Finally got the head problem figured out. Upon pressure testing the head a
pinhole in the head was located in the combustion chamber of #2 cylinder
around 1/4 inch from the spark plug hole. Magnafluxing didn't show it up SO
this rule will always apply for me from now on. ALWAYS have the head pressure
tested!!!! So another head goes to the machinist tomorrow to be rebuilt which
leads to several questions. Is it really necessary to have stellite seats put
in along with Bronze guides? Will a lead additive take care of the no-lead
fuel problem?
And here is another interesting side bar I would like some comments over. I
have another motor that was built many years ago BUT never ran. I
disassembled the complete motor and reassembled after checking all critical
tolerances. Motor is a 948 bored +40 over with flat top pistons. New rods,
new oil pump, cam gears etc... and it is evident the unit was also balanced
due to the machining on all the rod ends and crank throws. New guides with
all new valves, Isky dual valve springs with anodized retainers, new rocker
shaft and rockers along with anodized pushrods (in comparing weights of these
push rods versus stock, these are definitely lighter). The cam is an Isky
W725 OU5 07 MM66. The lift on this cam is 325 and duration is 286 with 107
lobe centers. According to Isky the valve lash is to be set at 20 hot.
SO.......... My question is: with the cam and piston combo is this motor
combination streetable? Inquiring minds would like to know.
Leo
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