2f compression

[timmbuck2]

how bad is 90 on each cylinder?

 

[wesintl]

not so good

 

[RicardoJM]

how bad is 90 on each cylinder?

Are you speculating or talking about actual numbers? I hope it is speculation. If they are actual numbers I know an alley with a 1F already mated to a transmission and x-fer case that is ready to be dropped into something.

 

[timmbuck2]

I have at least 2 2fs already. this is that 2f down in Parker...

 

[Rzeppa]

90 will run just fine. Not fresh, but probably not broken rings either.

I am sure you've probably already read about the trick of putting a teaspoon of oil into each cylinder to see if the number come up or stay the same; if they come up it's rings, if there's no difference it's valves.

A couple tricks an engine builder taught me about taking compression readings:

(1) Take all the plugs out.
(2) When cranking the engine, open the throttle so the cylinders get full air.
(3) Try the reading 2 or more times to make sure (this is actually basic metrology).
(4) At higher altitudes, you can never get sea level numbers (this is basic physics).

The absolute pressure in Denver is about 12 PSI, versus 14.7 at sea level. Expect compressions numbers to drop by that ratio (12/14.7=0.8) or to convert Denver readings to sea level divide by that number (90/0.8=113). A nominal 150 PSI engine should read about 120 in Denver.

 

[farnhamstj]

My 78 was between 95-105 at 8,000 ft. Seemed ok to me. Not fast, but not the slowest 40 either. I could do 45 up Vail pass. Little known fact of Land cruisers body numbers. The numbers match the max speed while traveling west from Denver, For example..
fj40....expect 40mph just before you enter the tunnel
fj60....expect 60mph
fzj80.... now we're talking.
uzj100...look out for the police.

 

[MDH33]

fj60....expect 60mph

I would be in heaven if my 60 could reach 60mph on I-70. 35 tops going up that hill...

 

[60wag]

My 60 had 150psi after the rebuild measured at 5400ft. There were days I could do 55 going up I70 - low head wind, no extra passengers, etc.

 

[treerootCO]

The 2F in my 40 has 60 on the best cylinder. My lowest one is 30

 

[DaveInDenver]

My lowest one is 30

So that's about 6 psi for each 100,000 miles on it?

 

[treerootCO]

the beast still runs great! I could care less that I don't have 120 on every cylinder.

 

[CardinalFJ60]

Uh, yeah...

I would be in heaven if my 60 could reach 60mph on I-70. 35 tops going up that hill...

X2 !!!

 

[Rzeppa]

the beast still runs great! I could care less that I don't have 120 on every cylinder.

Same here. On the F I pulled from my 71 year before last, I was down to about 60 on #4, but it still fired. The reason I pulled it was rod knock, not compression.

 

[PabloCruise]

90 will run just fine. Not fresh, but probably not broken rings either.

I am sure you've probably already read about the trick of putting a teaspoon of oil into each cylinder to see if the number come up or stay the same; if they come up it's rings, if there's no difference it's valves.

A couple tricks an engine builder taught me about taking compression readings:

(1) Take all the plugs out.
(2) When cranking the engine, open the throttle so the cylinders get full air.
(3) Try the reading 2 or more times to make sure (this is actually basic metrology).
(4) At higher altitudes, you can never get sea level numbers (this is basic physics).

The absolute pressure in Denver is about 12 PSI, versus 14.7 at sea level. Expect compressions numbers to drop by that ratio (12/14.7=0.8) or to convert Denver readings to sea level divide by that number (90/0.8=113). A nominal 150 PSI engine should read about 120 in Denver.

Good stuff Jeff - you don't really want to move to Alaska, do you?

 

[Rzeppa]

Good stuff Jeff - you don't really want to move to Alaska, do you?

No I don't really want to move there, would probably get S.A.D. in the winter, but we definitely plan to drive up and visit this summer. Say hey to Mark Whatley and the shop crew, visit with all my Calgary buddies either on the way up or back, visit Talkeetna, etc.