Posted by JohnP on September 26, 2004 at 02:56:06:

In Reply to: Series IIA Engine swap posted by Bill Wheeler on September 25, 2004 at 12:40:16:

I ran a 250ci chevy 6 in my 5 door IIA (not a Defender!) for years with no such issues. This seems to be an over exaggerated problem. If it was set up right to begin with you would not have had a problem. I had a special 4 core radiator that kept her cool. Mounted to the radiator I had the biggest electric fan that would fit. The fan was run off of a simple coolant temp sensor. When water gets hot, fan comes on. This worked for years until the fan died. After that, I converted to a mechanical flex fan. Even the flex fan worked well enough to keep the motor cool, and I was skeptical about that. Fan clearance was not an issue either, and my radiator panel was not moved out to be flush with the fenders (as on true Defenders). Basically you need to start with a high quality radiator. Call around to radiator shops, someone should be able to build one to fit. Or better yet, find one yourself that is close to the correct size, and have the shop add a third and fourth core (most radiators are two core). Then add a good fan, as above. P.S.- Make sure that your engine is not running lean, and that all your water passages are not blocked up with rust. Run a block cleaning agent through the system.