Airwolfe

iTrader: (1)

Good to know. I guess I will have to bite the bullet and spring for a DeWitts radiator and listen to my wallet scream as all the Eagles flow out of it when I do my RamJet 430 engine clone swap.

TheMagikMan

Honestly, I think that because I was having the issue previously to putting this radiator in, it isn't what caused the problem. I also fully intend to design myself a more professional top mount for the radiator and possibly sell them as well, so it will look better than my quick and dirty little hooks there.

dabomb6608

iTrader: (3)

If your condenser was getting hotter than it should've due to the gaps all around the radiator, it would've been heat soaking the air trying to cool the radiator.

Or, maybe this is a situation of "more isn't better". That radiator is HUGE. Looks like it is a solid 4" thick. That is a whole lot of air resistance to try to pull air through 4" of radiator fins. The fans maybe could work on a factory or two row core radiator but due to the massive radiator you are running they are being taxed beyond their capabilities. Lack of sealing around the radiator certainly isn't helping either, or maybe it is helping...the condenser will only introduce more resistance pulling through its fins. On top of this, that thick radiator pushes everything very close to the accessories on the engine. This could also contribute to air resistance.

Following the cascading effects any/all of the above issues have, the condenser would be running hotter than normal. Which adds even more heat to the radiator. Which only compounds your issue.

I'm not saying it's not a good radiator. I am sure it is well built. But it could be overkill to the point of negatively affecting things.


Think about it. At speed the air dam moves a LOT of air into the underside of the car ahead of the condenser/radiator. More air than most fans could dream of moving. So much air in fact, that the ECM shuts the fans down above certain speeds. With zero ill effects to cooling capability. Your extra thick radiator can really shine and do its job then. But once you cross under that line of reduced extra underside air being forced through, the fans need to be able to compensate by producing airflow as close as possible to that amount.



Edit: I know you had this issue before hand with your old radiator and "new" LS1 fans. But going off your previous statements of "I bought them brand new off RockAuto " and about looking at the "Four Seasons Taurus Fan", that inclines me to think you bought aftermarket branded LS fans as well. Aftermarket replacements aren't always "equal" to OEM fans motors. This is why I am purchasing GM Original vs Aftermarket when I convert to my brushless fan setup.

ULTM8Z

Air will definitely take the path of least resistance. So if it's easier to go around the radiator/condenser, rather than through it, that's what it'll do.

ULTM8Z

The other thing is, does your aluminum shroud have little vents in it on the side facing the engine?

I remember I was helping a friend a long time ago with a cooling issue and we traced it to the shroud having too many of those vents. The fans were pulling air through the vents rather than through the radiator. On a setup like yours with a super thick radiator, that could also be another path of least resistance that's bypassing the radiator.

On LS1 fans, sometimes the shroud has vents too, but they have little flapper doors that are normally closed, but air pressure will push them open when the car is at speed.

ULTM8Z

Just saw this.. very cool. Fellow Mech Eng here. And yes, we do have a tendency to over-think things.

Tom 400 CFI

I wonder if the OP will ever tell us what "too hot" is? "It runs too hot". No number though. It's really hard to comment on the guy's cooling system performance when we really don't even know what that is? Aaron R mentioned that he'd read 210 in some other thread. OP, is that right? What is "too hot", to you?

ULTM8Z

Did you read his opening post?

It's also been discussed that those temperatures are not "overheating". This is a matter of getting predictability in the cooling system.

Frankly I wish more people could post with that level of clarity and detail. Often times you'll get these "HELP!!!" threads where the OP posts a bunch of random statements about what they did, often in one huge run-on sentence with no punctuation, etc, then expecting people are going to decode the gibberish and offer up the silver bullet on what's wrong.

72buickgs

Was the engine flushed?

Tom 400 CFI

At least 3 times. Maybe I'm blind.

EDIT: I AM blind. Just re-read, now eating my Humble Pie. I see 220 gauge//210 IR @t-stat.

Not a problem, but I'm with dabomb, fans aren't doing what they should be.

T.L.

Get a Griffin radiator, single row with 1-1/2 inch tubes.
The more rows a radiator has, the more air must be pushed through it.
I also agree with sealing the sides so that air must go through and not around...

