FU

"Supposedly" the later ZR1's had higher RPM cooling fan motor's on them. How much higher would be a guess. Also by going by the AC Delco part number's . It can be said that these "upgraded" cooling motor's and fan's are also replacement's for the later madel LT1's. There aren't any spec's to be found for comparison of these upgrade part's either.

Rkreigh

Rick Minson's car has a single large fan (not sure what brand). I think it's a 16" fan and works very well. why the factory went with two little ones is a bit confusing. I would like to see more of the radiator core with airflow being pulled through it.

another option would be an "add on" pusher fan. not as efficient as a puller, but it seems like an thermostat controlled pusher fan would be EZ to add and help with cooling.

since going to the Ron Davis and the chip revised fan (turn on at 180 both fans), my car never runs much over 200. the factory fans seem to be enough if you have a good radiator, even a clean stocker.

Hib Halverson

The Fluidyne 9-tube oil cooler is also a drop-in modification on the later cars and may require some bracketry changes on the earlier cars. Fluidyne was the OE supplier of oil coolers for 93-95 ZR-1s. The original part Fluidyne prototyped for GM was the 9-tube cooler. To cut costs and save weight, GM came back to Fluidyne and said that, since it was going to synthetic oil for MY93, the engine could sustain a slightly higher oil temp and to make the cooler a 7-tube. Fluidyne hung onto the design and introduced the 9-tube ZR-1 cooler as an aftermarket product.

If you are running a 10W30 or better Red Line oil in your LT5, the optimum oil temperature during severe duty is 225-250 degrees. I don't know what the optimum temp with Mobil 1 is but I suspect it's about the same. In normal driving, the oil temp will be quite a bit below that.

As for the air flow and fan issues also discussed in this thread, the key to more airflow through the cooling stack is not bigger fans---with the later cars don't expect more powerful fans to make much of a difference. The problems are 1) two restrictive heat exchangers ahead of the radiator (the oil cooler and the HVAC) and 2) restriction to air flow exiting the radiator and fans. Cut holes... :lol: .... in the hood and you'll see some better cooling in traffic.

With earlier cars there might be something gained by adding the later fan motors and fans listed by Frank Urbanati.

91mongoose

I've often wondered what would happen if you removed the fan shroud (the one with the fans in it) and replaced the dual fans with one large (15-18") fan wired to a custom harness (2 relays hooked to the original 2 fan power leads so the new fan would come on any time either of the old ones would have). The new fan would be a universal "push pin" type mount. That would remove that restrictive shroud allowing better cooling at speed while at the same time moving more air when the fan is on at idle. I was going to do this when I replaced my radiator but I ran out of $$$. A fringe benefit is you would have nothing to trim to drop a Ron Davis Nascar style radiator in.

Anyone else done this or thought about it?

OldZR-1Guy

After a very unpleasant experience with super hot oil temps at the track my Ron Davis radiator is coming out. In its place will be a special Fluidyne unit made for Kryder Racing. The rad is 4 inches thick with an integrated oil cooler. They use this set-up in a racing ZR-1 and have had no overheating issues; they've also found a way to make it all fit and retain the AC. If all goes well it'll be in by the end of the month. I'll try and get pictures.

USAZR1

A 4" thick radiator? Man,that almost sounds like overkill for a streetcar,Steve. I'm interested in seeing pictures of that set-up.
Clint

xsmph

I think LPE did a "special" trick on Bob's 385 black Zr-1. I think they installed a transformer of some sort to be able to get more current/voltage
to the stock fans to make them run more rpms...

I've never had a overheting problem with my griffin as long as I'm moving.

Now try grid-lock traffic in Ocean Drive (ocean blvd, watching babes), and when it is 90 deg. outside and sunny the Zr-1 will see 230-235 deg. F. after 20-30 min, of iddling in this traffic with the AC OFF!!... that is max... I will not dare to turn the ac on....

My C-5 on the other hand will do 220-225 with AC ON under similar conditions..but is just too slow!!! :D

xsmph

one thing I'd like to add, is that eventhough we see sometimes hotter water temp. in traffic and severe street scenarios, the OIL temp never gets hotter than the coolant temp. At least that is what I've seen.
When I got the 230-235 deg. f of coolant temp , the oil is around 200 or so (less than half mark on the gage). the C-5 on the other hand sees 235 oil temp when the coolant is at 225 in traffic.

The thing is that all that heat rejction pulled through the oil cooler gets re-pulled through the radiator. When a C-5 is using 90 deg. of ambient air to cool the radiator, the ZR-1 is using 100-105 to do the same, as the air has to cool the oil cooler first, and then the radiator. Turn on the AC, and the condenser is now at 115 deg. f...That really heats up the air, which reheats with the oil cooler. By the time it gets to the radiator is too hot to do anything...unless you are moving...

91mongoose

4" thick!!! Holy smokes :eek:

Is that two 1.75" (or about) rows or is it a three row core?

You must run longer sessions at the track than I do. I can't get the temps up with a 20-25 minute session now that I installed the RD.

Rkreigh

what is the part # for the Fluidyne integrated radiator/oil cooler (top of the line). when I called them, they didn't have an "integrated" unit, only a separate radiator, and oil cooler like the factory. I would like to see a high efficiency radiator on the bottom, and the oil cooler up top so the heat from the oil cooler doesn't flow through the radiator core. is this how the fluidyne racing unit is set up???

thx

OldZR-1Guy

I'm not sure how the thing works, but I hope to get a good look at the set-up when I take the car out there in a couple weeks. I'm told it runs so cool that in the winter I may have to block off part of the rad to get oil temps warm enough. We'll see.

Rkreigh

a simple thermostat change back to stock should cure that. but I agree that the "card board" trick is pretty EZ!!! keep me posted. my LPE runs the oil a bit hotter than all my other z's in the 230-245 range. not dangerous, but it does up FAST with every WOT blast and takes too long to come down.

is the 93-95 oil cooler smaller than the early cars due to the switch to Mobil 1???

my 95 runs a ron davis and the oil never gets much over 200. fluidyne mentioned that 220-240 is the best oil temps to keep the water boiled out and sludge free. most Zr1s run the oil in the 190-210 range from what I can tell, and I think that's where the NASCAR guys run the oil at too for best power. not sure.

:confused:

Zrxmax

Hi All
I have a Ron Davis radiator for sale... it is 31" wide, by 19" tall, by 2 & 1/4
thick... If it fits your car, make me an offer... it is clean... it has 2 additional fitting for a heat exchanger ( I believe ) on the lower outlet...
It use to be in one of the Morrision Snake Skinner cars...
I paid $500 for it...
E-bay # 1846259995
Ted
90 ZR-1 # 334
Sun City, CA


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