Building a TIDI from a couple motors plus new parts

Howdy guys,

We bought a 93 TIDI parts F350. PO ran straight water and it froze in the big Texas Freeze. Visible cracks, freeze plugs blown clean out like lungs with Biden's 9 mil. The cab is already gone, off to a son who's putting it on his 97 F350 cclb with 86 Bully front clip. I swapped him that clean Texas cab for tearing down the TIDI and crating up the parts in a TIDI crate and IDI crate.

So the plan is to tear down the motor, toss the block, separate TIDI parts from IDI, and have a machinist sleeve one of our spare IDI blocks to put them in. I spoke with Classic Diesel Design a few weeks ago and he said I'd need the following parts off the TIDI that are different on an IDI. Did I miss anything?

1. pistons
2. rods
3. cylinder heads because of the better valves
4. snail, turbo, valve covers, intake, any fasteners and brackets that differ from IDI

IP and injectors we'll get from Classic Diesel. Then we just need to rig up a good oil feed for the turbo. Buy new rings, a big downpipe, and all the 100s of other things that will no doubt pop up that I forgot.

This will go in a nice 89 F250 that got piston wall perforation at 108k miles. No interior cracks, red cloth, XLT Lariat, everything works except cruise, original body, nice grandpa truck. Too bad it's not a 350 4wd but hey it will be great around here in the country. We did a ZF5 swap on it last year.

You need to keep the crank, flywheel and ballencer off the tidi, they are a different offset and ballence. You can get away with just the flywheel and ballencer off a tidi, but the carnk from a idi would need sent to get reballenced.

I believe that the intake manifold itself is the same between the N/A and Turbo engines. Why can't you use the original oil feed for the turbo? Don't worry about the hole being 1/8" NPT instead of 1/4" NPT. Most, if not all, of the aftermarket turbos use a 1/8" NPT hole for their oil feed and have no problems.

IDIBRONCO said:

I believe that the intake manifold itself is the same between the N/A and Turbo engines. Why can't you use the original oil feed for the turbo? Don't worry about the hole being 1/8" NPT instead of 1/4" NPT. Most, if not all, of the aftermarket turbos use a 1/8" NPT hole for their oil feed and have no problems.

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Do you mean the oil port at the back of the IDI block on top, that's often also used for an oil pressure gauge? That's suitable for a turbo oil feed? Cool. Sure is a *pita* to get at once the motor is in the truck.

Ferdy Mint said:

Do you mean the oil port at the back of the IDI block on top, that's often also used for an oil pressure gauge? That's suitable for a turbo oil feed?

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Yes. That's where the ATS 093 and the Factory Turbo get their oil from. The Factory Turbo engine has a 1/4" NPT hole there, but it would work just fine as it is. I think that most of the other aftermarket turbos get their oil from the oil galley on the driver's side, lowest part of the block, behind the oil filter, right in front of the engine adapter plate. You can get your oil from there too. The reason that I mentioned the galley that has just the oil pressure sender on N/A engines is because you should already have everything that you need to use this hole. You'd have to take the N/A lower hex shaped piece and use the brass adapter from the Factory Turbo set up. That's a pretty easy swap to me.

I noticed that Moose Diesel has an IDI crank for sale. I wrote to ask if it's TIDI or IDI. See their answer below. Others here in the forum have held that a TIDI crank has different counterweights and a different harmonic balancer.

Can anyone set this issue straight? Are TIDI and IDI cranks the same? I'd like to have a spare crank around. We have several IDIs that cry at night because they have no turbo.

"To the best of our knowledge there have been no changes to the crank through the history of the IDI engine family. 6.9 or 7.3, turbo or normally aspirated. Ford claims that a different crankshaft damper and flywheel are used with the 7.3 factory turbo IDI, however in our experience, no one has reported any issues using any combination of crank balancer and flywheel."

Here's my .02 on this for what it's worth. While there may or may not be any difference between the 6.9 and 7.3 N/A cranks, there is a visible difference between a N/A crank and a Turbo crank. I've seen pictures posted on here. If all else fails, you can have your rotating assembly balanced before putting your engine together. I also have to say that, at the shop I used to work at, we did mix and match Turbo and N/A parts. We also mixed and matched 6.9 and 7.3 N/A parts. Right or wrong, I'll chalk it up to lack of knowledge. Remember, my boss told us that you couldn't buy replacement pistons for Turbo rods so we tossed them in the scrap iron. Sure, he probably didn't want to pay for the extra pricey pistons. I certainly didn't know any better back then, but I do now. We did have a noticeable vibration issue on only one engine. That was in a 1994 Ex cab, dually, ZF5 that had a Factory Turbo. There was a vibration when the engine was on fast idle, but nowhere else. The customer didn't like it because his dash was loose and rattled when on fast idle. We (I) pulled the engine back out and installed another one and there was no more vibration. The customer was happy, BUT there is one thing to add. His second engine ran just fine, but the first one, with the vibration, was the best running IDI that I've ever experienced except for Wes's old Shop truck engine. By the butt dyno, that thing would out run a stock first gen 7.3 PSD any day of the week. It was simply amazing. We couldn't figure out why it ran so good. The guy who dealt with our account at the machine shop said that the only thing that he could figure is that there must have been something different with the cam. My guess is that he was right. I'm guessing that that engine had one of Russ's earlier cams in it.

