compression test - results needed

[orangefj45]

hey guys.
i'd like to see who's done a compresion test on their 2F engine, how many miles are on the odometer and what test results you came up with.

i have an engine that's supposed to have "x" miles on it. the compression test went well as far as i'm concerned, with all 6 cylinders between 135 and 145 psi.

lemme know what you guys found when you did a comp test.

thanks in advance!

georg

 

[lehiguy]

hey guys.
i'd like to see who's done a compresion test on their 2F engine, how many miles are on the odometer and what test results you came up with.

i have an engine that's supposed to have "x" miles on it. the compression test went well as far as i'm concerned, with all 6 cylinders between 135 and 145 psi.

lemme know what you guys found when you did a comp test.

thanks in advance!

georg

That sounds like a very healthy 2F.

 

[rchalmers3]

George,

I think you will find a variety of answers to your question, as we all use a variety of gauges for testing. And who knows if any of them are reliable or accurate! At the least you would have a hard time making heads or tails of any comparison!

Until we all use the same compression tool on our motors, under similar ambient conditions, it will be difficult to speak meaningfully about comparing compression readings.

The grouping of your results (less than 10% difference between highest and lowest) is more meaningful of the health of your motor than the specific PSI. If the motor cranks evenly, has a good Carmel color on the plugs and does not exhibit any mis-fire, you are looking fairly secure.

Rick

 

[orangefj45]

hey rick.
mucho gusto. i realize that ambient temp, the test equipment, altitude, engine temp,.....have an affect on the compression readings. i'm also aware that what you're really after is a very short "range" of variation between the cylinders.

what i'm after is to confirm that the engine i have on hand either has low miles on it and/or has been rebuilt. it came out of a truck with 200k plus miles on it and i don't think there's any way it would run as well as it does if it had'nt been rebuilt.

so i'd like to see how many miles other owners have on their 2F engines and what comp #s they've come up with.

thanks a lot!

georg

 

[Trapper50cal]

That sounds like its on the high end IIRC 150 is tops, as long as they are all pretty close...doesn't sound like 200K. Drop the pan and look at the cylinder walls. Should be freshly honed right?

 

[rchalmers3]

Why not stick a boroscope in through the plug holes and have a gander for cross hatching on the cylinders?

Rick

 

[orangefj45]

i appreciate the input and your effort. i've been around this stuff for a while. i worked at a shop rebuilding engines, i've spent time working on cruisers and everything that comes along with them.

what i'm really asking for are actual results from other owners. i know what i have on hand. i just want somebody else's results for comparision sakes.

the compression tests i have done in the past have always come up with #s between 110-145. well, that's what i thought of as acceptable as long as the difference between cylinders was'nt more than 10-15psi. i have done several leak-down tests as well............


don't get me wrong, i do appreciate the input.

 

[Scotty]

Hey George,

Its Scotty, the guy who delivered that buggy chassis to you a couple years ago.

Anyway, sometime next week I am picking up a 60, and I will do a compression check on it when I get it for you to compare #s.

BTW, is Brian still hanging out with out there? How did he like the 4runner I sold him last month?

 

[orangefj45]

hey scotty!
good to hear from ya! how's things going in CO? brian is pretty happy with the runner, got great milage on the way home and ran really well. he flew back home two weeks ago.

lemme know what you come up with!

 

[mrlocksmith]

George

1985 FJ60

185 185 182 175 185 185

Read on the 3rd crank, 138XXX Miles, It has had Synthetic Oil in it since 1988

Mark

 

[2mbb]

Here are my results from the last two times I've done it. I'm approaching 210K miles, so I'm due for another. I test with the engine hot/warm and all the plugs removed. I test each cylinder through four or five compression strokes. The gauge I have is old (my dad's probably from the 70's) and I don't know how accurate it is...

 

[orangefj45]

holy cow, those #s are up there!

 

[FJ40Jim]

Spec is 150-165 for a 81-87 2F.

Unless an engine is huffed, my gage always shows them at 145-165.

There was a 200K 82 FJ60 in recently that was a little weak and smoky. It had numbers in the 135-150 range w/ one cylinder down at ~120, IIRC.

I see far more valve problems than wear problems. Those can show all the way down to zero if the valve is warped enough. Unmaintained engines can have a burned exh valve at 60K.

I guess the real question Georg is what does your gage usually show? Are 2Fs all 135-145?
If yes, then that engine is good.
If no, then that engine may be tired, though it is rare for an engine to be uniformly tired on compression.

 

[Butt Ugly Chuck]

My numbers after a fresh valve job at 261K

Can't find them, but the numbers were UGLY before the valve job.

Butt

 

[D'Animal]

I have now idea what the actual mileage on some of my rigs are.

1974 FJ40 was 100 - 105 with 122,00 miles ?
1976 FJ 40 was 125 -130 with 60,000 miles ?
1977 FJ40 was 103 - 135 with 128,000 miles ?
1981 2F from FJ40 135 - 145 with 81,000 miles ?
1984 2F from FJ60 135 - 145
1986 2F from FJ60 135 - 140
FJ60 2F I got from you 125 - 130

 

[orangefj45]

thanks for the replies guys. the engine in question runs very well. i'd venture to say that it's the best running 2F in an fj60 i've ever ridden in or driven. no smoke, no noise, definetly not tired.

it's amazing to see so much variance in the comp tests, especially since the engines realistically never had more than 165psi compression from the factory yet a few owners have some up with #s as high as 185psi. obviously a test equipment issue there......


i've tested a bunch of them and usually associate 135-160 psi with being a healthy engine, as long as the compression is fairly equal in all 6 cylinders.

i've also tested engines that measured out closer to 100psi and still ran good, but you could tell they were getting tired.

either way, thanks for the input and data guys!

 

[D'Animal]

Some of number will be effected with a "wet" engine or a dry engine.



But you knew that.

 

[Tinker]

Don't forget carbon buildup on the piston, valves, & head increasing compression (& pre-ignition).