Jump to content

Z31/camspecs php: Difference between revisions

From Z31 Library
← Older editNewer edit →
Inline image refs: rewrite to local archive; clean empty image artifacts
CleanupBot (talk | contribs)
839 edits
Residue cleanup: re-convert body verbatim from archived source; restores 78 dropped text blocks
Line 1: Line 1:
{{ImportedFrom|site=Xenonzcar|title=XenonZcar|url=https://dev.z31library.com/xenonzcar_archive/z31/camspecs.php.html|archive=https://dev.z31library.com/xenonzcar_archive/z31/camspecs.php.html|fetched=2026-05-15}}
{{ImportedFrom|site=Xenonzcar|title=XenonZcar|url=https://dev.z31library.com/xenonzcar_archive/z31/camspecs.php.html|archive=https://dev.z31library.com/xenonzcar_archive/z31/camspecs.php.html|fetched=2026-05-15}}
== Z31 Camshaft Specifications and Upgrade Information ==
One of the ways you can make more power with your Z Car Engine is by upgrading the Camshafts in your engine. There were a few different cams used in the VG30E, VG30ET, VG33E, VG33ER Engines throughout the years of production.  https://dev.z31library.com/xenonzcar_archive/2025siteimages/cams.jpg


== Understanding Camshaft Specs ==
== Understanding Camshaft Specs ==
Line 11: Line 15:
In high-RPM engines, longer durations help air continue flowing into the cylinder even at fast piston speeds. In low-RPM engines, too much duration can reduce power due to poor timing with piston movement.
In high-RPM engines, longer durations help air continue flowing into the cylinder even at fast piston speeds. In low-RPM engines, too much duration can reduce power due to poor timing with piston movement.


'''Note:''' Most engine builders use duration measured at `0.050"`
'''Note:''' Most engine builders use duration measured at 0.050" lift to avoid advertising tricks based on looser standards like 0.020".
 
lift to avoid advertising tricks based on looser standards like `0.020"`
 
.


=== Centerline ===
=== Centerline ===
Line 26: Line 26:


* Remove all lash, place dial indicator on retainer or follower.
* Remove all lash, place dial indicator on retainer or follower.
* Rotate engine forward to
* Rotate engine forward to 0.050" lift. Note opening (e.g., 10° BTDC).
`0.050"`
* Continue rotating until it drops back to 0.050" on the other side (e.g., 39° ABDC).
 
lift. Note opening (e.g., 10° BTDC).
* Continue rotating until it drops back to
`0.050"`
 
on the other side (e.g., 39° ABDC).


Duration = 10° (BTDC) + 39° (ABDC) + 180° = '''229°'''
Duration = 10° (BTDC) + 39° (ABDC) + 180° = '''229°'''


Lobe Centerline = (229 / 2) - 10 = '''104.5°'''
Lobe Centerline = (229 / 2) - 10 = '''104.5°Note:''' If intake opens ''after'' TDC, subtract it instead. Example:
 
'''Note:''' If intake opens ''after'' TDC, subtract it instead. Example:


Duration = -10° (ATDC) + 39° (ABDC) + 180° = '''209°'''
Duration = -10° (ATDC) + 39° (ABDC) + 180° = '''209°'''
Line 52: Line 44:
Duration = 44° + 8° + 180° = '''232°'''
Duration = 44° + 8° + 180° = '''232°'''


Lobe Centerline = (232 / 2) - 8 = '''108°'''
Lobe Centerline = (232 / 2) - 8 = '''108°Note:''' If exhaust closes ''before'' TDC, adjust accordingly:
 
'''Note:''' If exhaust closes ''before'' TDC, adjust accordingly:


Duration = 26° (BBDC) - 10° (BTDC) + 180° = '''196°'''
Duration = 26° (BBDC) - 10° (BTDC) + 180° = '''196°'''
Line 71: Line 61:


