Radiator options

[Karl]

Been looking at Porsche 928's (not to purchase) and they all have pusher fans in front.

Looks like that is the key to a cool engine with the a/c on stuck in traffic.

https://www.google.com/search?q=pors...ml%3B480%3B360

[rkreigh]

my temps creep up a bit with the ac on in traffic

the ron davis helps "recover quicker" once moving but to me the stock fans just aren't strong enough to pull the cfm required in stop and go

I'm curious why Hib you don't think more fan flow will help?

I like the fluidyne core with the heavy duty oil cooler

it seems more logical than "stacking" the components and the core is more efficient and a bit thinner so the fans aren't over stressed trying to pull air through the really thick cooling stack which I believe is the problem

I got dewitts fans setup which looks nice, when summer arrives I'll let you know if it helps!

[Pete]

Some early C4's had a pusher fan from the factory.

Freaken bean counters.

Pete

[Hib Halverson]

Originally Posted by rkreigh

(snip)
I'm curious why Hib you don't think more fan flow will help?
(snip)

If the cooling system is working properly and you've got the right combination of coolant, thermostat, fan-on cal and radiator, in my experience, ECT, even with the A/C on is not an issue.

Well...unless your goal is to have ECT below 210 or so with the AC on. If you feel the need for that then you have to look at additional modifications such as an even bigger radiator and, well...maybe more air flow.

So, in theory, sure more flow from the fans might further cool the engine but I'm really only interested in what's necessary rather than what's possible.

That said, if you were going to go for more air flow, you'd have to upgrade the electric fan electrical to support fan motors which draw more current.

Lastly, I didn't know Fluidyne now made a radiator with an EOC built in. If that's the case, I agree, it makes more sense.

[Dynomite]

Originally Posted by rkreigh

my temps creep up a bit with the ac on in traffic

the ron davis helps "recover quicker" once moving but to me the stock fans just aren't strong enough to pull the cfm required in stop and go

I got dewitts fans setup which looks nice, when summer arrives I'll let you know if it helps!

It is Ambient Temperatures of 100+ deg F that cause the LT5 Hot issues. It becomes obvious to me that Air Flow is the culprit in that once the ZR-1 is moving at say 20-30 mph the Coolant temperatures quickly get back in the 200 - 210 deg F range. The LT5 engine is rapidly cooled from 215+ deg F (higher if I did not turn off AC) with the ZR-1 not moving on 100+ deg F days once the Dynamic Air Flow is created by moving forward at 20-30 mph.

So the additional Air Flow required to do that (keep the engine in the 200 deg F - 210 deg F Range on a 100+ deg F day) is obviously that Air Flow hitting the front of the ZR-1 at 20-30 mph. I am thinking one can get higher pressurized Air Flow with a Pusher Fan within say 1/4 inch of the front of the ZR-1 Cooling Stack pushing Air through that stack.

1. The First Trick then since we can assume the Tony Davila Pusher Fan Solution works is to refine that solution such that the fix for a temporary LT5 HOT situation on a HOT day does not interfere with the normal Cooling of the ZR-1 Cooling Stack using only Stock Fans.

2. The Second Trick would be to operate that Pusher Fan(s) only when in stop and go traffic on a HOT day using a simplified Relay that can be activate remotely. The Relay wired directly from the battery to the Push Fan. No Modifications to ANY existing Electrical wiring or Electronics.
This would make for a very simple and inexpensive Solution to an otherwise complicated problem

12V 15A Relay Remote Control Kit DC Connector 15 amp Heavy Duty

3. The third Trick is to identify and control how much Air (using Stock Dual Fans or Stock Dual Fans with an Auxiliary Pusher Fan) Passes Through the AC Condenser, Oil Cooler, and Radiator rather than go around (through the gap) between the AC Condenser and Oil Cooler.....and through the gap between the Oil Cooler and Radiator. When you turn off the AC, The AC Condenser is not heating up the air passing through. The Oil Cooler is contributing (Oil Temperature Thermostat-Open-203 degree F, Fully open-266 degree F). Engine Lubrication System Functional Discussion

4. Or......install higher flow rate Puller Dual Fans replacing the Stock Puller Fans. But then we have a situation where we are pulling more air 99+% of the time when we do not have to.

See LT5 Engine Cooling Issues on Hot Days

[Karl]

So I went with the Fluidyne and installed a 13" spall pusher fan rated at 1360 cfm in front that I will wire up later to a separate on/off switch for extreme hot weather conditions.

The three row looked easy enough to install but I was not able to guarantee a snug and tight fit without removing the a/c condenser and oil cooler to check clearances. Cutting the lower mounts would have been easy enough using a micro dremel. All my a/c stuff is new and I don't want to touch it so I had to change plans.

The swap was pretty easy after taking my time and using a 7mm ratchet wrench to help get the job done.

Anyway I have a question for the Fluidyne what size is this fitting?

It's not a 1/8" so I am guessing 6mm or such? I am going to call Fluidyne tomorrow but thought I would ask here.



This is the line that goes from the fill tank to the radiator. The factory radiator has a male connector the hose slides over.

Guess the Fluidyne is not a direct fit after all...

[XfireZ51]

Karl,

Pretty sure I used a pipe fitting. Had to slip the hose over it. Pete should be able to answer your question. He did for me, I just can't recall the spec right now.

[Hib Halverson]

Originally Posted by rkreigh

(snip)

I'm curious why Hib you don't think more fan flow will help?

(snip)

Well...all I can say is my ZR1, at the 500-hp level cools fine...even in traffic in Palm Springs in the summer. The one thing I haven't done is continuous lapping at a track day in the summer. It's possible that a lot of high rpm in hot weather might have the coolant bypass a problem.

Beyond that, now that I've read some more of this thread, the argument about fans seems pointless.

Pushers, pullers...if people don't think there's enough airflow, add both!

[WVZR-1]

Originally Posted by Karl

So I went with the Fluidyne and installed a 13" spall pusher fan rated at 1360 cfm in front that I will wire up later to a separate on/off switch for extreme hot weather conditions.

The three row looked easy enough to install but I was not able to guarantee a snug and tight fit without removing the a/c condenser and oil cooler to check clearances. Cutting the lower mounts would have been easy enough using a micro dremel. All my a/c stuff is new and I don't want to touch it so I had to change plans.

The swap was pretty easy after taking my time and using a 7mm ratchet wrench to help get the job done.

Anyway I have a question for the Fluidyne what size is this fitting?

It's not a 1/4" so I am guessing 6mm or such? I am going to call Fluidyne tomorrow but thought I would ask here.



This is the line that goes from the fill tank to the radiator. The factory radiator has a male connector the hose slides over.

Guess the Fluidyne is not a direct fit after all...

I would think that fitting size is 1/8NPT which is 27 TPI. I wouldn't think they would mix a metric spec into a product where ANSI specs have been used for so many years. First hand knowledge -NO but it would be my first choice to try. It is a tapered spec so you can expect a friction tightening at maybe 6 - 8 threads. I believe a total of likely 10 threads on the appropriate fitting.

[Karl]

Typo, I have a 1/8" npt fitting and it is the wrong size.