--- Elon Ormsby wrote:
> Scott asked . . . the mechanical cam going into my
> 440 plymouth has an
> advertised lift of .557 inches with rockers that
> have a 1:5 ratio. How much
> would 1:6 ratio rockers affect this. . .
> Scottt, your ratio is actually 1.5:1 or 1.6:1 (not
> 1:5 as you indicated).
> The difference between the two is (1.6 - 1.5 = 0.1)
> or 10%. 0.557 X 110%
> = .613 lift for the 1.6:1 ratio.
Elon... maybe I'm off here but IME you get final lift
by multiplying the true cam lift(differencee between
base circle and full lobe measurement) by the rocker
arm ratio. If Scott's got an advertised lift of .557"
with 1.5:1 rockers, that results in a true cam lift of
.371"(.557 divided by 1.5).
*Note: Cam needs to be measured to be exact IMO as
I've found many of the bike cam manufacturers are off
from what's stated.
Then take the .371" true cam lift and multiply by new
rocker arm ratio of 1.6:1 resulting in a lift of
.594". This is how I've always done and it seems to be
correct on the harley's I've set up and measured
during assembly. I understand about the 1:5 or 1:6
incorrectly written compared to 1.5:1 or 1.6:1(chuck
it up to miscommunication) but not sure I agree with
the formula you've used to achieve the lift by using
percentages of original rocker arm ratio? I'm here to
pay attention and learn, but as my dad always said..
"son, if you don't ask questions how can I tell you
how ignorant you are"... so my question is, have I
been figuring something wrong here?
Todd- just a youngster taking cotton out of his ears
and putting back in his mouth
__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com
/// unsubscribe/change address requests to majordomo@autox.team.net or try
/// http://www.team.net/mailman/listinfo
/// Archives at http://www.team.net/archive/land-speed
/// what is needed. It isn't that difficult, folks.
|