Crank Swap???

[crimeinc2]

Hi All,

My buddy damaged the crank in his 260 and was wondering if the crank from a 225 promax could work in it?

[Jay Smith]

Yes it will "work" with the correct top bearing cap. But why would you want to use an oiler crank in a non oiler motor and create all that volume on #2 crank case side ???????????

FYI : That choice of crank change will end up creating a VERY lazy #2 vapor velosity with the volume it creates........

Jay

[TEXAS20225]

I think it will only work if its a small bearing 260 which has only 7 sealing rings anyway( i think) i just tore a 260 apart it had seven ring crank it was original owner motor never been apart ,am i wrong ????? thats at least what ive been looking at but when you get old as dirt sometimes i dont remember just like it was :rolleyes: i also tore one down last year that was a1994 model it was small bearing it had seven ring crank.big bearing crank will only fit big bearing block (i think ) Jay has tore down a lot more of the hipo motors then me but im not sure about the top cap thing maybe he will bring me up to speed. what is the year model of the motor

[Jay Smith]

99 % of all 260 are seven sealing ring motors....As the 225 PM..

Jay

[TEXAS20225]

yes your right both have 7 what difference would there be if one was a oiler gear and the unmachined counter weight with no sealing ring???? and i know early 260 had 11/2 dia top shaft bearing with small bearings and pmax had 13/8 with big bearings my last personal 260 had a 9 ring crank it was a 98 model but i think i was a 280 crank because it had the balance weights on the throws just curious on the crank deal i also just tore down 2 bridge ports one of the a later model which had the same crank the 260s had so guess they use what they have go figure

[Jay Smith]

ALL press on V-6 2.5 bearing cranked motors have the reduction in size of the top throw to make room for the thicker bearing and ALL will have "heavy metal" welded on to the top throw to make up the weight loss difference........Those cranks were installed in 260 from about mid 1995 and ALL 280's...


Jay

[MARCSOTO]

jay, can you use a 2.4 crank on a 260 small bearing case?

[Jay Smith]

I think the radius on the con rod bearing area on the cranks are different from top guide type rods ( 2.5) verses bottom guided rods ( 2.4 )

Jay