Engine builders chime in
06-06-2012, 04:32 AM
#11
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Plastigauge works so well for the job because it acts like oil when you tighten the end caps up. When it gets squisjed down, it shows how much clearence it would havebetween the bearings and rod/bearings and crank, and is therefore super accurate. 
Then compare that with what tolerances came with it from the factory in your specific block by the letter codes, and you can assess how well your oil of choice was doing its job in protecting against contact ware as well as the condition of your oil pump through the rev range.
Then compare that with what tolerances came with it from the factory in your specific block by the letter codes, and you can assess how well your oil of choice was doing its job in protecting against contact ware as well as the condition of your oil pump through the rev range.
06-06-2012, 06:24 AM
#13
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haha... 
If plastgauge is as accurate as you guys claim, how come legit machine shops that assemble engines dont use it?
I mean, you guys are looking at plastigauge are gonna be able to tell the difference between a .0018 and a .0020?
fyi- an average human hair is about .004
If plastgauge is as accurate as you guys claim, how come legit machine shops that assemble engines dont use it?
I mean, you guys are looking at plastigauge are gonna be able to tell the difference between a .0018 and a .0020?
fyi- an average human hair is about .004
06-06-2012, 06:48 AM
#14
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Cuci, yes, the F20C has color coded bearings. They block and crank also have letter codes for which bearings to use just like on a B series. Your best bet before you start tearing things down is to download a manual. Plastigauging is also a very good way to ensure your tolerances are in spec after you have figured out which bearings to use. ACL bearings have performance coatings and materials built into them but they tend to be a bit on the loose end of the recommended tolerances to allow for more oil to surround the bearing/ journals. What do you intend to do about the pistons and sleeves? I'm sure you are aware that the stock sleeves are not overbore friendly...
PS: If you do plastigauge, don't forget to account for the extenstion on the sockets which will require a few lbs more than what you're aiming for. Ask me how many times I torqued and retorqued my first motor with loose readings before I figured this out. haha Good luck and have fun
PS: If you do plastigauge, don't forget to account for the extenstion on the sockets which will require a few lbs more than what you're aiming for. Ask me how many times I torqued and retorqued my first motor with loose readings before I figured this out. haha Good luck and have fun
06-06-2012, 08:18 AM
#16
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haha...
If plastgauge is as accurate as you guys claim, how come legit machine shops that assemble engines dont use it?
I mean, you guys are looking at plastigauge are gonna be able to tell the difference between a .0018 and a .0020?
fyi- an average human hair is about .004
If plastgauge is as accurate as you guys claim, how come legit machine shops that assemble engines dont use it?
I mean, you guys are looking at plastigauge are gonna be able to tell the difference between a .0018 and a .0020?
fyi- an average human hair is about .004
06-06-2012, 08:24 AM
#17
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06-06-2012, 11:07 PM
#18
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What I do with ACL's is start off with putting in just standard H's ....torque everything down and check with a dial bore gauge. Depending on the measurements, you swap bearings around- HX's are .0005 bigger and H -.025 are .0005 smaller. Repeat the torque/check procedure. When you get down to where your close and your .000X away from what your goal clearances are you can measure the actual bearings themselves with a bearing micrometer and find one that is exactly what you need.
Yes, the tools are expensive and yes, you might need multiple packs of bearings to do it this way but it pays off if you build engines regularly. You'll have the tools forever and next time you go to build a motor you already have lots of spare bearings laying around
Yes, the tools are expensive and yes, you might need multiple packs of bearings to do it this way but it pays off if you build engines regularly. You'll have the tools forever and next time you go to build a motor you already have lots of spare bearings laying around
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