Overheating 454....any ideas?

454 cooling problems!
Bottom line is Im restoring a 73 Nova SS that was setup as a
1/4 mile car.....I have already changed things up from the original config to address cooling.

Current engine specs:
- 454 bored 30 over
- Compression 12:1

- Cam: Intake duration at .006 lift is 300 and intake duration at .050 lift is 240 lift at cam is .330 - lift at valve is .560 - intake centerline at 110 and lobe sep. angle at 112

- 373 rear gear
- MSD ignition

- Holly 850
- Edelbrock intake
- Hooker headers
- 3" Flowmasters

- Griffin 31x19.5 alum radiator (50/50)
- 16" Pusher fan on front of rad. (17cfm)
- Mechanical flexfan pulling (no clutch)
- Replaced thermostat w/160 (also tried just restricted)
- Replaced gauge cluster and sensors
- Water pump pumps great!

PROBLEM:
Car runs fine at speed 190dg at 45mph, 200-205dg at low speeds. And generally climbs up to 210-212 at long stoplights.....
then comes back down again with speed.
HOWEVER,....it does continue to get hotter and hotter at idle....
if I got stuck in traffic I would be in DEEP trouble as the gauge will get to 230 at about 4 minutes of idle...then I shut her off.
I am running 93 octane and an octane booster.

ISSUE: 1ST SHOP that messed with her set the timing waaaay back. (dont ask me why)

NEW race mechanic wants to do following:
1) Set timing where it SHOULD BE
2) Lock out distributer
3) Install 'starter saver' for easy starting with locked timing
4) Fill radiator with water and Water Wetter...no antifreeze (I
am in Florida)

5) I then run 3-5 gallons racing fuel with 11-12 gal 93 octane premium.
Racing fuel has lead,.....he also mentioned that helps with the cooling.

He said the car will then not get increasingly hotter,....it will reach a point...but not continue to climb indefinately.


Any opinions on this situation,......Im not looking for a daily driver out of it.....but jesus...there has to be a reason it just gets hotter and hotter and hotter......and I feel the cooling system is pretty much maxed out...

thanks!

First off, the higher octane fuel will have little effect except will allow you to run the timing where it sounds like he wants to go. That can help some on cooling. The lead comment I won't even address, but I am shaking my head.

Now for a real fix. Get rid of the pusher fan, and since you didn't mention any other form of fan I guess that's the only one. There's a clue in your description. Notice that it ran hotter at lower speed than higher speed. That's because the pusher fan is BLOCKING air flow. The high paid engineers that build these cars originally always try to have the fan on the back of the radiator if they can. Also, using the OEM's for guidance, a shroud around the fan (either mechanical or electric) draws ALL the cooling air through the ENTIRE core. Make sure there are no gaps around the outside of the radiator where it fits to the core support. And if the car originally had a rubber strip across the top of the core support to seal to the hood when it's closed, replace that if it's missing.

BTW, thanks for giving a thorough, well thought out question and information. It makes it a lot easier than the guy who pops up with "My car runs hot, what do I do".

Hey Streets for us poor old Arizona boys could you define what "HOT" is in NY :toocool:

Yes, the timing does affect the temp.

Yes, I firmly believe the shroud helps that much. The reason the pusher
helped your situation is that you are compensating for two other problems.
First the fan. When you say "flex fan" I picture one of those flimsy,
aluminum blade (shaped something like an elongated tear drop) fans that were
popular 20 years ago. They're junk!! 17" sounds like a good size, notice
that the factory fans are more of a "square" or rectangle shape, and have
some flexibility. These are much more effective. Second, your fan is too
far back to be effective. It should be about 3/4" to 1" back from the core,
not 3". For the shroud to work with the fan effectively, the fan pitch
should be 1/2 to 2/3 into the shround. If the shroud you are getting from
Griffin doesn't have it, you might want to make provision for high speed
cooling. You might have seen on OEM shrouds where there are "windows" cut
in the shroud with rubber flaps over them. At idle the pulling motion of
the fan keeps these flaps closed allowing the fan to pull air through the
full core. At high speed (freeway say) there is enough ram effect from the
air coming through the grille that it "blows" the flaps open to allow more
flow through the shroud.

Whether or not you have other problems is hard to say from here. But with
all the stuff you've described so far I would suggest fixing those issues
and seeing where you sit then before trying more diagnosis. Process of
elimination of the most obvious you know.

Bob,...
It is not a teardrop antique fan....it is a typical 17-18" 6 blade
'flex fan', aftermarket.....it had slightly curved, flexible, rectangular blades mounted to a black anododized frame....however the shroud scenario you mention is far from my current setup...
the distance from blade to radiator is apprx 2.5-3". The distance from blade tip to shroud is apprx 4-5 inch. The amount of coverage of blade from shroud is about right,...but the shroud itself covers only about 80% of the radiator and is not flush to it....there is a 1/2 gap down the left side......

All this will be rectified on monday with the arrival of the proper shroud from Griffin for my radiator.....

I would assume the mechanical fan alone should be sufficient at idel to pull a towel towards the grill (mine does not at all). Ofcourse, with the electric fan on it will suck a 4lb beach towel to the grill and hold it there :-)......(still rising heat though :-(

Just something to think about, How many pounds is your radiator cap? Something that small might of been over looked

One other thing about the shroud I forgot. The hole for the blade should clear by 1/2", so an 18" hole for a 17" blade for example.

Bob,....thx on that size info. It will all help monday night when I install the shroud......

Awsum....not 100% sure on the cap....but I do not have any overflow problems....I am not 'overheating' yet.....the temp does just keep rising at idle though......I shut her down around 230...I do not want to experience overheating.....I just want to know the 'ceiling' when she will stay at a certain temp without rising anymore......BUT I will check on the cap.....or get a new one....
What psi should it be?????

