If I missed a post regarding this, sorry, I can't find it. Is 800F normal? It kind of freaks me out how hot it is when I open the hood, but car has always ran OK, usually around 195-210F at thermostat. So after buying a 4 oz $80 can of zybar ceramic paint, I think I got screwed with another miraculous item. I followed the directions sanded, cleaned manifolds for a long time. I was able to put 2-3 coats by brush fully on both before I ran out. It did lower my temp at the manifolds from 800F to about 720F. But the can states it would lower the temp over 90%. Maybe with 30 coats? It goes on like water, so I didn't want to buy another can. It seems to be holding up well. Looks much nicer than rusted old manifolds. I used wrap on the pipes and fuel line insulation, but my underhood temp is still over 700F. I never had vapor lock but I must be close to it since gas line is measuring around 200F. Any other ideas to lower temp. I was thinking of adding an electric fan but they pull 80-120watts. Why did Chrysler route the fuel line inches away from the exhaust? Any danger or safety factor to rerouting the gas line instead to coming in from back of engine? Thanks for the help.
Therez no way the air temp iz anywhere near that. I think your thermometer iz reading the surfase temp uv the exaust manifoldz.
If the air temperature wuz a stedy 400 most plastics woud melt, the paint on everything woud fry, the rubber woud turn to crumbly junk. And, needless to say, the fuel woud boil long before any uv that happened and stop the enjin.
Joined: Wed Nov 17 2010, 03:28PM
Location: florida
Posts: 1311
if motor runs at 195-210 why so concerned about how hot under the hood?your ambient air temp under the hood is not 800 degrees ,like someone mentioned ,things would start melting.not sure where your sensor is pointing to but if its near the manifold then temps would be high.temps at the ports can reach 1200 degrees and exhaust is going to be hotter than actual motor.i would guess it never gets above 300 degrees in a typical engine compartment based on most performance parts being rated in that range for extreme conditions.
Thanks for the replies guys. Original 1969 distributor has petronix in it and runs/starts good for last 10yrs, but I think my vacuum advance isn't working too well since sometimes it takes off when floored and other times, it stumbles and feels like its going to backfire first, then it takes off. (Could be the 1080CFM thermoquad carb since I found Holleys and Carters need constant attention and horrible emissions which my neighbors complained about) I don't care about speed and hardly ever floor it, so maybe thats why it boggs out sometimes. Once I floor it, its reacts fine until I park it. The engine has 144K miles, so distributor shaft is probably worn. valve timing is probably worn too. I have a timing gun and seems like its correct, but I'm an amateur mechanic so would these things matter with increase in heat?
on 85F weather, after driving around town for 1/2hr with A/C off, - 800F is at the exhaust manifolds which is hottest point in the engine bay. 500F at heater hoses right next to exhaust manifolds, 300F at top of intake manifold, 200F at the fuel line, 140F at bottom of carb above spacer. Thermostat hovers between 195-210F and no vapor lock for 15yrs I had it, so I guess I'm OK? Does this sound right or am I slowly ruining my engine?