Navarro six, camshaft specs

[Tom Jennings <tomj@xxxxxxx>]

OK, I put the camshaft on V-blocks and worked out cam specs with a
dial indicator. Timing is probably within 5 degrees, I used a
36-tooth timing gear as "degree wheel", it's 20 crankshaft degrees
per tooth, I figure I can accurately guess 1/2 a tooth trough or
peak.


.318" lift (I and E both) at the cam.

timing at .050" lift at the cam:

I open  45 btdc
I close 15 abdc

E open  75 bbdc
E close 15 btdc (-15 atdc)

240 degrees duration, I'm too tired to work out overlap tonight.

An older desktop dyno program produces the following numbers:

rpm	hp	torque
2000	77	202
2500	98	206
3000	113	197
3500	132	197
4000	150	197
4500	164	192
5000	173	182
5500	175	167
6000	173	151
6500	164	132
7000	148	111
7500	132	93
8000	108	71

I know the actual numbers are fiction, but the relative numbers
(hp peak at 5500) seems about right. Seems like a nice cam!


If I retard the cam 15 degrees, hp climbs to 191. I know the
actual numbers are fiction, but does the relative change make any
sense? I know how cams work, and the idea behind lead and lag, but
it's all on paper and in my head, very little hard experience.

Since I'm having to guestimate absolute cam timing (eg. it's on a
damn bench, not in a motor) maybe "retard 15 degrees" means
pushing it to the right position; eg. my bench setup is off by
that much.)