Hey GTOken or whoever can help out!
i was looking on your website, at the page for your engine, and i saw how you had rerouted some of the cooling lines between the carb and where the distributor goes...where are you rerouting it from/to? and what all benefits are you getting?better coolant flow? thanks
Nick

Sounds like you are describing the heater outlet line. It goes from the back of the passenger side head to the heater core.

There has been discussion in the Pontiac world that tying the two rear water passages together would offer better and equalized cooling to the rear of the heads. I have seen guys that have went to much greater trouble than I did to try to accomplish this. Personally, after having done this and giving it more thinking, I don't think it helps any at all and it a total waste of time. I believe the original Pontiac engineers knew exactly what they were doing and how best to do it. ALL that rear water port is for is to circulate a very small portion of heated water to the heating coil. The cooling system will work best (I believe) either as produced or with the rear port plugged. I was having cooling problems at one time and my temps did not change with or without my setup. I have yet to see anyone prove this actually does any good. So bottom line, just leave it like the factory did it.

GTOKen,

Oh my friend, you are just the guy to assist me this winter with figuring out my heater lines! I've had my car for several years and have known that the heater box hoses were removed and re-routed along the block. This means of course: Two copper tubes coming out of the firewall are not connected to anything, they are and have been wide open for many years.

So, bad heater/radiator box inside the car, maybe leaking all over passenger? Is that why they were disconnected? I dunno, but the more money I pour into this baby the more reason I have for driving her in the winter, hence the need for heat, or at least defrost!
You ready to help?

thanks GTOken, just was wondering about it, plus had a friend one time said he did some research on how to run cooling lines better on a pontiac to make the coolant flow better, this is probably what he was talking about, but i will definatly find out for sure what he meant, but of course he is a chevy guy!haha
thanks again
nick

Ask away..... I will answer any questions I can. If I can't, well there are over 3000 other members on this forum to draw from.

Leaking heater cores are common. If you have it apart, I would definately put a new one in. They aren't that expensive. The lines are easy, there is a 5/8" line from the head to the core, and a 3/4" line from the core to the water pump housing. At least that is how my 68's are.

John,

If I read your post correctly, the heater core has not been connected for some time. They may have been disconnected because the heater core was leaking (and if you think replacing your kick panels was fun, try the heater core). I recommend you attach a couple of pieces of heater hose. Plug one end and attach an air fitting to the other and apply a small amount of compressed air and listen for a leak under the dash in the heater box. You don't want to attach heater hoses and then find antifreeze leaking onto the passenger side floor board.

Tom

GTOKen, thats interesting , I have been contemplating doing that extra "T" to get 'extra' cooling , sounds like it may not be worth it...
I have a heater valve that will not close 100%, so I installed an 'inline' shut off valve (a la Home Depot )to keep my feet cool in summer, I open the valve for winter use...and after I changed my heads out last winter to 5C`s , milled down to 88 cc, added 1.65 rockers,plus I leaned out the carb some, it ran a little rich... my engine has now run a little bit warmer...rather than the steady 190F before it now runs 200-215 in summer( dep on speeds) ,in Texas 95F plus weather, so I was contemplating adding the "T" to be able to run that little water that normally goes to the heater core all the time thru the back of the pass. head...you`re saying it wont make much difference?...if so, youre saving me some unnecessary work...

Think about it like this; The radiator which does all the cooling has like 1-3/4" hoses, right? The rear heater passage is like 1/2" I.D. Even if you put a custom fitting in the head you might could get a 3/4" or 7/8" hose on it, I just don't think it will ever flow enough to make a difference. I would have to assume the engineers designed a specific "flow path" through the block and heads. Changing that flow path as far as I can tell does not improve cooling.

I will say that it seems like everyones cooling problems are different and are not always solved by a common solution. I had a cooling problem that I tried "everything" to solve. Ended up that a simple flex fan did the trick. I was getting inadequate air flow through the radiator at highway speeds. The clutch fan might have even been restricting air flow at speed. I would get in town it would cool back down some. Put on the flex fan and had to take out the 160° t-stat and put back the 180° t-stat cuz it would not get over 160°. Now it stays a 180°.

Also Bjorn, if you are getting hot air coming out even with the lever slid to cold you might want to re-gasket your flappers in the heater box and check your cable adjustments. I get no warm air coming out in the summer (that I can detect).

I might check those flappers, good idea!....the cables work fine...

Ken , I know about the fan stuff, mine had when I bought it an electric 'helper' fan in front...the car then ran at 210-220F , I found out the car was missing one of the rubber fillers at the side/base of the rad. support, also no X fillers, but it DID have the bottom valance filler...I added the X fillers, got it to 200F, added the rubber filler , got it to 195F, took off the restricting electric fan , got it to 190F....drove 2 yrs , then did my engine work... as for the temp. I think its fine, I rather run it at 200F and carb set right than run it rich at 190F....as long as its not over 210F , I think its fine...