[Sizzler]

If you go with the Shelby block, you might want to have it blueprinted and made ready in the states. As this man in Germany is learning, Shelby doesn't always produce perfect products:



Bore sizing finishing Shelby Aluminum Block
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We´re getting conflicting Infos on the bore size of the shelby alum. block.

The bore in our block is slightly undersized with a 4 thou taper.

We called Shelby twice and got two different answers - my feeling is that it needs to be finished honed to size - but not sure if there is anything special to look out for because of the differnt expansion characteristics of the alum. block.

What do you think ??

Mike (Germany)
68 GT500


.004 Taper?.... October 7 2003, 4:54 AM

Im a little confused by your post. Has the engine been finish bored? That .004 taper is way too much, not good. Trying to finish hone it will not take care of it either. It sounds like it was rough bored and needs to be bored again to a finish size (or a few thousands under) and then final honed to match the clearance recommendations on your pistons. If you leave it go with that much taper, it will definately lead to problems.

Doug


Yes there is a difference of 4 thou between top and bottom of the bore..

Mike (Germany)
68 GT500

Curious about a few things here........ October 7 2003, 7:01 AM

Do the cylinders have a bored finish or a honed finish? It would be hard to bore a cylinder with .004 taper with any kind of a decent boring machine. On the other hand, you can create a taper with a hone with improper set up or an inexperienced operator. How much undersize is the largest part of the taper? If it is .002 or smaller than finish size, you should be able to straighten it out with a Sunnen hone or equivalent (experienced operator required). Seems like for the price of those blocks, they could have done a better job.

The walls have a finished hone crosshatch .. October 8 2003, 12:41 AM

Since the wall had the finished crosshatch on them we kind of expected it to be perfect... but they are not.



Mike (Germany)
68 GT500