IDI block = IDIT block

[Ferdy Mint]

If you have an IDI block you can make it into an IDIT easily. The blocks are the same. Only the rods, wrist pins and pistons are specific to the turbo. I'm not sure about the crank. Both have under-piston oil cooling. There are stories on the internet about webbing in the casting being different, or firing order. But all three of the specialists I talked to said they cannot see any differences at all. I talked to Accurate Diesel, Classic Diesel Designs, and R&D Performance.

On the other hand, they also said that 10% of the IDI blocks they see have offset cylinder cores, so they strongly recommend sleeving any IDI you rebuild. My local machine shop only charges $60 per cylinder to sleeve. So if you've been looking for an IDIT truck for years, just build your own instead. The vibration damper, flywheel and clutch need to be turbo versions too.

R&D sells forged 7.3 PSD rods that are machined to fit an IDIT. FYI

 

[IDIoit]

FIRST AND FOREMOST THIS IS A BOOB COMMUNITY

THEREFORE, THEY ARE CALLED TIDI'S

TIDI blocks also have larger oil galleys.
TIDI uses a differently balanced crank, which the flexplate/flywheel and balancer is also different.
TIDI also used different material in the valves....
TIDI also uses a different oil cooler

i have Brian Crower PSD rods at R&D right now.

converting your 7.3D is not as easy as you think to make a 7.3T

 

[Ferdy Mint]

Somewhere a feminististist is raging. Who could not like tidis?

Back to mechanics. So you say the guys at the other shops are wrong, OK. But I'm tired of looking for a TIDI block and I'm going to make my own. It sounds like only the larger oil galleys will be missing from my mongrel TIDI block. The crank, damper, flywheel, rods, pistons, wrist pins and exhaust valves will all have to be TIDI versions. As for oiling the turbo, I'll use the Classic Diesel Designs method. Maybe one of their 250cc IPs too. But then I'd need to figure out an intercooler.

 

[IDIBRONCO]

FIRST AND FOREMOST THIS IS A BOOB COMMUNITY

THEREFORE, THEY ARE CALLED TIDI'S

 

[IDIBRONCO]

I'm going to make my own. It sounds like only the larger oil galleys will be missing from my mongrel TIDI block. The crank, damper, flywheel, rods, pistons, wrist pins and exhaust valves will all have to be TIDI versions.

As for me, the only Turbo parts that I'm going to use are the rods and pistons (with their special attached parts). I'm going to use a N/A block as it is. I'm also going to have the rotating assembly balanced so that I don't have to try to find the special Turbo Crank, balancer, and flywheel. I may go with the iconel exhaust valves though.

 

[Ferdy Mint]

As for me, the only Turbo parts that I'm going to use are the rods and pistons (with their special attached parts). I'm going to use a N/A block as it is. I'm also going to have the rotating assembly balanced so that I don't have to try to find the special Turbo Crank, balancer, and flywheel. I may go with the iconel exhaust valves though.

Didn't I read somewhere that the TIDI flywheel is heavier? Gottta search the folds of my brain...no, it's too late.

 

[IDIoit]

first off, i highly doubt Justin would argue the fact that there are several differences, as i posted earlier
i know the guy personally, and the differences i pointed out arnt my opinion or hearsay.
they are indeed fact.

anyone that knows these engines will admit to this.

but the only difference that i know of in the actual casting of the block is bigger oil galley.
TIDI is 1/4" NPT to the turbo feed.
N/A is 1/8" NPT. to the oil pressure sensor
and most likely can be drilled out if youre into that thing.




i run TIDI's in my rigs because ive waisted 2 N/A blocks.
i havnt destroyed a TIDI block.....YET
its more superstition than anything to be honest.

when i built my first IDI, i bought 3 engines. all N/A
i ended up building one, and slapping 2 oki built them together to make complete engines on stands.
one of them, had pimple faced pistons from a glow plug tip.
on 4 cylinders. i figured what the.heill.

i ended up using this block in a 63 ranchero build.
intended to be just a mock up engine while i build the truck.
but. the danm thing RAN!
and ran pretty ok.

to this day, it receives 25+ psi right to the gut on twin turbos.

i cant kill it ive tried.

 

[IDIBRONCO]

Didn't I read somewhere that the TIDI flywheel is heavier?

Quite possibly, but they are balanced differently than the N/A ones are. While you may still be able to find Turbo flywheels, I think that Turbo flexplates aren't available new anymore. At least I don't remember anyone saying recently that they've found one.

 

[Fision]

Quite possibly, but they are balanced differently than the N/A ones are. While you may still be able to find Turbo flywheels, I think that Turbo flexplates aren't available new anymore. At least I don't remember anyone saying recently that they've found one.

