Another cooling thread

[944-spec#09]

P.Dilly

I know much of this has been discussed before but I think it needs more effort so I have moved your private message to the forums.

 

The bumper and screen you have should have no effect, however, make sure you have a shroud around the bottom and sides between the front openings and the radiator as this can have a significant effect preventing air from escaping around the radiator. The factory pan cover accomplishes this but most of us take that off. I made one from a sheet of aluminum, a long rectangle with the sides going up and bolting to the side bolts on each side of the radiator mount. I made a cardboard template to fashion this.

The thicker radiator is stock for the 85.5 and later cars, if you have an 86 or later body, I think it should fit fine. the parts number for these I put in an old thread so you will have to look them up. The thicker radiator was just a change in the last 2 digits (number 00 to 01 or something like that). The early body will require you to fudge and force a little but it should fit. The oil cooler should also help, in fact, by the rules which allow any external oil cooling, you might try what I am doing. I am leaving the factory oil/coolant exchanger for the NA engine and adding a sandwich plate with lines to the external oil cooler. You may still be able to use the turbo external oil cooling lines but I fabricated new ones. You can get this sandwich plate from http://www.racerpartswholesale.com/mocal.htm. You may find other places too. We have at least one car with this arrangement in AZ.

Also, my first engine had overheating problems which, at the time, I attributed to an old radiator or thermostat, however, I sprung a hose leak and blew the head gasket on this engine. When we broke it down we found the cylinders were scored by debris (almost like sand) from the coolant that got past the head gasket when it blew. I think now that this was aluminum oxide that had built up in the cooling passages, possibly from a prior owner not using phosphate free coolant. From what I have been able to learn, aluminum oxide is about 5 times less heat conductive than solid aluminum but even if not, the corrosion would inhibit flow both by it's rough surface and by obstruction. I don't know if there is any way to remove this corrosion; maybe there is a good flush kit specific for removing aluminum corrosion that someone knows about.

 

P.Dilly wrote:

 

Hey Steve,

yeah I'm not sure why? The head is stock, so CR should be normal? I'm at low 130's on the HP range so haven't squeaked out the most from an '88 engine. I didn't want to take advantage of the later '88 engine and then just be that guy with the best option. So I left it stock when I had the valves replaced (broken belt). I did run some race gas last time and that helped. It's a new radiator, but maybe just a regular? When you say late model radiator, which is that? I do have a grid over my radiator for protection from rocks etc. but that shouldn't be stopping the air? My front bumper was compressed in by the previous owner but I didn't notice until after painting the car and sitting it next to someone else's car. I wonder if that is creating more of a brick wall effect and the air is not "slicing" under the bumper and into the radiator? Does adding an oil cooler help everything else run cooler i.e. engine temps?

 

Thanks for the thought.

 

P.Dilly.

[Tim Comeau]

Dilly,

Interesting idea on the front bumper affecting airflow because the front bumper shocks have been removed.

It would act like less of a splitter. I support the idea of adding side walls from the front spoiler to the radiator to prevent air from spilling around the sides of the radiator. That's legal.

Any way, I wanted to add that the screen you use in front of the radiator can affect the air flow to a great extent.

My favorite material is stainless steel "wire cloth." It's not welded or galvanized in a grid so it can flex in any direction. I use 1/4 inch spacing weave, i.e., the holes in the screen are about 1/4 big.

Even so, HERE'S THE KICKER.....

If you read the specs on the material, the flow rate is only about 66%! Choose your screen material wisely. The angle that you mount your screen at will also affect the airflow through it. The more upright, the better. You'll want it perpendicular to the airflow.

One more thing, I would try to mount your screen so that it can't catch and hold chunks of rubber which would also impede air flow.

For what it's worth, my car is completely stock with regards to radiator, thermostat, fan switches, water pump. I use distilled water and Red Line water wetter.

[PeanutinCA]

Interesting idea on the front bumper affecting airflow because the front bumper shocks have been removed.

 

For what it's worth, my car is completely stock with regards to radiator, thermostat, fan switches, water pump. I use distilled water and Red Line water wetter.

 

I use those products also? The shockls are not removed. I guess the previous owner just ran into the back of someone? The shocks are compressed. But if I pull it out now, I'll have to repaint the bumper also. DOH!

 

Do other people run screens? It is the 1/4" type open screen. Whic I did have something punch through before. So better that than my radiator. Got a hole on one side, but not the bottom or other side? Looking at the front of my car with the bumber in (someone once thought it might be an advantage), it's more like a brick wall than something that would 'slice' through the air? I will see how it goes through these cooler months?

 

P.Chilly (not).

[944-Spec#94]

I run a screen.

 

It is made from cheap diamond shape material.

 

I installed it when I took out the center bar. I really did not want to see rock going through the radiator, Plus the rubber is easier to remove from the screen vs radiator itself.

 

 

As you can see the nose has tanken its share of abuse. No radiator problems, Since this picture I added a stock turbo oil cooler and placed it behind the right fog light hole. I enlarged the hole in the spoiler to cover the entire foglight cavity and the cooler was just the same size. I install a screen of the same material for the oil cooler to protect it as well.

 

Since installing the cooler (no stock NA cooler) the car has run cool maybe in fact too cold.