I put the severe duty clutch on for lower speed travel to act as a crutch until I have time to install the Allisport rad. I knew from last time temps were getting spicy so decided to use the severe duty instead of the HD. I've been running the inline for awhile so almost all my temp tracking is done with that. I have some early comparison data from when I first put on the inline in Extincts long thread somewhere.

 

ok - so your big temp reduction was at lower speeds while climbing then - I got ya.

 

Sorry, I meant Saudi Grille, I have seen them called both I think. I make my own using the Home Depot gutter cover mesh. Max area.

No idea. We ran water wetter in a big KLX650 woods racer with overheating issues but could not tell if it really made a difference.

I think extended periods over 210 increases HG wear. Have had HG's blow with no significant overheat. On the other hand I have run as high as 230 for short peirods when towing with no significant issue. I think one of the biggest things I did to reduce HG blows was to stop running a pressurized system. When you get hot with the pressure cap tight it really leads to pressure trying to blow out the gasket.

Does not matter.

 

well my grill is cracked in two places in the middle anyway so going to take a shot at a Saudi and see if it helps

the pressure issue is why you suggest to turn the cap back one full turn from fully tight l, correct?

 

I have not had a D2 in westerm mountains but mine seems to top out about 210 on climbs on the east coast, at least when I am not towing. Towing you have to stop and let it cool if it is a long climb and some are just not possible (wintergreen mt. pulling a Disco).

Remember, the cooling capacity is related to the volume of the radiator, not just the surface area. So thicker is better. By my calculation we would need 40% thicker radiator to hold 180 at 70mph in 100 degree weather on a stock truck.

 

Worth about 5 degrees in my experience.

Yes, no diference in cooling capacity and it prevents major damage from overpressure.

 

so I took of my grill to start looking at where to cut it, figure out how it will stay together if I start removing the middle, etc.

And then I decided to go for a drive to check out if not having a grill blocking air flow would help - yes I realize you should not drive around for extended periods of time without a grill to at least help a little, plus its ugly.

But tonight the temp is 77 degrees here in Ft Worth.

At 70 mph on my GPS - with no AC I was 185-190 and with AC on full I as 195-197.

I backed the pressure cap off a full turn also.

 

Mine has new water pump, nissens radiator, new fan clutch, new hoses, inline mod, new coolant and gets to like 183-185 then drops to like 172 and will keep cycling like that until I drive it for awhile. Hasn't gotten over 188 at idle yet with temps in the high 60s and lows 70sCould there still be air in the system.

 

Sounds completely normal, don't see anything to worry about there.

 

Without back checking your previous data points it sounds like your load has moved your truck to the ambient plus 120 degree range with the AC on at 70. So once temps hit 100F, you are looking at cruising temps of 220. Not ideal, but survivable.

I too have been researching larger radiators but waiting for summer to arrive to get them a good test. Kinda pointless until we are in the 90s which probably won't happen for another month on the east coast. You guys out west already there.