dyno 3 was another fail
Thread Starter
Joined: Mar 2011
Posts: 3,699
Likes: 168
From: Wilmington, DE
dyno 3 was another fail i got tuners permission before posting, despite still going with his diagnosis of new injectors but read on
tried dynoing this thing again. if u remember, dyno 1 was around aug 2019. erl motor that was not built proper and bottom end failed but had nice sweeping curve that just never made power.
dyno 2 around may 2020 was new shortblock with same top end except for msd intake. then that one had an issue with pushrod holes being too small in heads, so we pulled heads to make larger. never skimmed the hesds for reassembly since it didnt seem nevessary but bought new gaskets. so we then ran crower rockers, taller valve covers, new pushrods, longer new plug wires. reassembled it
dyno 3 today, now you can hear it stumble slightly in lower rpm when rowing through gears on dyno. it has 3 dips in it, largest around 3000 where larger heads typically dip, one less large around 3800 and a small dip somewhere in the upper 4 to low 5000s. it seemed as the dyno pulls progressed the dips got larger. the dyno number is also rolling over around 6100 and is making around 510 and the torque was 500 or so. if u look at last pull on dyno 2, you can clearly see the pull still rising at 5600 despite the pushrod issue, while 5600 now is leveling off.
the other interesting thing is it made more power when he went from 13.0 to 12.5 which isn't right, interestingly enough he saw in the logs that 1 bank was lean whole the other is rich and since the sniffer is in the y pipe it's averaging it out to 13 which makes it look good when they are not. also on both banks, 2 plugs were black while 2 were white/visually looking lean.
we tried new plugs, used gm wires, readjust rockers since the heat was added, tried gm coils and just for ***** tossed in new o2s, which one was struggling anyway so no biggie. we virtually eliminated the spark issue I guess, and can sorta rule out fuel to the rail since it's missing down low and not really up high, at least not that we see even though it probably is. and obviously the misfire counts are turned off.
the only thing it can be is injectors at thus point or the injector data for some reason is off, even tho the injectors worked fine a year ago at dyno 1 and didn't appear to be screwing up at dyno 2 2 months ago.....are we missing something?
tried dynoing this thing again. if u remember, dyno 1 was around aug 2019. erl motor that was not built proper and bottom end failed but had nice sweeping curve that just never made power.
dyno 2 around may 2020 was new shortblock with same top end except for msd intake. then that one had an issue with pushrod holes being too small in heads, so we pulled heads to make larger. never skimmed the hesds for reassembly since it didnt seem nevessary but bought new gaskets. so we then ran crower rockers, taller valve covers, new pushrods, longer new plug wires. reassembled it
dyno 3 today, now you can hear it stumble slightly in lower rpm when rowing through gears on dyno. it has 3 dips in it, largest around 3000 where larger heads typically dip, one less large around 3800 and a small dip somewhere in the upper 4 to low 5000s. it seemed as the dyno pulls progressed the dips got larger. the dyno number is also rolling over around 6100 and is making around 510 and the torque was 500 or so. if u look at last pull on dyno 2, you can clearly see the pull still rising at 5600 despite the pushrod issue, while 5600 now is leveling off.
the other interesting thing is it made more power when he went from 13.0 to 12.5 which isn't right, interestingly enough he saw in the logs that 1 bank was lean whole the other is rich and since the sniffer is in the y pipe it's averaging it out to 13 which makes it look good when they are not. also on both banks, 2 plugs were black while 2 were white/visually looking lean.
we tried new plugs, used gm wires, readjust rockers since the heat was added, tried gm coils and just for ***** tossed in new o2s, which one was struggling anyway so no biggie. we virtually eliminated the spark issue I guess, and can sorta rule out fuel to the rail since it's missing down low and not really up high, at least not that we see even though it probably is. and obviously the misfire counts are turned off.
the only thing it can be is injectors at thus point or the injector data for some reason is off, even tho the injectors worked fine a year ago at dyno 1 and didn't appear to be screwing up at dyno 2 2 months ago.....are we missing something?