'''Analogy:''' Like a garden hose, opening more increases flow — but only to a point. After that, additional opening does nothing.
'''Analogy:''' Like a garden hose, opening more increases flow — but only to a point. After that, additional opening does nothing.
=== Nissan VG30/33 camshaft Information ===
==== OE Camshafts ====
{| class="wikitable"
|-
! Manufacturer
! Duration Intake
! Duration Exhaust
! Lift Intake
! Lift Exhaust
! Intake Centerline
! Exhaust Centerline
|-
| Stock “early” Z31 (7/83–7/87)
| 252 / 193 @ .050
| 252 / 193 @ .050
| .393"
| .393"
| 106°
| 116°
|-
| Stock “late” Z31 (8/87+)
| 248 / 189 @ .050
| 248 / 192 @ .050
| .393"
| .393"
| 114°
| 114°
|-
| J-Spec Z31
| 252 / 193 @ .050
| 252 / 193 @ .050
| .393"
| .393"
|colspan="2" | —
|-
| European Z31
| 264
| 262
| .393"
| .393"
|colspan="2" | —
|-
| NISMO Z31
| 264
| 262
| .393"
| .393"
|colspan="2" | —
|-
| VG30 Truck (D21, WD21, J30)
| 248 / 189 @ .050
| 248 / 192 @ .050
| .393"
| .393"
|colspan="2" | —
|-
| VG33 (All)
| 240
| 244
| .366"
| .366"
|colspan="2" | —
|}
==== Colt Cams ====
{| class="wikitable"
|-
! Grind
! Duration Intake
! Duration Exhaust
! Lift Intake
! Lift Exhaust
|-
| [http://allthingsz.com/store/index.php?main_page=product_info&cPath=1_5_8&products_id=4 Stage 1 NA/Turbo]
| 256 / 202 @ .050
| 256 / 202 @ .050
| .420"
| .420"
|-
| [http://allthingsz.com/store/index.php?main_page=product_info&cPath=1_5_8&products_id=5 Stage 2 NA]
| 262 / 210 @ .050
| 262 / 210 @ .050
| .428"
| .428"
|-
| [http://allthingsz.com/store/index.php?main_page=product_info&cPath=1_5_8&products_id=6 Stage 2 Turbo]
| 262 / 210 @ .050
| 256 / 202 @ .050
| .428"
| .420"
|}
==== Schneider Racing Cams ====
Advertised duration @ 0.006
* 256/256 – .420"/.420" – CLSA 110
* 262/262 – .420"/.420" – CLSA 110
* 270/270 – .440"/.440" – CLSA 110
* 280/280 – .450"/.450" – CLSA 110
* 262/256 – .420"/.420" – CLSA 114 (Turbo)
* 270/262 – .440"/.420" – CLSA 114 (Turbo)
* 280/270 – .450"/.440" – CLSA 114 (Turbo)
* 284/274 – .450"/.440" – CLSA 114 (Race Only)
==== Motorsport Auto ====
* 262/256 – .420"/.420" – Stage 1 Turbo
* 270/262 – .420"/.420" – Stage 2 Turbo
* 260/260 – .420"/.420" – Stage 1 NA
* 270/270 – .427"/.427" – Stage 2 NA
* 280/280 – .435"/.435" – Stage 3 NA
==== Iskendarian Cams ====
* 262/258 – .450"/.450" – Turbo and NA (~$200, Exchange Only)
==== PAECO ====
* 280/280 – .328"/.328" – DSV-5800 Street ($230 each + $250 core)
* 288/288 – .360"/.360" – DSV-6200 Street/Strip
* 302/302 – .373"/.373" – DSV-6800 Race
==== Jim Wolf Technology ====
* 260/260 – .440" – Stage 1 Turbo (S1)
* 266/266 – .473" – Stage 2 Turbo (S2)
==== Custom Grinds ====
* Tempestas Custom Turbo: 270/270 – .480"/.480"
=== Nissan RB20DET camshaft Information ===
{| class="wikitable"
|-
! Specification
! Value
|-
| Duration Intake
| 248°
|-
| Duration Exhaust
| 240°
|-
| Lift Intake
| 7.8 mm
|-
| Lift Exhaust
| 7.8 mm
|}


=== Valve Spring Information ===
=== Valve Spring Information ===
Line 82: Line 227:
=== Selecting a Spring ===
=== Selecting a Spring ===


* Choose springs that give correct seat and open pressures.
# Choose springs that give correct seat and open pressures.
* Spring pocket may need to be machined to fit larger OD springs.
# Spring pocket may need to be machined to fit larger OD springs.
* Positively locate springs to avoid harmonic wear or forced failure. Proper seating offers longevity.
# Positively locate springs to avoid harmonic wear or forced failure. Proper seating offers longevity.


