What would you do?

[ubtripn]

Hi everybody,

I am in a tight spot. I have the new engine in my truck, everything is running fine BUT when it gets warm out I start creeping above 180 degrees. I am running a normal clutch fan. I know Summit has electric fan kits that automatically turn on at certain points but that is too much money right ow. They do have one 18 inch pusher electric fan for 70 bucks. I have a 4 row radiator so I know this would be enough but here is the rub. would you:

1. Wire it to a switch and just turn on when needed?

2. Wire it to turn on with engine? I was considering this because the thermostat will still allow it to get to 180 even with the fan running right?

What do you think? Thanks.

Just remembered another question - is a puller fan mounted on the front of the rad? Thanks again.

[BigRed76]

Honestly I think 180 degrees is nothing to worry about. As long as you've got a good cooling system and no leaks it should do fine running in the 190-195 range.

[67ChevyRedneck]

Don't spend a penny. Nothing is wrong.

[71swb4x4]

180 is a little on the cool side. Above 210 and I would start wondering, 210 and lower and no concerns.

Edit: a puller fan pulls air through the radiator, so it goes on the engine side.

[ubtripn]

Sorry, I should have been more clear, in the summer when I am not moving it moves up to 200 and it keeps going. Given the right conditions it will break 220. Happened only once then I got moving so no damage. But it will move high when not moving if it is above 65 out.

Thanks for the puller answer as well.

[Thanos]

Originally Posted by ubtripn

Sorry, I should have been more clear, in the summer when I am not moving it moves up to 200 and it keeps going. Given the right conditions it will break 220. Happened only once then I got moving so no damage. But it will move high when not moving if it is above 65 out.

Thanks for the puller answer as well.

100% agree, it has a ton to do with where you live/drive. I remember running a 180 therm in Texas in 112 to 115 degree in the summertime and it damn near cooked my engine,trans and I recall the AC barely making a difference.

I can still recall all the "stock" cars and trucks blowing head gaskets like crazy even brand new ones.Had to get a aftermarket rad and a 160 to get it to run at 190 in stop and go traffic+ AC... lol

Now when I moved to Colorado that all changed, moved up to a 190 or 195 and it would drop 30 below often in the winter however I would never run a engine over 200+

[rsgt]

I was just wondering how you have your timing set on your engine. I was reading about how an engine with the vacuum advance hooked up to full vacuum will have a cooler engine at idle. Here is part of what I was reading:
Plugging your vacuum advance into a direct source will allow it to engage at idle, which is good for a number of reasons. Much like cruise conditions, engines run leaner at idle than they do under load. Again, this means the mixture burns slower and needs an earlier spark to optimize the burn. Ensuring that the mixture has a complete burn before leaving through the exhaust port also helps the engine to run cooler at idle. All carbureted cars were set up with direct vacuum to the distributor before more stringent emissions requirements reared their heads.

[71swb4x4]

Do you have a fan shroud? If yes. How far into the shroud does your fan go?

[ubtripn]

I do not. I figured it was either a shroud or this but I was not sure if the shroud would fully solve the problem.

[67ChevyRedneck]

There are so many things to consider before using an electric fan as a band-aid.

You are correct, the 4 row radiator should cool just about anything with an auto and A/C.

What engine is in the truck? Is the radiator a factory style 4 row or some aftermarket piece? This could be a timing issue or vacuum leak. Auto or Manual? A/C, no A/C?

Yes, you absolutely need a shroud - try this first.

[ubtripn]

It is a built 350 (Supposed to be 383 stroker, cannot confirm, mystery crate engine I got for a grand.) No Ac, does have automatic, standard 4 row radiator. Thank you for the advice.

[71swb4x4]

The shroud is extremely important. Without the shroud the fan is pulling air from the engine bay too. The shroud will make the fan pull the maximum air through the radiator that it can.

[ubtripn]

Sounds good to me, I hope LMC can overnight. Thanks again.

[ubtripn]

I want to make sure I get the right one, do you know the standard diameter for the shroud?

[Andy4639]

A couple more things to make sure of.
Normal temp is 190-210 on most GM products and these are guide lines not stone.

No air pockets in the system. Buy a cheap over flow plastic tank and install it. Make sure you have a good mix of water antifreeze.
Buy the shroud to fit the truck. By year model. When you have a fan pulling air with out a shroud it pulls the air with the least resistance so any air moving is around the hood and motor not through the radiator when sitting still.

[jeffahart]

Example: Volkswagen beetles are air cooled, but without a shroud they will overheat. The air needs to be directed, and forced where it does the most good.

[muley]

And make sure the pressure cap works as it should.

[ubtripn]

10/4 - thanks everybody!

[special-K]

The shroud is essential to cooling at low speed and sitting when there is little to no natural air flow.

[ubtripn]

Got it, start with shroud.

Yeah, it gets hot here, way hot and fast . I will have to check the timing and try that, I think I am running a bit rich as well.

[Mrturner1]

Originally Posted by ubtripn

Got it, start with shroud.

Yeah, it gets hot here, way hot and fast . I will have to check the timing and try that, I think I am running a bit rich as well.

Lean will get it hot, but I don't think rich does so you're okay there. Just went through this myself. The shroud is essential, and the thermostat is more influential than you might think. I had a 160 degree t-stat and I kept creeping over 210 at lights, put a 180 t-stat in and it solved the problem.

Definetly would NOT do a pusher E fan. If anything that's going to restrict airflow being mounted on the front of the radiator. I could be wrong but after a lot of reading and trial and error, it seems pusher fans really benefit drag cars at the track, but for daily drivers they hinder cooling

[ubtripn]

What is our stock fan size in inches, does anybody know. Just want to make sure I have the right one, thanks.

[snipescastle2]

Might have to "Burp" the coolant system.... try drilling a small hole in your thermostat to allow the air to work itself out. I once had a 2002 Grand Prix that took me an hour to get the air out of the cooling system, and temps kept climbing, finally got it done, what a chore. but, as someone else mentioned earlier, 180 degrees isn't bad at all, but with an outside temp of 90 to 100 ambient temperature, I'd be looking at some auxiliary cooling myself.
Ben

[Stocker]

Originally Posted by ubtripn

What is our stock fan size in inches, does anybody know. Just want to make sure I have the right one, thanks.

18" (on a thermal clutch) on my '72 w/factory A/C, 350/TH350.

[GASoline71]

Also, if you're using the original 40 year old radiator... it might be full of crud.

Second... is the temp sending unit in the drivers side cylinder head? Or is it in the intake manifold. If it's in the intake manifold, it will read hotter than in the cylinder head.

From my experience, the aftermarket shrouds fit like crap. I was able to source an original shroud for my truck from Wes at Classic Heartbeat.

Gary