2270 Valvetrain Geometry, Learning my way though this build! |
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2270 Valvetrain Geometry, Learning my way though this build! |
vjb206 |
Mar 19 2024, 07:57 AM
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#1
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Newbie Group: Members Posts: 30 Joined: 23-December 19 From: New Jersey Member No.: 23,760 Region Association: North East States |
Hey Folks!
I’m in the process of a 2270 build (I’m a bit of a n00b, but using this as a great learning experience) and have some questions I was hoping the collective wisdom of the board could help me out with… Dual springs I’m running a WebCam #163/86b. This cam calls for dual springs which I had my machinist install. Of course I read the Jake Raby Valvetrain Geometry article after my 1st trial-run of test-fitting the adjustable pushrod to gauge lift. The springs are –so tight– that I bent the pushrod. He warned us, so I can’t complain. My question is - will I do damage to the cam test-fitting like this? I can deal with a slightly bent adjustable pushrod here and there, but I don’t want to damage the internals. Thoughts? Rocker assembly Do I need a shim on either side of the rockers? Or can the rocker make contact with hexagonal support/blocks directly? I’m getting .004 on the feeler with just a solid spacer, 2 shims, 2 rockers, and the 2 support/blocks. This means that I have only 1 shim per rocker, leaving one side un-shimmed, and abutting up against either the support/block, or the solid center spacer. Is that problematic? As usual, thanks in advance! vb |
Jack Standz |
Mar 19 2024, 12:14 PM
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#2
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Member Group: Members Posts: 280 Joined: 15-November 19 From: Happy Place (& surrounding area) Member No.: 23,644 Region Association: None |
Dual Springs
Are you sure the pushrod was seated in the cup of the lifter? If it is riding on the edge of the lifter, you can end up with zero lash and bend the PR. Is the adjustable PR installed and adjusted correctly? If it's too tight, you can end up with zero lash or negative clearance and bend the PR. Rockers Clearance the spacers (make them thinner) as needed and use different thickness of shims to have the rocker approximately centered on the valve stem with a good wiping motion. It's an iterative process until you get it right. Start with multiple shims of varying thicknesses |
Jack Standz |
Mar 19 2024, 12:40 PM
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#3
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Member Group: Members Posts: 280 Joined: 15-November 19 From: Happy Place (& surrounding area) Member No.: 23,644 Region Association: None |
The above assumes the cam/gear was installed correctly. All bets are off if it isn't.
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VaccaRabite |
Mar 20 2024, 05:05 AM
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#4
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En Garde! Group: Admin Posts: 13,465 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
As long as you used a good assembly lube you will not damage the cam or solid lifters.
Did you already do the math the show what your max lift, range of acceptable lift, and exact mid lift should be? Do you know the approximate starting length of your adjustable pushrod? I'm assuming that you are building your rocker arms with the soild bushing kit EMW and TIV store sells? If so, that kit is sold oversized and is intended that you mill down the spacers until everything fits. When I did it, I used 400 grit sand paper on a pane of glass and cutting oil. I'd suggest taking pics and posting them up of what you are attempting. And talk to the vendor of the rocker bushing kit and get instructions on how its supposed to fit. Its been a while since I did it (like 15 years) so the kit may have changed... Zach |
vjb206 |
Mar 20 2024, 07:06 AM
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#5
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Newbie Group: Members Posts: 30 Joined: 23-December 19 From: New Jersey Member No.: 23,760 Region Association: North East States |
Thank you @Jack Standz, and @VaccaRabite
I'm going to find time this weekend for more fiddling and will follow up with pics/GIFs (and likely more questions!). Thanks all! |
Jack Standz |
Mar 20 2024, 10:17 AM
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#6
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Member Group: Members Posts: 280 Joined: 15-November 19 From: Happy Place (& surrounding area) Member No.: 23,644 Region Association: None |
Didn't you mention that you're having Tabari (from the Samba) machine your rockers for swivel feet? If so, why not have him machine them for setting up the spacers?
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vjb206 |
Mar 20 2024, 11:30 AM
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#7
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Newbie Group: Members Posts: 30 Joined: 23-December 19 From: New Jersey Member No.: 23,760 Region Association: North East States |
Didn't you mention that you're having Tabari (from the Samba) machine your rockers for swivel feet? If so, why not have him machine them for setting up the spacers? He just sold me the swivel feet, he's not doing shims / blocks AFAIK. I've asked him and if he says yes, obvi I'll pull the trigger. |
GBX0073 |
Mar 20 2024, 04:39 PM
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#8
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Member Group: Members Posts: 164 Joined: 21-December 20 From: Illinois Member No.: 25,007 Region Association: Upper MidWest |
Tabari
Will sell you cut down blocks and Shims you will be loading up on shims with the cut down blocks |
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