??----If you machine the warped head to be flat.-----The cam bearings will no longer be in line when head is installed.
it wont just be the bottom mating surface that warps but the whole head. surfacing will just flatten the bottom. with that said install cam and bearings without valves and or cam followers and see how they spin. i think you will be fineso is the warp of the head the problem or is the milling of the head surface the problem?
if the head was not warped and all the cam bearing are still in line, then resurfacing the head should not be a problem, right?
from what I am understanding, it does not have anything to do with the milling of the head, it is to do with the possible warping of the head before or during the weldingIf a machine shop cannot keep the cylinder head surface parallel to the cam shaft bores maybe they should not be in the business of reworking a cylinder head.
A machine shop should be able to deal with both warping and milling while keeping the cam shaft bores aligned.from what I am understanding, it does not have anything to do with the milling of the head, it is to do with the possible warping of the head before or during the welding
The guy that will be doing it for me welds aircraft engine cases, very well respected and definitely knows what he is doing. Obviously it will get preheating and heat treatment of sorts.If the weld doesn't warp it you'll be fine.
i would think it also had to do with they way the runners were designed... maybe letting moisture linger longer than desired?Just to be clear...
The cams spun freely when the head was removed, and after checking with a straightedge, there was NO warpage - nada. zero. It did have some mild corrosion, which my machinist brought to my attention as being a possible problem that could cause the head gasket to blow later. The original failure was corrosion of the block, which ate away the ENTIRE deck. The head got a little corrosion, and my machinist offered to have me find another head. However, these motors often blow balancer gears, the bits of which plug the oil passages and destroy the cam bearings, rendering the heads useless. I plan on doing a balancer delete on this engine to avoid those issues.
Since I can't find a good head, and a new one is as much as an entire new motor (well not as much, but still a ton of money) the machine shop will grind away the corroded areas of the water passage near the deck and the deck itself, and will send them to a reputable welder. The head will then be decked to cut the welds flush, not because it is warped.
Just a little backstory, maybe most of you know:
When the fourstrokes where coming out, they were so heavy that a material with a higher specific strength was needed to bring the weight down, and so they did. Except that the new alloys would rot like crazy, especially in the case of yamaha (looking at the F225) and to a lesser extent, suzuki. Most of the newer motors have that issue sorted, but there are plenty of motors out there that are in the corrosion years (i'd say somewhere between 2000-2014) so buyer beware!
soda can metal... a lot of yamahas of this generation had the corrosion problems, most notably was the F225.i would think it also had to do with they way the runners were designed... maybe letting moisture linger longer than desired?
what kind of soda are you speaking of?soda can metal... a lot of yamahas of this generation had the corrosion problems, most notably was the F225.
Probably speaking of recycled aluminum tho I don't know if it is a problemwhat kind of soda are you speaking of?