: Just pulled down the new engine we had just
: built. The #6 and #4 pistons had broken tops
: (#6 real bad) located at the thin area next
: to the valve pockets caused by what we think
: was the rings end butting due to heat. Top
: ring lands broke straight up and off the
: pistons and exited through the valves after
: smashing plug on #6. Does not look like any
: burned pistons or any melting from
: pre-ignition at all. Used 0.020" over
: KB 2.2 hyper-eut pistons with Hastings
: rings, with the ring gaps opened to
: 0.026" per their instructions. Engine
: has a figured 11:1 comp ratio (35cc head and
: 0.025±" neg deck). Was runing 32° total
: advance and 180° thermostat and running 94
: Sunoco with lead replacement. Cylinders
: appear to be OK with just a hone job
: required. All bearings had some alum go
: throught them and will be replaced. Alum
: parts went out the exhaust, but the head and
: valves appear to be OK.
:
: Any suggestions on replacement pistons? Expect
: to buy 6 new, and if we have to, will bore
: block, can go to 0.080" or 0.100"
: over. Engine was balanced, but if using 6
: matched pistons, should be OK. Car ran like
: H###. Engine pulls great from 1,500 to
: 5,800+ rpm with no soft spots at all. A
: touch rich on #6 and #1 like all 4v carb
: 6s. Fully expect mid 14 sec an street
: slicks with closed exhaust. Out pulled my
: 5.9 R/T on an uphill on-ramp and was
: actually gaining before my son pulled out of
: it!
:
: KB pistons looked real nice going in, and we
: did follow the instructions of KB and our
: machine shop to the letter about the ring
: gap. Hate to install 2nd head gasket to
: lower comp ratio, as we would lose quench in
: the chamber. Have access to piston coating
: for the piston tops and skirts if needed,
: but don't know about increasing ring gaps to
: 0.035". Any and all comments would be
: of great help.
: Thanks
: Smith

: Just pulled down the new engine we had just
: built. The #6 and #4 pistons had broken tops
: (#6 real bad) located at the thin area next
: to the valve pockets caused by what we think
: was the rings end butting due to heat. Top
: ring lands broke straight up and off the
: pistons and exited through the valves after
: smashing plug on #6. Does not look like any
: burned pistons or any melting from
: pre-ignition at all. Used 0.020" over
: KB 2.2 hyper-eut pistons with Hastings
: rings, with the ring gaps opened to
: 0.026" per their instructions. Engine
: has a figured 11:1 comp ratio (35cc head and
: 0.025±" neg deck). Was runing 32° total
: advance and 180° thermostat and running 94
: Sunoco with lead replacement. Cylinders
: appear to be OK with just a hone job
: required. All bearings had some alum go
: throught them and will be replaced. Alum
: parts went out the exhaust, but the head and
: valves appear to be OK.
:
: Any suggestions on replacement pistons? Expect
: to buy 6 new, and if we have to, will bore
: block, can go to 0.080" or 0.100"
: over. Engine was balanced, but if using 6
: matched pistons, should be OK. Car ran like
: H###. Engine pulls great from 1,500 to
: 5,800+ rpm with no soft spots at all. A
: touch rich on #6 and #1 like all 4v carb
: 6s. Fully expect mid 14 sec an street
: slicks with closed exhaust. Out pulled my
: 5.9 R/T on an uphill on-ramp and was
: actually gaining before my son pulled out of
: it!
:
: KB pistons looked real nice going in, and we
: did follow the instructions of KB and our
: machine shop to the letter about the ring
: gap. Hate to install 2nd head gasket to
: lower comp ratio, as we would lose quench in
: the chamber. Have access to piston coating
: for the piston tops and skirts if needed,
: but don't know about increasing ring gaps to
: 0.035". Any and all comments would be
: of great help.
: Thanks
: Smith

