I have a 67 326 no AC, this engine has been completely rebuilt 30 over. The problem is heat,
she loves to hang around the 210 mark and when you come to a red light, she will go even higher if you let, and then she starts to Vapor Lock.

I have done the following, please see if there is something I may have missed.

New themastat 160 (2 Times)
Smaller Pully on the water pump.
2 new radiators (3 Core)
Racing Antifreeze to keep motor 10 15 deg cooler.
Electric fan only, 16 inch

all parts on this engine are all brand new, today after putting another new radiator on it, she held 180 for about 10 minutes ideling, when I took her on the road she climbed to 210, I turned on the heat to help disipate and anti freeze started coming out of the heater core inside the car.

What am I missing, I live in SC and it was not that hot here today, anybody with any sugestions, please email me at lancehendrix@charter.net

Thanks

A couple things your might check. Is your timming set right? there is a part that fastens under the front valance. Its purpose is to direct the air flow so you get more through the radiator. I left that off when I restored my car but quickly put it on and it does make a diffrence. Could you be missing this part? Good luck.

That seems to be a common problem with Pontiacs! The Performance Years BB has a section dedicated to heating and cooling with 90% of it hot motors. Besides the normal stuff, timing, fuel mixture, shroud, there is a lot of discussion about the impeller on water pump, cast preferred over the stamped steel impeller. Another item is the flow of standard thermostats (some guys drill a couple of holes in them). It is either not enough air or not enough water movement (or both).

I just picked up a new water pump for my 67 that I am going to try!

Did you install the thrust plate behind the water pump and use new seals?

I have always had problems with the pontiac engines overheating. always. everyone tells me to put on aluminum heads to fix the problem.
i have done everything under the sun except that so i am going to try that next. i even had a custom built 4 core radiator built for my bird.
timing waterpumps you name it and ive changed it.
when i win the lotto and can afford the edelbrock heads i'll let you know if they worked for keeping temp down.

I have a bird for 17 years and have never had an over heating issue..and it's a 455 in Florida.

Mine is 1969 w a 72 400 , it was running hot when I bought it, now its fine ,after I installed the X fillers and replaced one of the missing mastic fillers at the bottom sides of radiator, here in Texas w 95-100F most of the time...
Bjorn

tnims68..do you have all of the air directing pieces in place? If not you will have a lot of air going around the radiator instead of through it. I don't think changing heads is necessarily the answer. You should not have an over heating problem using the factory heads.

I have been told that Pontiacs are notorious for running hot.

I have read that a lot of other Pontiac owners have switched to aluminum radiators and this has solved their problems. I live in Phoenix and have had to upsize the radiator in my truck twice now, so I will be going straight to aluminum for my 'Bird project.

so far i have not run across a stock engine which could not be fixed with stock parts to get it to cool properly. (knock on wood) but i have not dealt with many (or maybe any) pontiac v8's with this problem. i have a 6 and it runs at 190. (or it did for many years-under reconstruction currently)

i have heard about running CLR thru the system to clean out waterjackets. probably not good for rubber or plastic. dont know how it affects aluminum.

i have also seen electric fans wired backwards, new radiators put in without cleaning the condensor (a/c cars), liscence plates installed so as to restrict flow, and weird things like cardboard put in the way for the winter because they took the thermosat out for the summer. i have worked on cars which had a bleeding sequence, or needed the radiator end of the car raised up to get the air out.

i actually didn't know until fairly recently that antifreeze does not cool as well as water, and therefore always reccommend using a 70/30 mix as climate permits. they prob'ly taught me that in school, but i forgot (and my dad's a chemist. go figure).

i dont think pontiac would design a car which would overheat with stock heads. they would've had too many complaints. maybe that CLR thing would work for you, trims68. there is always a solution, and i dont think you need to win the lottery to find it.

i wonder if mr. hendrix figured his problem out.

I think most of you are right, Salmon is right , yes they all 'tend' to run hot , Sixstarved is right , they should not using all the factory parts...problem is lots of years have gone by and some parts could be missing...usually its the easy stuff that gets overlooked...rather than worry about heads, thermostats, timing ,radiators etc, ( unless missing thermostat = water runs thru too fast , no time to cool, clogged radiators, timing way off etc),you need to see that the 'fillers' are all there and in correctly...my X fillers made a direct change of about 15-20F , and later I found the missing masticated filler mnissing on one side , it changed anoter 5-10F...when I bought the car in Ft Worth , driving it back in august it ran 210-220 (uphills at 230)doing 80+- mph...now it runs 175-185 , 195-200 in really tight traffic, stop n go, this is only w/ adding in the missing pieces...

also make sure the air baffle under is there..
Bjorn

check the resitantance of the gauge sending unit
or a bad temp gauge maybe its not as hot as it is
just a thought

bill

hmmmm, i need to check this bottom pieces that are to keep air going through radiator. i dont have those parts!!! what are they called and where in thr heck do i get some??? i do have the 400 and the fillers are in the top part but nothing below under or beside radiator.
it stays cool as long as i keep it moving at around 140 or so, ok maybe 65mph but when i cruise or stay still it gets warmed up so much that if i shut it off it doesnt want to start back up cuz i think its getting my starter too hot.

battery cables which are old or corroded at either connection can cause that too. i dont have any underside air directors on my '68, but i have the six. wish i could be more help.

As far as Pontiac motors running hot I can say none of mine have overheating problems. My Firebird sat in traffic at Woodard for 2 hrs. moving not more than a few inches at a time and ran fine. I made sure it had all the parts that it should have when I restored it. As far as those that get hot and wont start I would sugest a good starter silenoid and a heat sheild. The exhaust pipe runs too close to the starter. That solved my starting problem.

Tnims68, What you are missing (probably) are the fillers that Ames calls "seal kit" FP454 for cars w/o a/c, or FP455K for A/C cars...in my older Ames catalog F-8C ,pg 103. they are/were $14 for a set..."these are the masticated rubber seals that are located between the core support and the radiator. They are used in conjunction with filler panels FP191K and FP191L"
which are the "X" fillers.....

And if it wont re-start when hot , you probably have haedars , right? or you might need this anyway...its the #FN405 , "solenoid heat shield" $10.00 ,"originally designed foir the 67 HO and RA applications, this shield helps insulate your starter solenoid from exh. manifold heat. can be used on any Pontiac V8 to reduce hot start problems. This willn not work on FN402P ( which is the "high torque starter")

hope this helps you!
Bjorn

Thanks guys.
Another question?
Why when my car is warm I stomp the gas and it boggs way down before it takes off?
I do not have headers. Do I need them?