Building turbo IDI

[prerunnin]

I picked up a spare 7.3 and e4od today, gonna tear it down and pray that theres no cavitation. But what kind of modifications are usually done to these motors to run boost? where can I get parts.

I've built gas motors before with the basics for FI(low comp pistons, mls gaskets, ported heads) but I've never heard of anything on a diesel build. any good articles or anything for me to check out on it? Planning on running twin turbo

 

[icanfixall]

Welocme to the forum.. Will this turbo idi be a daily driver... If so a twin turbo setup probably wont be the best of ideas. A turbo engine is a basic non turbo engine. About the only real differance is the rods... The turbo rods have a 33mm pin where all other non turbo engines has a 28mm pin. All the 6.9 and 7.3 engines use the same internals. The cam, crank, oil pump, gears ect are the same so parts are easy to come across. Buying a set of turbo rods can be expensive... Try Diesel Direct in Florida. A few years ago they had two pallets of these rods for $42.00 each... No core charge... Ford will kill you on the price and the core so buy from them as a last choice. Mahle was the oem supplier for pistons in all the 6.9 and 7.3 engines too. They still make several differant pistons for these idi engines too. Figure around $600.00 for a set with rings and pins... Make sure you balance the rotating parts. Other machining will give you more freedom for hp. Line boreing or honing the crank webs is a must. It will reduce the friction in a twisted block on the bearings. Porting is not something most can do to these engines. I have done several sets and my pics are everywhere I have no secrets as to how I do this work. No reason for that... If you want the best injection pump talk to Agnem here on this site... He works with a pump builder and you wil not find a better pump. Typ4 has a torquer cam available too. These guys are on this site so just look for them and talk out what you want. These engines are able to take plenty of abuse and keep running... One member here revs his engine to around 4500 rpm and almost 30 lbs of boost on stock head bolts.... Not everyone can do that and he will tell you that too... ARP is the only real source for head studs. A few have tried to make them but the outcome was not good. I had a set of DPS studs that were H13 material with a 270,000 psi breaking strenght... They broke... My ARP ar 220,000 psi have worked great for around 10,000 miles. ARP does not sell an actual 7.3 idi head stud kit... They sell a 7 inch long stud that fits.... We use 34 studs.... Stay with a turbo from the big three and you will have a realiable rig for many years. Only Hypermax sells an intercooler setup for their turbo but... You can make an intake hat for any turbo and use their intercooler. Hope this gets you started and ask any questions here... Someone is always online here....

 

[prerunnin]

I'm not worried about manifolds as i would make my own. I'm planning on running turbo designed for a cummins 5.9 with a wastegate(got it fo freeeee). I think what I'm going to do is build the manifolds for the 7.3 I just got and drop that in till it blows then i'll open it up and get ceramic coated pistons and better head gaskets. Changed my mind on the twin turbo since I'm going wastegate now. As far as boost goes on these non-turbo pistons/heads what can they take really? And what would you change to make them take more abuse?

 

[dyoung14]

Im the one who has pushed there rig beyond the limits, i turned 4500 rpm every since i built the engine, it always held up, when i turboed it i started out running 15psi, then i wired my wastegated shut and ran 20 psi, held like that for a couple months, then i bought a turbo injection pump and maxed it out and made 28psi and it blew the water passege between the head and block, but i can go out right now pour somewater in it and pull out on the road and leave a burn out from here to the end of the road then pull out on the main road and make 28psi and watch the water blow on my window

I held that much boost on stock head bolts, but i only did that because i couldnt afford studs, i have seen peoples gasket blow at 10 psi, mine chose to blow at 28psi, not sure why but thats what happened

Then engine i want to build is:
19:1 compression ratio
studded everywere- heads, rods, mains, intake, and exhuast manifolds.
moose or super moose pump, moose misters, intercooled, and twin turboed that should be very fun, and hold together

 

[93_444idi]

erm, i guess before we get into a bunch of detail on how to do this, how old are you? a lot of teenagers think they're gonna save every dollar they make at walmart and make some amazing build and then they get bored with the idea or realize it isnt feasible after a while after all the time and ideas others put out.

dont mean to be a jerk, just wondering if you are actually going to do this.


dyoung, is it necessary to stud exhaust manifolds? would think there would have to be a lot of pressure to push an exhaust manifold out, dont see how that pressure would build up when the air isnt trapped there.

and i think yours may have held out longer because first year 6.9s had lower CR factory then the rest. but 28 is really high. i think 19:1 or 19.5:1 would be a great CR for boost, some day down the road I'm gonna build up a 6.9 like that.

