. 67 over heating problem

[franklinair]

I should've known, but I had to ask.:wink:

Neil

 

[robert campbell]

not snowing here!

 

[Ruppstang]

Rob is would be easier to get you here than the car there!

 

[Ruppstang]

It is finally warm enough to give Craig's 67 a good test and guess what same problem. I noticed the gage needles jump a bit so I changed the instrument voltage regulator. Was not it, at least when the dash was apart I installed a mini tach in the clock position so was not a total wast of time. Next changed the temp sender. Was not that either. As some of you suggested I pulled the thermostat again. I forgot last time I put in a 160 it was working but when you would drive 20-25 miles the temp just kept going up.I think it was open full time and never gave the radiator time to cool. Put in a new 195, seems to have solved it. Yah!!! We drove it Saturday about 80 miles it was rock solid at 5/8 the range. The real test will be when it is in the 90s and the AC is on but at least when he comes home in 2 weeks he can drive his car. Thanks everyone for all of your help. Marty

 

[PFSlim]

Marty

I have been doing some research on this myself for my 390FE cobra engine. These things are hard to figure out. But here is a couple of things that you may not be interested in pursuing. First, the small hole in the thermo would be an 1/8 hole. I put two in mine just to make sure.

Second, we have tried several different types of caps. Know that sounds crazy but it has fixed a few of our overheating problems. Try 9 pound to 16 pound and see if it makes any difference.

Third - you might have to install a more serious fan. Currently, I am at a 2100 CFM electric fan for my cobra. I know a lot of guys who use up to a 3600 CFM fan. Lastly, I have heard of a guy in Houston that uses a Taurus Fan (rated around 4700 CFM) to cool his cobra. Electric fans are not period correct - but you might need if you want just a driver. If you decide to try an electic fan - very important to bench check - make sure the blades are pushing or pulling like they should (or the direction you want them to go).

My FE has a puke tank. We chased bubbles for quite some time. We found a place to relieve pressure (bubbles) on the top of the manifold. That seemed to help lower the temp right away. Also, somebody mentioned timing - which is important and how the carb is set up. Another important factor in cooling. Lastly, believe or not, the air filter size has some to do with cooling.

So...maybe there is nothing there to use. Just hoped I could help some.

Good luck and let us know.

Paul

 

[franklinair]

Marty-
If you're going to run A/C in the summer, I have found that a 3 row core w/shroud is necessary to keep the temp range within reason. (In FL I ran a 4 row core w/shroud for 95 degree O/S temp, in traffic.) Also, a 14# radiator cap.

Neil

PS:
I've been offline for the past week - in FL for family re-union, Sun-N-Fun Airshow, grandaughter's wedding.

 

[Mosesatm]

Marty,
I worked in a radiator shop for a couple years prior to my government employment. Re-cored radiators and heater cores. Lots of remove and replaces. Lots of makes, models, of both cars and trucks and even heavy equipment stuff like bulldozers.

Always check any thermostat by boiling on the stove with a candy thermometer and see that it opens as specified. If you basically have a Sunday driver, then use a 180. If you are a “year rounder” I use a 195 in the winter at least. The bleed hole that Steve speaks to is a great add.

I wonder if you are suffering from initial timing being set to close to zero TDC. Your engine is recommended to be set a 6 degrees BTDC. This was the main culprit in Amy’s “satan” story. She started out with an extremely dirty system, but it was not the final problem. Her’s was retarded ignition timing. By the way, the head gasket story will kill a motor, but as bad as it sounds, it does not happen all that often in my experience. The are prominently marked “front” and most hobbyist do not make this mistake.

First I need to know more about your engine. Bone stock with a 2 barrel Autolite? Single diaphragm distrubutor?

I would check my timing and see where it is now hot idle with vacuum hose removed from distributor. If you are running the stock vacuum line and location out of the carb, which means you are using “ported” vacuum. Normal for that engine. Idle should be slow at 600 to 700 RPM when you check it. As said, normal setting is 6 degrees BTDC. Does it “ping” at all before it gets “too” hot under heavy acceleration? If not, then sneak it ahead (towards 10 degrees BTDC) 2 degrees at a time. As you do this you will have to reduce the curb idle each time. The engine will run “freer”. Engines love as much advance as you can give them and they generate less heat! And more power and better mileage. A win win win win!!! A bet this will solve you heating problem. You may end up adjusting your air mixture screws before this is all over. Another story.

We have Amy’s stock 302 around 14 degrees BTDC. It is cold as a cucumber now! Running on a old radiator I gave her that is ok, but not optimum as a new one. 6 degrees BTDC, as the recommend factory setting, is a conservative guideline back in the day that ensured no pinging on regular. Our gas today is totally different than in 1968! Each car should be tuned to the gas you run and its intended usage. If you run 87 then tune it to 87. All stock motors should run fine on 87 and putting 92 in is a waste of money if it is tuned to 87. The 92 gas will ignite slower and do nothing over the 87.

