| Author |
Message |
    
Jb
Member
Username: jbthehut
Post Number: 6
Registered: 11-2006
| | Posted on Wednesday, November 29, 2006 - 01:39 pm: | 
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would someone please tell me what the compression should be in a 1977 350 260hp? |
William J. Myers
New member
Username: captain_william_myers
Post Number: 1
Registered: 12-2006
| | Posted on Friday, December 01, 2006 - 03:18 pm: |
|
JB
with all the plugs out 120 to 130 real good,
70 lbs bad. |
King Benson
Visitor
| | Posted on Monday, December 04, 2006 - 10:36 pm: |
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How about a 1984 Crusader 270 compression? |
Bondo
Member
Username: bondo
Post Number: 58
Registered: 12-2006
| | Posted on Saturday, December 30, 2006 - 11:16 am: |
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For All Gas motors that are found in Boats,.....
200psi is High,.... Probably a Hot Rodded motor.....
135/195psi is an Average # seen......
Anything below 100psi is a Dead cylinder......
And,......
With a Compression Test,.....You're Not looking for a particular #,.......
You're looking for #s that are Close to each other,.....
No More than 15% Differences between any 2 cylinders..... |
josh hudgens
Visitor
| | Posted on Saturday, April 26, 2008 - 05:30 am: |
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I have checked each cylinder on my Crusader and each one reads around 90 except 1 which reads 116.
The engine ran pretty hot for about 20 minutes last year (running from a storm). Ran rough for a short while after that and now will not crank at all.Not sure but thought rings may be stuck.Any help would be greatly appreciated.
Lamar |
Bondo
Advanced Member
Username: bondo
Post Number: 956
Registered: 12-2006
| | Posted on Saturday, April 26, 2008 - 09:08 am: |
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Ayuh,......
That's sounds like it's time for an engine Rebuild...... |
RM
Member
Username: rmm
Post Number: 46
Registered: 05-2006
| | Posted on Sunday, April 27, 2008 - 10:05 am: |
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When originall y did this tested with the plugs in. Going to redo with plgs out but wondering what kind of differences this would give? |
Fastjeff
Senior Member
Username: fastjeff
Post Number: 4331
Registered: 09-2003
| | Posted on Sunday, April 27, 2008 - 07:06 pm: |
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It should be a bit higher. Be sure the throttle is open.
Jeff |
Tim Griffin
Member
Username: alaska_av8r
Post Number: 29
Registered: 03-2008
| | Posted on Sunday, April 27, 2008 - 08:34 pm: |
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Here is what you are looking for from the Crusader Operation and Maintenance Manual
"A uniform variation of +/- 20 psi, from 130-170 psi is permissible, the compression of all cylinders should be uniform within 10 psi.
A reading above normal indicates excessive carbon buildup (or water in cylinder)
A reading below normal indicates leak in cylinder gasket, piston rings or valves.
A low even compression in two adjacent cylinders, indicates a head gasket leak.
To determine between rings vs valves, squirt appx tablespoon of oil into cylinder, redo test if pressure remains unchanged valves likely culprit, if pressure increased 10 pds or more rings likely culprit.
During test if pressure fails to climb steadily and remains same during first two successive strokes, but climbs higher on the succeeding strokes, or fails to climb during entire test, it indicates a sticking valve.."
I essentially summarized what it says in the manual or I would still be typing tomorrow...
hope that helps. |
