December 8, 200916 yr comment_396579 Hey guy I have a friend that needs a Crankshaft for her 4age and I don't know how to tell the difference between big port and small port. I don't even know if there is any difference between the crankshafts or not. Probely not but I thought I should ask. Report
December 8, 200916 yr comment_396582 small port has a 42mm bigend and the bigport has a 40mm bigend. you can tell the engines apart from the size of the inlet ports, assuming someone hasn't changed the head. Report
December 9, 200916 yr comment_396766 small port has a 42mm bigend and the bigport has a 40mm bigend. you can tell the engines apart from the size of the inlet ports, assuming someone hasn't changed the head. 7-rib bigport has same size bigend as the smallports... Report
December 9, 200916 yr comment_396889 what crankshaft are you after? the better one out of the 2 is the smallport being stronger. Report
December 9, 200916 yr comment_396898 what crankshaft are you after? the better one out of the 2 is the smallport being stronger. One that fits the motor :hmm: Urm, yeah the small port is better (some might disagree) but its not so better if the motor in question is the big port which would mean having to pull the motor down to swap con-rods and pistons.... But, yeah, as Hiro said have a look at the side of the block and see how many ribs it has - 3 its a big port 40mm big ends or 7 its a small port 42mm big ends. But if the cranks out of the block use a Vernier Caliper or two engineers squares (or something like it) with measurements on one to do the same thing. If the motor in question is a big port you could get away with the crank from a 4a-c 4a-f but you'll won't be able to use the 4a-g flywheel. Report
December 10, 200916 yr comment_397194 But, yeah, as Hiro said have a look at the side of the block and see how many ribs it has - 3 its a big port 40mm big ends or 7 its a small port 42mm big ends. Unless it's a 7-rib bigport, which has 42mm big ends but no oil-squirters and still has the bigport head. Report
December 11, 200916 yr Author comment_397429 Thanks for the info guys. Where abouts are the ribs located on the block? Report
December 12, 200916 yr comment_397496 Thanks for the info guys. Where abouts are the ribs located on the block? Intake-side 7-rib block 3-rib block (upside-down) Edited December 12, 200916 yr by Hiro Protagonist Report
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