2270 Build thread, Looking forward to making all of the mistakes! Options

[vjb206]

Hey folks! I've got...

• Case halves from an old 1.7 (cleaned as best I could)
• 2270 crank + P&C kit
• #163/86b Web Cam
• 2.0 heads with 44X36 valves, where I'll be installing dual springs and 38mm exhaust valves
• Upgraded oil pump and other goodies

So my first question for the community has to do with ensuring the rotating mass is spinning freely/correctly…

I started by measuring all of the the main journals on the crank and I got a range from 2.358” - 2.360” (I used a digital caliper and I'm pretty sure I did this correctly).

Then I “dry-fit” Silverline STD/STD main bearings into the case (sans crank), torqued everything down, and got 0.003” in radial play (I used a cylinder bore dial gauge for the first time, and I think I did it correctly).

The spec-sheet says radial play should be between 0.06” - 0.10” (0.03” - 0.09” for #2); and I have 0.003." I'm a MINIMUM of 0.057" off, is that normal? What's my next step?

1. Stop pretending I know what I'm doing and take it to a machinist for test-fitting and honing (I'd like to keep cost down so this is my less preferred option)
2. DIY: hone 0.06" off all bearings (what's the right honing tool / approach here?)
3. Order different bearings (if so, which?)

[Superhawk996]

Also I want to take a second and commend you for learning how to do this. Don’t want these posts to come off as any sort of chastisement.

Learning to use micrometers and snap gages takes time to use them accurately and repeatably. There is a great deal of “feel” to it. You have to have the same feel for each measurement. Otherwise, you can easily be off 0.0005” when using micrometers. Snap gauges even more so. As Ninja said, the snap gage has to be held perpendicular to the bore and can’t be bumped while you lock it or while you remove it from the bore.

Dial bore gages seem easy to use but again as Ninja outlined, you have to have a solid process to “master” to otherwise you’re just adding measurement error.

You are playing in the deep end of the pool and maybe just treading water at the moment. Don’t give up. Keep measuring, learning, and compare results against Plastigage. You’ll be swimming soon!

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