[grandville455]

What pulleys again? the large 8"?It has to be in the engine build then? was the blocked completley cleaned? whats you deck height etc? Got to be something going on internally?... my car at the track sunday idling in staging with 85 degree temps kept it right at 170-175 with my fan on low, I am in the process of trying a different setup as it got to 190 down the highway,like the airflow was blocked some,cause it comes down as i slow down eventually.. anyway enough of my ranting..

[Tripower455]

I have no clue, but at this point I am willing to consider anything. The block was prepped properly, very close to 0 deck, I've got an 8" crank pulley.

I've got almost 14k on this engine, and I think if something big were the issue, then something more than running hot would have resulted.

I am about to pull this thing out and put a friggin 326 in it......

I am thinking that at speed the electric fan is blocking airflow through the radiator.

I think the mech fan is going back on........

[grandville455]

Originally Posted by Tripower455

I have no clue, but at this point I am willing to consider anything. The block was prepped properly, very close to 0 deck, I've got an 8" crank pulley.

I've got almost 14k on this engine, and I think if something big were the issue, then something more than running hot would have resulted.

I am about to pull this thing out and put a friggin 326 in it......

I am thinking that at speed the electric fan is blocking airflow through the radiator.

I think the mech fan is going back on........

hmm yea i would say so also!.. what size water pump pulley? do u have pics of your setup now?Thats why I am trying a dual fan setup.. i think the big lincoln one blocks to much of the radiator to get free air down the road.

[Tripower455]

I don't have the lincoln one. I've got the Taurus, which actually leaves some of the radiator exposed.

Not sure what the water pump pulley diameter is. I had a complete March underdrive setup when i put the engine together, and couldn't even drive the car for more than a few minutes before overheating, but there were other tissues. I replaced the crank pulley with 8 1/8" IIRC. It was the largest one I could find at the time.

I posted these pics on post 51 of this thread. But here they are again:







I've actually got it baffled now, and a CS144 alternator......

[1967Tempest]

Post some specs on that water pump pulley. It looks smaller than mine. Would LOVE to get a smaller one.

Dave

[grandville455]

Probably a stupid question , but the fan is turning the right way? and pulling correct?

[Tripower455]

Originally Posted by grandville455

Probably a stupid question , but the fan is turning the right way? and pulling correct?

Yup... I even pulled the wiring apart today to make sure I was using the high speed winding. And I was......

It has been really hot here, but this thing ran these temps when it was cooler too.

It's definitely pulling heat out of the rad. The controller works as advertised. It comes on slow speed until it heats up, then it runs on high. It never wavers off high speed though, since I have the cut in speed set for 180 or so, and it isn't able to cool it down that far.

As I said, regardless of thermostat rating, no thermostat etc., it'll run 195 all day sitting still. It's when it's moving is when it creeps up. Exactly opposite of what it did with the mechanical fan. Even the low/high temps are the same! Today, I got caught in a thunderstorm, and it was POURING (my poor car!) and it ran at 195 during the rain. As soon as it stopped, it crept up quickly to 210. I pulled in my driveway, let it idle a minute, and the temp was coming back down.

Mixture is good too (I run an LM1 all the time). I have to recheck my timing...... although the odds of it slipping at the exact time I changed the radiator and fan is like winning the lottery.

[1967Tempest]

Lower hose collapsing??? It sounds like it should cool better than it does.. Vacuum leaks? Carb tuning? In the rain it should be ice cold!!!

Video??

[Tripower455]

Originally Posted by 1967Tempest

Lower hose collapsing??? It sounds like it should cool better than it does.. Vacuum leaks? Carb tuning? In the rain it should be ice cold!!!

Video??

It might be the lower hose..... I put a spring in it, but maybe it's still collapsing...... That would make sense.........

[grandville455]

I want ya to try something if u can? Jet up your primary about 3 sizes, on your middle carb since that is the one u drive on correct? don't care what the meter says, I was using my meter earlier this spring and it said i was rich at cruise so i went down 3 sizes and sure enough it ran alot hotter! put them back in right back to normal.It was only like 65-70 sunday morning and my car stayed at 170-175 all the way to the track(about a 1/2 hr drive) fan didn't even need to be turned on! give it a try and report back

[Tripower455]

Thanks Gville, but that isn't it. It would cool down at cruise on these jets with the mech fan. I run 69 (holley) in the winter, and 68s in the summer. It's in the high 13's at cruise right now.


It has to be something with the new radiator/fan setup. These are my thoughts.

The Griffin simply doesn't have enough capacity for the engine (not likely, as others are running the same one with no issues)

or

The fan is blocking too much bypass air at cruise.

or

The lower hose is collapsing at rpm.

or

The water pump isn't pumping enough , and it was masked by the old Rodney Red (maybe it was larger than the Griffin?)


