It's Summer - Nuts must be overheating !!!!

[mike bell]

Well I thought that I had my overheating problem more or less figured out-WRONG!!!!! It was quite warm today with high humidity(94) so I thought that I'd take a little ride and see how the car acted in this heat. Everything was going good-it never got to180 while moving. While I was stopped at two traffic lights it crept up to 190 I was smilin' form ear to ear! Then on the way back home, I got stopped for road construction for about 7-8 minutes. I thought "AH, THE BIG TEST-I watched the guage go from 180 to 230 in that timespan. I wasn't sure how fast we would start moving again so I reved to motor to about 2500 to try to keep the heat down. It somewhat worked, it brought the temp back to about 220in about a minute and then they turned us loose and it cooled down to 180 in just several miles. So idleing is my problem!
When I got home and things cooled a little,I started looking everything over. The flex fan is inside the shroud just about half and half but the front if the fan is still over 2 inches from the radiator. Has anyone ever figured out just how much distance is correct and best? I've heard several people talk about the draw of the fan holding a shoptowel tight against the front of the radiator. At idle, mine will bearly hold a piece of looseleaf paper up to the radiator. It will not pull the paper into the radiator, I have to place it there and hold it for a second or two, then it will stay put. Is there just not enough draw through the radiator at idle?? I'd sure appreicate anybody's thoughts and ideas on this. I'm at a loss!! Thanks in advance!! Mike

 

[JimKwiatkowski]

That's Great news Mike, if you run a stat you should try a test without a stat, my 57 runs 5 degs cooler without a stat. It seems like our 348-409's like lots of coolant flow. Also check and seal any air gaps between your radiator and shroud.

Mike, I posted this 4 days ago. My fan blade is 3" from radiator, so I would rule that out. do you run a stat, do you have any air gaps between your radiator and shroud, if you do seal them like an air tight box so no air can excape. You might have a problem with your fan blade, what fan blade are you using, what size fan blade are you using and how big is the opening in your shroud were the fan fits in. Check your coolant again some crud might have broke loose from your engine block.

 

[Iowa 409 Guy]

Exactly

Pull the wire from the bulkhead connector and replace it with regular wiring.

We just did that very thing Monday to get my new setup to run right with the MSD.

 

[ROYALOAK62]

It's Summer- Nuts must be overheating !!!!

I'm have following these overheating threads for sometime now and I'm a little curious about something.

Has anyone looked into if the heat at idle is just rolling backover the radiator support and the hood?

Could someone try rolling up a fire-proof blanket and laying it atop the radiator support fender to fender and then close the hood. To see what happens.

Dave

 

[petepedlar]

Has anyone looked into if the heat at idle is just rolling backover the radiator support and the hood?

See post #69 in this thread.......... I have the panels although not installed yet.

Dave

 

[Nuts]

Has anyone looked into if the heat at idle is just rolling backover the radiator support and the hood?

That is one of the things I had thought of this past weekend, while at a local cruise. I'm going to work on it this weekend to see what it does, it's going to be 100* here on Saturday. Should be a good test. I don't have a fire proof blanket, but I was going to use some heavy cardboard.

Bill

 

[Nuts]

Hot wire ???

I hot wired the car and continued my drive.

Dave,

I have question that should be ovious, but is leaving me scratching my head !!! How did you do the "Hot Wire" ? I would like to try this before cutting into the wiring harness in the engine compartment. I think it would help my overall problem if I could get the vacumm advance hooked up and working correctly...

Bill

 

[petepedlar]

Bill............. a piece of wire with an aligator clip on each end........ attach one clip to the positive post on the battery and the other to the ign side of the coil....... basically what you are doing is sending the power direct from the battery to the coil.............. bypasses everything in the car's wiring.

................. that and a screw driver to jump the terminals on the starter and you can steal any 409 car........... (SOB I wish it wasn't that easy)

Dave

 

[oldskydog]

Here's some more info for consideration on overheating from an expert radiator guy:

"One possible cause for severe overheating is a blown core. Due to extremely high pressures in the coolant, typically a head gasket problem, you can balloon the cooling tubes in the radiator. When this happens the flat tubes try to go round and the cooling fins get crushed. Almost no air can get through the core and no cooling will be the result. Check the air flow across the radiator by placing a sheet of paper on the front of the core. It should pull it up there like a vacuum cleaner. You should be able to slide a zip tie right through the core in multiple places, if you can't, then this condition may exist. It's not easy to spot this because when the fin crushes, it does it in a very consistant pattern and it's not real obvious unless you know what you are looking for. "

:

 

[JimKwiatkowski]

Cecil thats a good thought, here's what Mike had to say in one of his posts.

