2F smoke and ring blow by

[pygpen]

As many of you know and tolerated over the years, the 2F in my 75 FJ40 smokes like Gramma used too.
Compression tests looked okay, but leak down was terrible with air leaking into the crankcase (Average 20PSI/85PSI=23%). I've tried soaking the rings with ATF in the past with no luck. I'm sure the rings are mucked up and stuck in their lands.

Should i do an "in the truck" hone and re-ring, maybe replace the rod bearings? (it's always had good oil pressure... when there was enough oil in it, lol). Also, the rear main seal is leaking.

All this before Rubithon 2025... Anyone have a good 2F thats not a million bux?

 

[Pighead]

All this before Rubithon 2025...

2F engines respond heroically to even the slightest attention. New rings would have it running like new

 

[newmexicokid]

When you do this type of thing I’m assuming you pull each piston and rod out and then replace the rings. Do you hone the bore while they’re out? Do you put new rod bearings back in it as we?

 

[Grayscale]

If the valve stem seals have not been renewed, then they need it. Lapping the valves would be important for sealing up the engine. Once the head is removed, you might stuff string at the edge of the piston, and hone the upper cylinder. This seems like the extent of in-the-truck rebuilding. To re-ring, is to pull the motor and work on it with on an engine stand.

I'd expect that any 2F actually showing oil-smoke would be a candidate for a leak-down compression test. The deposits and its effect will display a similar result as cylinder, and/or ring-wear.

 

[White Stripe]

Pull the motor, have a machine shop hone it, install fresh replacement rings, install new seals amd gaskets. Have the valves done if needed. Break motor in properly to seat the rings. Will probably cost 1500 bucks for a mild rebuild.