Bbc 454 build.
#132
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Joined: Jan 2009
Posts: 688
Likes: 177
From: Finland
Did some flow testing again, with my new ferrea 2.06" valves and small short turn reshaping, made the short turns 0.08" wider, valve has round back cut instead of 30 degree back cut and BOOM!!
BAD port 28"
0.100= 71.3cfm same
0.200= 157cfm +3cfm
0.300= 228cfm +22cfm
0.400=253cfm +24cfm
0.500= 261cfm +18cfm
0.550= 264.5cfm +16.5cfm
0.600=266.2cfm +14cfm
GOOD port 28"
0.100= 71.2cfm +3cfm
0.200= 154.5cfm +8.5cfm
0.300= 229.7cfm +21cfm
0.400= 265.7cfm +15.7cfm
0.500= 275.4cfm +25.4cfm
0.550= 272.2cfm +22.2cfm
BAD port 28"
0.100= 71.3cfm same
0.200= 157cfm +3cfm
0.300= 228cfm +22cfm
0.400=253cfm +24cfm
0.500= 261cfm +18cfm
0.550= 264.5cfm +16.5cfm
0.600=266.2cfm +14cfm
GOOD port 28"
0.100= 71.2cfm +3cfm
0.200= 154.5cfm +8.5cfm
0.300= 229.7cfm +21cfm
0.400= 265.7cfm +15.7cfm
0.500= 275.4cfm +25.4cfm
0.550= 272.2cfm +22.2cfm
#134
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Joined: Apr 2019
Posts: 498
Likes: 123
#136
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Joined: Jan 2009
Posts: 688
Likes: 177
From: Finland
#138
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Joined: Jan 2009
Posts: 688
Likes: 177
From: Finland
It is time to order timing set, comp 7101 seems perfect. ZZ502 camshaft has 110 lope and 108icl, so it is only 2 degrees advanced. Did some valve timing calculations with different ICL choices and compared the results to crane 731 and HP500 carb camshaft. here is what it looks like @.050.
.................................................. .................................................. .................................................. ............IVO ......................IVC ....................EVO .......................EVC ...........Overlap
-Crane 731, 226/236, 112 lsa, 107icl ground to cam .................................................. ............................6*btdc ..............40*abdc ..............55*bbdc.................. 1*atdc................ 7*
-HP500, Crane 611, 222/230, 110 lsa, 105icl ground to cam .................................................. ...............6*btdc.............. 36*abdc.............. 50*bbdc.................. 0*atdc................. 6*
-GM zz502, 224/234, 110 lsa, 108icl ground to cam, 4 degrees more advance, 104icl. ........................8*btdc.............. 36*abdc.............. 53*bbdc................... 1*atdc................ 9*
Not sure but with 104icl the ZZ502 cam would work with silent choice system.
.................................................. .................................................. .................................................. ............IVO ......................IVC ....................EVO .......................EVC ...........Overlap
-Crane 731, 226/236, 112 lsa, 107icl ground to cam .................................................. ............................6*btdc ..............40*abdc ..............55*bbdc.................. 1*atdc................ 7*
-HP500, Crane 611, 222/230, 110 lsa, 105icl ground to cam .................................................. ...............6*btdc.............. 36*abdc.............. 50*bbdc.................. 0*atdc................. 6*
-GM zz502, 224/234, 110 lsa, 108icl ground to cam, 4 degrees more advance, 104icl. ........................8*btdc.............. 36*abdc.............. 53*bbdc................... 1*atdc................ 9*
Not sure but with 104icl the ZZ502 cam would work with silent choice system.
Last edited by JaniH; 12-06-2019 at 10:52 AM.