Airwolfe

iTrader: (1)

I doubt he needs another radiator. Awhile back we put what is more or less the same Cold Case radiator in a 1986 Buick Grand National and it doesn't run as hot as I would like it to run. The temps as seen from the CTS input to the ECM displayed on the SCANMASTER-G are 176F with stock fan connected and 186F with it disconnected. The fan on and off points on the chip were mistakenly programmed for a 160F thermostat instead of the 180F thermostat that is in it. I like for the coolant temperature to be hot enough that the synthetic oil temperature is 216 to 226 degrees F to boil off moisture and blow-by gases that get past the rings.

My bone stock 1992 Firebird with LO3/700R4 and 2.73 gears runs 220 to 230 degrees F as shown on the gauge and my Snap-On MT2500 in Road Test Mode and I don't give a seconds thought about it. That is where it was designed by GM to run.

Tom 400 CFI

that the OP doesn't need a different radiator. He's got PLENTY of radiator, it looks like.

Not on the highway, but maybe in traffic.

Water evaporates (out of oil) at temps WELL below 216. In fact, even ice can and does, evaporate. DON'T NEED TO run your coolant at 216 to evaporate water out of the oil.

Airwolfe

iTrader: (1)

The 220 to 230 degrees F was in PARK idling, AC off, hood closed, with outside temps in the mid to upper 80's.

Tom 400 CFI

O.K.

TheMagikMan

@Tom 400 CFI @Airwolfe @ULTM8Z

Finally an update post after having some hotter weather to test. Sealing it off was the silver bullet! Huge thank you to specifically Airwolfe for pointing it out. I will say that after looking at photos of stock cars, they didn't seem to have seals between the rad and the core, so I thought I didn't need them either. So I cut up a foam square I usually use as a knee pad for under dash work and shoved it in between the core support and the rad. Lo and behold, even with AC on and in traffic, Icy cold. 190* was the hottest I saw, which is when my primary fan triggers. I also wired a gauge into my secondary fan though, so that fan now stays on all the time. Which quite frankly, until I rewire it to come on with the AC, is probably how I'm going to keep it. The car is actually super cool on the highway now, with that 'hi flow' thermostat that flows just a little bit of coolant even down all the way at 145, it seems to run around 170 rolling down the highway when it's 85* and sunny outside! AC also blows ICE cold.

Too many people just abandon their posts on these forums without coming back and confirming what worked. I'm going to close the thread now.

P.S. ULTM8Z, I'm a recent graduate and I'm looking for a job. If you have any pull at GM or any aftermarket manufacturers and you can help me out, please shoot me a PM

T.L.

That's great news...

Airwolfe

iTrader: (1)

I went out and looked at my Firebird to see how much gap it had between the core support, AC condenser and radiator before I replied earlier on in this thread.

There are two black rectangular shaped pieces of closed cell foam rubber that are glued to the core support on each side of the AC condenser that touch the AC condenser taking up the gap.

My Firebird is a very late production 1992 model. Hundreds of things are different about my 1992 Firebird compared to a 1991 and earlier Firebird and many things are different even with a 1991.5 Firebird. It's very well possible earlier F-body cars did not have the closed cell foam seals between the core support and AC condenser. The AC condenser and other parts of the AC system are different on my 1992 Firebird than earlier F-body cars.

Airwolfe

iTrader: (1)

How's the car cooling while pulling the grade up the mountain with the AC on?

My only wish is I would have been able to help you out before you were knee deep in time, effort, and money trying to solve your cooling issue. Being a young man that just graduated from college with your degree out looking for your first real well paying job you can use your degree on I imagine like many of us back then sometimes you don't have two nickels to rub together. A lot of the things you spent money on probably could have went to something far more fun to do to the car or just stayed in your wallet. That's life though. We live and learn something new everyday if we doing it right.

At least the fix was easy and cheap.

TheMagikMan

Sticks to under 200 with no issues. I've got a bit in savings, but I'm using some of it on development of a cold air intake that I plan to put up for sale because now my heat 'issues' are down to flowing enough air to feed the big motor while keeping MATs below 195 farenheit! If I can get the MATs down to about 100 degrees, that's a 15% bump in air density and therefore a similar bump in power. A hot air intake like the ebay one I currently have is a little rough around the edges for making power. I'm targeting a sale price of $500 or less to beat out that new $800 Hawks intake while also clearing larger radiators and including support for the inline MAF so people aren't forced to convert to MAP just for cooler air

80schild

iTrader: (5)

oh yeah I had this same issue. I replaced my radiator and all of my a/c components, but the a/c just wasn't as cold as it should be. I started investigating and noticed that HUGE gap above the radiator and condenser. I stuffed that whole cavity full of rubber 3/4 pipe insulation (the kind that's used for refrigerant lines). A/c is ice cold now.