Re: 2262-9 288 motor distribution tube

Posted by aljcampo On 2010/9/24 15:54:52

Hi, I have a 2262-9 with a 288 motor. I am looking into several items relate to overheating. A temp profile with a IR meter shows the hottest area is around Cylinder #8. I also have a failed #8 exhaust valve, probably because of the heat. I have the distribution tube out. It is clean and in good shape. There are 3 each holes on the valve side at the front that are 0.430" in dia, the rest on the valve side are 0.268" in dia. On the cylinder side, there is one 0.268" hole at the front followed by 2 ea holes that are 0.430" and the rest are 0.268" all the way to the end. These seem to be laid out and sized for a very specific purpose.
Questions:
1. What if I enlarge the last two holes on the valve side to get more coolant to the #8 exhaust valve?
2. How much should I enlarge the last two holes? I am aware that it will take away coolant from the other holes.
3. I am also very curious why the larger holes are up front and not in the rear, anyone know?
That's all on this post, I'll do another on a related problem.
Thanks,
Larry