Overheating 360 new engine

Slappy said
Hello guys I'm having an overheating issue. Little background info first. I was a master ASE tech for 30 years this one has me stumped. I have had this car at two separate shops also. Here are my engine specs for the cooling system. I have a champion 3 row radiator. March serp belt system, 180 deg t-stat, stock water pump, 2 12 inch electric cooling fans mounted diagonally, vintage air system, autometer pro comp ultralite gauge, also Edelbrock aluminum rpm heads (60779). The engine has had a few different radiator caps. The current one is a stant 16lbs. Engine has less than 200 miles due to this issue. Forgot to mention this is an LA360. ..........

^^^^Here is his base line of whats inside. Twin 12 inch fans. The big 3 core radiator and the March Pulley system makes it too tight for a mechanical fan.

Slappy said
.........First I will start with the shop experiences. First shop stated that my carb was running to rich and causing the overheat issue. I took it to another shop and they said the same thing and tried to work on the brand new out of the box holley carb. This just made it worse running. I went ahead and added a Holley sniper EFI set up on. What a difference in runability and power!

Then Carb info given to him was bogas. Running too rich will normally not run hot but can run hot in the header tubes when unburnt gas is still burning. He then put a Sniper EFI on and that helped on power but still over heated. ........

Slappy said
........Engine is still running hot. I have tried several different thermostats ranging from 160-195. 2 Different water pumps, 2 different electric fan setups. I had all the engine parts IE block and heads, crank ect checked at a local machine shop. Block was bored 30 over. Head gaskets have been tested chemically 3 times and all 3 times negative. The heads were not in the box but were new never used. But some small port work was done on them. This is why the machine shop checked them for me.

360 block bored 0.030 over. Aluminum heads, 2.02 and 65cc chambers, slight port job. Tried different thermostats. No head gasket leaks

Slappy said
.......One weird thing did happen. One of the freeze plugs on the left side of the engine blew out. Both times the engine was at a higher rev. I put a third plug in and it felt like it went in to easy so I JB welded it in. I know this method is not professional but aside from taking the engine out it was easier. No more issues with that plug. I should mention also that no oil or coolant appear to be mixing in the engine or radiator. I also had an oil analysis done and that turned out ok so far.

Core plug popped out two times, JB Welded on third try. Lots of water flow.

Slappy said
..........I decided today was the day to look deep into the issue. The starting coolant was 89f . I live in Florida. I went ahead and ran a suitable fan in front of the engine. The first temp check was gauge read 150f and my two infrared temp guns read 134F. At 180f both cooling fans came on and water was flowing well in the radiator. Next temp reading was 194f at the gauge and the gun read 184F. At this point I stuck in a thermometer directly in the coolant. I left the coolant thermometer in until 205F then I put the cap on. Temperature continued to rise on the gauge and on the gun until I shut the car down around 215F.

Seems like good water flow. Air flow suspect even with two 12 inch electric fans.

Slappy said
.......I did notice that the exhaust temps engine running and engine off were all over the place. The two middle cylinders were as much as 100f difference than the end ones. This was true for both banks. The Left side was considerably hotter than the right side. To give you an example I have my MSD box mounted with an air flow gap under it on the inner fender well and it was 147f with the hood open. The master cylinder was 160F.

Now what would cause the header tube temps to be so different? This was with the hood open during his tests. He does not give the temp readings on the high center tubes. He also has not said what his aircleaner type is and if its the common "Chevy" hotrod open filter, and the master cylinder is 160F then he is sucking a lot of HOT air into the engine.

Slappy said
.......Not sure if the blowing out of the freeze plug was a sign. Bad Machine work?? EXhaust temps have me baffled as to why they are all over the place. I dont know if the engine block has some sort of flow issue. Heads issue?? I did order a cylinder leak down tester which will be my next task. I can watch the radiator for bubbles with it for head cracks ect. The car runs great accept too hot.

In some later posts he did some testing with other members on here and was working toward a fix... And the Hurracane Ian hit Tampa Flordia.