R3W7 Assembly

why are the exhaust guides a different color? different material?


Good question. I don't know. Even the valve seats are a different color between exh and intake. I suppose I put my faith in the Chapman people knowing what they're doing. If these heads had come out of a 'mystery' shop, I'd be a lot more concerned but at the time, anyway, Chapman was considered top shelf. They still might be, I dunno. I've done some additional machining in non-performance affected areas and now I just need to order the valve springs and retainers to be done.

On these heads, I added some external drain lines that will reduce puddling of oil around the valve pockets. Without these drains (which will connect near the top rail of the oil pan) quite a bit of oil will sit until it reaches a level that allow it to run back through the lifter valley. By using the drain lines, the oil will stay away from the lifter valley altogether.

W7 oil drain npt.jpg

W7 oil drain ports.jpg