It's not the end of the world. It is not overheating, and is still running in the same operating range that it always has. It's just that I wanted the electric fan to keep it from creeping up at idle. I never thought it would reverse the issue.

[grandville455]

Ok well I just know mine showed high 13's to to even high 12's with that meter too and it ran alot hotter cruising... thats when i put back the 75's in the primary of my 850 Holley

[1967Tempest]

Originally Posted by Tripower455

Thanks Gville, but that isn't it. It would cool down at cruise on these jets with the mech fan. I run 69 (holley) in the winter, and 68s in the summer. It's in the high 13's at cruise right now.


It has to be something with the new radiator/fan setup. These are my thoughts.

The Griffin simply doesn't have enough capacity for the engine (not likely, as others are running the same one with no issues)

or

The fan is blocking too much bypass air at cruise.

or

The lower hose is collapsing at rpm.

or

The water pump isn't pumping enough , and it was masked by the old Rodney Red (maybe it was larger than the Griffin?)


It's not the end of the world. It is not overheating, and is still running in the same operating range that it always has. It's just that I wanted the electric fan to keep it from creeping up at idle. I never thought it would reverse the issue.

Well mine runs at 180 in 80-89* and 190-195* in extreme weather. If it is in the 70's forget about it. The car runs at t-stat.

So for you to be running at 190 in the driveway and them creep up when moving is odd.

I would start from scratch. Look at everything. I would even get a laser gun and see what the temps are at the top inlet and the bottom outlet. I know that mine is at least 30* cooler going into the engine.

The difference from the taurus to Mark VIII is almost nothing. The car SHOULD be running cool.

I will look over the posts to see if anything sticks out.

Rad cap pressure??

[grandville455]

You do have the cast impeller water pump? and not the stamped POS!

[Tripower455]

Cast impeller..... from the get go....... As much as it pains me to do so (I am tired of draining the thing every few weeks!), I am gonna pull the water pump and check the clearances again. When I put the engine together, I made the plate touch the impeller without a gasket, so the clearance is that of the gasket, I'm guessing 1/32 to 1/16"?

My LM1 appeared pretty accurate. When I was jetting the center carb, if I got right to 14.7 or higher, I'd get that lean stumble at cruise speed. One jet size larger and it was fine. Neither made the slightest readable difference in the water temp though FWIW. Like most Pontiac folks, I watch that gauge like a hawk....... and the bottom line is that the current jetting was fine with the mechanical fan.

This is the story of my life with this engine and I've been struggling with it for almost 5 years now. And I can say that NO expense was spared in trying to solve it.

[1967Tempest]

Is this an automatic? I read that a guys transmission was making his engine run hot because the tranny fluid was way to hot going into the rad.

I see that you have aluminum heads, can you run more initial timing with out detonation??

Spark plug heat range?

Brakes dragging while moving?

Underhood temps too high? My car is 30* cooler on the gauge with the hood off.

Obstruction in front of rad?

Are you missing the nipples in the timing cover from the water pump plate to the back of the cover?

Water Wetter? Makes a difference...

I know that some of these are DUH!! But a fresh set of eyes solves more problems than you think.

Plus when you drain the car enough to get it down blind folded, then we can talk. I can not remember how many time I drained mine!!!!

PLEASE POST PICTURES!!!!!!!!!!!

[Tripower455]

67T,

Thanks....

If any of those things were an issue, I think they'd have shown up in the 13,500 miles I drove the car with the mechanical fan. Nothing but the fan, radiator, alternator and lower rad hose have been changed (other than me trying a different thermostat/no thermostat. The reversal of the issue came about right when I changed those things.

As much as I hate to say it, I think I'm gonna put the mech fan/shroud back on and see what it does. At least that will eliminate one major thing that I changed.

I posted a few pics. What else are you interested in seeing?

[1967Tempest]

Water pump, t-stat. IDK just pictures i guess. Odd issue you are having. Curious as to what can be the issue.

Hmmm.........

[Tripower455]

It's definitely not the thermostat. I tried several and even removed it entirely. There was no difference at all in the way it acted.

Maybe the water pump is messed up in some way. It's been on there for 5 years.....

[grandville455]

well i just got back from testing my dual fans and had to have it on high all the time, came back put the lincoln fan on went for a drive samething! i was like wtf?..well i hooked up my factory gauge a couple of weeks ago i look at that one its not even close to 195 like the auto meter one says. so i turn the fan off when i get home just letting it idle in garage ,autometer starts creeping to 210 factory not even close as thats the middle on my gauge! take heat gun 165 at thermostat housing tap the auto meter gauge drops right away to 195 still too hot according to gauge, but something is funky there, also my sending unit top spins, i dont think thats normal?..so i will be ordering a new sending unit and then seeing what happens, but why that gauge would drop to 195 from 210 is beyond me if the sending unit is bad!...just something for u to think about or look at also ok!

good info here!

http://www.autometer.com/tech_faq_an...x?sid=1&qid=57