Old 6.9 idi

[Thewespaul]

Looks like this idit I tore down last year

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[Frstdiesel]

Wow

 

[DrCharles]

Check your cylinder bores for taper, although if there's no ridge it is likely pretty straight. I'd still do a few passes with a good hone before putting new rings in, though.

Go ahead and run that cam after polishing it a little, as already recommended. I rebuilt a Mercedes diesel once that had been run out of oil and spun a rod bearing, and the cam journals (which ride directly on aluminum towers) weren't pretty, but both the cam and the towers cleaned up pretty good with emery too. It had 50k miles mostly at 65-70 mph (3200 rpm) on the rebuild and was still going strong when the rest of the car rusted out around it.

I wouldn't try that on a 7000 rpm drag race cam with spring loads approaching 1000 lbs. at .800 lift, but our IDI's only turn 3300 or so, and have relatively small valve springs to match.

 

[bbjordan]

You might want to upgrade to the 7.3 rocker arms. It's a straight bolt in for added reliability.

 

[Frstdiesel]

Yes sir Dr Charles, I was going to check for taper and do a light hone to break any glaze and give a good surface for the rings. And I totally agree with your info about the cam. I was reading about the spring pressures and yes the low rpm of the diesels.
BbJordan, yes I am also planning to do the rocker upgrade. Any suggestions on a source for those?
Thanks guys.

 

[Thewespaul]

If you want to keep it cheap I’ve got many many used ones, but I think you can get them new on eBay and rockauto still

 

[Frstdiesel]

Ok thanks Thewespaul I'll keep you posted.
What's y'alls suggestions for an IP and injectors?
Have them rebuilt or replaced?
Thanks

 

[Thewespaul]

Having those rebuilt adds a lot of performance and reliability, but there’s a chance they are in good shape and don’t need it, it really depends on if you want to drop a grand on that now or change it further down the road.

 

[Frstdiesel]

Need recommendations for main, rod and cam bearings for this 6.9 rebuild. Got the crank back from the machine shop. Lightly polished and all I need is standard bearings.

 

[IDIBRONCO]

I'd say to go with a bigger named brand such as Sealed Power or Clevite.

 

[frankenwrench]

I had great luck with sealed power. Haven't had to try clevite yet but heard great things.

 

[Hydro-idi]

I would go sealed power. Stay away from enginetech.

 

[Frstdiesel]

Thanks for the input on bearings.

Are there any upgrades or modifications I should consider for the heads?
Heads are at the machine shop now getting checked out and vacuum tested. They are good and flat a 0.002 feeler gauge drags under the straight edge when I checked for warpage.
Thanks

 

[IDIBRONCO]

The 6.9 heads really aren't too bad. They have good coolant flow unlike the 7.3 heads.

 

[TahoeTom]

The 6.9 heads have open water jacket ports that are sealed by the valley pan/ intake gasket. The manual calls for gasket maker to seal the ports. The 7.3 heads have cup plugs to seal the ports. It seems like a potential for coolant to leak into the crankcase on the 6.9 and was addressed on the 7.3. I asked my machine shop to tap and install pipe plugs to close off the ports.