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Workshop => Engine and Bottom End => Topic started by: Kevhes11 on June 10, 2014, 08:12:15 PM

Title: Case boring size and stroke question
Post by: Kevhes11 on June 10, 2014, 08:12:15 PM

Couple questions here. I just bought a complete bottom end locally. Good shape and all I just have a couple questions. How can I assure myself that it has a stroker crank ( I was told it's a 4 mil ) and that the cases are bored for a big bore. I don't want to track down a big bore cylinder only to find out I have to tear the motor down first lol. Thanks in advance

Title: Case boring size and stroke question
Post by: patman13mia on June 10, 2014, 09:07:41 PM

use some calipers. should measure out to 3.350 or anywhere near that

Title: Case boring size and stroke question
Post by: Kevhes11 on June 11, 2014, 02:18:26 AM

Thanks I'll check that out

Is there a way to make sure the crank is a 4 mil ?

Title: Case boring size and stroke question
Post by: patman13mia on June 11, 2014, 11:08:24 AM

that i dont know. maybe the numbers on the side of the crank shaft will tell ya if you look it up

Title: Case boring size and stroke question
Post by: Kevhes11 on June 11, 2014, 04:29:08 PM

I was told it's an oem crank rebuilt as a stroker crank. I know Esr does it and I'm sure some other places do but is there a way to tell

Title: Case boring size and stroke question
Post by: traxman on June 11, 2014, 04:59:53 PM

Put in a wrist pin bearing and a wrist pin and measure the distance from the tin to the bottom of the wrist pin@ tdc and bdc.  Subtract the bdc distance from the tdc and you should have a measurement of 76mm for a +4mm crank. You don't have to use a wrist pin, you could use the bottom or the top of the wrist pin hole on the rod if you wanted. Either way, it should get you close enough to tell whether it's  a 4mill or not.