Good eye Charlie, my comment of a 2.008" big end was the rod ID, not the journal.  The journals are 1.889".


Charlie Burns Laton, Ca (South of Fresno)







BurnsRacing981@gmail.com

Back to the 338" Y-Block build.  Next is relieving the block.





Charlie Burns Laton, Ca (South of Fresno)







BurnsRacing981@gmail.com

Are you allowed to have those clothespins?

  Dennis in Lititz PA

Hi, Dennis, it's ok, they are snap-on.


Charlie Burns Laton, Ca (South of Fresno)







BurnsRacing981@gmail.com

The dial indicator shows all 16 valves has cylinder wall interference.  I started by tracing all the valve pockets in the head gasket onto the deck.




Charlie Burns Laton, Ca (South of Fresno)







BurnsRacing981@gmail.com

Charlie.
What valve lift are you running and how much have the heads been milled?  My "iron head" rule of thumb for cylinder wall notching is when the intake valve lift exceeds 0.535”.  Milling the heads does force the need for cylinder wall notching sooner.  The exhaust valve typically free drops into the cylinder so no notching has been required for those.  While I prefer that the top piston ring groove to be as close as possible to the top of the piston, that does compound the ability to have cylinder wall notches deep enough for the high lift camshafts.  In those cases, I’ll have the piston ring 0.350” from the piston top.

Lorena, Texas (South of Waco)

Charlie.
I neglected to ask if you have stock sized valves or are they larger?  Larger than stock valves does bring valve to cylinder contact issues to the forefront much sooner.

Lorena, Texas (South of Waco)

WoW!  They look bigger to me!   :rolleyes






NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Probably mentioned earlier, but what casting letters are the heads?.  Reason for asking is that in the case of ECZ-G heads for instance, it's my understanding, that valve shrouding occurs with overly large iintakes.?   I'm hardly an expert on Y-Block race engines, but I seem to recall that John Mummert, possibly (?) stated in the past that notching the block for valve clearance, often resuls in a noticeable loss in compression.. So, the extra lift at the valves may not be productive?.  As an example, a friend many years ago beveled the block in his Y-Block "D" gas racer. It didn't result in any improvement in  performance that we could see...    


Paul

Sorry, been away for a while, but back now.
Hi, Ted, in answer to your questions, the total lift is .556 on the intake and .553 on the exhaust.  I am still using those lightened and polished stock 1.54 rockers.  They have seen 7k rpm so many times and I am very impressed that they have held together.  It would be nice to have some 1.60 or higher ratio roller rockers, but this has always been a budget race program.

You also asked about the milling of the heads.  They have just been touched up and the lugs still measure 1.00".  You also asked about the valves and they are 2.02" on the intake and 1.60 on the exhaust.  Another concern is the top ring distance to stay below the reliefs.  These Racetec pistons were ordered by John Mummert after we discussed all the requirements for this build.  The rings are of course 1.63 mm (1/16") with extra crown, flat top, and the first land is at .400"


Charlie Burns Laton, Ca (South of Fresno)







BurnsRacing981@gmail.com