1989 Coolant Routing Simplification

[dunhamr1]

I'm starting to work on assembling my cooling system in my XR project which only came with the two main radiator hoses (to the thermostat housing and the water pump). With a lack of reference available for how the 89 is supposed to be plumbed, even after looking through the shop manual and searching here and turboford, it's been hard to pinpoint where things are supposed to connect without the hoses in front of me.

I pulled as many of the coolant hoses I could off of an 85 that I found in a junkyard, where the rubber wasn't cracked on any of the hoses. I've tried to assemble most of the system the same as the early Merkurs, but connecting the overflow to the radiator.

The only real challenge I see is the backside on the oil copler, coming to the T from the lower intake and back around to the heater core.

This will eliminate the water cooling to the turbo, as well as the hcv.

Here's my horribly-drawn rendition of my ideas on the system, please tear it down and point me in the right direction if I'm astray.

[Matt01]

do you have the expansion tank or not? its really simple on an 89. Im guessing by your sketch that you do. The only place I see an error is that the top (very small) exit on the tank goes to the upper rad hose and not the rad itself. Ill grab a pic later if i can.

[John Brennan]

do you have the expansion tank or not? its really simple on an 89. Im guessing by your sketch that you do. The only place I see an error is that the top (very small) exit on the tank goes to the upper rad hose and not the rad itself. Ill grab a pic later if i can.

Correct, if this is a stock rad/upper rad hose. Is that the case?

It appears you've eliminated the HCV valve. Beyond that, there isn't much more to do unless you want to go to a dry lower intake, and/or an external oil cooler. To do the dry lower, you have to relocate the ECT, the fan switch, and the temp gauge sender.

[my8950]

What is the purpose of running the lower dry, other than keeping the coolant out of it?

[dunhamr1]

do you have the expansion tank or not? its really simple on an 89. Im guessing by your sketch that you do. The only place I see an error is that the top (very small) exit on the tank goes to the upper rad hose and not the rad itself. Ill grab a pic later if i can.

I do have a stock overflow tank, but not the upper hose. I'm going to try and make it work with what I have, and I'm likely going with a different radiator (Saab 900) in the future. Trying to decide whether it would be worth it to get the stock 89 upper. Would it be more of a pain in the butt to tee into a hose or take it from the passenger side metal rail (like the 85-88 system)?

It has an interesting hose attached at the bottom, I'm not sure where the previous owner had plumbed it (Volvo radiator?) but there's a couple fittings on the drivers side of the radiator in addition to the main hose.

[John Brennan]

The Saab 900 radiator will have the right fittings in the right places-- you'll just need to fab a mount for it.

[my8950]

The Saab 900 radiator will have the right fittings in the right places-- you'll just need to fab a mount for it.

what year? Is it smaller than the original radiator for the XR?

[dunhamr1]

The Saab 900 radiator will have the right fittings in the right places-- you'll just need to fab a mount for it.

It'll go in with a Cosworth 2wd intercooler that I plan on using as an upper mount, I'll have to see how that all fits when I get there.

I realize I don't have any hardware for the upper portion of the radiator, the previous owner used straps from the support to drop it lower for whatever intercooler he was using. Is there a grommet that goes on the top?

[John Brennan]

The Saab 900 radiator will have the right fittings in the right places-- you'll just need to fab a mount for it.

It'll go in with a Cosworth 2wd intercooler that I plan on using as an upper mount, I'll have to see how that all fits when I get there.

I realize I don't have any hardware for the upper portion of the radiator, the previous owner used straps from the support to drop it lower for whatever intercooler he was using. Is there a grommet that goes on the top?

Cossie 2WD IC + Saab Rad is a proven, Old-School combo. I don't remember the exact years, but late 80's-early 90's sounds right. Someone correct me (or you can search, I know it's been discussed here a lot) on those years, please. Not sure what you mean by grommet, but you can probably find a grommet from a hardware store that'll work with what you're doing. I had a Saab rad once, but it's been a long time, and I can't recall the upper fittings, if any.

