staggered rod lengths

i have a brad 5 pm legal head 4.467x4.250
brad forged block/psi c blower 115 0d havent
decided yet on od
and lower plate is cut out
only have port nozzles (no dribblers)
nitro barrel valve
previous owner had total flow heads and 1 and 8 were 020 shorter
rods
the question. is their a certain cyl that usually needs a
shorter rod and by how much 010,020??
im getting ready to order rods and didnt know if i should
run it and after trying larger port nozzles go to a shorter
rod if not corrected by nozzle
sorry for all the questions
thanks duane

 

How much compression does it have?

You said it's a legal pm motor, so it probably was around 12.50 or so?

 

rods

compression will be 10.4
im shortening the rod length to get
the lower compression
rods were 7.291 i think i will be
080-.100 shorter
the compression now is 12.99:1
i poured 91 ccwith it all together
any input is appreciated
thanks
duane

 

compression/rod length

will.or ? the gasket was .062 stroke is 4.250x 4.467
the xtra stroke is i think why its higher comp. than
normal
brad 5 heads pm legal in 2.400 ex is 1.900
flat intake valve and dished exhaust
.100 tall brad block
poored volum is 91 cc with je pm11 pistons
with compression height of 1.425 dome says 16cc
jeremy said thats the only piston he has and to
shorten the rod
my calculations are 91cc=12.99:1
4.467every 010= 2.57 cc=2.1 comp ratio
.100 shorter rod=7.291-.100= 7.191
25.7cc +91cc= 116.7cc=10.35:1
perfect
i just need to repour to be sure

if all this was 4.150 stroke .050 difference it
would be 11.5:1 with 7.291 rod and 101.5cc(i subtracted
the shorter .050 stroke)


is lowering the rod .100 the wrong way to loose compression
i wanted to use a shelf piston but if their is a problem doing
it this way let me know
i will be running a psi c @115od and 9600rpm
please help me make sure this is correct before i order rods
i cant use
thanks to all
duane