'89 R3500 Crew Cab 2wd to 4wd conversion & beyond

[mrk5]

Yeah, I noticed there were captive nuts for a bracket that would go over the top of the core support. I think that was the way the radiator in the General was mounted. I remember it seeming to be taller.

I took the truck for test drive in the heat of the day. With a 195° thermostat it never went above about 200° or 205° until I stopped for stop lights and even then it was holding about 210° without the shroud.

However I did discover a couple of leaks around the thermostat housing. It has an unused port with a plug and I didn't get the plug tight enough. I never do on things like that because I'm always worried about stripping them out. It also looked like I didn't have the hose clamp tight enough. Really have to crank down on them with those universal hoses because the rubber is not as soft as the factory hoses.

Oh and another thing I should mention I didn't think about when I bought the radiator. This truck had the heater core returning back to the cool side of the radiator. I didn't realize that because the General was off the water pump. The Griffin didn't have a port since I ordered the "-X" model. Luckily I was able to tap off the water pump like the old truck was. Thought I would mention it in case someone else was looking at radiators they might remember to check that.

 

[mrk5]

Windstar fans are rather inexpensive

They are my vote

A seven blade fan would help too.

I had Windstar's on the General but one fan has a bearing going shot. Other problem is they are too wide. The overall width of the radiator with the tanks is 31" which is the same as the Windstar fans.

The fan in there now is 3-blade. I had Windstar's on the General but one fan has a bearing going shot. Other problem is they are too wide. The overall width of the radiator with the tanks is 31" which is the same as the Windstar fans.

The fan in there now is 3-blade.

I wonder if I could notch the corners to clear the hoses and petcock.

 

[kgblazerfive]

I did on mine. Being wider then the fins should not be an issue it is still going to pull air through the fins,

 

[miniwally]

The biggest thing I found and also have heard about any fan shroud is air leaks are bad

It doesn't matter which way you go you have to make sure the shroud seals to the radiator very well. if it doesn't the air act just like water and takes the path of least resistance.

A large enough air leak and you just pull air from the sides of the shroud and not through the radiator. I have confirmed that this happens with our dual electric fan setup int he race car, turn on one and you can feel the air rushing into the other fan hole.

 

[mrk5]

So would it be better for both fans to run at the same time? It would easier to wire that way. I would like a controller that would increase fan speed as the temps increase.

I do think it seems like the factory goes to a lot of effort to make the shroud snug to the radiator.

 

[MNorby]

don't run just one fan at a time. The windstars which it looks like your picture is of has a 2 speed on the larger fan so you can run a higher temp switch to it for when it gets hotter. Also can look into PWM controller that adjusts speed. I used stick on foam for like putting around your house windows or under a topper shell on a pickup bed between my shroud and radiator on the Sonoma.

 

[miniwally]

The way I control the fans is with one manual on off switch for one fan and the other is on a temp controlled automatic on switch.

Basically I have found that one fan will still pull a lot of air through the rad. even with the other one off, combine that with a bit of forced air through the rad and it seems to work. This has worked on our completely over designed and giant cooling system in the race car.

For rec. wheeling maybe do a head switch for one fan and put the other on another automatic type switching system. Make it so that you don't have to think to turn on fans, I have messed this up a few times. I do like to have a manual on/off switch that over rides everything and just turns the fans on full blast.

 

[454Sub]

Windstars move enough air with both fans spinning it blows smoke away from the rear end on a Suburban.

I had to notch my shroud for the drain petcock, very simple. I couldnt run my tranny lines through my radiator cooler, and I had to flip mine upside down to clear my BB but it doesnt effect fan usage. Actually made it easy to unplug fans if need be.

Word of advice if taking this route, since most likely your picking them up in a yard, take them apart and soak them in a bucket then blow them dry and grease them. Mine both locked up within 45min of use after first installing them, did that and work like a charm. I have left the truck running with them on for 4hrs now and have not missed a beat, and mine are wired to one switch until I order temp switches.

 

[mrk5]

With the size of my radiator I'm wondering if a the 2-speed Taurus fan would work better than the Windstar fans.

How hard will it be to find 2 places to put in thread-in temp probes. I don't really like the type that push into the radiator fins. Already 2 spots are being used, temp gauge and temp sensor.

 

[MNorby]

I had 2 temp switches in the sonoma 454. Been too long now to remember where they were though. Worse case I've seen a fitting you cut your radiator hose in half and put a spice fitting in there that you can do a switch in, its just not quite as sanitary.

 

[cybrfire]

I have two fans on my Griffin radiator.

