Max Acceptable Deck slope?

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Oh and why are we talkin about slopes here.

das racist.


BWHAHAHAHAHAHAHA
 
Paying attention to details like square decking the block, equalizing rod length, index grinding the crank, etc may not make tons more HP, but it does make a big difference in how the engine runs in terms of smoothness and "crispness" for lack of a better term. In essence, the difference between an engine that runs good and one that runs GREAT.

When I was a machinist, there was a joke we used to tell - What's the two things you don't want to hear from a machinist? "Oops" and "Close enough"!
 
Oh yeah... "oops" is always an attention grabber. Especially when it was followed by a thud or the sound of tooling breaking.
 
It is really hard to get precise measurements on an engine block unless you have a high dollar CMM. About the only guys who have that level of equipment are the serious race shops. When you try to measure the deck against the piston then you are adding measurement error on top of measurement error. The high end block machining tools such as a Rottler can do what you're asking for but those tools are expensive and they aren't fool proof. Someone still needs to have the correct fixtures and programs to end up with a deck that is perpendicular to the cylinders.
 
I once worked for an employer, that had an open pit policy. The customer was allowed to watch, from a safe distance,(if there was such a thing). Many didn't observe the no-go zone.
I used to pull the Oops-card occasionally, if a customer was getting in my way.Just drop something heavy, and say,Oops. They usually back up some. Job's took longer, and the extra time went on his bill, but their curiosity was satisfied.I often had to repeatedly ask them not to come between me and my tool box. Many never seemed to catch on.
Talk, talk, talk,talk, oh how they loved to talk.
 
FWIW, the machinist called last Friday to report on what he found. He referenced the deck angle measurement to the bore this time, and the deck angle was (drum roll)..... off by .005", top to bottom. Shazaaam, Sargent Carter! (Or, he just got overloaded, and 'said' he got that and milled the block the way we wanted it...#-o)

I am finally putting 2 plus 2 together that this particular subcontract machinist is a decent machinist, but not an engine builder. He mentioned having engines built by others, but never mentioned building engines himself. 10-4....

We'll get the block today and then check it all over again.

Edit to add: Well, he got the slope from .005" down to .002", not to .000" Going forward with that; not worth messing with this to get another .002" and with this guy. Will use a different shop next time for something like decking.
 
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