My compression test results
Thread Starter
|
Laughing Gas
Joined: Oct 2013
Posts: 947
Likes: 6
From: Manitoba, Canada
My compression test results
68 FE360. 109,000 miles. I only warmed the engine a bit, maybe two minutes. This is what I got:
Front
100 105
107 107
107 110
100 105
Rear
Any opinions on these numbers because I don't have a clue.
Front
100 105
107 107
107 110
100 105
Rear
Any opinions on these numbers because I don't have a clue.
Postmaster
Joined: Nov 2012
Posts: 2,806
Likes: 8
From: Langley, BC
You ideally want the engine at normal operating temperature, so two minutes could've been not enough. But, the readings are consistent and that's really what you're going for. They're not as high as I would like them to be but it seems like the engine is just a little aged. Is it completely stock? Are you noticing a lack of power?
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
That, and the carb butterflies have to be full throttle wide open. All spark plugs removed. Fully warmed up, half hour at highway speed? Fully charged battery, good serviceable starter running at crank RPM spec. Dry test, then wet test, avg of the highest of at least two runs per cylinder, etc.
Compression test is a bit more complicated than it seems for accurate result. Those numbers don't look too bad considering. Mentioned in another thread, a vacuum gauge connected to manifold will indicate engine compression indirectly, and a whole lot more, with a lot less hassle. If engine draws 18, 19 or 20 inches steady then the compression is fine. A proper compression test itself is awful hard on the starter and battery imo.
Compression test is a bit more complicated than it seems for accurate result. Those numbers don't look too bad considering. Mentioned in another thread, a vacuum gauge connected to manifold will indicate engine compression indirectly, and a whole lot more, with a lot less hassle. If engine draws 18, 19 or 20 inches steady then the compression is fine. A proper compression test itself is awful hard on the starter and battery imo.
Thread Starter
|
Laughing Gas
Joined: Oct 2013
Posts: 947
Likes: 6
From: Manitoba, Canada
.
It's stock and it's a project and it's not licenced for the road yet but I've driven it around the neighborhood a few times. I've got it all tuned up and it runs pretty good. Starts right up, idles good after warm up and revs up okay with no hesitation but when I drove it will fart at the carb a bit if I try anything beyond 1/2 pedal acceleration. Plan is body work and paint the exterior first. Phase two will be replace the tired drivetrain.
Postmaster
Joined: Nov 2012
Posts: 2,806
Likes: 8
From: Langley, BC
It's stock and it's a project and it's not licenced for the road yet but I've driven it around the neighborhood a few times. I've got it all tuned up and it runs pretty good. Starts right up, idles good after warm up and revs up okay with no hesitation but when I drove it will fart at the carb a bit if I try anything beyond 1/2 pedal acceleration. Plan is body work and paint the exterior first. Phase two will be replace the tired drivetrain.
Postmaster
Joined: Nov 2012
Posts: 2,806
Likes: 8
From: Langley, BC
It's a '68 though. The 390 of that year was 9.5:1. I doubt the 360 would be too far off. Maybe 8.5? Not terribly low.
Trending Topics
Logistics Pro
Joined: Jan 2011
Posts: 4,762
Likes: 54
From: Antelope Valley ,CA
TO my knowledge the truck 360/390 had 8.1 ish C/R the passenger car had 9.5-10.C/R year didn't matter
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Cargo Master
Joined: Apr 2001
Posts: 2,697
Likes: 46
From: Vancouver
I don't feel comfortable saying this to you, but I think 100 psi indicates a worn-out motor. Probably rings/cylinders; it it were valves the numbers would not be so consistent. A wet test might confirm my opinion. My wheezy 352 is 130 across and should be 150+ the experts tell me.
Eric
Eric
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
Sent from my iPhone using IB AutoGroup
Thread
Thread Starter
Forum
Replies
Last Post
nickydobbs
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
3
Sep 17, 2014 11:58 PM
Redneck1465
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
11
May 21, 2009 11:57 PM
tractoman
1973 - 1979 F-100 & Larger F-Series Trucks
11
Feb 19, 2006 02:18 PM