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Old 05-25-2010, 10:18 AM
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bluzurb bluzurb is offline
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Location: Norfolk, VA
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Default Heating Problem

I have 78 400, for the most part stock. edelbrock intake, lunati cam, very mild, 800 carb. I blew the head gaskets when i was at pontiac nationals doing the test and tune. I just got everything back together this weekend. I put a 160 thermostat in. She is heating up to about 205 degrees. I didn't have a fan shroud so i went out and bought some material and built one for it. i have a single 18" fan. Yesterday i took it for a drive and it was still wanting to rise above 205. so i shut it off. My next thing is taking the radiator out and getting it professinally cleaned. Rodded out i guess is what they say. If that doesnt' work, i am not really sure what to do. Any ideas?

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Old 05-26-2010, 02:27 PM
Pontirag Pontirag is offline
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you blew both head gaskets? was there any over heating problems befor you installed the cam and intake? any over heating problems after installing the cam and intake/carb set up? Did you check to see if the heads were warped befor you re installed them?

Do a leak down compression check so see if the head gaskets are leaking-might have warped one or both heads.

Determining when the overheating occured in terms of the components installation might indicate that there are tunning issues that are causing the over heating,

lean condition from the carb
timing problems from cam choice (vacuum signal)
Stuck or rusty advanced weights
New timing chain? sloppy old ones dont work with new performance cams. new timing chains installed incorrectly (some allow 2 or more degrees of advance or retard)
Harmonic balancer slipping (wrong timing marks)

that is just some of the possibilities. I have found that low compression motors do not like HP cams. tired old motors (vary familiar)

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Old 05-27-2010, 10:30 AM
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bluzurb bluzurb is offline
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Quote:
Originally Posted by Pontirag View Post
you blew both head gaskets? was there any over heating problems befor you installed the cam and intake? any over heating problems after installing the cam and intake/carb set up? Did you check to see if the heads were warped befor you re installed them?

Do a leak down compression check so see if the head gaskets are leaking-might have warped one or both heads.

Determining when the overheating occured in terms of the components installation might indicate that there are tunning issues that are causing the over heating,

lean condition from the carb
timing problems from cam choice (vacuum signal)
Stuck or rusty advanced weights
New timing chain? sloppy old ones dont work with new performance cams. new timing chains installed incorrectly (some allow 2 or more degrees of advance or retard)
Harmonic balancer slipping (wrong timing marks)

that is just some of the possibilities. I have found that low compression motors do not like HP cams. tired old motors (vary familiar)
I did have the heads checked before i put them back on. and no i didn't have a problem with the over heating after i put the cam in. that was a year and half ago, about. it seemed to start after the test and tune at the track. Right now i have radiator flush in the system. I drained it, put a gutted thermostat in, put the flush in, filled with water and ran it for about 10 minutes. I still had the hood open. I waited til it got to 200 and turned the fan on and heat on full blast. ran that for about 5 minutes, brought it down to right around 190. that's great. i closed the hood, shut the heat off, and it started climbing again. got to 205 and was still going up very slowly. So, i am going to go take it on the highway and run for about 20 minutes, come back, drain and flush the system like 2-3 times and then put the water wetter in with straight water. And go from there.

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Old 06-03-2010, 02:28 PM
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bluzurb bluzurb is offline
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I got the radiator back yesterday. did not put it in. It was still a little wet from the paint and it was hotter than hell yesterday. Hopefully today i can get it in and then do a flow test on the motor itself. Just gonna take off the top hose and stick a garden hose in the radiator and run it just to see if the motor is flowing. If it is, then put it all back together and fill it up and run it to see if the problem is fixed. I have about 20 days before the long haul to illinois.

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