 

[82F100SWB]

If you poke around through Dave S's posts over on FTE, he started having intake and exhaust manifold gasket issues around the mid 20 psi range on a new engine, and studs were indeed part of the fix.
With the turbos that the kits available for these engines come with, the exhaust housing is quite small, and the drive pressure is probably quite high, most likley well beyond a 1:1 ratio.

 

[prerunnin]

Dyoung what kinda work did you do to increase the redline? I always assumed diesels would stretch/bend rods and screw with internals over-revved. As for head gasket what were you running was it a stock coated in copper? Cometic MLS style gaskets are the **** for gassers, how about on these motors never heard of any MLS style gaskets on a diesel before? Lowering compression, it looks like Maule has a kit that would drop the piston .010+a slightly thicker gasket what kinda compression would I be looking at? I live in the desert and the truck is not a daily driver so I'm not too worried about the cold starting. But, when they do blow because of the high compression boosted applications, what goes first? is it only the head gaskets?

93_444idi, im 21 but dont worry i'm not just blowing air out my ass, i have money to spend on this but i'd much rather do it the cheapest way possible.

82F100SWB what is FTE? I'm not up on all the diesel sites yet as I'm just jumping into these idi motors.


Anyways I'm going to be pulling the 7.3 from the van tomorrow night and going to measure the stock exhaust manifolds so i can design the flanges for the turbo manifolds in CAD and i'll send them out to waterjet and have them done sometime next week.

 

[FordGuy100]

Head gasket failure seems to be the boost problem. I havent seen much bottom end carnage that could be associated with high boost applications. I believe the bottom end seems to be pretty rock solid.

As far as I know, no MLS style head gasket available. We have researched into getting companies to make them, but it would require an order of something like 50+ gaskets for them to consider making them. Couldnt come up with enough people (espeically at the price they wanted...).

 

[dyoung14]

All i done was put a high rpm govenor spring in, which im about to give away to a member on this forum and install it in his pump for him.

I reckomend balancing everything like icanfixall sadi, also studding everything gives you a peice of mind and makes it more reliable, who wants to change gaskets all the time,

Head gaskets were fel-pro, intake gaskets were re-used and copper coated, exhuast manifold gaskets were new and copper coated

 

[prerunnin]

Has anyone tried Cometic? My buddy got some made custom made .020 thou over stock for his toyota 3.4 for 240$...

 

[FordGuy100]

I believe that is who was contacted and they wanted a large order to even begin thinking about making them.

 

[icanfixall]

A stock 7.3 head gasket made by Fel pro is around 75 thousands thick already... they are supposedly 10 thousands thicker than any thing else out there... Don't have that as a fact yet either... About the best aftermarket head gasket is the Victor Reinz but... I'm running a set of felpro head gaskets and have never lost one...

 

[prerunnin]

I know with the sbc the felpro's are thicker, but they are also softer and they compress more when you torque equaling same compression ratio

 

[NMB2]

i use coated fel-pro's. ARP head studs, overtorqued to 110lbs. My truck runs 20+psi at will, unloaded, and I have made 1000mile trips with about a 9k load on it.

 

[Diesel JD]

I've been in NMB2's truck and it is a beast. I really hope you do have the skills to fabricate your manifolds and run the HX35 Cummins turbo, I can' wait to see somebody try it, but it would be a real challenge if you could not make your own stuff like that. If you do a nice job of it, others here might be interested in sending you some more projects and you could make a little cash. Head gaskets seem to be the major failure point, the ARP studs installed correctly along with a set of updated head gaskets usually keeps this problem at bay. RLDSL suggests that you use Hylomar spray to coat Victor-Reinz head gaskets. The thing NMB2 has done much differently than others to hold his 20+ psiG boost is to overtorque those ARP studs. I think most here only run 85-95 ft-lbs of torque on them as the instructions suggest. If you overtorque anything, be really sure you can trust your torque wrench. I wouldn't mess around with any special head gaskets as the spray and studs usually makes the head gasket issue much less of a problem. I really think with the knowledge of the collective there are some IDIs on this board that are very much more powerful than stock. For instance I'd really like to see Icanfixall's truck with Moose Pump and NMB2's truck with the DPS Pump and other mods on the dyno.