WRIST PIN FIT?

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“Pressing” the pins........in?

I always just heated the rod and they slide right in.

Pressed out...... yes.

The shop I worked at had the type of removal fixture I posted.
Worked great.
 
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CFD244 said:
What do I need to do to get good quench?
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Just search and read up.

SBM open chamber heads don’t make it easy........ and they have a pretty small quench area to work with.

That’s where the zero-deck-flat-top-closed-chamber-head-.040 gasket thing comes in handy.
 
Looks like at 9.5CR, 262 cam in at 106, a 340 would have the DCR at 7.98...... at sea level.

So, the trick is to get the piston to head clearance, in the quench pad area, to be between .035” and .050”........ and end up at around 9.5cr when you’re done.

The higher the elevation, the lower the DCR will end up(all else unchanged).
 
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CFD244 said:
Please continue.......I read someones post here, that aiming for between 7 and 8 DCR is the goal with pump gas? I have a brand new lunati 268, but I am trying not to build an engine that needs high RPM to be in the power band. Would this be better?
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No sir. 7.5 "or so" is about the limit for DCR with iron heads.
 
PRH said:
Pishta, if there is a shop near you with this type of fixture, the pistons can be removed without any damage to them.
The fixture supports the rod, and the piston still floats on the pin during the removal process.

After they’re off, they could be honed for a little more clearance, then reinstalled.

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Yeah, I'm familiar with that jig but never seen one in a shop. I think the presser may have slightly rolled 2 piston pin bore edges. Ill take a closer look and see if I cant correct the interference. Its a little scary to know there are 2 things questionable in an otherwise spec parts buildup.
 
Fwiw...... for a .040 over 340, pistons sticking out .018”, 10cc gasket, 7.5cc valve pocket, 68cc head..... I get close to 9.6cr.
 
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