Cooling system

[thistle3585]

Was a radiator shroud and coolant bottle stock on a 1978 CJ5 ? Is the bottle necessary? I have been looking for them in a junk yard but haven't found any and I hate to pay $AMC 150 for one. I have had two people reach in over the fan, while running, as I was working on the engine. It seems like these project Jeeps bring in a lot of gawkers in the neighborhood and I'd just as soon not have to be concerned with missing limbs.

 

[mylittlecj5]

I pulled a shroud off a '78 CJ5 , can't remember if it had a catch bottle or not. they are available for....Hmmm...$145.99...if your interested?

 

[Sasquach]

Yes they were

 

[BusaDave9]

The shroud makes a surprising difference in the cooling. It helps the fan pull air through the radiator. Without it the fan just seems to blow air around the engine compartment.

The overflow bottle will help prevent coolant loss. When the engine is hot it will blow a little coolant out the overflow. The bottle will allow the coolant to get sucked back into the radiator.

 

[jeffgtoman]

The bottle will allow the coolant to get sucked back into the radiator.

Yes, but don't forget. This part of it only works if you have the right type radiator cap and there are no small leaks in the cooling system. The cap must be a CLOSED SYSTEM cap with the extra rubber gasket at the top.

Are looks important? You can make a recovery bottle. Just secure a plastic jug to the inner fender and run a hose into the jug. It doesn't even need a lid. Fasten the hose so that the end is close to the bottom of the jug. 2 to 4 quarts should work well. Pre-fill it about 1/4 full.

The bottle is not necessary.

 

[BajaEdition]

the radiator needs a shroud, a old engine may work fine without one as the engine is not working at peak efficiency, but a rebuilt or new engine will soon tax a radiator system without a shroud

a radiator needs to have air pulled against it to work at peak efficiency, and without a shroud that is not happening

there is a small film of air that will remain around the fins of the radiator if it is not pulled away, unfortunately pushing air up against this film will not strip it and this air gets as hot as the fins, insulating them like using insulation in your walls. only by forcing air to come between the fins can we get this air to move, that is why most radiators have sucking fans. without a shroud I am sucking a significant amount of air around the entire radiator, if I use a pusher fan I get a lot of deflection and the fan has to work harder. the most efficient way is to turn the radiator sideways and have it with the air running past both side creating a ventura effect, this works great at speed but looses all efficiency at idle while sitting still and the temps go up real fast.
So we use fans that draw the air through the radiator with shrouds it make sure they are as efficient as we can get.

now,about the bottle, they are used in a closed system, if you are not set up with a pressurized closed system it is not needed, but is still a nive feature.