Originally posted by cougar694uOriginally posted by ner947 Crower part number 64463, "MITSU 420A ECLIPSE NON TURBO" Intake duration: 258? Exhaust duration: 254? Intake lift: .446" Exhaust lift: .438" (based on rocker arm ratio of 1.75, for both exhaust and intake) Intake valve opens: -3.0? ATDC Intake valve closes: 29.0? ABDC Exhaust valve opens: 35.0? BBDC Exhaust valve closes: -13.0? BTDC Lobe seperation: 110? Duration at .050" lobe lift Intake: 206? Exhaust: 202? Lobe lift Intake: .255" Exhaust: .250" All of this is 100% accurate, seeing as how I have the cam timing tag right in front of me }(
I'm not questioning you in any way, but what did it say the cam specs were measured at? I'm asking because the specs don't add up, maybe I'm being a dumbass today???? With IVO at 3* BTDC and IVC at 29* ABDC, that's 212* (180* + 29* + 3*) duration on the intake side. The exhaust is measuring 228* duration. It's odd because according to the specs the exhaust cam has more duration, which is common on V8's, but not I4's, but it's listed as have 4* more on intake side. It was funny to me, so I entered them into Desktop Dyno, and it showed the 212/228. Even if the measurements were at .050", it's still wrong, according to the card. Where's this extra 16* duration on exhaust side coming from? The overlap actually isn't that great, either. I'm wondering if the cams were measured at something like .025", but that still doesn't explain the exhaust cam. Maybe the specs on the card are wrong. Can anybody shed some light on this??
