GN Crank Casting 229

Got to measure and polish a 1987 GN only crank today:) Casting 229, 1985-1987. Measured nicely. The motor is reported to have only 40,000 miles on it.
gn-229.png

Good to have a posting in this section!
 
specs from gnttype

Factory Engine Specifications
Brian Sowle - [email]gnfast@together.net[/EMAIL]
Introduction
This document contains all the dimensions, clearances, and spring pressures for the VIN 7 87 Turbo motor. These are directly from the GM manuals not Chilton's. Now I know that certain engine builders use looser or tighter clearances so don't start a huge thread on how this or that clearance is wrong. Like I said these are from the GM manual. If I were doing a rebuild I would stick with the Factory clearances. How many 140,000 mile cars do we have currently running???
Notes
[h=2]Engine Dimensions and Fits[/h]
[h=3]General[/h]​
[h=4]Piston Clearance Limits[/h].
Top Land
.046 in. - .056 in
Skirt Top
.0008 in. - .0020 in
Skirt Bottom
.0013 in. - .0035 in
[h=4]Ring Groove Depth[/h].
#1 - Compression Ring
.185 in. - .194 in
#2 - Compression Ring
.186 in. - .194 in
#3 - Oil Ring
.188 in. - .196 in
[h=4]Ring Width[/h].
#1 - Compression Ring
.077 in. - .078 in
#2 - Compression Ring
.077 in. - .078 in
#3 - Oil Ring
183 in. - .189 in
[h=4]Ring Gap[/h].
#1 - Compression Ring
.010 in. - .020 in
#2 - Compression Ring
.010 in. - .020 in
#3 - Oil Ring
.015 in. - .055 in
[h=4]Piston Pin Length[/h]
2.900 in
[h=4]Diameter of Pin[/h]
.9391 in. - .9394 in
[h=4]Pin Clearance in Piston[/h]
.0004 in. - .0007 in
[h=4]Pin Press Fit in Rod[/h]
.0007 in. - .0017 in
[h=4]Pin Direction and Amount Offset in Piston[/h]
.040 in
Major Thrust Side
[h=3]Connecting Rod Specifications[/h]​
Bearing Length
.654 in
Bearing Clearance (Limits)
.0005 in. - .0026 in
End Play
.003 in. - .015 in
[h=3]Crankshaft Specifications[/h]​
End Play at Thrust Bearing
.003 in. - .011 in
Main Bearing Journal Diameter
2.4995 in
Crankpin Journal Diameter
2.2487 in.
- 2.2495 in
Main Bearing Overall Length.
#1
.864 in
#2
1.057 in
#3
.864 in
#4
.864 in
Main Bearing to Journal Clearance
.0003 in. - .0018 in
[h=3]Camshaft Specifications[/h]​
Bearing Journal Diameter
1.785 in. - 1.786 in
Journal Clearance in Bearings.
#1
.0005 in. - .0025 in
#2,3,4
.0005 in. - .0035 in
[h=3]Valve System Specifications[/h]​
Rocker Arm Ratio
1.55 to 1
Valve Lifter Diameter
8420 in. - .8427 in
Valve Lifter Clearance in Crankcase
.0008 in. - .0025 in
Minimum Valve Margin
.025 in
Intake Valve.
Head Diameter
1.715 in. - 1.705 in
Seat Angle
45 degrees
Stem Diameter
.3412 in. - .3401 in
Clearance in Guide
.0015 in. - .0035 in
Exhaust Valve.
Head Diameter
1.505 in. - 1.495 in
Seat Angle
45 degrees
Stem Diameter
.3412 in. - .3405 in
Clearance in Guide
.0015 in. - .0032 in
Valve Spring.
Valve Closed
90 lbs
+or- 4 @ 1.727 in
Valve Open
245 lbs
+or- 10 @ 1.340 in
 
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