: Just pulled down the new engine we had just
: built. The #6 and #4 pistons had broken tops
: (#6 real bad) located at the thin area next
: to the valve pockets caused by what we think
: was the rings end butting due to heat. Top
: ring lands broke straight up and off the
: pistons and exited through the valves after
: smashing plug on #6. Does not look like any
: burned pistons or any melting from
: pre-ignition at all. Used 0.020" over
: KB 2.2 hyper-eut pistons with Hastings
: rings, with the ring gaps opened to
: 0.026" per their instructions. Engine
: has a figured 11:1 comp ratio (35cc head and
: 0.025±" neg deck). Was runing 32° total
: advance and 180° thermostat and running 94
: Sunoco with lead replacement. Cylinders
: appear to be OK with just a hone job
: required. All bearings had some alum go
: throught them and will be replaced. Alum
: parts went out the exhaust, but the head and
: valves appear to be OK.
:
: Any suggestions on replacement pistons? Expect
: to buy 6 new, and if we have to, will bore
: block, can go to 0.080" or 0.100"
: over. Engine was balanced, but if using 6
: matched pistons, should be OK. Car ran like
: H###. Engine pulls great from 1,500 to
: 5,800+ rpm with no soft spots at all. A
: touch rich on #6 and #1 like all 4v carb
: 6s. Fully expect mid 14 sec an street
: slicks with closed exhaust. Out pulled my
: 5.9 R/T on an uphill on-ramp and was
: actually gaining before my son pulled out of
: it!
:
: KB pistons looked real nice going in, and we
: did follow the instructions of KB and our
: machine shop to the letter about the ring
: gap. Hate to install 2nd head gasket to
: lower comp ratio, as we would lose quench in
: the chamber. Have access to piston coating
: for the piston tops and skirts if needed,
: but don't know about increasing ring gaps to
: 0.035". Any and all comments would be
: of great help.
: Thanks
: Smith

: The top ring gaps can butt very easily on this
: type of piston. I would recommend calling
: Keith Black and give them all of you engine
: spec's to see if they recommend a different
: gap. The main factors that affect ring gap
: are cylinder bore diameter, combustion
: temperature(which increases with more
: cylinder pressure) and the distance from the
: top of the piston to the top ring land. The
: closer the top ring is to the top of the
: piston the hotter the top ring becomes,
: thereby requiring a larger top ring end gap.
: The drawback of the short distance from the
: top ring to the top of the piston is that it
: weakens the top ring land area making it
: very suseptible to damage from
: detonation/pre-ignition. Keith Black has to
: run a small top ring land area to draw heat
: out of the top of their piston to keep it
: from collapsing because of poor control of
: silicon dispursement in the alloy itself.
: This is the biggest downfall of their
: pistons.
: One other suggestion is that an 11.0:1 motor
: with a cast iron head is going to detonate
: on 94 octane gas. You are going to need to
: run 100 plus octane if you want to run the
: timing up where it needs to be. Also make
: sure that you run a ductile iron top ring.
: With 11:1 compression it is very easy to
: detonate and a ductile iron top ring will
: handle detonation much better than a stock
: cast ring will. Good Luck!

: Hello all,
:
: Why not just run a substantially larger end gap
: than their spec (like 0.050" or so)? I
: can't imagine the leakage losses are much at
: all when the motor is running, especially at
: high rpms. I seem to remember the stock
: Slant piston max end gap tolerance is around
: 0.050", which is about what mine ended
: up at on my last motor (10 years and 40k
: miles on it, including more than 100 1/4
: mile passes and 4 road course weekends).
: I'll recheck this tolerance number in my
: service manual when I get a chance, and
: maybe someone can correct me here. I don't
: get much crankcase pressure and I'm running
: about 11:1 static on 92 octane (big cam).
:
: Lou

: Lou,
: Are you the guy that was featured in Popular
: Hot Roddings August issue? If,so I would
: like to pick your brain regarding a buildup
: that I am planning for my 64 Valiant. I was
: really impressed by your car and the write
: up. I think you could help me a lot in my
: project.
: I can be reached by email at
: <A HREF="mailto:MikeMaurer321@msn.com">MikeMaurer321@msn.com</A> or by phone at 303
: 743-7893.
:
: Mike Maurer