=== Proper Spring Handling ===
=== Proper Spring Handling ===
Line 95: Line 240:
=== Nissan Valve Spring Part Numbers ===
=== Nissan Valve Spring Part Numbers ===


| Application |
{| class="wikitable"
Part Number |
|-
| 1983–1985 Outer Spring | 13203-V5000 |
! Application
| 1985–1989 Outer Spring | 13203-42L03 |
! Part Number
| 1983–1985 Inner Spring | 13204-W7000 |
|-
| 1985–1989 Inner Spring | 13204-42L00 |
| 1983–1985 Outer Spring
| 13203-V5000
|-
| 1985–1989 Outer Spring
| 13203-42L03
|-
| 1983–1985 Inner Spring
| 13204-W7000
|-
| 1985–1989 Inner Spring
| 13204-42L00
|}


=== Schneider Spring Specs ===
=== Schneider Spring Specs ===


| Description |
{| class="wikitable"
OD |
|-
ID |
! Description
Installed Height |
! OD
Seat Pressure |
! ID
Pressure @ .600" |
! Installed Height
Coil Bind |
! Seat Pressure
Part Number |
! Pressure @ .600"
| Spring set (12 inner & outer) |
! Coil Bind
1.380" |
! Part Number
0.810" |
|-
1.600" |
| Spring set (12 inner & outer)
110 lbs |
| 1.380"
240 lbs |
| 0.810"
0.910" |
| 1.600"
68022 |
| 110 lbs
| 240 lbs
| 0.910"
| 68022
|}
 
=== Sources Used ===
 
* [http://www.z31.com/mods/cams.shtml Z31.com]
* Schneider Racing Cams
* [http://www.redz31.net/pages/caminfo.html redz31.net]
* Geoff @ [http://www.coltcams.com Colt Cams]
* webcamshafts.com


[[Category:Imported from Xenonzcar]]
[[Category:Imported from Xenonzcar]]

Revision as of 22:20, 20 October 2026

Imported page. This page was converted from an archived copy of "XenonZcar" (Xenonzcar, fetched 2026-05-15). The conversion was mechanical, so tables, links and formatting may contain conversion artefacts. Compare against the archived copy if something looks wrong. The content belongs to its original authors.

Z31 Camshaft Specifications and Upgrade Information

One of the ways you can make more power with your Z Car Engine is by upgrading the Camshafts in your engine. There were a few different cams used in the VG30E, VG30ET, VG33E, VG33ER Engines throughout the years of production. cams.jpg

Understanding Camshaft Specs

Cam specs dramatically affect engine behavior. The four primary specs are duration, centerline, separation, and lift.

Duration

Duration measures how long the valve remains open, expressed in degrees of crankshaft rotation. For example, a cam duration of 220° means the valve is open for 220° of crank rotation.

In high-RPM engines, longer durations help air continue flowing into the cylinder even at fast piston speeds. In low-RPM engines, too much duration can reduce power due to poor timing with piston movement.

Note: Most engine builders use duration measured at 0.050" lift to avoid advertising tricks based on looser standards like 0.020".

Centerline

The centerline tells you when the camshaft lobe reaches its peak lift in relation to crankshaft rotation. It's critical for calculating valve opening/closing, aka valve events.

Valve timing is key to engine performance — valves must open/close in harmony with piston movement and crank speed.

Finding Intake Lobe Center

  • Remove all lash, place dial indicator on retainer or follower.
  • Rotate engine forward to 0.050" lift. Note opening (e.g., 10° BTDC).
  • Continue rotating until it drops back to 0.050" on the other side (e.g., 39° ABDC).

Duration = 10° (BTDC) + 39° (ABDC) + 180° = 229°

Lobe Centerline = (229 / 2) - 10 = 104.5°Note: If intake opens after TDC, subtract it instead. Example:

Duration = -10° (ATDC) + 39° (ABDC) + 180° = 209°

Lobe Centerline = (209 / 2) + 10 = 114.5°

Finding Exhaust Lobe Center

  • Rotate to 0.050" lift (e.g., 44° BBDC).
  • Continue to 0.050" off base circle (e.g., 8° ATDC).

Duration = 44° + 8° + 180° = 232°

Lobe Centerline = (232 / 2) - 8 = 108°Note: If exhaust closes before TDC, adjust accordingly:

Duration = 26° (BBDC) - 10° (BTDC) + 180° = 196°

Lobe Centerline = (196 / 2) + 10 = 108°

Separation

Lobe separation is the number of degrees between the centerlines of the intake and exhaust lobes, measured in camshaft degrees. Example: 108° separation.

Alone, this spec is not very useful unless you also know centerline and duration. It affects valve overlap and cam behavior but is best used in conjunction with full valve event analysis.

Lift

Lift measures how far the valve opens. If lift is too low, it restricts airflow. If it's too high, flow gains plateau.

Analogy: Like a garden hose, opening more increases flow — but only to a point. After that, additional opening does nothing.

