How much boost are you running with factory headbolts/gasket

[SuperTurboD24T]

Head studs are a must, and if you can do it, install the factory metal gasket. It is proven to not leak at manifold pressures of 2.5 Bar and above.

Without those two details, you could be ok with the stock turbo and ~25 psi, provided the stock head gasket is in good shape. The only problem is how do you really know if it is solid. The same would go for the head bolts.

I might suggest you get studs at a minimum, since they are very easy to install, and do not require you to remove much of anything compared to a head gasket install. Just replace them one at a time, making sure there is very little to no oil in the block threads.

[Jason]

I was wondering about changing out the bolts to studs. Its a common practice on the Cummins 5.9 engines, but the head is cast iron, not alum. How would you go about torquing it? I know there is a specific torque procedure, would you remove one at a time, and torque the new stud/nut to the first stage, and then do all the studs to the next amount after they are all installed? Or go all the way to the torque value plus the extra 1/2 turn (or is it 90 degrees, I forget) on each stud before removing the next bolt?

[Jason]

I like the idea of changing the dump valve to the new intake inlet location... The stock inlet does look rather small.

Jason

[SuperTurboD24T]

In general, follow the instructions from the company you buy the studs, paying attention to the type of oil on the threads where the nut is, as it affects the torque value.

Torque the nut to the factory spec or the spec from the stud manufacturer. Since the head gasket should already be compressed (we are writing of a currently used HG) you should not need to stage the tightening procedure.

[Jason]

The arp studs are one of the first things I would like to do. I'm thinking that I should be able to push 15lbs of intercooled boost with the stock bolts and gasket without too much trouble.

Jason

[jbg]

Originally Posted by Slobodan

[...] I have been thinking that I want to get the Turbine housing and wheel from a Mercedes 300TurboDiesel. I believe they have .48 A/R.

Slobodan, can you confirm if the turbine housing off a 5-cylinder Mercedes turbo diesel (W123-era) is the same "type" as what we have on the D24T? I had a conversation with Tom Bryant looking for a suitable replacement turbine housing if the funky integrated wastegate were to fail. My idea was to use the turbine housing from the MB because it looked very similar (wastegate, exhaust down pipe mounting (bolts instead of studs/nut)), etc.

This picture was pilfered from eBay auction #320349918326:



Any thoughts on the matter?

Jim

[cuaz64]

Originally Posted by jbg

Slobodan, can you confirm if the turbine housing off a 5-cylinder Mercedes turbo diesel (W123-era) is the same "type" as what we have on the D24T? I had a conversation with Tom Bryant looking for a suitable replacement turbine housing if the funky integrated wastegate were to fail. My idea was to use the turbine housing from the MB because it looked very similar (wastegate, exhaust down pipe mounting (bolts instead of studs/nut)), etc.

This picture was pilfered from eBay auction #320349918326:



Any thoughts on the matter?

Jim

Why don't use the gasser T3 exhaust housing? use the same flange, or not?

[Slobodan]

The Hitachi turbo is actually just Garrett parts that hitachi threw together. I just used the compressor backing plate, comp wheel and housing. The rest is the stock centre cartridge, turbine unit. I noticed it taking a little longer to build boost up to 6psi then after that it just bolts towards 12psi like no other.

[Jason]

If you can find a T3 of suitable trim, you can just bolt it up. You will probably have to make some kind of down pipe or modify the one you have. T-3 turbos are so common in many different trims, it shouldn't be too hard to find one that is very close to the same A/R as the stocker. Most will have an internal waste gate, which more than likely wont open at more than 8 to 10lbs wich is factory level for the D24T anyway.

Jason

[SuperTurboD24T]

Originally Posted by Jason

The arp studs are one of the first things I would like to do. I'm thinking that I should be able to push 15lbs of intercooled boost with the stock bolts and gasket without too much trouble.

Jason

25+ psi with the stock turbo (and it's associated BMEP) has been proven on stock engines (both d24 and d24t) with sound head gaskets without studs. It is cheap and easy enough to simply fit the engine with studs, so you would not have problems down the road, and should be considered.