Fluidyne Radiator

[Dynomite]

I was FedXed the Fluidyne Radiator in a matter of hours after purchase from Hib. I am saving the Original Fluidyne Colorful Box as a Souvenir pictured in the Link at the bottom of this Post.

1. Fluidyne Radiator.
A extremely well made ALL Aluminum Radiator.

The Stock Radiator with Plastic End Caps ...................................All Aluminum Fluidyne Radiator
http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite16/09ad53cc-d23f-498d-89e6-efef80eeccd5.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/Dynomite16/4721e142-2c53-4a11-a05c-ba163f40a13d.jpg

2. Removal of the Cowling.
A. Remove Corrugated Air Duct.
B. Remove Air Filter Housing Assembly.
C. To Remove the Cowling first remove all bolts/screws/nuts including the three 7mm on each side lower front of Cowling.
a. There are three 7mm screws on each side lower front of Cowling.
b. There are two 10 mm nuts on Passenger Side Lower Flange of Cowling on frame rail.
c. There is one 10 mm nut on Drivers Side Lower Flange of Cowling on frame rail.
d. There is one 13 mm nut on Passenger Side Lower Flange of Cowling on Frame Rail.
e. There is one 13 mm nut on Drivers Side Lower Flange of Cowling on Frame Rail.
f. There is two 10 mm bolts horizontal on Drivers side just below Coolant Inlet.
g. There are five 10 mm bolts holding the top of the Fan Housing to the Cowling.

D. I also remove the three screws on the bottom of the Fan Housing.
D. Remove the Oil Cooler Hose Adapter by removing the center nut from the Oil Cooler.
E. Unplug Air Sensor Passenger side front lower end of Cowling.
F. Remove sensors on Drivers Side of Cowling.

Now the Hard to Explain Part......
Lift the Cowling up on the drivers side so that is clear of the hood Pivot. With the Drivers Side lifted up high, go to the Passenger Side and lift up by bending the lower tabs of the Cowling so they squeeze by the AC lines. The Cowling should then be free.

3. Modification of Fan Housing and Cowling.
The Thicker Fluidyne Radiator fit under the Cowling without any modifications of the Fan Housing even though it was a thicker Radiator.
The 95' Cowling was cut in several places for removal by someone else so I replaced the 95' Cowling with a 91' Cowling.
The 91' Cowling only has one sensor attached (brass screw holes) and the 95' has three sensors requiring two holes each. I drilled the holes in the 91' Cowling to match the 95' Cowling.

Thickness of Stock compared to Fluidyne Radiator
http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite16/05afb165-e648-432e-b684-248d3ada3627.jpg

4. Fluidyne Radiator Installation.
Stock Radiator Removed .................................................. .......Fluidyne Radiator Installed
http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite16/6ea2df81-9b24-4635-8db3-41868adb183f.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/Dynomite16/0e613149-bf10-4fb8-8b4d-c71b50119e91.jpg
Lift the Cowling up on the drivers side so that is clear of the hood Pivot.
With the Drivers Side lifted up high, go to the Passenger Side and lift up by bending the lower tabs of the Cowling so they squeeze by the AC lines. The Cowling should then be free.

5. Filling with Coolant.
I fill with Coolant/Distilled Water. Then the BIG Secret......
A. I use a vice grips and close off the coolant to the Plastic Overflow under Passenger Headlight.
B. I fill Black Coolant Reservoir in front of passenger side window and when the bubbling stops.....Blow into/pressurize that Reservoir holding pressure for about 10 seconds. More bubbles will come from the top of the radiator hose. I refill with Distilled Water and Blow into/pressurize the Coolant System again. I repeat this maybe three times until no bubbles come back from the top of the Radiator. I then replace the Coolant Reservoir Cap and remove Vice Grips.....and fire up the LT5 keeping a hand on the Injector Housing Coolant Manifolds to assure they get warm within a minute. (That Happens with this method of Coolant Filling 100% of the time).

With this procedure you are pressurizing both sides of the radiator but with each pressurizing cycle more coolant is being pushed into the coolant system and more air is bubbling out from the top of the radiator.

6. The Test ride and Flushing out of remaining air in the Coolant System.
First........A Theory about Thermostats before the Test Ride to flush out any additional air in the Coolant System.
I use 180deg Thermostats in ALL LT5s. A theory I have is that the 165 deg Thermostat will open sooner but once fully open at say 170deg will flow the same as a fully open 180deg Thermostat at say 185deg. No Difference in Cooling after both Thermostats are fully open. The Exception is that on cool days the 165deg Thermostat will keep the engine cooler than at 180deg Thermostat....say 170deg. That is actually too cool and some block air flow through the radiator on those cool days to achieve what a normal 180deg Thermostat would accomplish.

http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite16/fd6ed2fd-56b1-4880-87b6-24dda80b0ae3.jpg

Blocking TB Coolant and Fluidyne Radiator (http://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759179)

[ghlkal]

Nice write up, as usual :-D

I agree with you regarding the thermostat. A 160* is too cool if you are driving it in cold weather.