One is thermostatically controlled on at 210 off at 190 I belive.

The second fan is on at 220 and off at 200. The second is also kicked on manually when the AC is used.

Normally the second one never runs unless I want it to.

 

[miniwally]

Scott I used a head location, you should be able to pull the plugs on the heads and use two staggered switches like Kert did and life should be good.

With good coolant and caps I'm not afraid of 200+ degrees on any engine anymore. Hell they want the newer stuff to run hot so it's more efficient.

 

[mrk5]

I'm thinking for now I'm going to run one thermostat controlled and the other will come on with the ignition with a manual OFF switch for the winter. Down the road when we have AC I'll set that up on the manual fan with a thermo switch.

 

[mrk5]

Scott I used a head location, you should be able to pull the plugs on the heads and use two staggered switches like Kert did and life should be good.

With good coolant and caps I'm not afraid of 200+ degrees on any engine anymore. Hell they want the newer stuff to run hot so it's more efficient.

That was the ONE thing that impressed me about the system that was in there. It got all the way to 250+ without blowing anything.

Is there just one head plug per side? The driver side is being used by the temp gauge sender now. The manifold plug is used by the sensor for the ECM. I have a plug on the t-stat housing that I suppose might work for the high temp fan switch so that fluid is actually flowing through there.

 

[454Sub]

Technically there should be enough plugs in the block, heads, and manifold plus waterpump to run what ya want. I know my 2000 BB has enough for it, I just cant find the switches I want. I wish they had them at Vatozone or something, I dont have the self control required to order parts online with my credit card, bad things happen.

 

[mrk5]

Yeah, I'm a SummitRacing junky. Every time I buy something I find myself thinking "what else can I buy while I'm at it..."

 

[miniwally]

Scott, I'm pretty sure there are plugs at each end of each head, meaning that you should be able to install temp probes in several head locations.

The heads will have the hottest water even over the thermostat location. In engines that we are able to monitor the head temp and manifold water temp we see minimum 10 degree differences and usually up to 20 degrees hotter in the heads than the manifold.

 

[454Sub]

I never believed that until I tried it for myself. And that is straight fact. I now prefer my gauges being hooked up in the heads vs the intake or t-stat area, more accurate reading.

 

[mrk5]

On this truck the gauge reads off the head and the ecm sensor is on the manifold. For what that might be worth.

Drove the truck home yesterday when air temp was around 90° and I was able to run 75mph without the temperature needle even touching the 210° mark! Before I would have been over 230° heading towards 250°.

 

[mrk5]

Today I took a break from the fluid systems. When I put the Magnaflow muffler in I just dumped it 6" from the muffler with a turn down. Problem was it was droning at idle. So I looped it up over the axle and added 27" of length after the muffler. Much better, but I forgot to take pics.

The other thing I did was to finally get a transfercase shifter installed. I got a cable shifter from JB Custom Fab. Jon donates a stainless steel twin-stick shifter every year for Blazer Bash, so I thought it would be good to do a little business with him.

I didn't get a good picture of the shifter itself, so I borrowed some from a thread on Pirate4x4.com.

The bracket can be moved around for multiple mounting options:

Shifter cable compared to a B&M cable (red).

They don't make a kit specific for the NP241, but he has a few parts to help you get it done.

They sent me a new lever for the tcase, and these ends with retainer clips.

I had to make a bracket to mount the cable to the transfercase. I decided the best approach was to run the cable towards the front so that it will loop around and pull the shift lever from the transmission direction.

I made a bracket that would use 2 of the 6 bolts from the tcase to adapter bolts. I have a clocking ring so it makes it easy to use them because they are studs and long enough to have room for the 3/16" thick bracket.

Here's the bracket:

The big hole is for the cable. The smaller hole above it was drilled in the wrong spot. The other 2 smaller holes are for the adapter bolts/studs.

Here's the bracket bolted in place:

Still needed to tighten up the adjuster nuts in that picture.

This is what the inside of the shifter looks like:

I didn't get a very good picture of the shifter mounted in the truck:

That's just a temporary spot but it works for now. You can note in the picture I have this nice big "grommet" to push the cable through.

I used a 60" cable, but I think a 48" may have been better.

Down the line I'm going to put a console in and them bolt the shifter to the side of that.

I didn't have much time to test it out. The only concern I have is when the lever is pulled all the way forward (4Lo) it might be too much in-line with the cable. This will make it hard to push it back. If it is an issue I will probably add a little extension to the end of my bracket that will drop the cable down some.

The cool thing with these shifters is that you can "stack" for multiple shifters: