Cool woes persist

[Lars]

My 70 has a cooling problem and I don't know where to start with it. I can cruise along at 60-70 MPH and it doesn't go above 195 deg. There is a light in town that about two miles before it I have to slow down to 35 MPH before I get to it. I sit at the light, no problem, I cruise through town at 30 MPH and it stays cool (varies between 180-195 deg.). However, on my way back home I was cruising at 70 MPH and it stayed stable at 195 (this was for about 4 miles) until I pulled into my driveway, in a matter of 20 feet from the road to my shop door it jumped from 195 to 210 deg. Car has a mild 360, standard water pump, 50/50 mix, repro 340 rad, and a Flex-a-lite repro clutch fan and clutch (about 3/4 inch from the rad). I have an external cooler for the tranny, but it is mounted on separate brackets about 4 inches ahead of the radiator. Any ideas?

Thanks

 

[camd64]

what degree stat are you running? also do you have a shroud? it sounds by the description like you either have an air flow issue because of it heating up when you are at slow speed or a stop or, possibly and, it could be the idle mixture is too lean. my 2 cents.

 

[Lars]

180 stat if I remember correctly. I do have a shroud, plugs read perfect on it. The weird thing is if I gradually slow down to a stop it doesn't heat up. But if I'm moving at a high rate of speed then slow down abruptly, that's when it gets hot. The radiator is a only a two core and it is really thin, I see guys running replacement rads all the time with hotter engines then mine, but this thing is so puny, it makes me wonder.

 

[camd64]

i know what your talking about with the 2 core radiator, i have one in my car. it doesn't get hot but i would feel a whole lot better if it were at least a 3 core. with the car running can you feel any cold spots on the radiator? a few guys on here have had new radiators plugged up.

 

[Lars]

i know what your talking about with the 2 core radiator, i have one in my car. it doesn't get hot but i would feel a whole lot better if it were at least a 3 core. with the car running can you feel any cold spots on the radiator? a few guys on here have had new radiators plugged up.

I guess I could check that with my laser temp reader, hadn't thought of that.