7.3 idit build

[AndrewLinderman]

Alright guys. This one is going to be a continuous thread with me asking many questions.

I am building a 7.3 idit. Plan is to get it rebuild right now and to add some upgrades later on.

When disassembling the motor I found out that 6 out of 8 pistons were cracked. This obviously means I have to buy new ones.

Well today I bought them. With new pistons and rings on the way it’s time to order everything else.

Build plans are as of now
Stage 1 turbo
Rd 110 injection pump
Stage 1 injectors
R&D Camshaft
Valve springs
Bearings
Headstuds


Which leads to my first question.

Are classic diesel designs headstuds tested and proven?

I see that they are said to be stronger and cheaper than arp. I can verify the cheap.

Any help along the way will be greatly appreciated and any advice is welcome. TIA.

 

[ISPKI]

It heavily depends on what the compared ARP studs were comprised of. CDD's off brand studs are noted as alloy 8740 which is a common material for head studs, and is in fact used by ARP for some of their hardware. CDD notes that their other brand studs are american made, fully hardened and heat treated, centerless ground, and roll threaded post heat treatment. Pretty much identical to the process that ARP notes for their studs.

8740 is actually listed as one of the low tier options from ARP and they have many alloys that significantly outperform it (Aermet for example, having tensile loads up to and exceeding 300k). However, who knows what the standard IDI stud kit from ARP used and lets be honest, even their lowest tier kit would be a major improvement over the stock head bolts. I am assuming the run of the mill kits they sold were either 8740 or their ARP300 alloys which should be on par with CDD's new brand. You are probably saving some $$$ due to not paying for the ARP logo.

 

[bulletpruf]

Your build sounds a lot like mine. Just finished assembling the short block; see my signature for a link to my YT channel with a video on the assembly. Top end video coming up soon.

FYI - I disassembled a 7.3 IDI-T and found a bunch of cracked pistons as well (details in Episode 3 of Project Brutus); I ended up junking the block because it was bored .040" and I went with an NA based block.

I went with Justin's head studs, his cam, his 90cc IP, and Comp 910 springs. Justin tells me that I can expect 550 ft/lbs as the rear wheels and that sounds mighty fine to me.

Are you going to be able to keep the block at standard bore? Have you checked the heads and valve guides yet? I had one head that was cracked, and someone had installed valves with oversized stems on the IDI-T engine but the valve guides weren't reamed out enough, so I had to deal with that.

Are you assembling this yourself or letting the machine shop handle it?

Scott

 

[hacked89]

Guys, CDD head studs are Gator HSK73IDI fasteners. CDD currently has the best price of any reseller that I’m aware of. Gator is a newer company, haven’t been on many trucks compared to ARP but they have had positive feedback.

 

[AndrewLinderman]

It heavily depends on what the compared ARP studs were comprised of. CDD's off brand studs are noted as alloy 8740 which is a common material for head studs, and is in fact used by ARP for some of their hardware. CDD notes that their other brand studs are american made, fully hardened and heat treated, centerless ground, and roll threaded post heat treatment. Pretty much identical to the process that ARP notes for their studs.

8740 is actually listed as one of the low tier options from ARP and they have many alloys that significantly outperform it (Aermet for example, having tensile loads up to and exceeding 300k). However, who knows what the standard IDI stud kit from ARP used and lets be honest, even their lowest tier kit would be a major improvement over the stock head bolts. I am assuming the run of the mill kits they sold were either 8740 or their ARP300 alloys which should be on par with CDD's new brand. You are probably saving some $$$ due to not paying for the ARP logo.

Yes. The arp studs that are available for the idi are the same 8740 material.

Your build sounds a lot like mine. Just finished assembling the short block; see my signature for a link to my YT channel with a video on the assembly. Top end video coming up soon.

FYI - I disassembled a 7.3 IDI-T and found a bunch of cracked pistons as well (details in Episode 3 of Project Brutus); I ended up junking the block because it was bored .040" and I went with an NA based block.

I went with Justin's head studs, his cam, his 90cc IP, and Comp 910 springs. Justin tells me that I can expect 550 ft/lbs as the rear wheels and that sounds mighty fine to me.

Are you going to be able to keep the block at standard bore? Have you checked the heads and valve guides yet? I had one head that was cracked, and someone had installed valves with oversized stems on the IDI-T engine but the valve guides weren't reamed out enough, so I had to deal with that.

Are you assembling this yourself or letting the machine shop handle it?

Scott

The block is at .30 over. WhenI talked with Justin(R&D). He said that it should be fine and the difference between .30 and standard wasn’t enough to really be a lot weaker.

I have not really checked heads in depth. I have looks at them and didn’t notice any cracks.

 

[bulletpruf]

Might not see cracks just with a visual inspection. I bought a lightly used Magnaflux yoke and some powder and magnafluxed the heads and block. One engine wasn't running when I tore it down and the other one was. The running engine had a small crack in between two valves one head and I ended up junking it.

 

[AndrewLinderman]

@bulletpruf. What does it take to do that? What is the cost?

 

[bulletpruf]

Here you go. You can buy a yoke for about $300 used and a bit more new.

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[bulletpruf]

and here's the block video.

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[AndrewLinderman]

Sweet thanks.

 

[AndrewLinderman]

Let the engine building begin.

Today we got the block on the stand and got it all honed.

There is some very minimal vertical scratching that is barely felt by fingernail. Unfortunately I forgot to get pics of that, but here is the crosshatch.

 

[Austin86250]

How much does a 7.3 block weigh?

 

[AndrewLinderman]

Not enough apparently

 

[Nero]

A fully assembled one weighs almost 900lbs, with the full rotating assembly removed, probably less than that.

 

[ttman4]

A fully assembled one weighs almost 900lbs, with the full rotating assembly removed, probably less than that.

When I tried to lift my last 7.3 that I was messing with I swear it weighed about 10K# (10,000#) at least! Had to get my forklift fired up!!