[flash]

the rule of thumb is to crank it until it stops increasing, and to do the same on all cylinders - 8 should be fine - i know that at 4 cranks i get the numbers similar to what you have (180ish) - at 6 i bump up to around 190 - another 2 and she gets pretty close to 200 - no increase beyond that

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[benspeeder]

Agreed on a great thread - busting out my compression guage for some fun.

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[xrad]

agree with Flash above. or I just count 4-5 seconds in my head while cranking

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[Cloud9...68]

I agree as well; I used eight cranks because I didn't have an assistant doing the cranking, so I couldn't see the gauge while I was in the driver's seat turning the key.

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[Vedder]

My engine was rebuilt aprox. 6000 miles ago, heres my numbers for reference.



Wet or Dry DRY

Date 04-Dec-08

Oil Temp less 50C

Time cranking 10 sec rev

Outside Temp 4C

Variables 5Min startup

Oil Temp 10W-60 mix 5w40

PSI/BAR Cylinder 1 Cylinder 2 Cylinder 3 Cylinder 4

200/13.7 198/13.6 180/12.4 193/13.3

Wet or Dry DRY

Date 07-Dec-08

Oil Temp 95C

Time cranking 10 sec rev

Outside Temp 4C

Variables 40 Miles drive

Oil Temp 10W-60 mix 5w40

PSI/BAR Cylinder 1 Cylinder 2 Cylinder 3 Cylinder 4

204/14.1 205/14.2 210/14.5 210/14.5

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[flash]

210 - wow - i am only a touch under 200 - looks like i may be due for a valve job - woohoo!

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[Cloud9...68]

Congrats on the solid readings, but ouch! for me and my anemic-sounding readings in the 170s. I'm holding out hope that my lower (but uniform) readings are due to gauge-to-gauge variations. That's my story and I'm sticking to it. On the other hand, it does make for a good excuse to ship the head to Pete for one of his fancy rebuilds. Might as well get the cams and exhaust while I'm at it, right?

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[flash]

YEAH YEAH - THAT'S IT!

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[Vedder]

Well, for me i had a chat with Pete before the summer n i followed Pete's advice regarding the Cylinder Walls, i didnt bored out , i just deglazed them ,then new rings and a Stage 1 rebuilt head from RSbarn with Competion valve job. Also break-in of the engine was done lets say not in a conservite way <img src="/forum/images/smilies/968/tongue.gif" class="smilie" alt="" />

Bear in mind that i also think those numbers are a touch on the high side. It could very well be that i didnt time the cams right,a touch on the advance could do this. but then again the engine doesnt ping and i saw temps in the south of Spain up to 47 Celsius <img src="/forum/images/smilies/968/blink.gif" class="smilie" alt="" />



Here's a list of all the Mods:

Not sure if some dont affect the readings in this way.



List of Mods

Porsche 968 Cabrio w LSD (220) 1994 MODS



Engine Fully Rebuilt Aug 2008

Compression numbers HOT

Cylinder 1 Cylinder 2 Cylinder 3 Cylinder 4

204 205 210 210

After 10 days rebuilt engine still did 4500 Miles in less than 5 weeks( gotta love the 968!!)

RS Barn Performance Head Stage 1

RS Barn Performance Cat Back

RS BARN Custom Performance Chip Stage 1

RS BARN 968 Lower Chassis Brace

AC Deleted

CS 1 Fan with Shroud

Hyperco Front Springs Progressive (orig 356 mm vs Hyp 310mm)

KLA SwayBar Support Brakets

KLA Strut Brace

KLA Rear Sway Bar Drop Links

Bored Throttle Body to 71mm w Knife edged Butterfly DIY

Throttle Body Coolant Bypass

HD chain for VarioCam Tensioner + New oil valve

968 Engineering Airbox Modification w Trim Rings

K&N Air Filter

NGK Iridium Spark Plugs

Magnecor Plug Wires KV85

New Sachs Clutch Kit w LUK DMF

Stuttgart Shifting Block

Tranny filled w 50% RedLine ShockProof n 50% Redline 75W-90

Cubby Gauge Panel w Vaccum,Oil Temp,A/F gauge

TechArt Rear Spoiler

FibreGlass Front Wings

968 Turbo RS Bumper Replica

Porsche 968 Turbo Front Splitter

Porsche M030 Sway Bars

Poly Bushes front and rear

Goodridge Brake Lines

Zimmerman Cross Drilled Rotors

EBC Red Brake Pads Front and Pagid in the rear

Ferodo 5.1 Brake Fluid

15mm Spacer Rear Wheels

Porsche Turbo I 18" Wheels with Kuhmo ECSTA MX (Summer)

Porsche Sport Classic 17" with GoodYear GSD3 F1 (rest of the year)

Porsche CS Steering Wheel

Motul 300v 15W-50 or Shell Helix Ultra 10W-60

ATF 6 on PS

Cabrio Hood Mod

4-wire Lambda O2 Sensor

CEL Light Mod(engine fault code reader)

Anti-Hijack Imob.

Cobra Alarm System

GPS\GSM Locator

Focal Speakers adapted to option M490

Sony Head Unit

Alpine 4x50 Amp



Some videos on youtube

http://uk.youtube.com/watch?v=3AX4D2bTX-4

http://uk.youtube.com/watch?v=01kdnlwXM80

http://uk.youtube.com/watch?v=5f5P042x6Ms

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