My 420a Build Questions

[tec_41]

Hello,

I recently blew up my engine and am just starting to build up a spare 420a block I have in my garage. I decided to start an ongoing thread to ask any questions I'll be running into along the way...I've been doing a lot of research and I think I'm starting to get a good grasp on what needs to be done.

Now here's my first question that I know has been asked before, but I just can't get it...The damn crankshaft sprocket! Not the pulley itself, the actual sprocket.

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I rented a medium sized gear puller from Auto Zone, but it was useless and just slipped right off the lip of the gear. I'm going to need a new crank anyways as this one has severe signs of a spun bearing, so is there a good way to just hack this thing off?


My next question is regarding all the machining work. If I bring the block to a machine shop, what are all the things I need to ask them to do? I want to start shopping around for price quotes and just need to know all the services I would want to ask for.

When it comes to checking cylinders for roundness (not sure I want to bore over or not yet if I don't have to) what's the proper way to do this?

Thanks for any replies...If you guys have any advice to throw in I appreciate it!

 

[LD25Delta9]

Ahh!!!! You should use a small 3 bolt pulley puller. You can't use a Jaw-type puller. I wouldn't recommend cutting it off for fear of the vibrations causing damage. I don't know that it WOULD cause any damage but I'm AR when working on my engine.

As far as the Machine work.....It all depends on what NEEDS done. If your cylinder walls are too far worn, then you'll have to get it bored. If the block is warped on the mating surface, you'll need it decked. If your head is warped, you'll need it milled. Also, if you have these things done, you'll need a custom cometic head gasket ordered, because either the bore or the thickness will need to be different than stock spec.

As for checking for the Cylinder being out of round....Depending on how far, having it bored can fix that....but if the block was stressed enough to warp the cylinders, I would worry about the rest of the block having weak points.

Hope this helps!