I tune my cars to run on the 92. I am out at 18 degrees BTDC on both engines. They have short advance curves and run at 38 total.

My favorite subject is gasoline discussions about then and now!! Don’t start me, I am warning you!!!

Rob

Timing is HUGE when it comes to cooling.

My blue car used to run warmer than I liked. It never boiled over but the needle was in the 3/4 range. I did everything I could think of. I changed the water pump, serviced the radiator, installed a fan shroud, changed hoses, adjusted the INITIAL timing to factory specs, and removed the thermostat. None of that did diddlysquat.

But there is another clue to this mystery for those of you (unlike me) who can put clues together.

When I drove the car with the engine warm it'd backfire every time I engaged the clutch to shift gears, but it wouldn't happen with a cold engine. I figured the carb was the reason for the backfiring.

I then decided to install a 160 degree thermostat. While working on that I pulled the vacuum lines off the front christmas tree port switch thingy and couldn't remember which hose went where so I temporarily looped 2 ports together and plugged the other. The car now runs great and the temp gauge needle doesn't go past 1/2. I thought the 160 degree thermostat fixed that cooling issue but since the car no longer backfires I now realize the vacuum lines were installed incorrectly, retarding the timing when the car got up to operating temperature. That one little incorrectly installed vacuum hose caused both the overheating and the backfiring.

So the morals of this story appear to be:
1. ALWAYS check the TOTAL timing as well as initial timing, when the engine is WARM
2. Vacuum sucks!!!

 

[robert campbell]

Arlie,
You are all over it!!! Timing was Amy's (satan's) problem from the get go. Get this right and many problems will go away!

Rob

 

[Ruppstang]

In 1994 when I restored our 68 fastback I had a similer problem. The freind that helped me start the motor the first time told me that one of the diaphragms in the duel vacuum advance was bad. We got it started and it ran great. I bought a new duel advance installed it and retimed the motor. it seemed to run great till I drove it and it would back fire everytine I backed off of it. I did not know what was wrong so I took it to the local garage and the told me that the valve train was too tight. I could not belive that because I had a very good engine builder. Then I the took it to a Ford dealer who had it for a week and could not figure out what was wrong till they started checking part #s. The found that the car a C code 289 2V that should have a duel vacuum advance and it did the new one I had installed. The trouble was when they checked the part # on the distributor it was for a 69 302 W/ single advance. That duel advance was doing its job retarding the spark and thus all the back firing when I backed it off. We in stalled a single advance and it ran great also that is why it ran great with the old duel advance that was 1/2 bad. Some times if you are not as smart as Rob and others on this site it can take a while to figure this stuff out. Marty

 

[CougarCJ]

In 1994 when I restored our 68 fastback I had a similar problem. The friend that helped me start the motor the first time told me that one of the diaphragms in the duel vacuum advance was bad. We got it started and it ran great. I bought a new dual advance installed it and retimed the motor. it seemed to run great till I drove it and it would back fire every time I backed off of it. I did not know what was wrong so I took it to the local garage and the told me that the valve train was too tight. I could not believe that because I had a very good engine builder. Then I the took it to a Ford dealer who had it for a week and could not figure out what was wrong till they started checking part #s. The found that the car a C code 289 2V that should have a dual vacuum advance and it did the new one I had installed. The trouble was when they checked the part # on the distributor it was for a 69 302 W/ single advance. That dual advance was doing its job retarding the spark and thus all the back firing when I backed it off. We in stalled a single advance and it ran great also that is why it ran great with the old dual advance that was 1/2 bad. Some times if you are not as smart as Rob and others on this site it can take a while to figure this stuff out. Marty

Those dual advance units were for emissions, so is the vacuum tree.

Rob, correct me if I'm wrong, everyone should use ported vacuum for the vacuum advance source, not straight manifold vacuum.

 

[robert campbell]

Ported vacuum for a single diaphragm cars without emission control for sure! The “tree” and the dual diaphragm “dis-turb-i-tor” bring in a whole new look. Arlie and Neil posted some great diagrams of how they hook up and I believe they get a “direct” vacuum source from the block behind the carb on the intake manifold.

Whether you have dual diaphragm or single distributor, I think timing is the key. Steve “mechanicalguy” and I had a thread somewhere on this subject.

First, do not be afraid to advance from stock specifications!! They were based on a safe setting on 1960’s gasoline. Lots of people afraid because they think today’s gas will ping on old motors because they were designed to run on 99-octane gas. From my experience (Marty has tons to, so don’t let him fool you) a 10 to 1 289 or 302 runs very similar on 91 or 92 octane today as they did on 99 back in the day. Gas today has been mixed to “not pre-detonate” on similar compression as the days of old. 9 or 10 to 1 compression.

Again, get your timing light out and see where you engine is set with all hoses off the distributor at hot idle of around 700 to 800 rpm in park of neutral. Note what it is and then advance it some. “Advancing” would be going from 6 degrees to 7 degrees before top dead center (BTDC). Retarding is going the other way from 6 degrees to 4 degrees BTDC.

