LT5 Cooling and Radiators

[Dynomite]

Originally Posted by secondchance

Frank,

I tried 3 1/8" holes 2 years ago. During the winter coolant temp refused to go above 153 degrees F. I was concerned with inability to boil off water build up in oil. Went to one 1/8" hole and recommended the same to Charlie.

A 1/8 inch hole in the thermostat flange has an area of .0123 square inches compared to an open (or partially open) thermostat (1/4 inch open and say 1.5 inch diameter) of 1.17 square inches.

I am not sure what .0123 square inches adds to the flow rate of an open thermostat? (maybe an increase of 1.18-1.17/1.17 or .85% (less than 1%)

I am also not sure what contribution a .0123 square inch hole creates in terms of flow rate through the radiator when the thermostat is otherwise closed. Or .0369 square inches with three 1/8 inch holes in the thermostat flange.

[secondchance]

Originally Posted by FU

Interesting , 153 degrees F is no good for a winter driver. What degree thermostat did you use to get up to 153 f ?

[FU]

I see 4 of 1/8" holes. What degree theromstat 180f or a stock 195f ?


Thanks for posting a picture of the thermostat.

[secondchance]

Originally Posted by FU

I see 4 of 1/8" holes. What degree theromstat 180f or a stock 195f ?


Thanks for posting a picture of the thermostat.

When I dug up the thermostat I realized I had drilled 4 holes and not 3. I believe this is a 180 degree stat.

[dredgeguy]

Greetings from Lagos, Nigeria.....1 day here and only 9 days left but who is counting. I put in a new 180 Stant in mine as suggested by Marc

[Dynomite]

Originally Posted by secondchance

When I dug up the thermostat I realized I had drilled 4 holes and not 3. I believe this is a 180 degree stat.

So...you always have a bit of flow through the radiator......... say four 1/8 inch holes or .0123 square inch additional opening total. It is amazing that the heater (hot side at the thermostat) is only a 1/4 inch diameter port or about .049 square inches total port area. That is about 4 times what you have with the 1/8 inch holes if you turn your heater on full blast.

The bit of flow you have all the time will run the coolant just a tad cooler so the thermostat will open just a bit later. Then as the thermostat approaches fully open the total flow is just a bit more adding in the .0123 square inches with the 1/8 inch holes (.0123 + 1.17 =1.18 square inches).

I am not seeing exactly what the benefit of the 1/8 inch holes gives you given the total flow area of an open thermostat may be over 1.17 square inches and with your four 1/8 inch holes now 1.18 square inches

I can see the thermostat opening a bit more smoothly having the 1/8 inch holes and not opening and closing as rather cold coolant is mixing with hot coolant as the thermostat initially starts to open

[secondchance]

Cliff,

I understand your calculation and logic. Interestingly, when stock (with Marc's chip), 6th gear cruise (say 70-75) on 80-85 degree day (it's been awhile...) coolant temp would stabilize around 211-213. In 5th gear it would drop to 203-205 probably due to increased coolant flow. With one 1/8" hole coolant temp would maintain, if I remember correct, around 197-198 regardless of 5th or 6th gear - just my experience.
When I dropped in my 380 coolant temp went up a bit across the board. Also, after two blown OEM radiators I opted for non-plastic tank radiator and while at it figured I would try dual core/extra fin area option.

[RICKYRJ1]

Originally Posted by dredgeguy

Greetings from Lagos, Nigeria.....1 day here and only 9 days left but who is counting. I put in a new 180 Stant in mine as suggested by Marc

Hey Charlie, I just got a email from Nigeria stating I won the nigerian lottery and to send money in good faith so I can collect the winnings, also said they are in love with me but need me to send them money so they can come visit me and another will buy my cay sight unseen and pay whatever I want for it just send them the balance of their over payment lol. you could have brought your Z with you to really test out the new radiator be safe brother

[Dynomite]

Originally Posted by secondchance

Cliff,

I understand your calculation and logic. Interestingly, when stock (with Marc's chip), 6th gear cruise (say 70-75) on 80-85 degree day (it's been awhile...) coolant temp would stabilize around 211-213. In 5th gear it would drop to 203-205 probably due to increased coolant flow. With one 1/8" hole coolant temp would maintain, if I remember correct, around 197-198 regardless of 5th or 6th gear - just my experience.
When I dropped in my 380 coolant temp went up a bit across the board. Also, after two blown OEM radiators I opted for non-plastic tank radiator and while at it figured I would try dual core/extra fin area option.

Good Information.......thanks
Blown Radiators is not good.....kinda like the time my new water pump impeller became disconnected from the water pump shaft.

What you find cruising in 6th versus 5th is what I found also which I attributed to higher Coolant Flow Rates in 5th gear as you suggested.

Also your stock radiator (with Marc's chip) coolant temperatures are a bit high (203 to 205 deg F) for an 85 deg F day but NORMAL for a Stock Radiator.

Basically your Coolant Temperature was in the range of your Cooling Fan Operational Limits set by Marc's Chip (ON 205 deg F and OFF 200 Deg F). That is about what I am getting with my Ron Davis on a 90 deg F day. The Coolant temperature stays around 190 deg F and rise to Coolant Termperature Fan Operational Limits when in traffic on a 80 to 90 deg F Day. A 100 deg F + day is a bit hotter Coolant Temperatures

ALL with 180 deg F Thermostat and CLEAN Radiator/Oil Cooler/AC Condenser.

[dredgeguy]

Originally Posted by RICKYRJ1

Hey Charlie, I just got a email from Nigeria stating I won the nigerian lottery and to send money in good faith so I can collect the winnings, also said they are in love with me but need me to send them money so they can come visit me and another will buy my cay sight unseen and pay whatever I want for it just send them the balance of their over payment lol. you could have brought your Z with you to really test out the new radiator be safe brother

Ricky, that's why I am here....to collect my winnings. You mean it is not True?
You should see the roads here, no way could a Z drive here, you need lots of ground clearance. Not much of a test for a radiator, only mid 80's.no humidity and a nice breeze.