Board index Flathead Power-Technical Questions, Answers, and Suggestions Indians Cylinder bore

Cylinder bore

Post Wed Jan 15, 2020 7:13 pm

Posts: 124
heres a set of 741 cylinders bored out to 2-7/8" sport scout size.
the max is supposed to be 70mm or 2-3/4" but these cylinders were obviously in service.
It gives hope to rescuing old cylinders but then SS pistons have a lower CH 1.525" so low comp.
741 = 1.65625"

https://www.ebay.co.uk/itm/Indian-741-7 ... 4331225357
Last edited by friday on Fri Jan 17, 2020 2:25 pm, edited 1 time in total.

Post Fri Jan 17, 2020 12:59 am

Posts: 1474
Location: Ojo Caliente,NM,USA
Wonder what stroke and rods they were running? Id always heard that 2 7/8" was a surefire recipe for broken cylinders. Even seen pictures of a few blowed in half. Those obviously ran a while though. I've got a 741 with Sport scout wheels n rods with GS850 pistons that has been rock solid and runs right on down the road.
Dusty

Post Fri Jan 17, 2020 2:33 pm

Posts: 124
cant possibly be SS stroke. would have to be 741 stroke and limping along with low compression.
I measured 1925 cylinder and is the same as 741 cylinder dimensions so 2-3/4 is normal bore max.
the Junior scout has the same cast as the early scout


because of low compression , possible candidate for super charge ?

Post Sat Jan 18, 2020 3:05 pm

Posts: 1474
Location: Ojo Caliente,NM,USA
Why can't it be 3.5" stroke? I've got a SS lower in a 741 With no problem finding 69 mm pistons with the right compression height but if you wanted to use the SS pistons a .250 stroker plate would be in order. But even though they got away with 2.875 on that set it seems to generally be a very bad idea.
Dusty

Post Mon Jan 20, 2020 1:40 pm

Posts: 124
yea , cylinder height diff


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