None of this presents any real difficulties as far as making things work. One thing to keep in mind is that the fans from the Turbo 900 models are better than the NA ones. I don't recall if there are any differences in the rads themselves.

You might also want to give a thought to Mike's Rad/IC Combo at Merkur Depot. He's expecting a new batch in a month or so:

http://www.merkur.50megs.com/photo2_1.html

[thesameguy]

Saab radiators came in a bunch of flavors between '79 and '93, but these days I think there is just one replacement, modeled after the 16v turbo and the "best" option anyway. The bottom of the radiator has two pegs which rest in the lower support, the top is a pair of horizontal M8 (IIRC) bolts that fasten to the upper support. There are six holes in the sheet metal "frame" - two bottom, four top - to support the fans, three screws each. There is an equal-sized inlet and outlet plus an overflow/purge fitting in the top left corner. There's a single M22 bung for a common fan switch at the top left and historically a petcock down at the bottom right, though I've heard the latest versions of these radiators don't have a drain. The radiators are adequate for maybe 250hp - I've had a lot of tuned Saabs and I wouldn't ask much more of these radiators.

[dunhamr1]

If I use a Saab radiator, it'll be coming out of a 87 900 turbo (double fan). I believe the motivation that people quote for using those is the lower mounts are the same, the radiator itself is shorter (allowing something like a 2WD cossie IC to be mounted above it), it has double fans, and it allows the relocation of the fan switch out of the lower intake.

Cossie 2WD IC + Saab Rad is a proven, Old-School combo. I don't remember the exact years, but late 80's-early 90's sounds right. Someone correct me (or you can search, I know it's been discussed here a lot) on those years, please. Not sure what you mean by grommet, but you can probably find a grommet from a hardware store that'll work with what you're doing. I had a Saab rad once, but it's been a long time, and I can't recall the upper fittings, if any.

None of this presents any real difficulties as far as making things work. One thing to keep in mind is that the fans from the Turbo 900 models are better than the NA ones. I don't recall if there are any differences in the rads themselves.

You might also want to give a thought to Mike's Rad/IC Combo at Merkur Depot. He's expecting a new batch in a month or so:

http://www.merkur.50megs.com/photo2_1.html

Those Merkur Depot radiators look lovely; I'm just not ready to spend the cash to upgrade just yet. I'd like to have the car on the road and drive it a bit and see if it's going to need a new radiator or what not. The goal right now is to get a working cooling system - at the minimum of cost and effort - but without cutting corners too much. I already have a cossie intercooler in my possession (thanks Jody Cook!) and know where there's a lovely 16V 900 Turbo I can nab the radiator off of.

As for the "grommet" was talking about, I did just mean a rubber bushing or what not. Just to separate the top of the radiator from the support. Does anyone have a photo of the stock setup?

[DAReese]

A cracked head costs more than a radiator. Just sayin'.

I like overkill on my radiator.

[dunhamr1]

A cracked head costs more than a radiator. Just sayin'.

I like overkill on my radiator.

Stock radiator will (hopefully!) be adequate to get the car running and have a basic tune (with lowered boost levels because LA3 + no IC = needs lowered boost until IC install). Intercooler installation will include an upgraded radiator for peace of mind, I do prefer overkill myself. Fall/winter in Michigan will also provide favorable ambient temperatures to stay cool!

I just don't want to go out and buy a bunch of expensive parts and not be able to get the car started and be stuck with them and a non-running car. (speaking of which I think my starter doesn't work...)

[jkxr4ti]

There's a few decent pictures of the details on the Saab radiator in my install post here ::
http://forum.merkurclub.com/forum/viewt ... &hilit=4x4

The top small connection on the Saab radiator is actually on the right side for the 89 Coolant bottle set up.

[dunhamr1]

There's a few decent pictures of the details on the Saab radiator in my install post here ::
http://forum.merkurclub.com/forum/viewt ... &hilit=4x4

The top small connection on the Saab radiator is actually on the right side for the 89 Coolant bottle set up.

Thanks! A few is actually a lot of good pictures, I'll likely come back to this a few times when I get to installing the saab radiator. A great write up, thank you for sharing.