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?)

[technicalninja]

That's the way...


Plasti-gauge can only be used on split bearings. The single piece bearings have to be measured.


It's HARD to properly torque up a rod without moving it.

The tiniest movement destroys the accuracy.

They missed some important tips.

Make your length of plasti-gauge that you're inserting in the journal slightly narrower than the bearing width. It's best to have .020" (.5mm) on either side of the strip or you will have a harder time cleaning the PG off of the bearing and the crank. The radius corners squish the piss out of plasti-gauge; try to keep it out of the corners.

It is IMPORTANT to carefully remove the plasti-gauge after testing completely.
I use soft rags, WD/40, alcohol, and a soft touch. The inner surface of an engine bearing is extremely soft. You can scratch it with your fingernail.
Don't damage this surface when cleaning.

[Superhawk996]

It's HARD to properly torque up a rod without moving it.

The tiniest movement destroys the accuracy.

@technicalninja

Much easier if done between centers where you can alllow the rod to sit against something to prevent inadvertent rotation on the journals. In this photo, I would allow the small end to rest on the ways which have cardboard on them to prevent damage to the rod while being torqued. Unfortunately I don’t have a photo in that position but I trust you get the jist of the setup.



Not a hint of smearing



When I did my first engine I didn’t have fancy tools. Just put crank on a soft surface to protect it (cardboard, shop towel, etc.). Assemble rod horizontally, while laying against bench top, again so the rod can’t rotate.

I’ve also had good luck doing it while case is mounted in engine stand, rods hanging down. Use something soft (wood dowel, cardboard, etc) to jamb the small end of the rod so it can’t rotate while torquing the fasteners.