Garage Build out - New Build in... Official Thread w/carnage pics

[84TD]

We have no choice but to do a full rebuild on this engine. The #8 piston is cracked in half!! This is the one that had the injector stuck open. Also lots of glowplug tip damage from the PO.

I would like some advice from those who have done a full build. I have heard it said on this forum that most builders do not know how to rebuild an idi 6.9. What is there to know beyond a normal rebuild? Is there anything special about the bore or deck? I looks at the rebuild specs it all look pretty straight forward to me.

This is the plan...
Block is going to the machine shop for a checkup and a .040 or .060 over bore
I will make sure they use "the tool" for new freeze plugs
Heads are getting valve job
Going to replace all the bearings and possibly the piston rod bushings

Rebuilding IP too

Going to try to do injectors and cam from typ4

maybe studs

and we have to do it all in the next 2 to 3 weeks.

What all am I missing?

I will keep the progress pics coming.

 

[84TD]

For some reason the pics did not attach, I got this...
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***?

 

[icanfixall]

What you list about rebuilding is correct but. My list is a bit differant and I speak from experiance. Bore the cylinders only what you need. Most engines will handle a 20 oversize easily but a 40 or 60 is a stretch. Deck the block and line bore or hone the main webs. Reuse the original oil pump. They are far better built than any aftermarket pump. Stud the heads is a must with a turbo. The front and rear main seals will need a speedi sleeve so the new seals are not cut up my the worn seal surfaces. Rebuild the oil cooler. Make sure what the piston height is. All the idi engines have the pistons coming up out of the cylinders as much as 31 thousands at tdc. Mahle is the oem piston and ring maker in these engines. They make a fine part. Not many better out there. Look at the bearings when you tear it down. Any side wear on the mains tells you the crank webs are bored off true center creating internal drag and uneven bearing wear. If the rod bearings show the same wear patterns it means the bores are off center to the crank. A good machinst will be able to bore them back to true center to the crank easily. This is how I feel about rebuilding most any engine. PS... The piston oil cooler jets will need to be removed to bore a cylinder. Hopefully you have the bolt in type and not the press in type. Only one person has that special press and alignment tool.

 

[hesutton]

What engine are we talking about, 6.9 or 7.3? Don't bore a 7.3 like that. I'd keep the 6.9 bore as small as possible to fix any cylinder problems. The deck on the block needs to be closely checked for warping or being out of square with the crank. The heads need to be pressure checked and magnafluxed. The valves, springs, seats, and guides need to be checked to ensure they are within spec as well. The heads may need some resurfacing, but as little as possible is best. Make sure the crank in good shape. When tearing that sucker down, keep track of where everything was and where it needs to go back. Like the main caps, they are numbered 1-5 and need to go back on the same main journal in the block. The rods are marked as well. Make sure you know what cylinder they came from and put them back in the same cylinder.

If the deck of the block is machined, think about using pistons with a lower compression height to ensure the pistons don't hit the heads/valves. Mahle and other make them. Keep the rockers, push rods, and lifters in the same holes if they are going to be reused. Get a box of sandwich bags and put all the little parts, nuts, bolts in them and lable them so you know what goes where and so things don't get lost.

Ask lots of questions and be specific. We're glad to help.

Heath

 

[84TD]

Finally made a web shots account.

comin out

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the dead hole, this would explain the crazy blowby

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These are why you should change your glowplugs and why you should pull your head if you lose a tip. besides all the dents a couple of these have that weird pattern burned into them. EGT burns maybe?

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that shiney thing IS the tip... it prob ruined all the pistons, its far more likely a tip would exit via the larger intake valve.

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[84TD]

Its a 6.9. So there is nothing strange except the oil jets and the line bore? A standard machinist that can rebuild a 460 can do a 6.9 right?

If you look at the 3rd piston pic there are 2 really deep scores from probably that dang glowplug. That is why were thinking 40 or even 60.

We are going to do the complete tear down tomorrow eve, will keep you guys posted.

 

[Knuckledragger]

If you are going to rebuild it, balance the rotating mass too. Should cost no more than $250 and is worth every penny. The previous posters are correct in all of their suggestions. Change your piston pin bushings, too. When magnafluxing the heads, look for cracks between the intake and exhaust valves, it is common.

These IDIs are simple to work on, but not the same as a gasser engine. They are heavy. Very heavy. 1100 pounds heavy dressed. The head bolts (or studs) have a very specific tightening sequence. The center of gravity (for hanging on an engine stand) is very high, about the height of the valley tray between the heads. Maybe higher. It will be tough to turn over the engine until the heads are on but if you have it balanced for the block, the heads will make it dangerously unbalanced.

Piston oilers - do you have the bolt in or press in type? The press in type have an aiming fixture that is no longer available from OTC to install them, so take pictures and make drawings of how they look before taking them out. PM me if you need any help, I made a couple of tools to take them out and install them.

 

[JRNOLL]

Having the engine apart you might as well ballence it. Ive found that on engines I have rebuilt that they seem to last longer than those I haven't ballenced.

 

[typ4]

Also , dont remove the original block freeze plugs unless they are leaking.
email me for more info
[email protected]

 

[icanfixall]

Thanks for the pics. I see what looks like an intake valve imprint in some of the pistons. I also see some overheated pistons too. Some look like the edges are eaten away too. As posted above about the freeze plugs. Try to leave them in. The factory used a special plug that is stainless steel. Only Ford or international will have those if you end up needing them. Never allow a shop to install aftermarket plugs that are fake stainless or brass or steel. They will not hold in the block. It appeasrs this engine did not have antifreeze in the coolant. So boiling out all that scale and rust may require the plugs to be removed.

 

[84TD]

Engine is completely torn down. Had bolt in oil coolers. All the bearings were in perfect shape, its a shame about that cylinder getting hossed with diesel. The block, heads, crank and piston are all off the the machine shop tomorrow. Did you guys know there are enough parts on and in a 6.9 to fill and 8x8 flatbed?

block pic

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[snicklas]

Block looks fairly good........

Just out of curiosity, what model Cub Cadet is that? It is a wideframe, with narrow front tires, my guess is an 86, or a 108 or 109.....

 

[84TD]

Its a 1971 Model 109. Its a clean original that I use every week to mow the grass.

Still waiting to hear back from the machine shop on how much they will bore. IP is in the shop getting built. Hopefully will have the cam and injectors on the way soon. BTW in case anyone is wondering it costs about $2500 to do a complete fresh rebuild doing all the non machine shop labor yourself. You definitely have to have the right truck to make this worth while!