
Senior User
Joined: Jun 2003
Posts: 281
Likes: 0
From: Bearspaw (near Calgary)
How hot?!!
n2music,
I did a search on hotrodders.com as I was having a similiar problem with my landcruiser. The word there is no hotter than 220. A bad rad cap or a worn timing chain can also cause overheating. My problem started with a bad fuel pump causing my carb accelerator pump to go bad which caused a lean cond. which caused the overheating.
I did a search on hotrodders.com as I was having a similiar problem with my landcruiser. The word there is no hotter than 220. A bad rad cap or a worn timing chain can also cause overheating. My problem started with a bad fuel pump causing my carb accelerator pump to go bad which caused a lean cond. which caused the overheating.
Last edited by rrawlins; Sep 6, 2003 at 09:48 AM.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Senior User
Joined: Aug 2003
Posts: 152
Likes: 0
From: Maple Ridge BC Canada
How hot?!!
The proper way to figure carb size is by the formula CFM= CID x RPM x VE divided by 3456. So 390 cid x 5500 rpm x 1.05 (105% volumetric efficiency) divided by 3456 = 651.69 cfm.
Sorry should have answered your question 180 to 200 degrees....
D44hd
Sorry should have answered your question 180 to 200 degrees....
D44hd
Thread Starter
|
Junior User
Joined: Jun 2002
Posts: 62
Likes: 0
From: Mid-Eastern US
How hot?!!
oh yeah, I removed carb and rebuilt this evening. Found one of the main metering jet holes had something black like a piece of sponge or something clogging the hole. A few of the gaskets needed replacing and gave the carg a good cleaning with some carb cleaner. Hopefully this will solve my backfire problems and maybe take care of some of the heating problems. Man at auto parts store said I should try running without thermostat and see if it gets hot. If it doesn't, he said old thermostat probably works, just doesn't open properly or all the way. Thanks for everyones input.
Junior User
Joined: Sep 2003
Posts: 97
Likes: 0
From: S/W Arkansas
How hot?!!
My Ford isn't running yet, but i will most likely run it without a thermostat. Mine doesn't have a shroud, I don't know if it came factory without one of one of the previous owners took it off. I have only had it 3 days 
.
.