Twin Scroll Turbo

[squaab99t]

Will the heat cycling from the manifold and head have any effect on bolts vs studs? I thought that studs were recommended to account for thermal expansion.

That is a good question. Don't really know if there will be a difference? I'm kinda painted into a corner due to the assembly envelope being too big if I use studs. One could add the studs after you have the flanges in position. The stud socket wrench takes up a lot of space compared to a box ratchet wrench.

[DrewP]

If there isn't room for the long spacers for the studs it shouldn't matter, the loaded part of the fastener that's "springy" and makes the clamping force will be the same length for studs and bolts if the clamping face is right on the flange. The tightening torque on them is so low that the difference in engaged thread length probably won't make much difference like it does for say cylinder head bolts vs. studs.

That being said, I did just look up a chart of CTE's and the 300 series stainless is something like 35% higher than cast iron.

Probably an interesting mind game to over-think, I'm sure it'll be fine.

[squaab99t]

If there isn't room for the long spacers for the studs it shouldn't matter, the loaded part of the fastener that's "springy" and makes the clamping force will be the same length for studs and bolts if the clamping face is right on the flange. The tightening torque on them is so low that the difference in engaged thread length probably won't make much difference like it does for say cylinder head bolts vs. studs.

That being said, I did just look up a chart of CTE's and the 300 series stainless is something like 35% higher than cast iron.

Probably an interesting mind game to over-think, I'm sure it'll be fine.

Maybe give these a go? Mechanically restrain the bolt from rotating.



Or this type?

[DrewP]

Ooh, those are cool!

[squaab99t]

Did some trail fitting of the tube and flange. You would think if you cut the flange port the same arc length as the circumference of a 1 5/8" dia tube, it should fit with a squashing of the tube? Not so simple. Headers are not easy if you do them correctly. Now one could oversize the port, filler up with filler rod and grind it to fair it in, but that ain't right.
What to do? You over crush the tube to a figure 8, tack the edges that do fit and hammer/dolly the tube to match the flange.

The attachment IMG_4624.JPG is no longer available

[Geoff]

Looks good. I have a few B engine headers that are round tubes attached to oval flanges. That never sat right with me but I haven't gone about modifying them.

Maybe give these a go? Mechanically restrain the bolt from rotating.

Those Stage 8 fasteners look interesting. I wouldn't use the other style (split bolt with a socket head bolt running down the middle). I've had enough problems with exhaust studs that those make me shudder.

[squaab99t]

Those Stage 8 fasteners look interesting. I wouldn't use the other style (split bolt with a socket head bolt running down the middle). I've had enough problems with exhaust studs that those make me shudder.

I talked over the issue of loosening fasteners on headers with my friend Kevin. Although the stage 8 is a good solution for the problem, the real problem is the crappy joint. The gasket between the header and the head is too compliant and the joint is never properly clamped. So why is there a gasket? To make up for OEM loose tolerance machining is our guess.
Our plan is to have independent flanges machined flat and go with a thin layer of high temp silicone inlieu of a traditional gasket. This way you get a proper clamped joint, no flexing and no backing out of the fastener. If she don't work, then go to the stage 8 solution.

[squaab99t]

After I worked on some electrical project on the house, I saw the flange/tube sitting on the bench and I thought to myself that has got to go.
Ball-peen hammer, 5# hammer, a panel beater bag I got the figure 8 out. Figured it was good practice to see how the material behaved.
It actually was very malleable.

The back side of the flange to transition back to round was fair. I think I over amped the dimpling.
One side is pretty nice.

The other, too much of a good thing.

I picked up a econo air chisel. Plan is to take one of the bits and make a nice rounded blunt nose shape. I'll use this to massage the tubing into its happy place.

[SwedeSport]

You make it look like you know what you're doing...

[squaab99t]

You make it look like you know what you're doing...

Not sure if I would go that far.
I got a chance to practice and learn on my buddy's big block header build, so my volunteering my labor on his project is paying dividends.

[squaab99t]

More tooling. Built part of the jig that will index the merge collectors relative to the head. Once built I will transfer the tool to the surrogate head and I can work on the bench.

I just need to hold the merge collectors in place in lieu of the whole turbo. This is the way to go, as if I held the turbo the jig would have to be very still as I rotated the head with turbo attached.

Cutouts made and fitted to the 2-1 primary collectors and secondary 2-1.

Welded the 1/2 hoops to the bracket, added worm clamps and safety wire to get everything to seat and hold it self together.
Bent some flanges to stiffen the plate.

Back in the car. Next I'll run a minimum of 2 struts from the bracket to some smart places on the head. From there I can remove the turbo from the equation and have the merge collectors indexed in space. One step closer to fabbing the primaries.

[squaab99t]

In honor of Memorial Day I designed and built something.
Continued on the getting the merge collectors indexed in space.

I used the truss to clamp my struts to and tacked the members in situ. Some tacks were easy and others I felt like I was standing on my head to see where to weld.

Now free standing and fit up to the turbo V band flange.

[Crazyswede]

When you get done with this project i bet you have close to $500 tied up in it.

[sjones]

When you get done with this project i bet you have close to $500 tied up in it.

What a bargain!

[squaab99t]

When you get done with this project i bet you have close to $500 tied up in it.

What a bargain!

$500 for the turbo hanger or the whole turbo relocation, twin scroll manifold project?
This a project that I'm not planning on recouping my material or labor costs. That is what makes it a project car.