roladude Posted December 8, 2009 Report Posted December 8, 2009 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. Quote
TRD ke70 Posted December 8, 2009 Report Posted December 8, 2009 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. Quote
Hiro Protagonist Posted December 9, 2009 Report Posted December 9, 2009 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... Quote
930LLO Posted December 9, 2009 Report Posted December 9, 2009 what crankshaft are you after? the better one out of the 2 is the smallport being stronger. Quote
towe001 Posted December 9, 2009 Report Posted December 9, 2009 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. Quote
Hiro Protagonist Posted December 10, 2009 Report Posted December 10, 2009 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. Quote
roladude Posted December 11, 2009 Author Report Posted December 11, 2009 Thanks for the info guys. Where abouts are the ribs located on the block? Quote
Hiro Protagonist Posted December 12, 2009 Report Posted December 12, 2009 (edited) 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, 2009 by Hiro Protagonist Quote
roladude Posted December 12, 2009 Author Report Posted December 12, 2009 Thanks Hiro your a legend :y: Quote
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