Lapping Rocker Arms?..

[1992suburban]

I noticed NR racing sells them... so I did mine on the head that I plan on installing. Not sure it will make a difference what do you guys think??

 

[anderkart]

I've never heard of this before but that site said "lapped and treated". After lapping to get a better fit together, I'd imagine "treated" means they've had to re-polished the rocker arm/pivot mating surfaces to get them smooth again.

 

[1992suburban]

they seem REAL SMOOTH i would guess helps distribute the load.. reduce wear

 

[freakboy]

Or the like the ricers think shiny adds horsepower lol. i think its more or less for smooth ooperation.

 

[anderkart]

they seem REAL SMOOTH

What grade/grit # Lapping compound did you use?

 

[1992suburban]

the water based.. and diluted it some more


so who knows man???

 

[anderkart]

The reason I asked what type of lapping compound you used is because they make serveral diferent grades/grits from extremely fine polishing (1200 grit) to extra course 50 grit that would leave the mating surfaces pretty rough. I just figured the lapping compound you used might say what grade or grit it is somewhere on the label.


Check out this site:
http://www.lapmaster.com/consumable...id=googleppc&gclid=CNGXg8b9sp0CFSANDQodRBlXig

(quote)
Lapping compound GRIT Descriptions Average Particle Sizes of Abrasive Grains

1/1000
inches Microns
(0.001 mm)

EFA 1200 EXTREMELY FINE
Polishing, High Precision Lapping 0.12 3
EFB 1000 0.20 5
EFC 800 0.38 9

VFA 600 VERY FINE
For fine Polishing and Lapping 0.56 14
VFB 500 0.68 17
VFC 400 0.90 23
FA 320 FINE

For Finishing, Valve Lapping, Bearings, Dies and Gauges 1.28 33
FB 280 1.75 44
MFA 240 MEDIUM FINE
For Cylinder Lapping 2.48 63
MFB 220 2.6 66
MA 180 MEDIUM

General Purpose for controlled Metal Removal 3.4 86
MB 150 4.8 122
CA 120 COARSE

For Higher Stock Removal Requirements
Fast material removal 5.6 142
CB 100 6.8 173
CC 80 15 267

VCA 50 VERY COARSE
For Fastest Metal Removal 18 463
VCB 36 28 710

 

[1992suburban]

for valves... thats the one

 

[anderkart]

Cool, that should end up pretty smooth.

 

[1992suburban]

these motors its all about the tenths of HP LOL

just got to get it put on..

OH and by the way I put stock springs back on although you can install the 26lbers with your fingers
they may be a bit much..