Chevy 350 HO connect and cruise running hot

[QBuff02]

Carburator, I know some folks do but I can't imagine going to EFI. Yes, the timing is at 8 degrees BTDC. No shroud and apparently the wrong fan so I ordered the right fan last night.

I saw in previous replies you said you had the thermostat removed, did you put it back in throughout your trial and error? Not only does a thermostat help to regulate temperature, it also acts as a restrictor to slow the flow of coolant down. If you run without a thermostat the coolant can flow through the radiator too fast and the heat won't be properly drawn off as the coolant cycles through the radiator. But also, not having a shroud can make a huge difference as well. Without the shroud the air at idle and slow speeds doesn't get drawn into and through the radiator and the fan basically pulls and circulates the air inside the engine bay until you get some speed to force the air through the radiator. i've seen 20 degree temp differences in coolant between having a proper shroud on the radiator/fan vs. not having a shroud at all. Sounds like you've got the most of it ironed out, but those are a couple tips that I know will make a difference. for example my 500 hp big block has all the right components and it doesn't care if its 55 degrees or 105 degrees it always runs right around 200 (with a 185 degree t-stat) degrees on an autometer gauge.

 

[Rusty Nail]

Yeah uhhhhh its the internet...requires pictures to work right.
Duh.

You must be registered for see images attach

 

[Gilmore]

You can't mix the two because the bolt spacing is different. I once modified my fan only to discover it blew air out the front of the vehicle.

Apparently you can mix them when you install the fan on a fan clutch…..

 

[Gilmore]

Well uninstalled the fan and fan clutch and the pulley and confirmed I do have a reverse rotation water pump GM part number 19168600. Now I just need to wait for the fan the pressure test is going well no issues there.

 

[Big Chip]

Like @QBuff02 said, the shroud should really be on the radiator. I doubt it will ever work as well as it should without it.

 

[Gilmore]

I hear ya, pondering how to do that since it was a diesel truck and the gas radiator is t the same size and I had to custom fab a bracket.

 

[CalSgt]

I have a dakota digital gauge and a Bosch manual gauge installed opposite each other in the thermostat riser so I know I have a good reading they are within a degree of each other.

Yes right now I have the thermostat out so it’s free flowing (wanted to eliminate the thermostat from the equation). I went out and checked my belt routing and it’s all correct. I did reverse my fan blades, which are turning counter clockwise and now it’s pushing (not pulling) a ton of air across the radiator and the truck only heats up to about 165 after running for about 20 minutes. I’d like to say problem solved but the motor needs to be sucking air not pushing otherwise it’s going to be working against physics when driving down the road. Correct?

Had a buddy put a ZZ350 crate motor in his FJ40 and started having overheating issues... Electric fan was wired backwards pushing air. Temp at an idle was fine but from about 10 MPH to whatever it would get hot. Fan was creating an air pocket in front of the radiator at speed. He was messing with it for weeks until he gave me a ride somewhere, I jumped out to run into a store and as I passed the front of the rig was getting blasted with hot air from the fan... Bingo, problem solved

 

[CalSgt]

I hear ya, pondering how to do that since it was a diesel truck and the gas radiator is t the same size and I had to custom fab a bracket.

Get a junkyard shroud and hack it up to make it work.

 

[IcePatch]

Another thing to check for: vacuum leaks.
I had a carbureted 350 that always ran fine in town, but as soon as I'd start driving it on the highway it'd start to overheat. I had traded the truck for labor on another car, and the mechanic that ended up with it found a MASSIVE leak under the carb due to the adapter plate being installed upside down by the guy that originally built it. He told me it started running much cooler once he got that fixed.

 

[Gilmore]

Another thing to check for: vacuum leaks.
I had a carbureted 350 that always ran fine in town, but as soon as I'd start driving it on the highway it'd start to overheat. I had traded the truck for labor on another car, and the mechanic that ended up with it found a MASSIVE leak under the carb due to the adapter plate being installed upside down by the guy that originally built it. He told me it started running much cooler once he got that fixed.

No adapter plate and it’s a turn key motor so most everything was pre installed.

 

[Gilmore]

Well put on the new fan and now she runs between 183-199. So the reverse rotation fan was the fix!

 

[oldretiredafguy]

Like @QBuff02 said, the shroud should really be on the radiator. I doubt it will ever work as well as it should without it.

x2. An engine compartment without a shroud is always going to run hot. The shroud directs the airflow to the radiator.

 

[Gilmore]

x2. An engine compartment without a fan is always going to run hot. The shroud directs the airflow to the radiator.

I haven’t done the shroud yet but the fan going the proper direction sure made a difference!

 

[DoubleDingo]

Glad you got this figured out.