[oldman]

For folks that care here are the 3 Lingenfelter blower cams:
GT31 217 / 231 Average duration 224, LSA 121 overlap - 11 degrees
This is sold as a smooth idle cam

GT34 229/233 Average duration 231, LSA 118 overlap -5 degrees
This is sold as a Muscle Car, semi-aggressive idle cam

The "bigger cam" GT35 made with either big or HUGE fuel lobe for high boost fueling is:

GT 35 210/237 Average duration 223.5, LSA 116.5 overlap -9.5
This is sold as a Muscle Car, semi-aggressive idle cam


Here we have the biggest cam with even LESS duration than the smooth idle cam, but because of the more performance LSA of 116.5, it is rated at more HP, and also ding ding ding… semi-aggressive idle. Note, less duration, tighter lobe (LSA) than the smooth idle cam = semi-aggressive idle.


Conclusion, when duration is DECREASED by .5 average GT31 to GT35, from the smooth idle cam a 4.5 change in LSA results in rough idle, therefore LSA is fundamentally and is the largest contributor to idle. By formula it is 4x more effective, that any single degree of change from either intake or exhaust duration, and 2x more effective than an average duration change (changing BOTH intake and exhaust duration).


I think the GT31 cam makes the most sense a wide LSA, long exhaust.

I think the GT35 cam is an interesting way to make a high boost cam, drop the intake duration, expand the exhaust duration even further and tighten the LSA.


Both cams make up very interesting sides of the cam spectrum. My cam came as part of a package, I guess it would be called Pray stage 1 it has close to zero overlap and is more related to other builders. Pray has the dyno run of his stage 2 cam with a few degrees of overlap posted and that cam pulls to 7000 RPM and is making serious HP.


Actual LT1/4 supercharged cams rated by a top builder.