1968 289 cooling problems revisited...

[Midnight Special]

...Having experienced boil-over issues with TJ's (low mile) 289 and replacing numerous stats, caps, shroud, flushing radiators and reading over & over the posts here by Arlie, Marty & like on the subject, TJ came to me Friday evening and said "Dad, we're going after those head gaskets!". (Rob - I swear he's YOUR kid! ;-)

Something has been pressurizing the cooling system and forcing the water out over time since the new motor was installed. It didn't get hot unless levels were low and there was no steaming exhaust or power loss, but something wasn't right. He's always had to add water about every four days of daily driving. With all other means tried - we figured why not.

So into it he goes! We pulled the intake and heads, cleaned, inspected, checked for warpage, cracks and vallah! a small breach (separation) in the gasket that looked to be tossing compression into a water channel!

I am posting this to hopefully end any further head scratching and to give validity to to an otherwise unpleasant task. Total time for us amateurs was about 8 hours...

Upon replacing the head & intake gaskets, the results were magnificent! No water loss, smoother idle and no boil-over during about two hours of test driving.

 

[Ruppstang]

Way to go guys! Hope that is the end of the over heating story for you. That was was the first problem on Craigs car. It does not get hot now unless you go 70 mph for a while and still has not boiled over. We may try a 3 core radiator some time. For now it keeps him from speeding. Marty

 

[green56]

overheating again

Iam still haveing problems with overheating if i leave car idel for 5min the temp climbs right up so iam going to pull the heads off an d put new head gaskets is this the right way to go the engine and heads were boiled out new frezplugs new crank cam water pump rad 3 pass 4 blade fan timming at 8dreg it is a after market water pump but i could put a ford 289 rebuilt on any other help Need help very bad afraid to take it out in summer because of our out side temp gets up around 85 to95 hot and humid so it heats up very fast in summer Thanks every one that trying to help
Thanks Tom

 

[Midnight Special]

Tom, I'm not sure the heads should be pulled in your case just yet. I would rather discuss everything (symptoms) on the phone with you (perhaps) before you go to the trouble! PM me with a number and/ or see what others here have to say first.

If your car only heats up at prolonged idle, but otherwise runs normal temp when driving (without spitting water) - don't attack the head gaskets yet!! Let's get more verbal info!....

 

[green56]

cooling problems

Tim Phone is 414-541-7934 best time 9am- 1pm- 7pm not to night have car meeting give me your email address and will get to gether

 

[Midnight Special]

...'Just had a nice conversation with Tom
He has a new radiator, water pump, 160 thermostat, proper shroud and fan on a 300-mile rebuild w/ '66 heads on a '68 block. He says it runs normal temp on the highway, but climbs through 220-degrees at stoplights. Air pulled though the radiator by the fan at idle seems strong as well... Any more thoughts??

 

[Mosesatm]

Remove the cap at idle (before it pressurizes) and see if the water is flowing, and see if the water in the radiator is hot.

 

[Ruppstang]

I would try a 195 T stat. Might help the radiator cool a bit more between cycles. It helped on Craig's 67. If the T stat does not have a small hole in it drill a 1/16th hole in it. Also check for correct fan and fan pully. Marty

 

[green56]

heating problem

Marty i have a 4 blade fan on know but i had a 6 blade before also the pully is org before it would heat faster until someone told to check the timming it was off change to 8 degrees then the temp came down to what it is when driving it stays at 1/2 temp but you stop and idle the temp just climbs right up in no time. Will check running the car with the cap off and check on whats going on. Will check to see if the head gasket tabs are in front?

 

[CougarCJ]

Wrong engine timing, and either a rich or lean condition of the carburetor will also contribute to a hot running condition.

Those 4 blade fans are also clearly marked "Front", make sure that they are installed correctly.

 

[green56]

over heating

Today checked the gasket for the heads they are on right also took rad cap off water flow ok no bubbling put rag in front of rad it pulled the rag on rad

 

[Mustanger]

Marty i have a 4 blade fan on know but i had a 6 blade before also the pully is org before it would heat faster until someone told to check the timming it was off change to 8 degrees then the temp came down to what it is when driving it stays at 1/2 temp but you stop and idle the temp just climbs right up in no time. Will check running the car with the cap off and check on whats going on. Will check to see if the head gasket tabs are in front?

A 6 bladed fan can help, check these out:

http://www.mustangsplus.com/xcart/Racing-Fans/

They may also be available at Summit Racing ... also, when installing it, 1/2 the blade should be in the shroud and 1/2 should be out ... good luck :thumb: ...

 

[green56]

overheating

that is what i am going to do is change the fan blade and put on a rebuilt water pump oem so we will see what happens

 

[Mosesatm]

Have you tried advancing the timing up to 12-18 degrees?

 

[franklinair]

Arlie;
12 - 18 degrees-with or without vacuum connected?

Neil

 

[Mosesatm]

With.

18 is really pushing the envelope but 12 should be no problem, but you may need to run premium fuel to prevent detonation (pinging).
I'm running at 22 degrees with no problems. Of course, that's with an aggressive cam.

 

[Mosesatm]

Here's a little blurb from a hot rod site.

DOING THE NUMBERS
The "hot rod advance curve" used mostly on a 9:1 engine with a mild camshaft (duration less than 220 degrees at 0.050-inch of valve lift) is 10 to 12 degrees initial timing plus 22 to 24 degrees of additional advance from the mechanical advance mechanism. In most cases, full advance (32 to 36 degrees) will have occurred before 3,500 rpm.

An engine with camshaft duration of above 240 degrees, but less than 260 degrees of duration @ 0.050-inch valve lift, will respond well to 18 degrees of initial timing; however, the total timing will remain the same (32 to 36 degrees).

The ideal ignition timing for power occurs just before the point where detonation or pinging takes place. Correctly timed ignition will cause peak cylinder pressures to occur around 12 to 15 degrees after TDC. If the peak cylinder pressure is reached too early, power will be lost as the piston fights to compress the burning air/fuel mixture. Detonation may also occur, which can lead to engine failure. Conversely, if peak pressure is reached after the 12 to 15 degree range, energy is wasted and dispersed through the exhaust system as heat.

The key seems to be that you want the timing right around 36 degrees at around 3500rpm, which you can check with a timing light.

 

[Midnight Special]

...Very helpful as always Arlie. Thanks!

 

[Mosesatm]

If the car heats up only when it idles but it has good water flow and air flow is it possible the vacuum lines to the distributor are hooked up incorrectly or the vacuum christmas tree isn't working properly?

Just thinking out loud here:
The rear distributor hose should have full vacuum when the christmas tree port is open, which retards the timing, so at highway speeds if it's retarding the timing as the vacuum advance is advancing the timing it would be no big deal, and the car may or may not overheat, but when the car is idling there is no vacuum advance to counter the retarding action from the rear hose. If it's a 2-hose system.

Could that cause the car to overheat when idling?

 

[Mosesatm]

Here's another thought; did you paint the radiator?