Turbo mounting studs

[brsvo]

I have a Rods header and it has 3/8 16 studs. When I installed it last spring I used 304 stainless studs and lock nuts. While this worked to keep everything tight it didn't when I wanted to take it apart. The stainless on stainless galled and destroyed the studs. I am thinking of using titanium studs this time with the stainless nuts. Any one have experience with titanium?

[svono50]

I would expect the 304SS stuff to gall up after several heat cycles, it can't handle the temps of our exhaust flanges. I haven't any direct experience with Titanium other than knowing it can handle heat cycles pretty well. I believe there are several titanium alloys, so choosing the 'best' one may be a challenge. Inconel and Monel were always the 'standard' for high temp fasteners, but a lot of the newer super alloys that have come out recently out perform the older standard materials. I have been doing some research lately for remaking my wastegate assembly and have picked up some info to pass along.

I know that you can find various suppliers of high-temp fasteners, but I always start by looking at McMaster-Carr, they have a decent selection and you can get things in single piece selections. I know they offer up items in Titanium, but also consider A286 and C276 for these fasteners. Looking at McMaster, the A286 bits you would need to purchase hex head screws and chop the heads off to get a stud and they have matching A286 nuts available. For C276, they have threaded rod along with nuts as well. Titanium rods and nuts are available, but the rods are only grade 2, so not a high strength version.

A286 is generally rated to 1500 deg F continuous with intermittent to 1800 deg along with good corrosion resistance. I can't seem to find C276's service rating temps, but it is quenched at 2050 deg F, so our 1400-1600 deg F exhaust temps should not be an issue for it. Both of these alloys have great corrosion resistance at the elevated temps, so again our exhaust system seems a natural fit for them. In any case, let us know what you end up going with.

[brsvo]

I don't know if it was the 304's fault or that I used like materials with the stud and nut. The manifold itself is 304 so I would think it can take the heat.

[Mike S]

I used this kit for my rods header.

http://trackspeedengineering.com/product_info.php/products_id/98

[svono50]

Bruce, like metals can be fine...if they can handle the heat cycles. 304SS can handle heat cycles, but looses a lot of its strength so it isn't great for exhaust manifold fasteners.

Mike S, that is a very nice kit that is well thought out. They certainly looked at the heat cycling requirements and tackled it with a proper material selection on the stud material along with a great choice for the threadlocker. Cotronics makes all kinds of super-high heat type of components for various industries/applications. I have used some of their epoxies for furnace/boiler repair in the past...good stuff. Thanx for sharing!

[brsvo]

Mike are you running a center mount? My studs were 3/8 16 when I got it and the 40MM would be too short for a turbo support? I should consider redoing the stud holes to metric as there seem to be more fasteners available for them.

[Raven855]

I have had good luck with some Cummins parts 3818823 and 3818824 for the stud and nut. Expensive but available and excellent quality. About $45 for 4 studs and 4 nuts.

[brsvo]

As I recall the Cummins studs were too short for the support brace also. I believe the lengths need to be 40 and 44mm for the brace.

[Raven855]

The studs I have are 42mm in length

[MikeFleming]

For the SVO brace, which is thinner than the [more better] one used on the 87/88 TC, the stock studs are 42/43mm x 4. For the TC (with the better, thicker brace) they used a pair of 43mm and a pair of 48mm long studs. 48 will fit in all four places.

BTW - it's MUCH easier to install just the turbine housing on the manifold as you can easily get a socket onto each of the four nuts. Completely eliminates the need to use (bend?) assorted open-end wrenches and offsets and one can use a proper torque wrench. Then install the CHRA, oil in/out, coolant in/out, outlet elbow, inlet elbow, wastegate actuator, etc. be sure to use a bubble level when clocking the CHRA for proper drainage.

Downside is you pretty much have to do it with the manifold/turbine housing/brace on the engine to get the lower brace bolt hole properly lined up. Unless you're very good at guess-alignments. Which I am not.

Depending on the year and/or day. Ford also supplied an assortment of locking studs, locking nuts, nd free-spinning nuts (87+). The portion of the stud that goes into the manifold is always locking while the nut side came in two types: Locking, and non-locking.

A locking stud gets a non-locking nut. A non-locking stud gets a locking nut. DO NOT EVER install a locking nut onto a locking stud - they will never come apart again without ltears.

[Mike S]

Mike are you running a center mount? My studs were 3/8 16 when I got it and the 40MM would be too short for a turbo support? I should consider redoing the stud holes to metric as there seem to be more fasteners available for them.

Nope, it is Rods standard location header. I think you are correct about the lower ones needing to be a bit longer. The reason I got the kit was for the stage 8 locking nuts. I couldn't find available anywhere by themselves at the time. I used the inconel units for the top holes and regular turbo studs the correct length on the bottom.

PS: I did replace the turbo mounting plate with a new unit to get it flat and parallel. It came with the proper metric threads.