rod big end ID
Thread Starter
Joined: Nov 2009
Posts: 1,112
Likes: 16
From: phx the cactus patch
rod big end ID Hello , I am wondering what the experienced engine builders are ending up at after honing the big end to make round again . Before I started My rods big ends were mostly 2.223", 2.224", 2.223", 2.223", 2,224" and 2.225" as measured across 6 spots ,,,,,,so I'm thinking I should end up with the same locations being right at 2.226" ,,,,,,maybe My measuring equipment is .001" off? Thanx for any help/opinions
Launching!
Joined: May 2012
Posts: 209
Likes: 1
From: NC
Do you have another dial indicator you could measure against and compare the data?
Accuracy is only as good as the calibration of your tool. What you need to do is get an inner diameter that is true and measure against it with two tools. This does two things. It allows you to know the error rate of your current dial indicator and compensate accordingly against two measurements - another calibrated source/tool, and the known diameter of the piece you're measuring. I recommend a Mitutoyo 2in-6in. Steep price at $600, but it removes the possible guesswork scenario as mentioned here.
Also do not forget the compensate for rod stretch when the big end is torqued to spec- the difference should be mentioned from the rod manufacturer. It can also be found. This is mentioned for when it comes time for bearing clearance.
Accuracy is only as good as the calibration of your tool. What you need to do is get an inner diameter that is true and measure against it with two tools. This does two things. It allows you to know the error rate of your current dial indicator and compensate accordingly against two measurements - another calibrated source/tool, and the known diameter of the piece you're measuring. I recommend a Mitutoyo 2in-6in. Steep price at $600, but it removes the possible guesswork scenario as mentioned here.
Also do not forget the compensate for rod stretch when the big end is torqued to spec- the difference should be mentioned from the rod manufacturer. It can also be found. This is mentioned for when it comes time for bearing clearance.
Last edited by SS10Tech; Aug 25, 2012 at 03:59 PM. Reason: Added a few details
