My 77 440 that I am using to build my 511 stroker with has a large chamfer at the top of the cylinder bore. My machinist says there is no rhyme or reason to this but that it is sorta random for each block. My block is .055 over bore and the chamfer still appears large. The gasket will be 4.410 dia. but my machinist says it may still hang over. What needs to be done? I know it affects my compression ratio but will it create a hot spot at the edge of the exposed gasket and detonate or effect my quench? Would a larger gasket be the solution? Is it a non- issue? As usual, I'm clueless.

You cant run a gasket that hangs over the bore edge, or chamfer in this case.

Best thing you could do is deck the block some to get rid of that chamfer and then run a cometic gasket to achieve the compression you ar elooking for.....

either that or custom pistons.

Or just run a bigger bore gasket......maybe there is something off the shelf that could work...or a custom gasket?

Larger bore gasket, deck the block until the chamfer gets reasonable, sleeve the block or get another block are your only options. I've seen plenty of blocks that way and I don't understand why the factory did that. I suspect someone didn't know what they were doing.

A larger gasket is the easy fix... if you want more
compression then deck the block... that tends to be
a random problem on mopar blocks.. even on the same
block you can have all different chamfers

Thanks to all for the info. How much do you think this may affect my compression ratio? Now at 10.3 to 1 w/ indy EZ 75 cc chamber. Of course the motor isn't built yet but the block is at the shop and the stroker kit is on the way from Hughes. The piston is an icon w/ 26.7 cc "D" dish and 1/2 flat top for quench. Suppose the only way to know is do some measuring similar to the way you would cc the head, or am I just splitting hairs here? This is the 2nd block I have taken to the shop, the first one showed a crack after a magnaflux check.

The chamfer is not going to make or break your CR. Has the block been decked yet to get to zero deck? Not sure about the ICON's, but it is not uncommon to need a 0.020" or so cut to get to zero deck. At that point, see what you have a get a 4.5" bore gasket.

I honestly wouldn't be too worried about it. The edge of the head will gang over the same area the gasket would in most cases . One of my good friends/ customers runs an Edelbrock headed440 with huge chamfers on it. 11.2 to one on pump gas,bracket car.
Been running that block for several years with 1009 FelPro gaskets.
Keith

Not sure what it would do to the rigidity of the block, but you could deck until the chamfer is of a desired size then run thick head gaskets until you achieve the quench desired. On one of the 383/496 builds I was involved in, after decking the block to get it square, the pistons protruded something like .012" out of the block, so we ran some .050" thick head gaskets to prevent contact. It might have cleared at .027" quench, but we weren't going to risk it.

Thanks again to everyone for all the advice. Not sure if the block will be decked, my machinist will use one piston/rod assembly in each corner to check deck height and go from there. Just waiting on the kit to arrive in about two weeks.

So your machinist can't measure deck height without a piston/rod?
I do it with a 12" dial caliper.

R.

I know there are tools that will do this, even without a crank and I asked the same question. This is the way he prefers to do it. I was a bit skepitical but I asked several people from a variety of backgrounds about this shops reputation and all have only good things to say.