Compression test question
Thread Starter
Melting Slicks
Joined: Jan 2005
Posts: 2,658
Likes: 4
From: Clifton Park NY
Compression test question
I just had a quick question for you guys.
I'm doing a dry/wet test on my wifes 84 today.
Since I've never done it before this is what I've done
Warm engine
Remove spark plugs
Disable ignition by removing the primary wire that feeds the HEI distributor
Open the butterflies on the TB's
The only question I have is what about the fuel, do I disable that as well?
thanks
I'm doing a dry/wet test on my wifes 84 today.
Since I've never done it before this is what I've done
Warm engine
Remove spark plugs
Disable ignition by removing the primary wire that feeds the HEI distributor
Open the butterflies on the TB's
The only question I have is what about the fuel, do I disable that as well?
thanks
Thread Starter
Melting Slicks
Joined: Jan 2005
Posts: 2,658
Likes: 4
From: Clifton Park NY
You can disregard the question above. I already did my compression test and came up with this.
Cyl Dry Wet
1 130 90
3 110 100
5 120 90
7 128 90
2 122 100
4 100 120
6 139 100
8 100 100
Overall I don't think its to bad by I'm going to retest Cyl 4
In my directions it states that if the pressure goes up could be a piston/ring problem. but it doesn't say anything about when the pressure goes down. Still be ring blow by?
Cyl Dry Wet
1 130 90
3 110 100
5 120 90
7 128 90
2 122 100
4 100 120
6 139 100
8 100 100
Overall I don't think its to bad by I'm going to retest Cyl 4
In my directions it states that if the pressure goes up could be a piston/ring problem. but it doesn't say anything about when the pressure goes down. Still be ring blow by?
Le Mans Master
Joined: Apr 2000
Posts: 5,589
Likes: 0
From: DrunkDefender
CI 1-2-3-4-5-6-7-8 Veteran
CI-IV AutoX Champ
CI-IV Burnout Champ
St. Jude Donor '07-'10
I allways just pulled the fuel pump relay. I would check mine only for consistentcy therefore I would allways squirt a little WD40 in each cyl just before I tested it. You've got some pretty wide margins there, more than %20 from one cyl to another. Do you suspect a problem or are you just checking things out?
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
You can disregard the question above. I already did my compression test and came up with this.
Cyl Dry Wet
1 130 90
3 110 100
5 120 90
7 128 90
2 122 100
4 100 120
6 139 100
8 100 100
Overall I don't think its to bad by I'm going to retest Cyl 4
In my directions it states that if the pressure goes up could be a piston/ring problem. but it doesn't say anything about when the pressure goes down. Still be ring blow by?
Cyl Dry Wet
1 130 90
3 110 100
5 120 90
7 128 90
2 122 100
4 100 120
6 139 100
8 100 100
Overall I don't think its to bad by I'm going to retest Cyl 4
In my directions it states that if the pressure goes up could be a piston/ring problem. but it doesn't say anything about when the pressure goes down. Still be ring blow by?
Thread Starter
Melting Slicks
Joined: Jan 2005
Posts: 2,658
Likes: 4
From: Clifton Park NY
The reason for testing is because last summer I noticed that when she starts it,it will puff some smoke until it warms up. It bothers me NOT her.
And since the car her car has 219k on it I wanted to check compression.
After doing more checks yesterday my averages were these numbers.
Cyl Dry Wet
1 150 152
3 140 155
5 160 158
7 145 150
2 155 155
4 150 150
6 180 180
8 155 179
All in all I guess its not to bad of shape for having the mileage. I'm not gonna put a set of reconditioned heads on though. I'll just let it go and meanwhile maybe I'll pick up a core myself to build.
And since the car her car has 219k on it I wanted to check compression.
After doing more checks yesterday my averages were these numbers.
Cyl Dry Wet
1 150 152
3 140 155
5 160 158
7 145 150
2 155 155
4 150 150
6 180 180
8 155 179
All in all I guess its not to bad of shape for having the mileage. I'm not gonna put a set of reconditioned heads on though. I'll just let it go and meanwhile maybe I'll pick up a core myself to build.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Melting Slicks
Joined: Jan 2005
Posts: 2,658
Likes: 4
From: Clifton Park NY