Ford 8000 smoke/power issues

ford401

Member
I just got my 8000 that i rebuilt in the field for the first time. Block was brought to machine shop, new cam bearings, cylinders bored and sleeved back to stock, new pistons, rings. I
did cheap out, and reused the head, injectors, and inj. pump. Starts a little harder than I would think it should with a new bottom end, sometimes i have to use ether. My issue is when
i start it smokes blue/white/greyish smoke, seems to get a little better as it warms up but still smokes way more than my other 8000 (idle and driving without anything behind it), and
never really clears up. First hour on it, a lot of black oil came out of the exhaust pipe, but that seemed to clear up a bit. Got it out in field and pulled cultimulcher around and it went
from white smoke to black smoke, and didn't seem to have nearly the power of my other 8000. I'm really hoping someone here ca give me some ideas.
 
Sounds like possibly a low compression problem to me. Was the piston deck height checked when the bottom end was rebuilt? Was the valve recession checked before the head went back on?
 
I agree with Bern, much more should have been done measurement wise while engine was apart. I'd bet the head needs all twelve seats at least to bring the valves back where they belong.
 
I didn?t check check either of those. I assumed the head would be ok as it was running fine before. How would piston deck height change? Same crank and rods were used.
 
You said it got new pistons. If they were mis-machined in production, by even .010", that would be enough to make a hard starter out of it. If you had checked it, you wouldn't be wondering now.

Were the ring end gaps checked?
 
Yes the ring gaps were checked. Understanding that the deck height could be an issue (but hoping it?s not) and not wanting to spend a million bucks on this thing, is it safe to assume if I bring head in and have it rebuilt that it could solve these issues? I wasn?t sure if I should look at injection pump or injectors instead ?
 
If you're going to pull the head back off, then you can easily check deck height. This is done by measuring how much the piston top sticks above the block at true TDC. .011 - .023" is the spec for an 8000. If it's off, you'll need to try different pistons.

As for the head, you'll be wanting to check valve recession. You're looking for .060 - .085" max there. Valve heads sunk below .085" will require that new seats be installed.

If that all checks out, then I'm turning towards the injection pump.
 
OK thank you very much for the info. I have not checked compression on it yet, if i can get my hands on a gauge in the next few days and check comp in all 6 cylinders, and its 350-400 psi, that would rule out a deck height issue correct?
 

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