need some help transposing the compression ratio forumla to give me my deck height, i was never good at transposing formulea at school
i calcualted my compression ratio to 11.77 but have lost my calculations and no longer have the dti gauge which i borrowed of a friend to measure it again, i need to know as my head is with the machine shop and they’re waiting to know so they know how much to take the chambers out by
thanks.
you’ve got,
swept volume + X / X = 11.77 so,
swept volume = 11.77X - X
A bit of trial 'n error ought to get you pretty much to finding X, you can then redo the calculation for the desired CR.
sorry ethel, what does X represent?
i have all my other standard figures:
sv - 323.25
rlv - 0.9
pdv - 8.3
gv - 3.2
hv - 17.0
> sorry ethel, what does X represent?
i have all my other standard figures:
sv - 323.25
rlv - 0.9
pdv - 8.3
gv - 3.2
hv - 17.0
17+3.2+8.3+0.9=29.4
323.25+29.4=352.65 divided by 29.4= 11.995 - your current CR.
Play around with bigger values in place of 29.4 to get your desired CR how much bigger is how much wants to come off the head.
Just twigged, if you’re sure of your 11.77 that’s will be because of your deck height so try and match that CR first to find the extra volume (above 29.4) from the deck height.
Right so after some trial and error:
323.25+29.4=352.65 divided by 29.4 ** 29.95**= 11.77
so 0.55cc divided by bore sqcm 39.758952 = 0.0138333 cm = 0.00544 inches = deck height
sounds reasonable & negligible. You could check with a flat edge & feeler blade, not dial gauge accurate but practical.