Nissan VG30/33 camshaft Information

OE Camshafts

Manufacturer Duration Intake Duration Exhaust Lift Intake Lift Exhaust Intake Centerline Exhaust Centerline
Stock “early” Z31 (7/83–7/87) 252 / 193 @ .050 252 / 193 @ .050 .393" .393" 106° 116°
Stock “late” Z31 (8/87+) 248 / 189 @ .050 248 / 192 @ .050 .393" .393" 114° 114°
J-Spec Z31 252 / 193 @ .050 252 / 193 @ .050 .393" .393" —
European Z31 264 262 .393" .393" —
NISMO Z31 264 262 .393" .393" —
VG30 Truck (D21, WD21, J30) 248 / 189 @ .050 248 / 192 @ .050 .393" .393" —
VG33 (All) 240 244 .366" .366" —

Colt Cams

Grind Duration Intake Duration Exhaust Lift Intake Lift Exhaust
Stage 1 NA/Turbo 256 / 202 @ .050 256 / 202 @ .050 .420" .420"
Stage 2 NA 262 / 210 @ .050 262 / 210 @ .050 .428" .428"
Stage 2 Turbo 262 / 210 @ .050 256 / 202 @ .050 .428" .420"

Schneider Racing Cams

Advertised duration @ 0.006

  • 256/256 – .420"/.420" – CLSA 110
  • 262/262 – .420"/.420" – CLSA 110
  • 270/270 – .440"/.440" – CLSA 110
  • 280/280 – .450"/.450" – CLSA 110
  • 262/256 – .420"/.420" – CLSA 114 (Turbo)
  • 270/262 – .440"/.420" – CLSA 114 (Turbo)
  • 280/270 – .450"/.440" – CLSA 114 (Turbo)
  • 284/274 – .450"/.440" – CLSA 114 (Race Only)

Motorsport Auto

  • 262/256 – .420"/.420" – Stage 1 Turbo
  • 270/262 – .420"/.420" – Stage 2 Turbo
  • 260/260 – .420"/.420" – Stage 1 NA
  • 270/270 – .427"/.427" – Stage 2 NA
  • 280/280 – .435"/.435" – Stage 3 NA

Iskendarian Cams

  • 262/258 – .450"/.450" – Turbo and NA (~$200, Exchange Only)

PAECO

  • 280/280 – .328"/.328" – DSV-5800 Street ($230 each + $250 core)
  • 288/288 – .360"/.360" – DSV-6200 Street/Strip
  • 302/302 – .373"/.373" – DSV-6800 Race

Jim Wolf Technology

  • 260/260 – .440" – Stage 1 Turbo (S1)
  • 266/266 – .473" – Stage 2 Turbo (S2)

Custom Grinds

  • Tempestas Custom Turbo: 270/270 – .480"/.480"

Nissan RB20DET camshaft Information

Specification Value
Duration Intake 248°
Duration Exhaust 240°
Lift Intake 7.8 mm
Lift Exhaust 7.8 mm

Valve Spring Information

Valve Springs

Valve springs are one of the most critical and most overlooked components in your engine. Proper selection begins with identifying the application and selecting all valvetrain components to achieve your engine goals.

The spring must be matched with the valvetrain to reach full potential. A cam built to rev to 8000 RPM is pointless without the right spring. Improper spring choice, incorrect installation, and mishandling are common causes of failure.

Selecting a Spring

  1. Choose springs that give correct seat and open pressures.
  2. Spring pocket may need to be machined to fit larger OD springs.
  3. Positively locate springs to avoid harmonic wear or forced failure. Proper seating offers longevity.

Proper Spring Handling

  • Never clamp, pry, or strike valve springs. Surface damage causes premature failure.
  • Separate double/triple springs with soft plastic tools only.
  • Do not clean with aggressive or evaporative chemicals. Use the anti-rust coating as-is.
  • Apply assembly lube before installation to prevent dry starts and increase spring life.

Nissan Valve Spring Part Numbers

Application Part Number
1983–1985 Outer Spring 13203-V5000
1985–1989 Outer Spring 13203-42L03
1983–1985 Inner Spring 13204-W7000
1985–1989 Inner Spring 13204-42L00

Schneider Spring Specs

Description OD ID Installed Height Seat Pressure Pressure @ .600" Coil Bind Part Number
Spring set (12 inner & outer) 1.380" 0.810" 1.600" 110 lbs 240 lbs 0.910" 68022

Sources Used

Retrieved from "https://z31library.com/index.php?title=Z31/camspecs_php&oldid=8203"