Aye-yie-yi...... my head hurts........ <img src="/forums/images/graemlins/shiner.gif" alt="" />

Delta Cams tech says the truck cams would be best for building cylinder pressure - particularly with a blower, and that even if I increased cylinder pressure by advancing the Diamante cams, the extra 4* overlap would bleed off cylinder pressure at low-moderate rpms. I asked if there was a penalty on the exhaust side to using the Montero cams.... he didn't think so.... but then it took him a while to understand that his suggestion of simultaneously advancing the intake and retarding the exhaust couldn't be done on a SOHC engine - even with eccentric cam bushings.... unless he could figure out a way to twist my camshafts in several places. <img src="/forums/images/graemlins/lol.gif" alt="" /> <img src="/forums/images/graemlins/scared.gif" alt="" /> <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

The Dodge Racing tech cam designer at Custom Cams on Motorsports Drive in Martinsville, VA was next on my list...... he listened to my findings and concerns about intake closing point.... then proceded to take me to school. <img src="/forums/images/graemlins/wink.gif" alt="" /> Smart fella, that'un and well worth listening to. After running some numbers through his calculator brain, he asked for piston stroke, valve opening/closing points, LSA, C/L, duration, lift, lobe design, rocker ratio, etc.... and declared that the Montero cam was good on power to 6000rpms and the Diamante cam was good to 6300rpms.... but that the 115*ATDC centerline of the Diamante cams installed straight up is way too retarded give best power (Montero is 110*ATDC). He explained that while the intake closing point is important to cylinder pressure, what is most important is piston speed at the moment the valve is near maximum lift..... that's what really packs the cylinder. So, since he liked the longer duration for top end, his suggestion was to use the Diamante cams, but advance them to 110-108*ATDC, which rolls the Diamante cams forward 5-7* and coincidentally closes the intake valve exactly where the Montero cam does. <img src="/forums/images/graemlins/wink.gif" alt="" /> He also thought that rolling the Diamante cams forward would increase power from bottom-to-top AND move the torque ramp down a few hundred rpms.

So, he and I have arrived at the same conclusion for different reasons to resolve the same issue from different perspectives with the same remedy <img src="/forums/images/graemlins/scared.gif" alt="" />...... the most power from the cylinder - produced by the largest charge under the most pressure. The truth is, it's all important - the trick is to get as much of all variables resolved toward a best compromise... and to do it via guesswork.

I tell ya..... some days are better than others. In the end, you sometimes flip a coin, turn the wrench and see what happens.

Frank