Heating Problems

[kennels]

Just put a 350 crate motor in my car.At low speed around town in traffic the motor runs about 150 degree. On the freeway above 65 the temp goes up to around 200 and goes back to 150 when I slow below 60.
The car has a 170 thermostat new hoses and a new radiator.
I have noticed the fan clutch will only rotate about one -eighth of a turn with the engine off and having sat overnite. It also has the same type of resistance and turns the same amount when the motor is hot.
Could the cluch be defective and not disengaging enough at low speed but not locking up properly at high speed?

 

[Robin7TFour]

kennels, did you replace or clean out the radiator,while doing the motor work?sounds like a typical clogged rad. Robin

 

[kennels]

Yea radiator was done

 

[Jack]

Just put a 350 crate motor in my car.At low speed around town in traffic the motor runs about 150 degree. On the freeway above 65 the temp goes up to around 200 and goes back to 150 when I slow below 60.
The car has a 170 thermostat new hoses and a new radiator.
I have noticed the fan clutch will only rotate about one -eighth of a turn with the engine off and having sat overnite. It also has the same type of resistance and turns the same amount when the motor is hot.
Could the cluch be defective and not disengaging enough at low speed but not locking up properly at high speed?

Motors really don't like running as cold as 150 in traffic or at 55 mph ... too cold ... not good for it. Suggest 180 or 190 t'stat ... it might help balance temps out too. Check temps with known t'meter ... verify your gage is correct. Unable to determine fan clutch from your description ... nevertheless, it may be bad. You didn't mention if it loses any coolant. Here it is mid-summer and you're running 150 at 55 mph ... hard to believe ... a 170 t'stat does not make a motor run at 170 ... it simply goes wide open sooner than does a 180. In hot ambient temp at hiway speed showing 200 on a CORRECT gage is OK.
JACK:gap

 

[brusso]

Motors really don't like running as cold as 150 in traffic or at 55 mph ... too cold ... not good for it. Suggest 180 or 190 t'stat ... it might help balance temps out too. Check temps with known t'meter ... verify your gage is correct. Unable to determine fan clutch from your description ... nevertheless, it may be bad. You didn't mention if it loses any coolant. Here it is mid-summer and you're running 150 at 55 mph ... hard to believe ... a 170 t'stat does not make a motor run at 170 ... it simply goes wide open sooner than does a 180. In hot ambient temp at hiway speed showing 200 on a CORRECT gage is OK.
JACK:gap

I run a 180 stat and I'm also using a flex fan. I get similar readings on the temp gauge. 'round town or under 55 gauge reads about between the 200 and the 150 marks, on the temp gauge. On the highway, It reads straight up 200 and comes back down once I get off the highway. The flex fan is fixed to the water pump so it's always spinning at engine rpm. In other words, it sounds like your clutch fan is working fine. Like above quote, I'd probably go with a hotter stat.

 

[78SilvAnniv]

I have noticed the fan clutch will only rotate about one -eighth of a turn with the engine off...
Could the cluch be defective and not disengaging enough at low speed but not locking up properly at high speed?

I'm not so sure the clutch fan isn't the problem. I am under the impression that it should spin freely. I also agree that a higher temp t'stat would be better for your engine, certainly much better in colder climates.

I also run a flex fan after struggling for 11 years with replacing the clutch fan yearly (and sometimes twice a year). My running temps are at 180 in town, low speeds and speed limit hwy driving. Anything faster than 70 for any length of time only send my temp to 195. Even if we are pushing it hard (3000-4500rpms in 2nd gear) on the curvy mountain roads keeping up with other CAC members' C3s, C4s and C5s around Helen, GA.
Heidi

 

[brusso]

Could the cluch be defective and not disengaging enough at low speed but not locking up properly at high speed?

I was thinking that it should function just the opposite? Shouldn't it lock up ,when hot, at lower rpms and back off at higher rpms. Beeing that there is typically more air flow at higher rpms/mph.