VL cylinder questions

[Buster]

VL cylinders 001.JPGVL cylinders 004.JPG

Trying to sort out usable parts to build by mix matched VL motor. Hope my photos show up. One cylinder has two brazed spots in bore, the cylinder has been bored since the brazing repair. My machinest told me he can bore the cylinder with the brazing to the next oversize. Is this a usable cylinder or are there any problems with the fix. The other cylinder has a cracked area inside exhaust port in the hump were the exhaust valve and valve guide comes through the exhaust port. The two vertical cracks and a connecting horizonal crack are at the top tip of the hump. Is this worth repairing or how. If run as is, will this cause valve guide to overheat and stick? I believe both cylinders can be bored to 70 over. If I had to go to larger oversize, is it safe to sleeve cylinders. Thanks for any help.

[Jerry Wieland]

Nothing wrong with a good braze repair. Jerry

[Buster]

Does anyone have an idea on the cracks inside the area of the exhaust port at the upper area of the valve guide. A small area of the upper end of the valve guide would be exposed in the exhaust port. Exhaust gas would flow directly onto this and I am wondering if more exposure to the hot gases at upper area of valve guide would cause valve to stick. I also forgot to ask; all my valves are exhaust valves, can exhaust valves be used also for intake valves. Thanks!!