Fluidyne Radiator for Automatics

[1991ZR1]

I just bought a Fluidyne radiator. The order was for a radiator for manual transmission but they sent a radiator for automatic transmission. Does anybody know if this will fit without any problems? Any information will be appreciated.

[QB93Z]

I do not know if the Fluidyne radiator will fit properly in a ZR-1, but I just replaced the radiator in my Red 1990 ZR-1 and I can offer some insight.


First, the Fluidyne radiator with the auto transmission cooler is probably identical to the radiator for manual transmission cars except it has the trans cooler added to the right end tank.

The auto trans cooler connections are NOT visible at all when the radiator is installed in the car.

Here is a picture of the DeWitts radiator I installed so you can see the difference in a radiator without the auto trans cooler.



Are you planning to install the radiator yourself? If so, I just did it and I can offer advice if you want it.

Jim

[Aurora40]

I believe some of the cooling area will be replaced with the trans fluid cooler, so you may want to return it and get the right one.

Generally speaking they should fit the same, the only GM one now available has an A/T cooler on it yet people put them on their Z's no problem.

[QB93Z]

Originally Posted by Aurora40

I believe some of the cooling area will be replaced with the trans fluid cooler, so you may want to return it and get the right one.

Generally speaking they should fit the same, the only GM one now available has an A/T cooler on it yet people put them on their Z's no problem.

Bob, In the OEM version, the Auto trans cooler does not reduce the engine coolant tubes and fins area, but it puts a "cooler" in the right end tank that MAY reduce coolant flow by causing a restriction. But, that is the way Chevy designed it, and I guess they knew better than I do.

My observation is: for just about every C4 Corvette that has cooling problems and > 50,000 miles, the radiator fins will be clogged with debris and any replacement radiator will GREATLY improve engine cooling.

Jim

[GOLDCYLON]

I installed a GM replacement radiator this year and as pictured that was setup the same way for both both auto and MTs. It will fit fine from the picture you posted, just the AT lines are not used. The cooling will not be affected and as stated you should not have any cooling issues for years to come.

A friendly word of advise the lower rad hose is at an extreme angle that if your switching to Samco hoses at this time the only way to connect the lower radiator hose is to remove the top of the thermostat housing cover, secure the hose to the radiator and then to the thermostat hosing and bolt it back together. Trust me on this one. Good luck GC

[1991ZR1]

I plan to do this replacement myself so I hope I don't run into problems.
I already have Samco hoses and I believe someone mentioned in the past removing the thermostat housing. The main thing I'm hoping is that I won't have to disconnect any airconditioning hoses.

[Jerry#397]

Last year I installed a Ron Davis Rad. The drain is a alum plug. I called Ron Davis Rad and they said not to use Brass, SS or any metal drain valve other than Alum. which I can't find so I use the alum. drain plug. Your picture shows a brass drain valve, you might want to check on the use of Brass and alum.

Thanks,
Jerry

[QB93Z]

Originally Posted by 1991ZR1

I plan to do this replacement myself so I hope I don't run into problems.
I already have Samco hoses and I believe someone mentioned in the past removing the thermostat housing. The main thing I'm hoping is that I won't have to disconnect any airconditioning hoses.

You absolutely do not have to remove the AC lines. Disconnect all the fasteners. There are three screws on each side of the shroud low and forward that are hard to get to. Be patient, they will come out.

Then lift the left (driver's side) of the shroud first.

The hang up will be on the right side, under the oil cooler and AC lines. It is hard to do the first time, but the shroud is very flexible. The right corner of the shroud will flex enough to get it out from under those lines. It takes some force, but it will come out. I did it this week and I got it out and back in.

Once you have the shroud out, you may want to remove the fans. It is only three more screws and two wire connectors. It will make changing the hoses easier. Put the fans back in before the shroud.

Good luck.

PM me and I will give you my phone number if you need a friend to call.

Jim

[1991ZR1]

After a delay, I'm working on the radiator again. When I dropped in the first radiator that I got, the inlet pipe on the driver's side was almost against the fan shroud. I took a picture to the shop that got the radiator for me and they emailed it to Fluidyne. Fluidyne sent a new radiator, this time for manual transmission and there is more clearace.

The advice on cutting the shroud and removing the thermostat housing was a big help. It also helps to follow all the instructions in the service manual. Putting a little silicone grease on the rubber top mounts also helps.

Right now I''m having a problem on the driver's side. I think it's because the mounting tabs on the top of the radiator are a little over 1/8" farther apart than the stock radiator mounting tabs. I may trim the rubber to fit if I don't find any other hang ups. Getting the inlet hose on is also going to be a problem. The pipe looks like it's the same size as the stock radiator but they flared the end a little. I don't know why they did that. There is a little bulge just before the end of the pipe that should give a tight fit. If I can't get the hose on, I may have to cut a little of the flare off or bend it in a little.

By the way, using gloves to protect your hands really helps. I couldn't find mechanic's gloves that were small enough so I got golfing gloves.

[QB93Z]

Originally Posted by 1991ZR1

After a delay, I'm working on the radiator again. When I dropped in the first radiator that I got, the inlet pipe on the driver's side was almost against the fan shroud. I took a picture to the shop that got the radiator for me and they emailed it to Fluidyne. Fluidyne sent a new radiator, this time for manual transmission and there is more clearace.

The advice on cutting the shroud and removing the thermostat housing was a big help. It also helps to follow all the instructions in the service manual. Putting a little silicone grease on the rubber top mounts also helps.

Right now I''m having a problem on the driver's side. I think it's because the mounting tabs on the top of the radiator are a little over 1/8" farther apart than the stock radiator mounting tabs. I may trim the rubber to fit if I don't find any other hang ups. Getting the inlet hose on is also going to be a problem. The pipe looks like it's the same size as the stock radiator but they flared the end a little. I don't know why they did that. There is a little bulge just before the end of the pipe that should give a tight fit. If I can't get the hose on, I may have to cut a little of the flare off or bend it in a little.

By the way, using gloves to protect your hands really helps. I couldn't find mechanic's gloves that were small enough so I got golfing gloves.

When I put the Samco hose on the inlet pipe (driver's side) it took two people. I greased the inside of the hose and then started at the bottem of the pipe. Once I got it streched as far as I could, my assistant used a tool shaped like an "L" to pull the top edge of the hose up over the lip of the inlet pipe. After the hose was around the pipe it took a lot of force to get it push all the way on the pipe.

I recommend against trimming the inlet pipe. You need that lip to keep the hose in place when clamped.

The Samco hoses are a little stretchy. Just keep working at it and you will get it.

Concerning the fit of the DeWitts C4 replacement radiator, the core of the radiator is a lot thicker than the OEM radiator (it is double tube). There are two issues this creates:

1. The bottom rubber mounting blocks have to be trimmed about 1/8 inch.

2. Since the radiator core is thicker than stock, the fan housing will not fit properly against the back of the radiator. In the past, the fan housing had to be trimmed 1/8 inch on ALL of the front edges. Now, DeWitts includes two aluminum spacers that are installed between the fan housing and the radiator shroud. This moves the fan housing further away from the radiator core and gives proper clearance.



In this picture, the radiator shroud is on the left, the fan housing is on the right (with yellow stickers) and the new spacer is the silver piece between them.

This "solution" to the fit problem works OK but is certainly not very original looking. I will paint the spacer black if it bothers me too much in the future.

Jim