Need help with overheating issue on my 77 k10 with sbc 350

da_raabi · May 15, 2018

Snoots said:
I didn't notice that a clutch was installed. Fan does look too close to the engine. It should be just inside the shroud.

Lens77chevy said:
No clutch on fan

I meant that there should be a clutch there. I wonder if that's the problem? Maybe the PO had a problem with the clutch, and instead of replacing it they just removed it? That would pull the fan backwards a good bit, resulting in the problem at hand.

A nice new HD clutch will benefit you in two ways: 1. It will fix your cooling problem and 2. It will likely free up some power as the fan will only turn when needed. I'd definitely look into it!

4WDKC · May 15, 2018

da_raabi said:
I meant that there should be a clutch there. I wonder if that's the problem? Maybe the PO had a problem with the clutch, and instead of replacing it they just removed it? That would pull the fan backwards a good bit, resulting in the problem at hand.

A nice new HD clutch will benefit you in two ways: 1. It will fix your cooling problem and 2. It will likely free up some power as the fan will only turn when needed. I'd definitely look into it!

An HD clutch maybe over kill for what he needs, now could also be a good time to switch to electric if you have been thinking about it.

Blue Ox · May 15, 2018

Lens77chevy said:
Spring is in lower hose I didn't verify fan being on correctly but I believe its is also here is a pic of my normal running temp as of late

You must be registered for see images attach

To echo what others have said, try to get it back to stock if you're not going racing. A lot of people second-guess the engineers and it usually doesn't work out well.

And I like your substitute for the clock. That's a great idea. We have a thread here for that kind of thing:

http://www.gmsquarebody.com/threads...pic-thread-no-distasteful-photos.2443/page-26

Snoots · May 15, 2018

da_raabi said:
A nice new HD clutch will benefit you in two ways: 1. It will fix your cooling problem and 2. It will likely free up some power as the fan will only turn when needed. I'd definitely look into it!

X2

And, it'll be a LOT quieter!

Lens77chevy · May 15, 2018

So update I got a laser thermometer and at the er block where temp sensor it was 242 and I also noticed a 40 degree temp difference from left side to right side of radiator which makes me believe I need a new radiator again thanks for all the help I am also putting a 2 inch spacer on my fan

77 K20 · May 15, 2018

Just throwing this out there- there are short and long water pumps.

https://www.speedwaymotors.com/the-toolbox/chevy-small-block-short-vs-long-water-pump/28860

Perhaps you have the short pump and that is why your fan is pulled out of the shroud.

da_raabi · May 16, 2018

Lens77chevy said:
So update I got a laser thermometer and at the er block where temp sensor it was 242 and I also noticed a 40 degree temp difference from left side to right side of radiator which makes me believe I need a new radiator again thanks for all the help I am also putting a 2 inch spacer on my fan

Forget the spacer. Seriously. Get a clutch. It will work 1000x better.

da_raabi · May 16, 2018

Duplicate post. Stupid thing error-ed out on me.

You must be registered for see images

roundhouse · May 16, 2018

They also
Made some reverse rotation water pumps on some vehicles

As another poster said

Take the rad cap off and make sure you can see water flowing out of the tubes

A new heavy duty radatior is worth a try

Goldie Driver · May 19, 2018

77 K20 said:
Just throwing this out there- there are short and long water pumps.

https://www.speedwaymotors.com/the-toolbox/chevy-small-block-short-vs-long-water-pump/28860

Perhaps you have the short pump and that is why your fan is pulled out of the shroud.

Sorry to thread jack, but this has me thinking. Mine does not overheat, but runs hotter on the freeways mainly based on oil pressure- the gauge never gets to the halfway point .
It will cool off at idle.
This is with a new Advance Auto water pump- thank the fan is too far in ?
Thanks !

You must be registered for see images attach

Goldie Driver · May 19, 2018

Oops - double post - not sure how to delete.

77 K20 said:
Just throwing this out there- there are short and long water pumps.

https://www.speedwaymotors.com/the-toolbox/chevy-small-block-short-vs-long-water-pump/28860

Perhaps you have the short pump and that is why your fan is pulled out of the shroud.

Sorry to thread jack, but think this can is too far in?

This is after a new Advance Auto water pump- I never thought to look at the length...

You must be registered for see images attach

Lens77chevy · May 21, 2018

Update I put on a new radiator, 2inch spacer and put 8n a 180 tstat in now I am running just above the half way line on gauge this morning hoping that is where is will stay

chengny · May 21, 2018

Goldie Driver said:
Sorry to thread jack, but this has me thinking. Mine does not overheat, but runs hotter on the freeways mainly based on oil pressure- the gauge never gets to the halfway point .
It will cool off at idle.
This is with a new Advance Auto water pump- thank the fan is too far in ?
Thanks !
You must be registered for see images attach

You must be registered for see images attach

If you’re running a belt-driven fan, there are a few things you need to do in order to maximize the engine cooling that the fan can provide. It’s critical that the fan be positioned properly within the fan shroud and that there is just enough clearance around the fan blades. The first thing we want to make sure is that you actually have a fan shroud. If you rely on a belt-driven fan for engine cooling, a fan shroud is a must to pull the air through the radiator. Without a shroud, air will take the path of least resistance, pulling air from over and under the radiator instead of through it. Most people that have cooling problems with a belt-driven fan at idle and slow speeds don’t have a shroud – their fan is drawing very little airflow through the radiator, and most of their cooling comes from ram air being driven through the radiator at speeds above 40 mph.
If you have a fan shroud, the position of the fan blades in the shroud is very important to maximize airflow. Looking from the side of the engine, the fan blades should be half in and half out of the shroud.
If the fan is too far inside of the shroud, it won’t pull as much air through the shroud as it could. Instead it will create turbulence inside the shroud, spinning the air, but not efficiently pulling it through. If the blades are not far enough inside the shroud, the fan will pull air from around the shroud rather than through it.

It’s also important that the fan blades do not extend past the top, bottom or sides of radiator surface. This causes dissimilar resistance along the length of the fan blades, which stresses them.
The other very important fan to fan shroud measurement is the distance around the circumference of the fan and the circular opening of the shroud. If there is too much space here, the fan won’t be as efficient as it could be in pulling air through the radiator. If there is not enough clearance, you run the risk of the fan contacting the shroud with natural engine movement and body flex that affects the radiator and fan shroud mounting. This can damage the fan shroud and the fan. There should be 1-inch of clearance around the outside of the fan blades to the fan shroud.
The last measurement you should check is the distance from the face of the fan to the radiator. There should be at least 1 inch of clearance between the two. This is to accommodate normal engine and radiator movement, and also the flex that occurs in the fan blades at higher engine rpm.
Checking these measurements when running a belt-driven fan and a fan shroud will solve overheating problems and fan contact problems caused by improperly placed fans and shrouds.

Need help with overheating issue on my 77 k10 with sbc 350

da_raabi

Trailer Park Supervisor

4WDKC

Full Access Member

Blue Ox

Turning Diesel Fuel Into Fun

Snoots

Full Access Member

Lens77chevy

Junior Member

77 K20

Full Access Member

da_raabi

Trailer Park Supervisor

da_raabi

Trailer Park Supervisor

roundhouse

Full Access Member

Goldie Driver

Full Access Member

Goldie Driver

Full Access Member

Lens77chevy

Junior Member

chengny

Full Access Member

Similar threads

Latest posts

Forum statistics