Email between Mike and I:

Hi Again.

1. You do not necessarily need a clutch on a fixed fan, however it in addition to the reasons I mentioned in the post (i.e. HP loss, and noise), it is also easier on the water pump pulley especially at high engine RPM, where any imbalance in the fan is magnified. Additionally, fans designed to run with a clutch generally have a steeper pitch than fans designed to run direct. This results in their being able to pull more air when the clutch is locked than a normal direct drive fan.

2. Absolutely. Unless you have a fan I haven't seen before (I read your post were your explained the fan you have, and I know the fan your referring to) the aftermarket units flatten out at a lot lower RPM (even a little at Idle) reducing their effectiveness. The Ford fans have a little steeper pitch, and are made a little stiffer, which is why I would use one of those over the aftermarket type, if I couldn't run a clutch.

3. A good shroud is CRITICAL, I didn't spend a lot of time addressing this as Bob had already pretty much covered it. All of the cooling system components must work together, a good fan AND fan shroud should make all the difference in the world as far as cooling.

4. The "Tricks" your mechanic mentioned are RACE CAR ONLY things, that are NOT RECOMMENDED for street driven cars. A car that only see a 1/4 mile at a time require different things than car that is used to go up and down the street. My main concern is that he recommended things that will only make a very insignificant impact on the cooling problem. After the timing was set correctly and the car still overheated, he should have quickly diagnosed the likely problem as the fan/fan shroud/electric fan and explained this to you rather than trying all this other stuff. Chances are when this didn't work, you would have still been down to putting a fan and shroud on it. By the way were you going to have him put the shroud on at the same time he did this other stuff. If you were the shroud would be what would make the difference, not the advance limiter and then the starter saver.



PS Als suggestion about checking the radiator cap is a good suggestion and example of that I just said.


Mike

Thanks to all who are offering advice,....I am trying to get everything sorted out as best I can before I take the care to 'new' mechanic on Wednesday.

MAIN PROBLEM: car temp rises steadily at idle. Have not overheated yet.....but I shut her down at 230. Has NO problem running at 25-50mph...stays around 200-205 tops.

Shop 1 (last week): Replace 480? rear gear w/373. New torque converter and installed Griffin 31"x19.5" radiator. They ALSO set the timing waaaay back. I do not know how far....I do not know how to check this :-(

Result:This helped some.
At Idle car would not draw a towel towards vent.

I ADDED 1700cfm 16" pusher fan on front of radiator, added new
gauge cluster and sensor and put in 160degree thermostat (did not have one in there before??). Car also has 18" 6 blade flex fan and crappy ill-fitting shroud.

Result:This helped ALOT and car easily pulls towel at idle and runs much cooler. I feel comfortable driving around evenings as long as I dont sit too long......

I have called a new shop and have an appt for this wednesday.
The new mechanic who has not worked on the car yet wants to set the timing back to 'proper'. He says the backed off timing is causing the heating up. He also wants to lock the distributer and install a 'starter saver' AND drain the radiator and fill with water only and water wetter. He says I must run a racing gas mix to prevent detonation as well (fine with me).
I HAVE NOT HAD the above work done yet.

On MONDAY (2 days before above work is scheduled) I will install the proper shroud, and hopefully a good solid pitched blade as well.

I am still searching to determine if the set back timing is causing the heat......IN ADDITION to the fact I do not have a remotely adequate shroud or good solid pitched fan for that matter.
AND if locking the timing will cause me TROUBLE or not.
PERHAPS I should just have him set back the timing to normal, and NOT lock the advance?????

Again,...thanks to all and anyu further advice will be MUCH, MUCH appreciated!

Jeff Dobrow
"new,....but learning"...
btw - Pic of the troublemaker is in my photo gallery now :-)

16 lb cap will do, Like what was said earlier, timming running lean will cause you to run hot, Just something else to think about, you might have to rejet the carb.

Here's a link on over heating you might enjoy:
www.inccn.net/techforum.htm

Doc,
One more thought I forgot. We're all assuming your gauge is giving you an accurate reading. If it is connected with a single terminal sensor, make sure there is no thread sealant (e.g. teflon tape, or plumbers dope) on the sensor.

I just replaced teh gauge and sensor....and no tape on it. Actually, it appears to be a little better that the previous gauge by about 5 degrees HOWEVER the problem is climbing heat levels...not really about an absolute temperature.

REMEMBER,...the car will continue to climb at an idle,....I do not let it go past 230....but currently I am sure it would just rise and rise and rise.....so whether the gauge is 10 degrees off or not really doesnt matter....what matters is the constant rise in temp.
If I KNEW the car would sit and idle at 230 I would have no complaints,....I know BB's run hotter than most,....but this darn constant rise is the problem!

BOTTOM HOSE is tight as a drum. Good and solid.

All I can hope for is 2 things:

1)New proper shroud that actually fits will help or cure.

2)Setting the timing to its proper place will cure. (pray, pray, pray)

3) Going to 100% water and water wetter in radiator will help.

Something I have not mentioned,....and am not too knowledgable on (yet)....is the seperate trans cooler my car has. It is a blade type,....like a small radiator....and it is mounted in front of the left side of the radiator. It has about 1-2 inches clearance to the radiator.

Is this a bad place for it to be? Is it contributing to a lack of flow?

Where else could it go? I assume it needs to benefit from ram air effect and should somewhere behind the grill of the car? (where the radiator also is).....

Any ideas? or os this fine and dandy....?

My transcooler does NOT attach to my radiator in any way...(as far as I can tell).....

And it is mounted on the far left quadrant (far as It can go) of my grill/radiator area.

Proper shroud arrives today (wish me luck)!

Any tricks involved with installing a new shroud?....