Radiator working too well!

[secondchance]

Last summer when I flushed the radiator I bought a new 180* Stanton stat and drilled 4 1/8" holes on the flange and installed it. Combination of modified stat and Marc's chip kept the water temp between 180 to 195 or so during the summer months unless I was stuck in a heavy traffic at which point I might see 213 or so.
Well, today around DC temp dropped to 28-30*F and driving in 5th gear around 50-70 mph water temp stabilized at around 154 and oil temp was at 163 to 165.
Anyone see any issue with running the car at such low temp? I imagine she may be running in an open loop mode.
I removed both cats, EGR programmed off and air injection disabled.
BTW car runs incredibly strong and silky smooth.

[sammy]

hate to say it but you drilled too many holes in the thermostat. i found out the hard way also. i ended up drilling 2/-3/32 in hole 180 degrees apart and the car now runs 180-184 on the freeway. which is where i personally like it to run . for me 160 degrees is too cold

[secondchance]

I hate to admit it but I think so too. May I ask 180-184 at what kind of ambient temp? How about in stop and go traffic?

[Hib Halverson]

Mine runs 170-180 on the highway and I have no holes at all in my thermostat.

What's up with that?

[secondchance]

Originally Posted by Hib Halverson

Mine runs 170-180 on the highway and I have no holes at all in my thermostat.

What's up with that?

Factory rad? 180 stat?
Even with a brand new radiator lowest I have seen on highway was 197* on a cold day. 5th gear 65 mph in summer wasabout 203 and in the 6th was about 213.

[Hib Halverson]

Originally Posted by secondchance

Factory rad? 180 stat?
Even with a brand new radiator lowest I have seen on highway was 197* on a cold day. 5th gear 65 mph in summer wasabout 203 and in the 6th was about 213.

I have a Fluidyne radiator and a 170 'stat. I think I got the 'stat from AO Engineering, but that was a long time ago and I can't remember for sure. I've also used the Stant 180...great product.

Fluidyne no longer makes the 90-96 C4 radiator, but back when they did (98-04), I was involved with the development and validation of the product back in the 96-97 period. We did hot weather testing in the Palm Springs CA area. Back then, Jim Van Dorn's "Automasters" was in nearby Palm Desert and we used his shop as a base during the testing...mainly because he was air conditioned and had cold beer.

Nowadays, Van Dorn is a cranky old bastard who lives in Bowling Green with a Beagle. But, I digress....

I don't drill thermostats. Waste of time.

I was cracking a joke in asking the question.

In theory, drilling little holes in 'stats, might change the flow through the coolant bypass, but in practice, ie: getting a significant reduction in ECT during long periods of WOT, the idea is BS. The amount of flow through those tiny holes compared to the flow though the much larger bypass makes the holes a minor influence in a practical sense.

I think the only way to gain a significant improvement in sustained WOT ECT is to restrict or block the coolant bypass and to do that, you have to raise the system working pressure to the point that the OE radiators, some OE-replacement hoses and some hose clamps would fail.

To restrict or block the bypass, you first need to have a system that will be reliable at 20-25 lbs pressure. Then you have to have an aftermarket radiator which is reliable at a higher pressure and you have to have a way to upgrade hose retention such that its reliable at the higher pressure. Older engines may also have issues with head gasket sealing between water passages cylinders at 20-25 psi.

That pressure level in transient spikes might even be higher, too. Back when Fluidyne was still building it's radiator for late C4, after we brought the product to market, I started a test program to investigate restricting or plugging the LT5's coolant bypass. I installed a coolant pressure gauge in the system and had some Delrin restrictors and plugs made for the bypass. The Fluidyne guys were confident, based on their building NASCAR Cup radiators, that the radiator would handle the pressure. It was the hoses and clamps we were wrestling with when I pulled the plug on the project due to lack of my time and Fluidyne budget cuts. At the time, I'd settled on a 24 psi radiator cap and restricting the bypass to approximately half its original flow as a first step.

[secondchance]

Originally Posted by Hib Halverson

I have a Fluidyne radiator and a 170 'stat. I think I got the 'stat from AO Engineering, but that was a long time ago and I can't remember for sure. I've also used the Stant 180...great product.

Fluidyne no longer makes the 90-96 C4 radiator, but back when they did (98-04), I was involved with the development and validation of the product back in the 96-97 period. We did hot weather testing in the Palm Springs CA area. Back then, Jim Van Dorn's "Automasters" was in nearby Palm Desert and we used his shop as a base during the testing...mainly because he was air conditioned and had cold beer.

Nowadays, Van Dorn is a cranky old bastard who lives in Bowling Green with a Beagle. But, I digress....

I don't drill thermostats. Waste of time.

I was cracking a joke in asking the question.

