Demise of an 'F' head

Well, after swapping the Weber and repositioning the oil filler tube slightly, I took the Jeep out to the mountains - Everything was running Great!
At around 7500 feet, on the side of the mountain, I noticed some smoke from the tailpipe, then the oil pressure dropped to zero, but came back up a bit - maybe 10 pounds or so. I heard a new metallic clicking noise, so I shut it down to check the oil.
When I opened the oil filler, the dipstick was no longer attached to the cap, but had partially wrapped around the crankshaft.
I managed to remove the broken piece, then added a quart of 85w140 gear oil (it was all I had).
Made it back down the mountain and off the trail - where it got loaded on a trailer for the ride home -
As far as I can tell, there is at least one cracked piston, causing engine oil to be pumped into the exhaust - it appears to have oil leaking from the pipe at evert joint. It does still run (kinda) on 3 cylinders, but I fear it's days are done.

The worst part? I'm pretty sure I caused the problem by bending the dipstick tube away from the block and rotating it 90 degrees to clear the fuel line on the Weber - this caused the dipstick to hit the crank and vibration did the rest.

 

Sorry to hear that

 

Bummer, dude! Glad you made it down OK with no injuries or further carnage.

 

Thats a drag Whats the plan from here rebuild or upgrade?

 

Look on the bright side, the F head had a long life with many hours on it.

 

That stinks. If it were me I would upgrade to either a :v6: or a 4cyl diesel. Just my 2 cents.

 

OMG!!! Very sad to hear that

 

Sorry to hear that.

It'll make a great campfire story some day though.

I wouldn't count the F134 out till you take it apart though. These engines are very durable and forgiving. See if you can find a used piston, fix the leaks, and see how it runs. Might surprise you.

 

Well, I was kinda disappointed with the lack of power - couldn't pull 3rd gear in overdrive on the flat parts of the highway - ran in 3rd direct at 3000 rpm for the duration of the road portion of the trip.

Plans at this point are:
install gm 4.3 tbi engine, hooked up to a t-15a transmission, and a large hole dana 18 case with the overdrive - then upgrade to an open knuckle dana 30 front differential with 5.38's and a detroit locker.

As with all plans and projects - everything is subject to change, but fixing the old beast is pretty low on the list right now -
I just spent 6 days in the Intensive Care Unit due to a throat infection which started to close off my airway - all is good now, but it was a BIG wake-up call, and my priorities have been redirected. So, the Jeep shall rest peacefully for a bit, and will be reborn after the dust settles.

 

Sounds like the fhead was doing about all I'd expect it to do. Unless he put the Clifford cam in it, we're running mostly the same mods and making quite a bit of power, for an fhead. Just rough calc'ing it, those 36" tires are almost another 25% overdrive. I would not expect the fhead to pull a combined ~50% overdrive if brand new.

 

Yup, the 36" tires really suck up the power - BIG difference from the 33's I was running -
The overdrive was a godsend in low range - 1st gear was a little too slow, but 1st O/D was perfect!!

On the highway, downhill, in 3rd O/D, the Jeep topped out at 116 kph!! That's 72.08 MPH!! (as shown on my GPS)
Not too shabby!

 

My :hurrican: in the 3b ran on 3cyl for about 6 years. They'er tough boogers!

 

Well, just pulled the oil pan and took a look around - other than dirty oil, and a spot on one of the crankshaft counterweights that scraped the dipstick - I can't see anything wrong.....
So, I pulled the cylinder head to take a look - the spark plugs from #1 and #2 were oily and wet - took a look at the tops of the pistons - there is evidence of oil in all the cylinders, but #1 and #2 look wet.
The cylinder walls are not scarred at all - they seem to be too smooth - like a mirror finish - no cross-hatch.

Any thoughts?

 

:iagree: Mine was very tired like yours, Burning oil ( 1 qt every couple hours ) and barely pulling itself around in 3rd gear ( had to really get into the throttle on any kind of pull ).

You will not believe the difference a proper overhaul will make, You wont know its the same engine. I can pull slight grades in 3rd now like they were level ground and half throttle will willingly pull all but the steepest grades.

It really idles around in low range better too, Granted I am running tires under 30 inches with 5:38 gears. Dont give up on the F-Head just yet

 

Did you check the compression befor you pulled the head? Can you measure the bores? Maybe a re-hone and ring and bearing job would do the trick. How do the valves and seats look?

 

You'll be back on the trail sooner to get your fix of offroading if you overhaul the F head. Although a new TBI engine would be nice, I'd stick it out with the Hurricane.