C3 4ME

I finished installing my repro front pace car spoiler on my 79 today. I have learned that 79 L-82's with A/C either had a front spoiler or and ugly extension riveted onto the factory air dam, both to help direct more air into the radiator. Well, I've run with just the factory air dam for 12 years and the car has always run a little hotter on the interstate than around town, so I hoped the spoiler would make it run just as cool on the interstate as it does around town. Instead it had the opposite effect and it pinned the temp gauge, and started pushing coolant out of the overflow bottle's top. I pulled over and called for a tow to get me home rather than risking serious engine damage. Now I've got to figure out why it runs hotter with the full spoiler than just the little air dam. The only thing I can think is the spoiler is pushing air around the car rather than up through the radiator. Anyone had any similar or relateable experience?

Edit: See post 12, I'm now thinking I've got a coincidence because it overheats just idling.

Edit 2: see my final post. It looks like a bad thermostat was to blame.

gkull

The function of the chin spoiler is to keep air from passing under the radiator creating a lower pressure behind the radiator for flow through the radiator

You just need to create the same effect. I made a custom chin spoiler very close to the ground

The Punisher

Picture please

C3 4ME

Yeah, I tried to take a pic last night but it wasn't showing up due to bad lighting in my garage. Will try this afternoon outside of the garage.

MelWff

Look at post #3 in the link below. Are you preventing air from going through those three cutouts in front of the air dam?

https://www.corvetteforum.com/forums...am-wanted.html

jb78L-82

This is the spoiler extension you need for superior cooling:You could probably make your own:>>>>>

C3 4ME

double checking of those cutouts are blocked is one of the very first things I'll do when I get home today.

The Punisher

Nice, what material did you use?

0Willcox Corvette

I make the reproduction of the original here...

It was originally used only on L-82 with a/c and h/d cooling and without the spoiler option. This option also included the trap door fan shroud. Which is not available but can be made out of a existing original shroud.

https://willcoxcorvette.com/corvette...oling-l-82-eng

jb78L-82

I bought mine from a GM dealership in the 80's...about $20...Deal of a lifetime-it is an OEM GM 1979 Spoiler extension..the real deal......My 78 L-82 has heavy duty cooling, A/C but GM did not offer the spoiler extension until 1979 after the heating issues with the L-82's in 1978 with the new body style. The trap door referenced by Willcox and the internal auxilliary electric fan in the bottom of the fan shroud of the 79 L-82's is really not needed if you have the spoiler extension...this item really improves the cooling. My 450 Gross HP rebuilt L-82 can run all day long in 90 degree heat with zero issues on the highway.....

v2racing

I don't believe the Pace Car Spoiler is the cause of your overheating. It mounts behind the air inlets for the radiator and should move more air through there than the stock spoiler. Most people will see better cooling with the Pace Car Spoiler.

I would check over your cooling system good. I'm sure you will find something amiss. Could be many different things or even a combination of things. Stuck thermostat, low coolant level, collapsed lower radiator hose, bad radiator cap, bad water pump, the list goes on.

Mike

C3 4ME

Here's pics as requested. disregard the unpainted nature of the spoiler. It's on for fitment and testing and will come back off to be painted. Now, for the thickened plot. I started the car and let it run on the ramps as you see, and the temp just kept creeping up to the red at an idle, something it's never done before, so now I think I might have a coincidence on my hands that something else is wrong, that just happened to happen when the spoiler was installed because obviously the spoiler should have no effect on the idle temps. I've bought a new thermostat to install tomorrow once it completely cool again. I figured I'd start with the cheapest possibility. I didn't sit in the car the entire time it warmed up, but I didn't see the temp needle drop like it always does when the thermostat opens.

C3 4ME

After today's idle only test, I think you're exactly right. (see my comments above), but the lower radiator has a spring in it, the cap should be good, the water pump is not that old, coolant level is fine now, and nice and green, so therefore, at this point, my money is on the thermostat.

cagotzmann

Well it is not the spoiler. My 78 had the original factory extension only. When I added the pace car spoiler it added additional cooling as expected. I now have dual electric fans with my ZZ383 and on the highway the dual fans never kick in. There is plenty of cooling / air flow to never require the fans to run.

C3 4ME

That's exactly what I was expecting, and I'm now betting you're exactly right.

0Willcox Corvette

How crazy is that... I too, ordered in a new one for my own personal car in the early 80's when we were a chevy dealer.... I actually ordered 2 in for me so I would have one extra.... and that is what we used for the pattern to make the reproduction.

It's funny but about the only way I'd know what the special options were to obtain this spoiler was the fact that it came on my car new. It looked almost like it didn't belong or as if Bubba got hold of the car... but it was indeed a factory installed part, with the generic rivets and all. I just saved it and when we kept getting calls for this item I decided to make it off the original item.

Willcox

jb78L-82

You are the man...Just ordered the nylon Speedo gear for 3.70 ratio 4 speed car from you after the cable came out of the tranny this past weekend and dropped my nylon gear somewhere on the highway..Now you know who I am.. Lol

BTW-personal preference but I always liked the spoiler extension much more than the pace car spoiler package front and rear which I thought looked like someone had an after thought at the last minute and just glued them on the body...never was a fan...to me they look like a poor aftermarket addition. I think the 80-81's with the integrated front and rear spoilers look GREAT, on the other hand!!!...one of my favorite C3 body styles are the 80-81 where they cleaned up the spoiler package and it looks like it belongs on the car

C3 4ME

Well, I think I can put this one to bed. I put a new 195 degree thermostat in and just got back from an hour drive, back roads, interstate, and idling for 5 minutes immediately after getting off the interstate, and the temp pretty much didn't move. It's showing about 200. It's 20 degrees cooler outside tonight than the last drive when I overheated. Now I'm curious as to how it will run on the interstate on a hot day with the A/C on, but I guess I'll have to wait for a hotter day. Thanks for all the replies and suggestions.

BLUE1972

BE sure you have the foam in place on the shroud and radiator. It helps a lot.

mikem350

And make sure to keep the rad/coolant bottle full!