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urmyboyblue · 08-09-2020, 10:10 AM

You haven't said if it gets hot idling or running down the road. If it gets hot idling, you have too little fan. If it gets hot running down the road, you have too little radiator. Also, check your timing with the engine around 3000 RPM to look at total timing, not initial. I would check to make sure the distributor is working correctly- you are getting both vacuum advance (check by pulling the vacuum hose to it- timing should change) and mechanical advance (timing should change as RPM changes). I run mine around 32-36 degrees total timing (checked at 3000 RPM. Total timing is more important than initial because it is approximately the RPM the engine runs down the road. Also check the fuel pressure and make sure you are not running the engine lean.

As for cooling, I have BBC's in two trucks. My 66 has a 400 hp 427 that uses a Champion radiator and an HHR electric fan. I drove it 400+ miles a few weeks ago in 90+ degree weather and it never got above 195. This is a cheap fix all around and is easy to fit. My 65 has a 550 hp 489 and uses a cheap chinese radiator that has been custom fit (aka hacked a little) and a high dollar Derale dual fan set up with a radiator controller. It keeps the temps below 200 as well.

I would do the easy things first- check the tune. One last suggestion- make sure the fan is pulling air thru the radiator and not pushing it. Sounds silly, but I have made that mistake before as well.

08-09-2020, 10:10 AM	#21
urmyboyblue Registered User Join Date: Feb 2015 Location: Montevallo, AL Posts: 272	Re: BBC overheating You haven't said if it gets hot idling or running down the road. If it gets hot idling, you have too little fan. If it gets hot running down the road, you have too little radiator. Also, check your timing with the engine around 3000 RPM to look at total timing, not initial. I would check to make sure the distributor is working correctly- you are getting both vacuum advance (check by pulling the vacuum hose to it- timing should change) and mechanical advance (timing should change as RPM changes). I run mine around 32-36 degrees total timing (checked at 3000 RPM. Total timing is more important than initial because it is approximately the RPM the engine runs down the road. Also check the fuel pressure and make sure you are not running the engine lean. As for cooling, I have BBC's in two trucks. My 66 has a 400 hp 427 that uses a Champion radiator and an HHR electric fan. I drove it 400+ miles a few weeks ago in 90+ degree weather and it never got above 195. This is a cheap fix all around and is easy to fit. My 65 has a 550 hp 489 and uses a cheap chinese radiator that has been custom fit (aka hacked a little) and a high dollar Derale dual fan set up with a radiator controller. It keeps the temps below 200 as well. I would do the easy things first- check the tune. One last suggestion- make sure the fan is pulling air thru the radiator and not pushing it. Sounds silly, but I have made that mistake before as well.