All good.
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Really appreciate it. It appears to me that the 74 head is kind of a crosd between open and semi closed chamber.
Surprised at the stock compression numbers. Compression makes power!! Thank you for shating.
Sharing!!!!
- Thread starter
- #45
stock compression is 135-160 (dry) with f.5 head compression from 170 (dry) and higher..
Looks like I need to find a 74 60051 head! I am trying to contact the previous owner of my FJ40 to determine how much, if any, was shaved of the head during rebuild about 30k miles ago.
- Thread starter
- #47
This time, I checked the compression correctly (dry).
1: 180, 2: 180, 3: 185, 4: 185, 5: 180, 6: 185
idle vacuum -20 inHg (at 650-660rpm) timing set at 11 degrees BTDC
1: 180, 2: 180, 3: 185, 4: 185, 5: 180, 6: 185
idle vacuum -20 inHg (at 650-660rpm) timing set at 11 degrees BTDC
really good numbers, when last i checked I was in the 135-140 range and like 16-17 on vacuum
- Thread starter
- #49
I'm just trying to find out why there's oil on the second spark plug and what kind of gas she needs.
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Oil on plugs is from the rings. Maybe your oil control ring is plugged. Let a good dose of Marvels mystery oil soak in for several days. Then take it out for an Italian tune up
- Thread starter
- #51
I haven't noticed the engine burning oil... I can try Marvels oil soak.
- Thread starter
- #52
This is how the pistons looked before I swapped the head — about 300–400 miles ago.
I cleaned and installed a rebuilt head from a '74.
I didn't touch the block, only cleaned and put a new gasket.
Is it just me, or does the second piston look a bit greasy and oily? If so, it is more likely the ring issue.
I cleaned and installed a rebuilt head from a '74.
I didn't touch the block, only cleaned and put a new gasket.
Is it just me, or does the second piston look a bit greasy and oily? If so, it is more likely the ring issue.
You are officially my HERO!!!
- Thread starter
- #54
I look inside the second cylinder today.
This is how wet it is ..
top view with one open valve
This is how wet it is ..
top view with one open valve
That cannot be good. Are you thinking sticky rings or bad rings?
MMO might free up sticky rings - could take several treatments - maybe thin some with acetone to help it penetrate. Soak for a day or two then go burn it out, soak R/R Cheap, likely not to cause damage.
Broken or worn out ring(s), damaged piston/bore... you can't fix that so easily or sadly cheap. The longer you wait the more damage you can cause.
Broken or worn out ring(s), damaged piston/bore... you can't fix that so easily or sadly cheap. The longer you wait the more damage you can cause.
- Thread starter
- #57
After 2 days of treatment with MMO (I need to add MMO multiple times, because it drains every 8 to 10 hours)
Compression increased from 180 to 190
I have run the engine for 30 minutes (regularly accelerating to 2K rpm)
Smog is still coming out after this, but much less.
I checked the cylinder: there’s oil on the piston and the spark plug
Hmm.. valve sealing or still oil ring?
I hear a clicking noise in the rocker arm area for about 30 seconds during a cold start (around the second cylinder).
Compression increased from 180 to 190
I have run the engine for 30 minutes (regularly accelerating to 2K rpm)
Smog is still coming out after this, but much less.
I checked the cylinder: there’s oil on the piston and the spark plug
Hmm.. valve sealing or still oil ring?
I hear a clicking noise in the rocker arm area for about 30 seconds during a cold start (around the second cylinder).
- Thread starter
- #58
How long does it take to burn it out?
Not very long. I leave the spark plugs out and use the starter to whirl it over so it can blow out as much as can.
I have fresh rebuilt 2F -5spd and you’re dreaming if you think your going to pull 65-70 up hill….slight incline no problem, kingsbury grade not happening.
