I need to replace an exhaust valve guide. The guides available are oversize, two steps. The workshop manual doesnt mention this so which one to choose? Further the wsm says to heat the head in boiling water before drifting out the old and the new one in. Unfortunately I do not have a big enough container. So any bright ideas? I rather doubt that wrapping in black plastic and leaving in the sun will do the trick .......

 

we used an old pizza oven, it was wide enough for long aluminum heads, just be careful not to much heat, around 300-400*F.

while your at it, measure the surface flatness, if its not bad you can straighten it out, with the heat, then
when all guides and straightness is done a nice light resurface cut.

something to remember is if the head is warped,the cam bearing bores will be out of alignment also, could lead to future problems.

 

I did my friends bmw head by boling water in a five gallon bucket and did one side at a time