Short duration cam, installed retarded - thoughts?
#1
Short duration cam, installed retarded - thoughts?
I've been toying with cams again and I'm just curious what others would think of a setup like this. Instead of larger lobes, installed at an advanced centerline to boost DCR and keep the powerband in a useable range, or even medium durations installed straight up, what about this:
220/224 109 LSA 112 ICL
IVO -2 BTDC
IVC 42 ABDC - power peak about 6200
EVO 38 BBDC - long power stroke, great torque
EVC 6 ATDC
Overlap 4*
Overlap Bias -4* - intake biased, pull well past peak
Compared to a 228/232 110 cam which seems rather popular right now, the shorter cam has 6 degrees less overlap. When setup with the same IVC (in this case, installed +2, which is 1 degree biased to the exhaust) and should make much more low end power, without giving up much top end.
Is installing such a cam 3 degrees retarded a bad idea?
220/224 109 LSA 112 ICL
IVO -2 BTDC
IVC 42 ABDC - power peak about 6200
EVO 38 BBDC - long power stroke, great torque
EVC 6 ATDC
Overlap 4*
Overlap Bias -4* - intake biased, pull well past peak
Compared to a 228/232 110 cam which seems rather popular right now, the shorter cam has 6 degrees less overlap. When setup with the same IVC (in this case, installed +2, which is 1 degree biased to the exhaust) and should make much more low end power, without giving up much top end.
Is installing such a cam 3 degrees retarded a bad idea?
#3
I played around with the idea of a 224/228 on a 108 or 109, retarded to get the intake closing to 42* or 43*. I think something like this could work excellent for the reasons you stated.
#4
TECH Senior Member
iTrader: (7)
EVO of 38* requires a very good exhaust to make power in the higher rpms. Just having a lot of negative overlap bias isn't going to ensure that will pull well past its peak. You'll be helped by having a late IVO, but you're facing a lot of pumping loss with such a late EVO.
I think a 110 ICL might work as well or better for an overall street cam.
I think a 110 ICL might work as well or better for an overall street cam.