[XfireZ51]

The motor needs to get to ~ 64C in order for ECM to enter Closed Loop. It needs to be at 80C in order for the LEARN mode to be active. Otherwise the ECM doesn't modify the Long Term Fuel Trim.

[Hog]

The motor needs to get to ~ 64C in order for ECM to enter Closed Loop. It needs to be at 80C in order for the LEARN mode to be active. Otherwise the ECM doesn't modify the Long Term Fuel Trim.
Some conversion for my friends South of the border.
64ºC=147º 80ºC=176ºF

So the 160º would be fine so far as fueling is concerned. With aggressive ECM/PCM calibration in vehicles with better cooling than the C-4 Vettes I swap out my 160ºF therms for stock 195º thermostats for the Winter.

In my trucks a 160º will cause the coolant temp to rise and fall as the thermostat cycles. This doesn't happen with the C-4 due to the lesser cooling capacity effects due to the tight packaging on the C-4. There was a great discussion of this in another thread.

[XfireZ51]

The 160 would be ok if you're running open loop, but if you don't get into LEARN mode, u r really defeating one of the attributes of closed loop.

[Hog]

The 160 would be ok if you're running open loop, but if you don't get into LEARN mode, u r really defeating one of the attributes of closed loop.

Yes of course, it all depends on what the coolant temp is. I wasn't suggesting you run coolant temps that would be under the enable minimums. I was guessing that in the C-4 Vette cooling system packaging that a 160º therm would allow for ECT's above the LT5 enable points. But I don't have that data.

I'm assuming that in the LT5 calibrations that the Enable points for fuel trimming are NOT adjustable?

[A26B]

I don't think such data would exist as hard points for a 160F thermostat that would be relative to anything more than one specific test. Actual coolant temps will be affected more by engine rpm (pump curve & bypass valve), cooling system thermal transfer efficiency and ambient temperatures, than the thermostat.

The only given for the 160F thermostat would be that coolant temps would be above 160F, just as you stated.

Setting up the calibration for an open loop tune with 160F coolant temp could be done, but to what end? The conditions that would have to be present, cold ambient air (WAG~<45F), would restrict use to winter conditions. Besides, how will it affect combustion efficiency? How will it affect the tight clearances already built into the LT5 for 19F higher operating temperatures. Dropping to 160F is going to make them incrementally tighter.

So, for more real conditions of operation, wouldn't it be back to the open/closed loop system? If so, the range of coolant temperature begins at 176F on the low side and 195F on the high side with optimum cooling. How much performance gain will occur from only a 19F differential?

I think there is significantly more gain to be realized from cooler intake air temperature than 19F coolant temp.

In summary, the 160F thermostat makes for a good topic of conversation, but little else.

A more tangible topic would be discussion of the coolant flow restriction of the thermostat, relative to the rest of the cooling system, and how drilling 1~4 0.125" holes in the thermostat flange can result in significant results.

[XfireZ51]

You can change the enabling of Closed Loop, but I was referring to the LEARN FUNCTION where the ECM is using the short term fuel trim and modifying the Long Term trim based on it. Without LEARN, it won't modify or optimize the fuel
Tables. It will basically be chasing the optimum as opposed to having it stored.
I have not found a parameter that enables LEARN at anything
other than above 80C and below I think 114C.

[tpepmeie]

I have not found a parameter that enables LEARN at anything
other than above 80C and below I think 114C.

This is editable in the calibration. I've done it. But why? You really want the coolant temp at 177* (80C) or above, unless you are looking for max power on the dyno.

Jerry said it, all the 160F talk is interesting, but not terribly relevant. I want my LT5 running >180F and <200F on the street. I think you'll find most other tuners do also.

[Hib Halverson]

This is an intriguing conversation for someone who's only experience with calibration is with MY96 and later and that's because I lack all the special stuff you need to burn and erase those EPROMS in pre-96 cal chips.

It's interesting to read about how cal work was done back in ancient times.:) Thanks for posting that stuff "XfireZ51".

Today, most cals after late 90s have a parameter you can change which sets the ECT at which LTFT enables.

I fool with that all the time when I'm building "test" cals I use for running on the VE tables only or on the MAF only and without any fuel trim to skew the lamda number I get from my WBO2.

