When is it necessary to have this done? When you have an engine with a rod knock or has been badly overheated I would think you would want to true up the main sadles. But, you have a good running engine and are going to freshen it up, and all the bearings have normal wear. Is align honing necessary? AL
I'm sure someone more knowlegable than I will chime in....... But I think if the crank is not in need of turning than you should be able to get away with it. Why did you take apart the bottom end? If the reason was some major motor damage alsewhere you might be well served by taking the block to a good machine shop to make sure. It would really stink if you got it all back together and find out the hard way that you should have taken care of it when it was all apart. my 2 cents D.
From what I read on the BBB, this is a critical area and usually needs done. That's not to say that every block needs it and if it is a stock rebuild and the bearings looked good, you may be fine. If you can at least have it checked, I would suggest doing so. From the way I understand things, the huge mains on the crank provide a lot of the structural strength of the bottom end and after years of heat cycles it is common for the main bores to shift. Like MANY people on this board suggest, have a shop with Buick experience do it! I have spent money to have things machined and had them better off before I spent the money and I think a line hone tends to be one of those operations. It isn't as cut and dry as shaving a cylinder head and because of the size of the mains on a Buick, many shops may not even be equipped to do it right or wrong!!!! I know there are MANY good machine shops out there but I can tell you there are also many I wouldn't take ANYTHING to. TRUST ME, I have worked at two such shops!! :Smarty: Ken
I think it was Grumpy who said if a known straight crank with new bearings with the right clearances spins real free in the block it good enough. I don't know if he was being sarcastic or not. But I agree, having it done by a shop that is not good at that sort of thing can make more problems than it fixes, like a real loose timing chain for one thing. Tom
My shop would only do it if the block needed it. It didn't so they didn't. This, of course, only works if you have an honest guy running the place.
The align hone will ensure that the mains are both concentric and perpendicular to each other. A reputable shop should be able to check your block to see if it is necessary.
The shop I used to work in we used a machined straight edge and feeler guage to check mains, kinda the same as checking the decks or heads. Probably isn't the most high tech, but with a little practice I could get a good idea how far off things were. Tom
Thank you for all the reponses. What Smokey Y said makes sense and so does having a shop check to see if it is necessary. Thanks Allen
Hey guys, don't forget to check not only for alignment but also for proper bearing crush- I personally like bearing bores to the minimum spec.