I have a TIDI flex plate if anyone needs, for the shipping charge. Came out of an TIDI-automatic (obviously) but the engine is going with a zf5, so I don’t need the flex plate.

 

[Finn]

One of the significant upgrades made to the 7.3 IDI engine when the turbo version was introduced was the relocated cross drilled cooling passage in the cylinder valve bridge area. The passage was relocated slightly to reduce cracking in the bridge area. The modification significantly reduced metal temperature and temperature gradients in that area. What I recall is that the drill size was reduced slightly in order to accommodate a slightly different angle, reducing metal thickness and subsequently improving heat transfer in that area.

Blocks were slightly modified to incorporate the turbo feed line, but there were no significant core or structural changes.

Piston pin bore size was increased to control pin bore cracks. I think the *** tube diameter was increased to increase oil flow to the underside of the pistons. I don’t remember if the oil pump width was increased for more oil flow ( because of the increased piston cooling oil flow—- it’s been thirty years!). Crown thickness was increased, and rings changed to keystone to prevent sticking.

The original concept was to productionize the aftermarket ATS kit that was available at the time, but it ended up being total garbage. Every piece had to be redesigned, and the base engine needed upgrades to accommodate the increased cylinder pressure and thermal loading from the higher fuel rate and boost. The engine was qualified at a slightly higher horsepower but, at the last minute, the top end fuel rate had to be tapered back for emission certification. I recall that the governor regulation was tightened slightly for emissions, too.

Original program targets were for 5000 incremental sales with the turbo version, but over 50000 were sold. A pleasant surprise, to say the least.

 

[Old Goat]

Here is some interesting info on the IDIT 7.3 engine.
Original specifications.

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

 

[Randy Bush]

That is a lot of good information to have. I find it interesting on internal changes done to the engine the crankshaft was not one of them. Has always been my claim , externally balanced .

 

[YJMike92]

Older thread I know, but I have a question about the turbo cooler feed at the back of the block. I'm building a NA block to be as close to a TIDI block as possible. Has anyone drilled and tapped the block at the oil feed hole to the larger turbo block size 1/8 NPT TO 1/4?

 

[IDIBRONCO]

Has anyone drilled and tapped the block at the oil feed hole to the larger turbo block size 1/8 NPT TO 1/4?

You certainly can. On the other hand, most of the aftermarket turbo kits use a 1/8" NPT port for the oil feed and have no problems at all. It seems like a lot of work for no gain to me.

 

[1mouse3]

I have a tidi clone but cant assemble it for use at the moment, it got decked more than asked and cant use the pistons I have. Had someone local mod PSD rod, had to tell him to use a rotor table in a mill to cut the big end to match oem. The side getting cut is the one with the bigger chanfer, then chanfer is cut to match oem. I am also going to use PSD rod bearing as well, since fit fine. I have a new luks solid flyweel for a zf with turbo ballence spec but had had to settle on a used turbo balancer, could not source a new one. The turbo balancer has a fair bit more weight add at one point, and same with the flywheel. The NA crank ballenced out fine with these, without having to get weight added. Im not on the 1/8 oil passage being a issue, so thats left alone. Think I still have a turbo oil cooler, but not sure if I mixed them up. The ball by the thermostat is not going to be used and passage drilled a size bigger, so steam cant be traped. That also gose for the freeze plugs in the deck and heads, there removed and hole will be needed in the gasket. As for pistons, Im going to have to come up with some thing since dont have ones with a raised pin hight. I have done some thinking on it and think a steel one would be ideal, just not sure if can get it down to same weigh. Say for this set, the way the skirt is shaped could give the needed reduction in weight.

M57 Steel Piston and Connecting Rod Package

In the 500+whp realm, the factory M57 cast aluminum pistons and powder forged cracked cap rods start to become a wildcard. Billet or forged aluminum pistons would have been a simple solution to handle the power short term, they cannot be made with a steel top ring land and consequently will only...

whitbreadperformance.com

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This is another one I found but dont remeber where.

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This is something I found used with the detrot 6.2/6.5, to help get the heat away from the pre-cut. Them doing this and using there dimond cups, was a solution found for issue of stuff cracking. Not sure on how this transfer over to the 7.3, but want to experiment with this.

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So my tidi build part are going to spend time on the healing bench, hope they dont rust on me. I am gather stuff slowly to set up a cnc mill, welding robot, and lathe. As far as I am so far, is all the parts for the water cooled server. For now have a cobbled togther NA block with just cooling mods, will be easy on it and hope it will hold out. The compresion drop from the glow plug deleat, might be enough to keep it alive if I dont feed it a alot of fuel. I have it set up for a 12v grid heater instead.

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