Has anyone ever figured out just how much distance is correct and best? I've heard several people talk about the draw of the fan holding a shoptowel tight against the front of the radiator. At idle, mine will bearly hold a piece of looseleaf paper up to the radiator. It will not pull the paper into the radiator, I have to place it there and hold it for a second or two, then it will stay put. Is there just not enough draw through the radiator at idle?? I'd sure appreicate anybody's thoughts and ideas on this. I'm at a loss!! Thanks in advance!! Mike

 

[raymar58409]

Cecil and Jim,
Both good thoughts. That loose leaf paper should get sucked right out of your hand in a heartbeat if the fan is turning.
I've never seen a radiator blow the core like that but sure would be posible and create lack of airflow.
What I have seen is an aluminum radiator running straight water be drained for the winter and the cores be filled with lime corrosion. Unable to view on a crossflow when you look down the fill neck.

 

[Nuts]

So, I'm going to check to insure that I'm getting full 12v to the coil. I have the small block wiring harness with no resistor on the cowl. According to the wiring diagram the wire running to the coil is a "resistor" wire.

The question is, if it's a resistor wire, what should the voltage be at the coil ? I should be able to check the output with my meter ? Another question is, if I run the wire from the battery to the coil and unhook the exsisting wire, shouldn't I be able to start the car with the key ?

Some times things have to be explained to simple minded Idaho folks !!!! Not that all Idahoan are simple minded, just this one !!!!!

Bill

 

[Nuts]

Same Same here !!!!

At idle, mine will bearly hold a piece of looseleaf paper up to the radiator. It will not pull the paper into the radiator, I have to place it there and hold it for a second or two, then it will stay put. Is there just not enough draw through the radiator at idle?? I'd sure appreicate anybody's thoughts and ideas on this. I'm at a loss!! Thanks in advance!! Mike

Mike,

You have the exact problem I have !!!! If I'm moving, no problem !! If she is at idle for much time :eek: The only difference is I can hold a shop towel up in front and it will suck right up, no problem. It will hold a waded up towel, with no problems.

I'm looking into two issues with mine.

1st, is the "hot" air being pulled over the top of the radiator from the engine compartment. Going to install a tempary cardboard dam between the support and grill to check this out.

2nd, Is the MSD distributor voltage issue, a contributor to the problem ? I don't have the vacumm advance working, because if I plug it in I get pinging. Even without it plugged in I have the initial advance set to 8-9. Which is actually retarded, so that is not a good situation, but it doesn't ping ! I'm going to run a "hot wire" to the distributor and hook up the advance and see if I get any binging ! Wish me luck !

Bill

 

[Don Jacks]

Nuts,with the coil hooked up,the voltage through the resistor wire will be about 7 to 8 volts.If your not running a MSD ignition,then this is fine,as much more will burn up the ponts in very short order.If you can find the wire that feeds the points,jump around it ,connecting at the firewall plug to the plus side of the coil.If you are not running an aftermarket ignition,then as good as this car is running ignition isnt going to be your problem.

 

[mike bell]

Nuts, GOOD LUCK with your experiment! I had so free time over the weekend and I noticed that I have about a 3/8 inch gap between the shrroud and the radiator,all the way around. I could feel quite a bit of air sucking in between that gap. I found an old hunk of trunk weatherspripping in my junk collection. I jammed this into the gap and could hardly feel any suction anymore and the
'draw on the front of the radiator was much better!!!!! Now all I have to do is find something to seal up that gap. I remember a trunk weatherstrip that slipped onto a lip(shroud in this case) and the meat of stripping stuck streight out. That would work good in this case if I could remember what type of car it was on. I'm like some others around here, can't remember s#%t!! Also I'm not real sure that it will take the heat? I guess try it and see,huh. If my fadding memory ever returns, I'll get a length of that weatherstrip and try it out and see what happens. All this thinkin' is giving me a headache-I think I need a beer. If anyone has an idea what perticular stripping I talking about or someone has a better idea, please let me know!!! Thanks Mike

 

[Nuts]

Alright, I checked the voltage at the coil, it's 17.5, which is the same as across the battery terminals. Don't know what to make of that ??? The wire is Red/White barber pole colored and joins with a Green wire at the coil ?

I maybe using the meter incorrectly so here is a picture of the setup I used ?

I have been wrong before, just ask Linda !

Bill

 

[Nuts]

Now all I have to do is find something to seal up that gap.

Mike,

I had thought about using a piece of hose, like the vacumm hose to the brake boster and spilting to slide over the shroud ?

Just a thought
Bill

 

[Don Jacks]

:eek:You have it set up correctly you need a new meter 17.5 volts would fry everything in the car:evil

 

[Brian Thompson]

Bill-

As Don said, something is wrong. Check the voltage with another meter. It shouldn't be more than 14.8 volts. If it is still at 17.5 (or higher than 14.8) then your alternator/generator is over charging and you will definately want to get it checked out.

 

[62impala409]

Mike,

I had thought about using a piece of hose, like the vacumm hose to the brake boster and spilting to slide over the shroud ?

Just a thought
Bill

I believe in an earlier post Cecil mentioned using foam pipe insulation. Leo.