In theory, drilling little holes in 'stats, might change the flow through the coolant bypass, but in practice, ie: getting a significant reduction in ECT during long periods of WOT, the idea is BS. The amount of flow through those tiny holes compared to the flow though the much larger bypass makes the holes a minor influence in a practical sense.

I think the only way to gain a significant improvement in sustained WOT ECT is to restrict or block the coolant bypass and to do that, you have to raise the system working pressure to the point that the OE radiators, some OE-replacement hoses and some hose clamps would fail.

To restrict or block the bypass, you first need to have a system that will be reliable at 20-25 lbs pressure. Then you have to have an aftermarket radiator which is reliable at a higher pressure and you have to have a way to upgrade hose retention such that its reliable at the higher pressure. Older engines may also have issues with head gasket sealing between water passages cylinders at 20-25 psi.

That pressure level might even be higher, too. Back when Fluidyne was still building it's radiator for late C4, after we brought the product to market, I started a test program to investigate restricting or plugging the bypass. I installed a coolant pressure gauge in the system and had some Delrin restrictors and plugs made for the bypass. The Fluidyne guys were confident, based on their building NASCAR Cup radiators, that the radiator would handle the pressure. It was the hoses and clamps we were wrestling with when I pulled the plug on the project due to lack of my time and Fluidyne budget cuts. At the time, I'd settled on a 27 psi radiator cap and restricting the bypass to approximately half its original flow as a first step.

Great info! Back in 2001 I had a 160* stat installed and we, myself and the mechanic, had no clue of bypass on the factory stat. Needless to say, resulted factory radiator bolwn out - learned the hard way.

[Kb7tif]

Oil cooler is playing a part

[secondchance]

Well, I got another Stant 180* stat and this time drilled just one 1/8" hole and replaced it last Sunday. After being spoiled by Jim's and Rich's garage (hydraulic lift and full compliment of tools), doing this w/ factory tire jack in a condo parking garage was a torture.
Finally took the car out this moring and in 40* ambient temp, at steady state cruise she is running at 184* coolant and 165-170 oil temp. In stop and go traffic about 188-195* coolant and 165-174* oil temp. Sitting and idling fan turned on at 205 (Marc's chip) and broght it down to 198* and oil temp was around 185*.
In summary, coolant and oil temp in general was about 12-15* lower compared to before - I like it!

[2ZR1S]

Originally Posted by Hib Halverson

I have a Fluidyne radiator and a 170 'stat. I think I got the 'stat from AO Engineering, but that was a long time ago and I can't remember for sure. I've also used the Stant 180...great product.

Fluidyne no longer makes the 90-96 C4 radiator, but back when they did (98-04), I was involved with the development and validation of the product back in the 96-97 period. We did hot weather testing in the Palm Springs CA area. Back then, Jim Van Dorn's "Automasters" was in nearby Palm Desert and we used his shop as a base during the testing...mainly because he was air conditioned and had cold beer.

Nowadays, Van Dorn is a cranky old bastard who lives in Bowling Green with a Beagle. But, I digress....

I don't drill thermostats. Waste of time.

I was cracking a joke in asking the question.

In theory, drilling little holes in 'stats, might change the flow through the coolant bypass, but in practice, ie: getting a significant reduction in ECT during long periods of WOT, the idea is BS. The amount of flow through those tiny holes compared to the flow though the much larger bypass makes the holes a minor influence in a practical sense.

I think the only way to gain a significant improvement in sustained WOT ECT is to restrict or block the coolant bypass and to do that, you have to raise the system working pressure to the point that the OE radiators, some OE-replacement hoses and some hose clamps would fail.

To restrict or block the bypass, you first need to have a system that will be reliable at 20-25 lbs pressure. Then you have to have an aftermarket radiator which is reliable at a higher pressure and you have to have a way to upgrade hose retention such that its reliable at the higher pressure. Older engines may also have issues with head gasket sealing between water passages cylinders at 20-25 psi.

That pressure level in transient spikes might even be higher, too. Back when Fluidyne was still building it's radiator for late C4, after we brought the product to market, I started a test program to investigate restricting or plugging the LT5's coolant bypass. I installed a coolant pressure gauge in the system and had some Delrin restrictors and plugs made for the bypass. The Fluidyne guys were confident, based on their building NASCAR Cup radiators, that the radiator would handle the pressure. It was the hoses and clamps we were wrestling with when I pulled the plug on the project due to lack of my time and Fluidyne budget cuts. At the time, I'd settled on a 27 psi radiator cap and restricting the bypass to approximately half its original flow as a first step.

I bought one of those fancy 160 deg stats and destroyed a stock radiator and a Fluidyne. It swelled in the middle and would not cool properly.