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-   -   Need help with overheating at idle. (https://camaroforums.com/forum/67-69-general-43/need-help-overheating-idle-80409/)

Milan 08-27-2016 04:44 PM

Need help with overheating at idle.
 
New 383 stroker. New radiator, duall electric fans, hoses, high flow water pump, 160 High Flow thermostat. Driving down the highway temp. stays at 180F. The minute I stop the temp climbs to 220. I dont know how high it would go since I shut it off at 220 and wait for it to cool down. I'm at a loss as what to do next. I have replaced everything I could think of. Would a intake leak cause overheating?

flat tire 08-28-2016 06:46 AM

loose the electric fans. go with a mechanical fan with a shroud
ask me how I know
my 383 532 hp can sit in traffic for 15 minutes and it will only climb to 190

Milan 08-28-2016 09:04 PM

Tried it. Still the same. I'm thinking I have a intake leak.

Camaro 69 08-29-2016 01:46 AM

I'm running just a single electric fan, and it doesn't get hot in traffic. If you had an intake leak, I think you'd know it by the engine running crappy.
What distributor do you have, is it vacuum or mechanical advance, and what is your timing set at?

Everett#2390 08-29-2016 05:45 AM

As said, check timing and how much there is at speed.
And hopefully, manual fan with the proper shroud.

You might duct tape in cardboard panels from the header and valance to radiator support, for troubleshooting purposes, and add a a length of 2"inch square foam across the top of rad support sealing the hood. all of this would help prevent recycling of engine heat back through the radiator again while sitting.
GM also had panels at the headlamp assemblies to plug them off.
Headers give off a lot of heat moreso than cast iron manifolds and a singular pipe per sdie.

Milan 08-29-2016 08:06 AM


Originally Posted by Camaro 69 (Post 714050)
I'm running just a single electric fan, and it doesn't get hot in traffic. If you had an intake leak, I think you'd know it by the engine running crappy.
What distributor do you have, is it vacuum or mechanical advance, and what is your timing set at?

Mechanical advance. Initial is 12 advance is 30. I pulled the plugs and they are white which tells me its running too lean. I changed the jets from a 55 to 65. A little better but still too lean. I must be sucking air somewhere. I sprayed brake clean around the manifold, carbs, hoses but nothing obvious as to a leak.

Camaro 69 08-29-2016 11:07 AM

Try readjusting your idle screws. I have the same kind of tunnel ram setup, but running lean at idle/low rpm is not a problem that I have.
Also, that 160 thermostat isn't doing you any favors. Might want to step it up to a 180 or even a 192, which in effect will give the coolant more chill time in the radiator. Your engine is staying at 180 on the highway with a 160 thermostat. What does that tell you? The coolant temperature is staying well above the open rating of the thermostat, and the thing is staying open. You might as well be running without a stat, which often times can cause a hotter running engine. "A lower temp thermostat makes the engine run cooler" is a common misconception.

Milan 08-29-2016 01:24 PM


Originally Posted by Camaro 69 (Post 714060)
Try readjusting your idle screws. I have the same kind of tunnel ram setup, but running lean at idle/low rpm is not a problem that I have.
Also, that 160 thermostat isn't doing you any favors. Might want to step it up to a 180 or even a 192, which in effect will give the coolant more chill time in the radiator. Your engine is staying at 180 on the highway with a 160 thermostat. What does that tell you? The coolant temperature is staying well above the open rating of the thermostat, and the thing is staying open. You might as well be running without a stat, which often times can cause a hotter running engine. "A lower temp thermostat makes the engine run cooler" is a common misconception.

I had a 180 and that's when I went down to the 160 I will try 190 to see if that's gets any better by the way how much vacuum are you pulling at idle mine sits about 1

Camaro 69 08-29-2016 04:12 PM

If I ever checked mine, I can't remember. I want to check where mine is at because I would like to change over to a vacuum advance distributor. But I've been so busy with other projects, and haven't had the car out for the last 2 summers.

Everett#2390 08-30-2016 05:59 AM


Originally Posted by Milan (Post 714068)
by the way how much vacuum are you pulling at idle mine sits about 1

It must have a ton of duration and overlap.
Or it needs some ign advance and some air bypass.
Or another vacuum gauge.


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