BBC rod bearing clearance
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Re: BBC rod bearing clearance
I do not see you getting an accurate measurement with dial calipers in this case. Take it to someone with the right equipment and get it checked.
Abbott Racing Heads and Engines
Re: BBC rod bearing clearance
I know exactly why all the plastigage didnt flatten in the center: I had ordered the wrong bearings. I ordered the bearings for an aluminum rod, one that has the dowel hole in it. But I was told I could use them with my steel rod. I also researched here and abroad that many different engine builders have done this before too.
I also didnt have 2 rods on the journal before I torqued the bolts. The cap may have moved around a bit and not flattened correctly. The next post will be plastigage with 2 rods side by side:
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Eric
Re: BBC rod bearing clearance
It looks like the PG at the bottom of the pic is showing more like 0.0010-0.0015" gap vs. 0.0020" at the top! When you re-do it with both rods, put snug-fitting feeler gauges between the rods JIC, to prevent twist.
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
Re: BBC rod bearing clearance
This is just an idea of my .003 measurement that I came up with, measured with plastigage. 2 rods side by side. This measurement doesnt show .003 unless you are suppose to double the measurement for the other side....I know its not an accurate measurement but it is a little offcenter, since the dowel hole (non smashed plastigage) isnt shown in the plastigage.
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Last edited by Bishop540 on Tue Sep 25, 2018 4:35 pm, edited 1 time in total.
Eric
Re: BBC rod bearing clearance
Great idea. I didnt even do that this time. But i did measure it with a .015 feeler gauge. But didnt think about leaving it there when i torqued the caps. Now I am out of plastigage.......
Eric
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Re: BBC rod bearing clearance
Get more plasti-gauge and play with it until you can get consistent results. It is WAY better than the dial caliper and math method you started with!