Immediately you will see the idle pick up slightly before you put the hoses back on. Slow it back down with the curb idle stop screw a bit. When you but the hoses back on it may change a bit on a dual diaphragm, but should not be much. Should have no effect on a single diaphragm distributor. By the way, with the engine off, take a hose and hook it up to each diaphragm, suck on it and put your tongue over the end. Hold it for 10 seconds. If the suction bleeds off you need a new diaphragm.

Ok, now you know your diaphragm is good and you advanced the engine 2 degrees and the engine is at FULL operating temp. But not overheating! Cork up the headers, roll up the windows, turn the stereo off, and tell passenger Rob to shut his pie hole. Find a freeway on ramp or a slight hill and put the car in second and slow down to about 20 mph. Put it to the floor and listen immediately for “very hard” pinging or knocking. My guess is you will get none. If you were smart and brought the timing light and ½ wrench to loosen the distributor, pull over and advance it another 2 degrees. Keep advancing until the engine pings. A slight ping when you first floor it in this situation with the engine “lugging” at low RPM is fine. You are very close to optimal. Pinging ANY time you pull a grade is not good, so retard it back until gone.

Keep in mind if you do this on 92 octane and then put in the 87 it may ping. You are tuning to the octane of gas you have.

The purpose of the dual diaphragm and the “tree” was an emission control attempt. An engine running with less timing advance burns the gas more completely. But its trade off is less power and in some cases reduced gas mileage. And more heat. The diaphragm closest to the carb on the dual diaphragm actually pulls advance out of the engine at low RPM’s. City driving when you develop the most heat is when this device pulls out the most advance. Not good.

If I was a concurs guy and had to have the full emission array on my car, I would plug the back diaphragm or the hose coming to it. I would tune the car and even work with front diaphragm and possibly recurve the distributors centrifugal timing to achieve a curve close to a non-emission distributor. I have heard of some people taking the guts out of the air pump and blocking them. Looks concurs, but does nothing.

I think I will get close to one of these cars with a dual diaphragm and tree on it. Just experiment with getting good ported vacuum to it and plug the back diaphragm. Amy’s “Satan” would be a great candidate. See if I can come up with some revised stock specs that get one closer to the ballpark. Each engine is different and tuning by advancing slowly to pinging is always the best way to optimize your engines performance.

Rob

 

[Mosesatm]

The front vacuum tree operates just like a thermostat. One of the ports is an inlet port, which brings vacuum into the tree, and the other 2 ports are the outlets. As the water warms up a valve in the tree moves, which either opens or blocks (can't remember which) the outlet ports. The vacuum lines MUST be installed correctly for this system to work as designed. Hook it up wrong and the car will backfire and run hot.

 

[robert campbell]

The tree and the dual diaphragm dizzy! Infant attempts at emmision control gone bad in my opinion!! More heat, less power, and less mileage.....

Rob

 

[Midnight Special]

...This is great information all around and Arlie, you are absolutely correct. You verified to a tee what I discovered by trial & error. Excellent thread Gentlemen!!

 

[robert campbell]

Arlie or Neil or Marty or ???? posted a Ford diagram of how the hoses went for the tree and the dual diaphragm. I took it with me to work with "Satan". If you hook it up wrong, it could really be a problem! Or if the tree quit working it may shut off all vacuum to the diaphragms. If the forward diaphragm is bad that would be huge also.

Rob

 

[rvrtrash]

Late to the party, but I might add, there is no guarantee your harmonic balancer is correct after all these years. The outer ring may have shifted a little. The only way to be sure is to find TDC on your engine and insure the pointer is at the right spot. If not, 1)get some Harmonic Balancer tape, or 2)paint your new TDC and set point, or 3)replace the balancer. #3 isn't a bad idea as my original balancer blew up last year. Luckily nothing was damaged except the timing cover seal but it could've been worse.

Steve

 

[robert campbell]

Late to the party, but I might add, there is no guarantee your harmonic balancer is correct after all these years. The outer ring may have shifted a little. The only way to be sure is to find TDC on your engine and insure the pointer is at the right spot. If not, 1)get some Harmonic Balancer tape, or 2)paint your new TDC and set point, or 3)replace the balancer. #3 isn't a bad idea as my original balancer blew up last year. Luckily nothing was damaged except the timing cover seal but it could've been worse.

Steve

Great advice!! And again, why you tune your engine in a few degrees at a time. Timing marks "can" be crap and performance is what you want! If you find yourself a long ways from original specs (20 degrees or more) then your balancer is a time bomb!!

Great info Steve!!

Rob

 

[Mosesatm]

Great advice!! And again, why you tune your engine in a few degrees at a time. Timing marks "can" be crap and performance is what you want! If you find yourself a long ways from original specs (20 degrees or more) then your balancer is a time bomb!!

Great info Steve!!

Rob

If it doesn't ping under load go back into the garage and turn the distributor a few more degrees.