Engine running too cool after installing fat shroud

[mhjo]

I replaced electric fan with clutch fan after experiencing cooling issues.

Just to be sure, I installed an aftermarket "fat" shroud. Now the engine only gains 1/4 on the temp gauge. What causes this?

Should I get a stock shroud that lets air in from the sides?

 

[hhead]

I might check the temps with a mechanical gauge first. And then go from there. Your stock gauge might be off. Glad to hear the temps came down. That's definitely better than too hot.

 

[j69302]

what degree thermostat do you have installed? That controls the minimum temp of the water. Put a higher rated one in 180 or 190ish is a good choice. That temp range is ideal.

 

[RGS0907]

OK, I'll bite.. What is a 'Fat' Shroud?

 

[TeamEntity]

i think he means that the shroud is deeper. the o.e. ones are really shallow.

 

[tx65coupe]

I agree about the 180-190 degree T stat. I currently have a 180, but I'm planning on switching to a 190 Motorcraft one.

If you want to know what the true operating temp is you need an infarred thermometer. I use this one since its inexpensive.

Micro Temp MT-100 - Spark Industries Micro Temp Digital Infrared Pyrometers - Overview - SummitRacing.com

I run this shroud on my 65 with a Fluidyne aluminum radiator and the when it warms up the temp gauge reads about 1/3 of the scale. Is this the same shroud you have? Its a composite material with the caution decal on top.

Mustangs Unlimited - The Premier Source for Mustang, Shelby and Cougar Parts and Accessories

 

[mhjo]

i think he means that the shroud is deeper. the o.e. ones are really shallow.

Exactly

 

[mhjo]

I run this shroud on my 65 with a Fluidyne aluminum radiator and the when it warms up the temp gauge reads about 1/3 of the scale. Is this the same shroud you have? Its a composite material with the caution decal on top.

Mustangs Unlimited - The Premier Source for Mustang, Shelby and Cougar Parts and Accessories

Yes, it is that one. I am starting to think that the deep shroud fools the clutch to engage when it shouldn't by only letting in air through radiator (the orignial shroud had opening on sides). I also have tried two Thermal clutches from different sources (Summit and Haydn), but they look the same.

 

[TeamEntity]

there has been some good tech on these shrouds and they cool too much. yes thats right. Not good for the engine to not reach proper temperature. You should switch back to the old shroud and keep the thermal clutch.

 

[S-Car-Go]

I had a similar problem where the motor would not reach operating temp even though I had a 180* thermostat. It turned out the thermostat had so much bypass even when cold the motor wouldn't warm up. I was using a "high-flow" thermostat. I put in a standard ford unit and problem solved.

 

[D.Hearne]

there has been some good tech on these shrouds and they cool too much. yes thats right. Not good for the engine to not reach proper temperature. You should switch back to the old shroud and keep the thermal clutch.

Wrong answer. The correct fix is to use a hotter thermostat. Too much cooling capacity is a good thing and far easier to compensate for than an inadequate system.

 

[htwheelz67]

YUP!

 

[horseballz]

Wrong answer. The correct fix is to use a hotter thermostat. Too much cooling capacity is a good thing and far easier to compensate for than an inadequate system.

+1 Agree

 

[TeamEntity]

no not a wrong answer. wrong shroud. As stated above. Whats the point of installing a deeper shroud if you going to compensate the over cooling with a hotter thermostat? Kinda dumb.

 

[D.Hearne]

no not a wrong answer. wrong shroud. As stated above. Whats the point of installing a deeper shroud if you going to compensate the over cooling with a hotter thermostat? Kinda dumb.

Nothing dumb about it. Why would you want less cooling capacity when you have it when you need it? The purpose of a thermostat is to regulate the engine's operating temperature and keep it in the optimum temp range. If you needed more cooling, it's there for the thermostat to give it when it's needed. If you decrease cooling capacity, then need it, what are you going to do then? You're not going to stop on the side of the road and put the shroud back on are you ? THAT would be dumb.

 

[ForceFed70]

no not a wrong answer. wrong shroud. As stated above. Whats the point of installing a deeper shroud if you going to compensate the over cooling with a hotter thermostat? Kinda dumb.

The only cause of an engine running too cold is a bad thermostat. You don't "compensate" with a thermostat except the other way around... when the engine tends to run too hot.

That's about 4 of us now. Instead of trying to tell us we're wrong, please think about why we may be right.

 

[tx65coupe]

I agree about keeping the better shroud and going with a 190 degree Motorcraft thermostat, instead of a 160 or 180 high flow. Even if it is running cool, there may be times like 100 degrees in traffic etc when you will wish you had the extra cooling ability.

Its not dumb to compensate for it by running a hotter thermostat. The thermostat is what regulates the temp anyway. Besides, Ford originally intended for a 190 degree T stat to be used.

 

[mhjo]

Well, as mentioned earlier, one problem is thaat the fan runs all the time!

So, we will first try to change to a stock shroud (which will let cold air in from the sides as well as hot air from rad) in order to give the fan clutch the right temperature. The hotter thermostate idea we keep for the next step.

I will post results next week.

Thanks all!

 

[D.Hearne]

There are different types of fan clutches. Not all work the same. One type runs all the time at lower rpms, then disengages at higher rpms. Another will not come on until a certain temp is reached. Could be you have the first.

 

[mhjo]

There are different types of fan clutches. Not all work the same. One type runs all the time at lower rpms, then disengages at higher rpms. Another will not come on until a certain temp is reached. Could be you have the first.

I have tried 2 clutches, both thermal (both from Summit). I turns itself on and off, but too often on.