ZR1

OK, you guys wanted it so you guys get it. This is hopefully a helpful tutorial on the installation of a new radiator for your ZR-1. Unfortunately, I did not start from the very beginning as I already had the upper shroud off the car so I did not get in a couple hot tips on getting those six (three on each side) lower screws out that hold the upper shroud to the lower bucket. I'm sure you will get them after countless frustrating hours. So, let's get started here.

First you will see that in order to get to those lower sheetmetal screws it is much easier taking some stuff out to get to them. Yeah, it is a pain but worth it. On the driver side here, I have removed the air pump to get easy access to the screws.




OK, the following image really sucks but the camera can't get close enough to get good detail. What I was trying to show were the tinnermans that hold the sheetmetal screws on. These are what grab the threads so you can secure in the screws.





These next two pics, I am attempting to show you how they come from the factory slipped onto the upper shroud. I put some paint there so you can better see how they are attached. On the second picture, you will see the tinnermans on the lower bucket. This is your hot tip for the day. Take the tinnermans off the uppershroud and put them on the bucket. That way, when you reassemble the parts together you can replace the six sheetmetal screws easily coming in from the front air intake and screwing them from there.




Man these images suck.





OK, so lets start on the removal of the old radiator. It is a fairly easy operation.





First you have to pick up the oil cooler and airconditioning pack and mover it out of the way. You can easily do this without having to remove any lines. You only have to move it a bit out of the way and you can have access to the cooling radiator. To remove the radiator remove all the lines going to it and simply lift it out of the bucket.





Here, you can see just how dirty a radiator can get under just normal driving conditions. This radiator probably had 20% of it's cooling capacity restricted.




Next, from under the car remove the fan harness.




There are three screws holding the fan assembly to the lower bucket. Remove those.





And now you can pull the fan assembly out.






Next, remove the lower radiator pads from the bucket. You are going to have to cut these to size to allow the new radiator to fit. It is a fairly easy operation.




Here you can see the difference between one I have cut on and one I didn't.




You may notice I slot the lower pads to allow even more room for the radiator. This keeps it firmly in place as there are "feet" on the radiator for these to fit into.





And you verify your cuts by fitting it on the radiator itself.





The upper radiator pads go on the upper shroud. You will need to cut these back also. Here I have one I have cut and one that is stock.



Next you will need to modify the fan assembly. I remove the fans as it is easier to work with. First, I measure just how much I need to cut off the assembly to make the sides fit flush with the radiator face. This is usually about 3/8ths of an inch. I then mark on the fan assembly the measurement. What I do is to take some duct tape and put it all around where I am going to cut to give me something easily followed. I then make my cuts using a sabre saw and a hack saw. I have tried using a die grinder but the speed is too fast and will melt the plastic. Once I make the cuts I clean up the piece with a hand file and sand paper.









Now, there is one other place you will need to make some cuts, that is in the bucket itself. Remember the lower pads and how we had to cut them down to allow the radiator to fit. We also have to make some cuts to the bucket to reflect these same cuts. I generally use just a cutter blade and a die grinder to rough it in.





All that is left to do is to replace the pads in the bucket, drop the new radiator in, and move the oil cooler and air condidioning pack back over and there you have it, a rdiator install!




[Modified by ZR1, 8:12 AM 10/29/2001]


[Modified by ZR1, 8:16 AM 10/29/2001]

Tyler Townsley

Excellent post as always. Another tip on this job is when you refill the radiator slip a flat blade screwdriver under the hose on the right top hose by the ps pump and fill until you have water comming out. This usually reduces the air purge steps quite a bit.

Tyler

xsmph

Very nice!!, no wonder mine was a Bear to fit. I did not cut the bottom rubber supports at all, and I could not fit the upper supports as a consequence.
Another hard part was to fit the bottom radiator hose (which must be cut) to the thermostat housing....

W i l l

Thank you ZR1 for an excellent "how-to" write-up and pictorial!! We are all very lucky to have you share your helpful hints which make these projects immensely easier.
Forum members, as a show of appreciation, lets all chip in and buy ZR1 some tennis shoes. As we see from the photos, the old ones have gotten soiled from traipsing through the sheep pens in Nepal.

ZR1

Hey! Those are my shop shoes, not my Sunday go to meeting shoes! I have several pairs of them floating around the shop. I will try and get to the other projects (like the coil overs) as soon as I can. With my impending layoff coming who knows, I may be able to do a whole lot more of these.

Hey Julio, getting the lower hose on is a snap when you take off the thermostat housing. I also grind off the little tab on the hose clamps so I can open them more and slide them on easier. I generally "grease" the hoses with some dishwashing liquid to get them over the hose fittings. And yeah, you have to cut those pads down so everything will fit in very nicely. You just have to make sure you leave enough room for the oil cooler. It is also an excellent time to clean out the air conditioner condensor. I use a BBQ grill brush to get the heavy stuff out. It is soft metal and will not damage the cooling fins. Then, blow the fins out using your air compressor.

USAZR1

Ron Kreigh needs to save this procedure so he can install his new Ron Davis radiator. You out there,Ron? :D

Ultra Slow

Nice post! I have had the misfortune of replacing several plastic fantastic radiators in the ZR1's, but have not put a large one in like you did. I think I want to get one and try in in my 90 black car. Where did you get it? Also are you running the 180 stat? Thanks for your efforts.

Rkreigh

this really helps. thanks very much!!!

looks like a real PITA to get at a few things. having the pictures
really helps. nice tip on the air pump.

since I'm going to headers at the same time, is there any need to
put the air pump back??? kinda seems like useless weight to me.

If I remember correctly, the air pump is only for cold start emissions anyway.

I still need to pass VA emissions, but most of the techs have never even seen a ZR1 and probably won't know about the air pump anyway. let me know if you have any advice on header installation & the air pump thing.

thanks again. :D

Zrxmax

1st of all... A big "thanks" for the tutorial... You have without a doubt saved me much time and trouble with your experience...
Just a couple of questions...
Which Ron Davis radiator do I have ? This one has threaded fittings and a heat exhanger attached to it... Where do I find a hose kit to fit it ? I even went to a industrial hose vendor with the ZR-1 and the radiator in hand... they said they could not help me... and reffered me to someone else... Is there a vendor that sells the specific hose kit for this install ?
Thanks again,
Ted
90 ZR-1 # 334
Sun City CA



[Modified by Bigvmaxx, 10:39 PM 10/30/2001]

ZR1

First of all, if you are putting headers on you can ditch the air pump. Of course, if you have to pass emission inspection you will have to install cats which is a pain in the **** for sure. I will be having pics done when I do that. Now some cats do have accomodations for air pump fittings. It is required by law you have this. Now if you can get away with it I wouldn't do it at all as it is only used when the car is cold to cut down pollutants then. Otherwise, it is useless.

As far as what radiator VMAXX has, heck, I've never seen it. Ron Davis made two models for the ZR-1 as far as I know. One he made for Doug Rippie that was more rounded and, just my opinioin, a better piece. It fit in there a lot easier and just seemed to me to be nicer. Since a couple years ago, DRM has been using the one you see in these pics however. This radiator is the one you get when you order from Ron Davis. It is a very nice piece for sure and I like it a lot. I don't think the work involved is that much really and it sure boosts the capacity of the cooling system.

I know that Rick Minson has another radiator in his car that combines the cooling and the oil cooler in the same unit. He then ditched the fan assembly and had a big NASCAR fan put there to pull the air through.