1219 Sealed conversion.

[Legend79]

What does a newly built 1250 pump? I thought the 1200 was limited to stop it being quicker than the 1250, doesn't the 175 on each cylinder make it produce more power?

[knoxracing]

The 1250 will pump 160 to 180.  The pumping compression at 175 should be better than a 160, and would be it put together properly. A 1219 sealed motor built right pumping 175 would be an advantage over the 1200 pumping a a safe 160.

[Grape Competition Develop]

Absolutely no reason to sell a customer sleeves when going from stock bore 1200 or even the legal amount of overbore which is .5 mm.  1200's have a 77mm bore, 1219 is 78mm bore, the new 1250 is 79mm bore.  Some of the first callahan 1219's were left with full domes on the wiseco piston, ending up with the mechanical compression ratio over 11-1.  We were told to fix all of those we saw when we were part of the engine building program.