Cj7 w/ sb350 and cooling....and carbureting...

[mbryson]

I have a friend that struggled with overheating issues with a V8 powered YJ, typically at higher speeds. He tried several different radiators and fans but nothing fixed the problem. The problem ended up being a simple fix, the lower radiator hose did not have a spring in it and would collapse restricting the water flow. He put a spring in the hose and no more overheating.

I've had that on a Buick 455 before as well. (not the one I have now)

 

[Cody]

This is all good stuff. It's currently a quadrajet carb. Is that 670 carb the wrong size?

 

[Greg]

This is all good stuff. It's currently a quadrajet carb. Is that 670 carb the wrong size?

650 cfm is ideal for a stock SBC.

 

[jeepin4x4james]

Mine was an AMC 304 btw

 

[Hickey]

This is all good stuff. It's currently a quadrajet carb. Is that 670 carb the wrong size?

It could be that your float is set too high. Britney had a Quadrajet until last year, and she still climbed all over Sand Hollow with the previous owner.

 

[xjtony]

Like @Hickey said float level can cause issues like this. I've seen some guys also run a longer vent tube to help keep fuel from spilling out. At an angle the fuel comes out of the vent and right into the carb barrels causing a rich bog.

 

[Greg]

This is all good stuff. It's currently a quadrajet carb. Is that 670 carb the wrong size?

I used this all the time when I worked at Super Shops to determine needed carb size for any engine using maths... aka Volumetric Efficiency;

Cubic Inches x RPM / 3456 = CFM (cubic feet per minute)

A stock 350 probably isn't going to rev over 5,500 RPM, so 350 x 5500 ÷ 3456 = 557 CFM

Better to have a bigger carb than needed, verses smaller... so 650 CFM is just fine.

 

[Cody]

Sounds like I'm about to inherite a holley truck avenger carb from a family friend for free. New I'm told.

Hopefully that helps the running issue. Then to tackle the overheating.

Hoping to have it solved by Easter

 

[Shawn]

Although the overheating could be caused by the fan / radiator don’t overlook the block passages being clogged. When I ran my 4.2 in my CJ7 I put a motorcraft,,, 2200 or maybe it was a 2500 on it and it ran fine at angles. Still have it and it has very low miles on it.

 

[Shawn]

I just realized your running a small block, I ran the truck avenger and it did okay,