If the LT5 ECM won't enable LTFT until 80C or higher, with the 170° 'stat I had in Barney when I owned it, coolant temp would sit about 175-180 a lot of the time. I could see that kind of sustained temp because I was running straight water and a Fluidyne radiator. With a stock radiator, even with the 170 'stat, I seldom would see ECT that low.

I guess my LTFT was working sometimes and other times not.

[Hib Halverson]

(snip)
A more tangible topic would be discussion of the coolant flow restriction of the thermostat, relative to the rest of the cooling system, and how drilling 1~4 0.125" holes in the thermostat flange can result in significant results.

And a still more tangible topic would be what happens when you run an all-aluminum radiator (Fluidyne, DeWitts, Ron Davis, etc), bump the system pressure up to about 20 psi then either plug or greatly restrict the coolant bypass.

In fact, now that ole "Dynomite" bought my last Fluidyne, that's a great subject for him to test....right....Cliff? Cliff...are you there? Cliff...

[Hog]

I don't think such data would exist as hard points for a 160F thermostat that would be relative to anything more than one specific test. Actual coolant temps will be affected more by engine rpm (pump curve & bypass valve), cooling system thermal transfer efficiency and ambient temperatures, than the thermostat.

The only given for the 160F thermostat would be that coolant temps would be above 160F, just as you stated.

Setting up the calibration for an open loop tune with 160F coolant temp could be done, but to what end? The conditions that would have to be present, cold ambient air (WAG~<45F), would restrict use to winter conditions. Besides, how will it affect combustion efficiency? How will it affect the tight clearances already built into the LT5 for 19F higher operating temperatures. Dropping to 160F is going to make them incrementally tighter.

So, for more real conditions of operation, wouldn't it be back to the open/closed loop system? If so, the range of coolant temperature begins at 176F on the low side and 195F on the high side with optimum cooling. How much performance gain will occur from only a 19F differential?

I think there is significantly more gain to be realized from cooler intake air temperature than 19F coolant temp.

In summary, the 160F thermostat makes for a good topic of conversation, but little else.

A more tangible topic would be discussion of the coolant flow restriction of the thermostat, relative to the rest of the cooling system, and how drilling 1~4 0.125" holes in the thermostat flange can result in significant results.
No one here is suggesting setting up a 160º open loop tune, or any coolant temp below any of the stock Closed Loop and Block Learn Temps.
Rather than seeing a straight up power increases from lower ECT's alone, I was thinking more towards the detonation resistance it may provide, but that is a moot point considering the excellent detonation resistance the LT5 head provides. I know this was a trick in some of the aftermarket calibration kits offered for the LT1.

Just enjoying the conversation.

Nice to know that these parameters are adjustable in the OBD1 calibrations as well.

Those extra 1-4 holes in the thermostat would lengthen engine coolant warmup times, I would guess. But if they help overall cooling, that might be a good alternative for some.

[XfireZ51]

This is editable in the calibration. I've done it. But why? You really want the coolant temp at 177* (80C) or above, unless you are looking for max power on the dyno.

Jerry said it, all the 160F talk is interesting, but not terribly relevant. I want my LT5 running >180F and <200F on the street. I think you'll find most other tuners do also.

As you say Todd, why do it. If desired, just run Open Loop. No doubt the 80C has its influence on emissions and provides enough heat into the motor to encourage fuel vaporization as it enters the chamber.
So the range of 80C to ~114(check me on that Todd) is the optimum CTS range for the ECM to LEARN and modify the base VE Tables through the process of the
INT(STFT) leading to the BLM(LTFT).

P.S. 114 is too high. I think it's more like 104C..

[Dynomite]

And a still more tangible topic would be what happens when you run an all-aluminum radiator (Fluidyne, DeWitts, Ron Davis, etc), bump the system pressure up to about 20 psi then either plug or greatly restrict the coolant bypass.

In fact, now that ole "Dynomite" bought my last Fluidyne, that's a great subject for him to test....right....Cliff? Cliff...are you there? Cliff...

I am planting corn before it rains on Sun.....:p

My BIGGER issue was a Thermostat that was restrictive and started to open at 195 deg. And the Old Radiator it turns out had leaks on the plastic ends. Fluidyne is a very nice radiator and did not require shaving the internal fan shroud baffles. (The existing baffles were about 1/8 from touching the thicker Fluidyne.

I installed New Thermostat and also installed Jerry's New Heater Nipple when I had the thermostat housing removed (DO NOT ASK) :D

Anyway.....I did a run 87 deg ambient and temperature rose to 188 deg on Coolant System.....with a Fluidyne. That AIN'T BAD given before the Fluidyne and Thermostat temps rose to 213 deg on a 80 deg day.