OK guys we're into tearing down the freeze-damaged TIDI donor block now. Death and destruction, shock and sadness. Feast your eyes. My son is doing the teardown at his shop, I will go gander it with my own peepers today. But it looks grim. Hopefully all rods, crank, and most pistons are good. We'll see.

My question now is about the TIDI valves in that cracked head you see. The head is toast, but the valves should be OK. Uh, except that snapped-off intake valve in the pic... Note however bent pushrods. The dummy PO may have tried to start a frozen motor. smh...
Wondering if it's true that the only TIDI specific part in a TIDI cylinder head is the better exhaust valves. Can anyone confirm?

Ferdy Mint said:

I noticed that Moose Diesel has an IDI crank for sale. I wrote to ask if it's TIDI or IDI. See their answer below. Others here in the forum have held that a TIDI crank has different counterweights and a different harmonic balancer.

Can anyone set this issue straight? Are TIDI and IDI cranks the same? I'd like to have a spare crank around. We have several IDIs that cry at night because they have no turbo.

"To the best of our knowledge there have been no changes to the crank through the history of the IDI engine family. 6.9 or 7.3, turbo or normally aspirated. Ford claims that a different crankshaft damper and flywheel are used with the 7.3 factory turbo IDI, however in our experience, no one has reported any issues using any combination of crank balancer and flywheel."

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Here is some info on the turbo charged factory engine.



Goat

I saw the donor block today. Passenger side forward piston is gone, in pieces. I hope that rod is OK. Forged steel vs cast aluminum. I bet it's just fine. We'll spec it.

FYI, here is all that's left of the donor truck. A 350 frame, long pinion Sterling, front suspension, and a clean dually bed with minimal rust.

Old Goat said:

Here is some info on the turbo charged factory engine.

https://mid-atlanticema.org/wp-content/uploads/93-94-7.3-IDI-Turbocharged-Diesel-Engine.pdf

Goat

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Perfect summary on page 23 - thank you!

id be throwing that entire engine in the scrap pile. i doubt the rod is any good. maybe the crank and all the accessories.

im about to venture into a build too, i have everything but the time

IDIoit said:

id be throwing that entire engine in the scrap pile. i doubt the rod is any good. maybe the crank and all the accessories.

im about to venture into a build too, i have everything but the time

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You were right. That rod is pretzel. See my next post.

Progress report and questions about TIDI rods

Reminder on the project: I bought a TIDI with freeze damage to mate with a low-miles IDI that has cylinder wall perforation. Together I plan to make a healthy sleeved TIDI in a clean 89 XLT Lariat for my daughter's daily. It took months to find a TIDI donor truck. They are scarce. Texans have enough sense to keep them.

We got the donor TIDI torn down to the block (see pic). The PO must have tried to start it with massive freeze damage, and as you can see that trashed a piston, rod (see pic) and 1 intake valve. All the other parts look serviceable. The broken piston was in small pieces (no pic).

Questions for guys who have rebuilt TIDIs.

1) Each rod is marked on the BEB cap with punch marks (see pic). The damaged one is passenger side bank front and has 8 punch marks, the others with 1 thru 7. Is this factory marking on the BEB caps? Or does it mean somebody has already been in this motor?

2) Aren't TIDI pistons and rods all the same? It's been years since I rebuilt a motor but I don't remember the reciprocating parts being numbered by cylinder at the factory. This question affects the next question.

3) I'll need to buy at least one TIDI rod and one piston. The machinist might tell me I need more after spec'ing my donor TIDI rods and pistons. The donor IDI block needs sleeving, and I plan to sleeve it to stock. What's the best way to get a TIDI rod? I'd heard that nobody makes the rods anymore so we have to use 7.3 PSD rods that are machined to fit TIDI. I reckon I can find a piston easily enough.

My donor TIDI wrist pins mic out at 1.310 (see pic) with my crappy Aldi mic, which matches with IH's spec of 1.3086" so big sigh of relief there. Could have been an IDI that somebody converted. The seller was a clueless kid.

Thanks guys if you have any tips,

Part number for the pistons you have will be stamped on the face, just need to clean to find it. If it dont exist you will have to go by weight to find another that matches. Good luck finding new parts, pistons there might be a slim chance but rods no go. Some one might have used ones to offer up but you may be looking for another block to salvage. Powerstroke rods can be made to work, need a machinist with a rotory table on a mill to do it. It involves cutting the big end to match the tidi ones in thickness, cut the big chamfer side and then match chamfer. This set of rods will weight more, so a balance is do.