MG MGB and MGB GT Tech Talk
In preparation for the rebuild of my B engine I have been re-reading everything I own on the process. Lindsay Porter's book explains a process of gauging the clearance in the main bearings. He uses "Plastigauge" in the process. I found the web site for the company, but to get it I have to order from England. Is there an alternative to this process? Can it be purchased here in the US?
Any auto parts store or the machine shop your using would probably give you one.
I just found an old thread discussing it. Sorry for repeat, but while I have you, do you know what color I need for the main bearings?
both auto parts stores I worked for gave it away. Just tell them what you're doing and they'll get the right stuff for you. Most of what I've seen used was green.
It's been a while, but I think I used green. The colour gives you the range that it can measure. The ranges overlap, so there may be more than one colour that will work. It is easy to tell, though. It comes in a paper wrapper that has bars of differing widths that show the clearance after the plastic is squished. Just pick one that has bars in the range you want to measure.
"When reassembling your engine, you'll need a variety of Plasticgauge to measure bearing clearances. This popular assortment includes one blue strip for .004" - .009" clearances, two red strips for .002" - .006" clearances and two green strips for .001" - .003" clearances. Each strip is 12" long."
This was copied from another site and lists the color/ranges. Looks like green is what you need. Haynes says spec is 0.001 to 0.0027
