Compression testing - ZR-1 Net Registry Forums

Kb7tif · 02-02-2011

As I have tested several other engines for compression, (and forgot)
What should a good cond stock LT-5 test at please.

LGAFF · 02-02-2011

185-190+

Hog · 02-02-2011

Wow, I would have guessed higher.

peace
Hog

LGAFF · 02-02-2011

My 21K mile car is about 210-215.....I was told by one of the assembly line sups that they saw values up to 300....varied from engine to engine.

Hog · 02-02-2011

Cool, I can see there being quite the variance esp. with the cam drive system the LT-5 employs.

peace
Hog

Paul Workman · 02-02-2011

September 8th, 2010:

#1 = 220
#2 = 222
#3 = 220
#4 = 220
#5 = 225
#6 = 215
#7 = 230
#8 = 221

Sept 8th, 2009 (yes, exactly the year before):

#1 = 180
#2 = 195
#3 = 175
#4 = 180
#5 = 175
#6 = 178
#7 = 175
#8 = 100*

Both tests were conducted the same way with the same tool and with the same battery charger keeping the battery full. What was different is in the interim I ported the heads and a valve job was done in addition to replacing an exhaust valve in #8...AND after Pete timed the cams.

Because of the fresh valve job AND re-timing the cams took place, it's not possible to say just what made the difference. But, there you have two sets of data from the same motor to ponder.

P.

RedRiderZR1 · 02-05-2011

Quote:

Originally Posted by Paul Workman

September 8th, 2010:

#1 = 220
#2 = 222
#3 = 220
#4 = 220
#5 = 225
#6 = 215
#7 = 230
#8 = 221

Sept 8th, 2009 (yes, exactly the year before):

#1 = 180
#2 = 195
#3 = 175
#4 = 180
#5 = 175
#6 = 178
#7 = 175
#8 = 100*

Both tests were conducted the same way with the same tool and with the same battery charger keeping the battery full. What was different is in the interim I ported the heads and a valve job was done in addition to replacing an exhaust valve in #8...AND after Pete timed the cams.

Because of the fresh valve job AND re-timing the cams took place, it's not possible to say just what made the difference. But, there you have two sets of data from the same motor to ponder.

P.

My numbers are just like your sept 8, 2010 numbers last time I did a compression test.

Hog · 02-07-2011

Quote:

Originally Posted by Paul Workman

September 8th, 2010:

#1 = 220
#2 = 222
#3 = 220
#4 = 220
#5 = 225
#6 = 215
#7 = 230
#8 = 221

Sept 8th, 2009 (yes, exactly the year before):

#1 = 180
#2 = 195
#3 = 175
#4 = 180
#5 = 175
#6 = 178
#7 = 175
#8 = 100*

Both tests were conducted the same way with the same tool and with the same battery charger keeping the battery full. What was different is in the interim I ported the heads and a valve job was done in addition to replacing an exhaust valve in #8...AND after Pete timed the cams.

Because of the fresh valve job AND re-timing the cams took place, it's not possible to say just what made the difference. But, there you have two sets of data from the same motor to ponder.

P.

What was the power difference like SOTP?

peace
Hog

02-02-2011	#1
Kb7tif Join Date: May 2009 Location: S Nevada Posts: 352	Compression testing As I have tested several other engines for compression, (and forgot) What should a good cond stock LT-5 test at please. __________________ 1995 Convertible Supercharged Auto 1974 454 550hp (avatar car) On the blocks- -Scharger install ! 1992-Zr-1 Sold. Watson Headers Ported Plenum, Housings Random tech cats Fidanza Flywheel Chipped, Relocated Mat Woods 165 stat Borlas, Straights 1996 Lt4 Sold 1994 Lt1 Sold 2004 Z06 Sold AKA** Illenema

02-02-2011	#2
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: Compression testing 185-190+ __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

02-02-2011	#3
Hog Join Date: Jul 2010 Location: Woodstock, Ontario, Canada Posts: 1,275	Re: Compression testing Wow, I would have guessed higher. peace Hog

02-02-2011	#4
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: Compression testing My 21K mile car is about 210-215.....I was told by one of the assembly line sups that they saw values up to 300....varied from engine to engine. __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

02-02-2011	#5
Hog Join Date: Jul 2010 Location: Woodstock, Ontario, Canada Posts: 1,275	Re: Compression testing Cool, I can see there being quite the variance esp. with the cam drive system the LT-5 employs. peace Hog

02-02-2011	#6
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Compression testing September 8th, 2010: #1 = 220 #2 = 222 #3 = 220 #4 = 220 #5 = 225 #6 = 215 #7 = 230 #8 = 221 Sept 8th, 2009 (yes, exactly the year before): #1 = 180 #2 = 195 #3 = 175 #4 = 180 #5 = 175 #6 = 178 #7 = 175 #8 = 100* Both tests were conducted the same way with the same tool and with the same battery charger keeping the battery full. What was different is in the interim I ported the heads and a valve job was done in addition to replacing an exhaust valve in #8...AND after Pete timed the cams. Because of the fresh valve job AND re-timing the cams took place, it's not possible to say just what made the difference. But, there you have two sets of data from the same motor to ponder. P. __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry