I am rebuilding a 2.0L type IV that I just bought.

It looks like everything was done right, but was a few years ago.
It is VERY clean and has had almost all of the oil plugs removed & drilled/tapped with new plugs installed.

So, I split the case and it looks like the case has already had at least one align bore (help on how to be sure?).

Anyway, I dont want to pay a shop to "align bore" it if nothing really needs to be done.

Any measurements I can do to decide if it is good or not?

Stu

not unless you have a machinists straight edge to lay along the bores to check for warp. and can take very precise measurements to get the diamentions of the bores with in .001 .

and these need to be made while the case and the cyliinders are torqued.

You can look for a couple of clues. If the case is worn you will see fretting at the parting lines of the main journals. The aluminum has a dull gray almost crystaline appearance. I haven't had a case that didn't have at least a little of this so, I guess it's really trying to find one that's not too bad. You can sometimes find the part # on the old bearings. You can use a known bearing and trial fit it. You can look at the thrust area and see how worn it is.

Best to let somebody with experience and the right equipment look at it.

Dave

if you have a set of new bearings that are the same as your current bore you can press them into the case by hand to assess the amount of crush you still have. If they take a bit of force to press in and pull out then you are very likely to have a good case still.

When they slip in easy and come out easy its time for an align bore as you won't get the proper crush under torque.

there is too much at stake to risk this to a guess. the case is the foundation of any engine. although I do check as Brer says, I take all mine to my machinist. cost vs benefit

how does your machinist check them? Does he have one of those fancy pieces of equipment that costs $$$ ?

yup. Dennis has a fixture. he checks dia and alignment. thrust gets checked simply w a mic but the fixture rotates a feeler thing on teh flange.
what does Don do to check it? he did a few cases for me but I didnt ask how. he cut 2 of 3