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Old 05-08-2017, 10:59 PM
duxthe1 duxthe1 is online now
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Join Date: Oct 2004
Posts: 4,177
Dropped the head off today. Looks like a 3 week wait due to my machinist taking next week off. I don't trust anybody else to do the work so the wait is what it is.

Meanwhile I've been researching the cams. I have a 57B exhaust cam, pretty standard part. My math says 197 degrees duration @ 2mm lift. My intake cam, a 67B doesn't exist as far as I can tell. I've found over a dozen cam codes, but no 67 mentioned anywhere. It appears to have a 32 degree advancer typical of most 104s. If its like any other 104 cam I've seen numbers for, it would have 180 degrees duration @ 2mm lift.

I've heard talk that an exhaust cam could be swapped for an intake. This gets the gears turning in my head. If I could swap an exhaust cam in for an intake that would pick up ~17 degrees of duration. I was also thinking that with the extra duration I'd use a M111 or M119 advancer on it for only 20-22 degrees of advance / retard. This would keep the valve events in a reasonable range despite the extra duration. The duration increase would lessen dynamic compression but the head is going to be milled to clean up the damage to the #4 fire ring so it will pick up some compression there. I gave my machinist the minimum spec, but I'm not sure it will clean up at the min so I told him go as far as necessary and I'd deal with the clearance and valve timing issues.

Would love to hear some thoughts on this idea from the 104 gallery.
__________________

90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE
104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff
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