YJ running hot.

[Van-go]

I recently replaced my water pump, thermostat, and radiator.
Radiator is 3 core all aluminum.
Thermostat works as it should.
I have an electric fan that pulls what seems to be plenty of air. I made a fan shroud for it out of a road sign. It is sealed around the edge of the shroud. Fan mounts to outside of shroud.
The shroud has a small air gap between the radiator fins and the shroud. About 1/4 inch.

I just got back from a wheeling trip and she idled at around 215 according to my stock gauge.
When I was riding it ran close to 230 or 235.
At first I thought my gauge was not accurate but it was running hot enough to boil my fuel and burst a fuel line.

I'll get some pics of my set up shortly

 

[Van-go]

 

[Fabrik8]

That 1/4 inch gap isn't enough, and very little airflow will be drawn through compared to the much lower pressure area where the shroud isn't. You're handicapping the radiator a lot in those areas. Basically you've got a radiator with a fan and a block off plate. 3 core aluminum radiators are often not an efficiency improvement, but that's got a lot to do with the particular radiator design and isn't an easy generalization to make. A better fan and/or larger space between the shroud and core would likely be very helpful, as easy spots for improvement.

If you're wheeling and the engine is under load at low ground speed, the only cooling you have is down to the fan and the marginal shroud. You may have other cooling problems as well, but the fan and shroud need to be improved no matter what.

Out of curiosity, who makes that fan?

 

[Van-go]

That 1/4 inch gap isn't enough, and very little airflow will be drawn through compared to the much lower pressure area where the shroud isn't. You're handicapping the radiator a lot in those areas. Basically you've got a radiator with a fan and a block off plate. 3 core aluminum radiators are often not an efficiency improvement, but that's got a lot to do with the particular radiator design and isn't an easy generalization to make. A better fan and/or larger space between the shroud and core would likely be very helpful, as easy spots for improvement.

If you're wheeling and the engine is under load at low ground speed, the only cooling you have is down to the fan and the marginal shroud. You may have other cooling problems as well, but the fan and shroud need to be improved no matter what.

Out of curiosity, who makes that fan?

That's kinda what I figured.
How much of a gap do you think will help me?
As you can kinda see in the photo, I have no room between my fan and my engine.
The engine sits about 1.5-2 inches forward from stock in the engine bay from previous owner(s)...

And I inherited many of the lovely Chinese upgrades such as this fan.

 

[Van-go]

I may need to modify the grill to allow me to move the radiator forward and just run the Taurus fan.

 

[Fabrik8]

Sorry, I meant who makes the radiator.

Depending the the radiator specs and fan diameter, I would say at least 3/4 to an inch gap. It's all based on pressure drop, so nothing is going through the shrouded area unless the pressure is low enough in that area.

Even though you have very little clearance between the engine and fan, going with a larger diameter but lower profile fan can gain some space for extra shroud depth. Plus, if you get a good quality fan then you'll know what you're getting for performance.

 

[Fabrik8]

I may need to modify the grill to allow me to move the radiator forward and just run the Taurus fan.

I think that's a good idea, because you can then make a tapered shroud for even better performance and more clearance for flow between shroud and core. I've never used a Taurus fan but I know they're really popular and supposedly work well (I'm no help there).