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GT182 · 02-15-2009, 10:57 PM

BC I'm running a 13# cap and no problems so far. I had it out today and she ran at a steady 175 degrees, But it was on the cool side today.... about 43 for the high.

67blackcherry · 02-16-2009, 12:16 AM

Quote:

Originally Posted by GT182

BC I'm running a 13# cap and no problems so far. I had it out today and she ran at a steady 175 degrees, But it was on the cool side today.... about 43 for the high.

Gary

If the ambient temp is a chilly 43*, I would hope your car is running cool!!!

That heat wave we had out here 2 weeks ago (80*+) and my car ran just fine, especially after I put a "non" vented cap on the radiator! No more puking anti freeze either, imagine that...

The hose on my 'bird sits a bit high and had that same running hot problem, I can't wait to get her back on the road and see if that solves the problem...of course I need to get off my ass and finish painting all the hardware from the front end and put it back together...

hectore3 · 02-16-2009, 10:49 AM

Excellent tech. My old motor always ran hot. I wish I knew about the earlier.

GT182 · 02-16-2009, 11:23 AM

Quote:

Originally Posted by 67blackcherry

Gary

If the ambient temp is a chilly 43*, I would hope your car is running cool!!!

LOL... I was waiting for someone to catch that.

But really, she's running great. D. Miles did a great job on this engine.

I checked the oil yesterday and it's just as clean as when I first out it in. Looks like brand new oil.

You know, thinking back to 1970 and 71, MY first 66 GTO never had an overheating problem. I wonder if it's all the newer upper hoses and how they're made is what's causing all this overheating. I don't think the manufacturers are make their hoses the same as they did back then.

kate`s67gto · 02-16-2009, 12:13 PM

The upper rad hose is a great find, for the high operating temps. Personally i believe the what is called gasoline today, is really a mixture of turpentine and other chemicals. Today's fuel is no friend of yesterdays engines. This is one of
our biggest enemy's in fighting high engine temps.

Scott

67blackcherry · 02-16-2009, 12:47 PM

Quote:

Originally Posted by GT182

LOL... I was waiting for someone to catch that.

But really, she's running great. D. Miles did a great job on this engine.

I checked the oil yesterday and it's just as clean as when I first out it in. Looks like brand new oil.

You know, thinking back to 1970 and 71, MY first 66 GTO never had an overheating problem. I wonder if it's all the newer upper hoses and how they're made is what's causing all this overheating. I don't think the manufacturers are make their hoses the same as they did back then.

Yes, I think that's the problem...

PLAY400 · 02-16-2009, 01:00 PM

I was told it was too hard for the cooling system to maintain a 160# temperature with a 160# stat. The thing would be open most of the time not allowing the coolant to cool off enough in the rad thus causing the temperature to creep. I currently run 180s in the Pontiacs and 195s in the 4x4s. Will be lowering the hose in the 55 from on top the alternator and raising the rad to ensure proper flow. Will also check the 68 but I put a closed system on it and do not have problems with it. Upper rad hose is run/mounted lower than cap.

With the cold winters do a lot of t-stat changes. Generally fill the rad to the top of the cooling fins or 2-3" low and let it run until I get heat out of the heater and it has burped atleast once. Then I get to put another gallon in. B!@#H getting some, like my old Dodge Dakota to burp.

BTW I bet my temp. gauge would show cool too with no water in the rad.

67blackcherry · 02-20-2009, 01:14 PM

I drove my LeMans yesterday from LAX to home, 2 hours+ in (mostly stop) stop and go traffic. Other than one short spike (up to 220*) that lasted only a few minutes she ran at 190* the entire time. The ambient temp was in the mid 70's.

She ran strong, too, and I'm so stoked!!!

I'm sure that radiator hose issue will solve the running hot problem I had with the Firebird, and the rebuild will help with the running crappy problem too!

Jim Scites · 08:51 AM

Quote:

Originally Posted by 77birdman

Now I have to run out to the COLD garage and check my upper hose. Interestingly mine runs hot on the highway and cools down around town. The again I have only 3K on the new motor and running 10W40 Rotella in it, maybe still not broken in all the way. Wondering of Mobil 1 5W-30 has enough zinc?

I don't know if anyone has addressed this one yet, I didn't read all the posts. What I found in the past with a problem like yours is the lower radiator hose is collapsing when you go up the road. Make sure the coil of wire is inside the hose that's there to keep that from happening.

IOWA552SLOW · 03-17-2009, 04:54 PM

i have always had an issue with my 326 running around 190 with a 160 stat. i just got the car back home last night from winter storage. will check my upper hose tonight. one quick question, at what level does the antifreeze stay in the radiator? my car seems to puke the antifreeze out until you can see the cores and then stops. runs cool when completely full, 190 ish after losing a little.

i know that the motor was freshened up before i bought the car, aftermarket hose and water neck. will see what happens tonight.

67blackcherry · 03-17-2009, 07:18 PM

Mine runs at 190* all day long, unless traffic is especially brutal...

Kitch428m21 · 03-17-2009, 07:29 PM

I'd sure like to see a pic from someone who went with a mid 70's water neck and upper hose from a FB, on a 70 GTO with the oem p/s alt bracket still in place.

pontiac 455ho · 03-21-2009, 02:54 PM

get a milodon high flow thermostant 180 with a milodon water pump my car runs 185 all dat when it is a112 out side.

GT182 · 10:59 AM

I posted this in Dean's "What's Too Hot" thread, and thought it should also go here.

Here's a thought I've had with overheating. Dumb maybe, but think about it.

Do you have a front license/vanity plate that is blocking airflow thru the center of the bumper? Plate attached by it's lower bolt holes so it sticks up higher and closes off the center of the bumper, and it's acting as an air deflector. Everything else can be as it should, but it sure looks to me like it's restricting airflow. Just my

I'm looking to find a way to lower my front plate and try it out. It sure won't hurt to let more air thru that bumper IMO.

================================================== ===============

Well, I went out and tried to reset the plate and frame to the upper holes in the bumper. These are only 2 3/8s holes, not the elongated holes that are in the bottom to attach the frame. Wouldn't work with the plate frame. So I drilled 2 holes inside the ones already there to enlongate them. Now the frame can be bolted on with the plate. And it opens up the bumper for more airflow.

I know, I hate drilling holes in a good bumper too, but this was time it had to be done IMHO. With the 180 thermostat I'm heating up too 195 or so going down the highway. Sitting in traffic at a light, a bit over 205 or so. In hot weather it would be even more I imagine.... red lights take too darned long to change here in DE. Also going back to the 160 stat and flushing out the radiator again. Anything to help keep it cooler.

Here's the new look.... LOL The old look is at the right, and you can see the big difference it makes.

Old Goat 67 · 04-10-2009, 11:00 AM

Gary,
Have you checked your water pump plate clearance?
Charles

GT182 · 04-10-2009, 11:04 AM

Yes Charles. When the motor was put together Donnie checked it all out, The clearance was spot on. No problem there, and it's the "good" water pump too.

I think the radiator needs flushing out again to get rid or the crap that might have accumulated from the rebuild. That and the 160 stat will sure help... I hope.

67blackcherry · 04-10-2009, 12:02 PM

Gary

That looked like a contributor to the problem, IMO...hope it helps!

GT182 · 04-10-2009, 01:34 PM

I hope so too BC. Thanks.

I hope the other guys see this and try it too. I'm curious to see if it'll help their cooling too.

67blackcherry · 04-16-2009, 09:29 AM

My Firebird is done, and I've put 50miles or so on the new engine. The upper radiator hose had to be cut down an inch, and she's running at 190* or less. I haven't had her in heavy stop and go traffic, but I'm sure that was the problem.

She's also got TONS of top end...

GT182 · 04-30-2009, 09:45 PM

I just flushed out my radiator and engine the other day and got a bunch of crap out of them. Little pieces of red silicone.... lots of the stuff. That crap must have been used instead of gaskets before I got the car and was stuck in the radiator. It didn't come from this 400, had to be the 389 that's being rebuilt. The 400 was checked and cleaned before it was put in.

I also replaced the lower radiator hose. Even with the wire spring in it it was collapsing at the radiator. Now with the new lower hose, spring, 50/50 mix antifreeze and 160 stat she's running down the road at 160 degrees. Stopped in heavy traffic waiting for a red light to change she goes up to 175 but comes right back down as soon as I'm moving again. And this is with no shroud or clutch fan. Those are the next 2 things I'll be adding soon.

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