help diagnose this sound.

[Toby_Goodmk]

Sound is in boost above 3500 rpm. I think it's exhaust header gasket. Sound appears at or near feet. I am not recording any KR, Compression is great, sound disappears as soon as the pedal is lifted. Before I take these headers off AGAIN I thought I would get another opinion.

 

[Toby_Goodmk]

going to install these and cross the fingers

https://www.summitracing.com/parts/php-68045/overview/make/buick

 

[John Larkin]

Don't be surprised if it's the crossover

 

[Chuck Leeper]

That link is fubar.......

 

[Wahoo]

I'm running the good thick gaskets, even had my manifold flanges cut straight but they still leak I believe because the crossover is pulling on the manifolds making them leak. So I need to add a flex piece in my crossover

 

[Toby_Goodmk]

That link is fubar.......

yea, sorry. Using the percys carbon XX

 

[Toby_Goodmk]

replaced drivers side header gasket, cross over v band gaskets, still the same. Thinking valve train noise. Going to wire the wastegate shut and see if the puck is making that rattling noise next.

 

[Toby_Goodmk]

puck wired shut still same sound, urgh!!!!

 

[Chuck Leeper]

Smoke test time??
Between the header and turbo?

 

[Toby_Goodmk]

oh joy

 

[Chuck Leeper]

Does the x over have a flex joint in it? if not, I'd suggest you add a hi Q piece. Stay away from the joints w/ the mest inner liners. They WILL fail, melt into a wad, and likely end up in the turbo.
Check the fit of the band clamp, vs the taper on the flanges. wrong clamp angle will not apply pressure to make the 2 surfaces mate properly.
When the flanges were welded on, was the pipe allowed to protrude past the end of the flange, on one side? If not, or the flanges don't have a alignment ridge/groove, they may not line up.
ATR used to have some very thin copper "gaskets" to help seal their flanges. Haven't seen them in some yrs.

 

[turbo nasty]

You are using the gaskets in the joints right? The graphite ones arent reusable. RJC has some alum ones that are.

 

[Toby_Goodmk]

Does the x over have a flex joint in it? if not, I'd suggest you add a hi Q piece. Stay away from the joints w/ the mest inner liners. They WILL fail, melt into a wad, and likely end up in the turbo.
Check the fit of the band clamp, vs the taper on the flanges. wrong clamp angle will not apply pressure to make the 2 surfaces mate properly.
When the flanges were welded on, was the pipe allowed to protrude past the end of the flange, on one side? If not, or the flanges don't have a alignment ridge/groove, they may not line up.
ATR used to have some very thin copper "gaskets" to help seal their flanges. Haven't seen them in some yrs.

Very good questions.

The crossover is a TA race pipe, it doesnt have any flex joints.

I did check the fit of the band clamp, and it appears tight, however who knows. The clamps used are 5 star brand supplied with the TA race header kit. I understand thoroughly after TONS of research that these are special clamps, that are wider at the APEX, which is the middle clamping area just for the flanges used on the TA cross over flanges. Most other flanges used in many applications have a 1/4" apex, these bands are .40" apex area. The clamps seem to be in good condition, as they are only a few months old, but again who knows.

The flanges did have metal pipe stock that allows alignment on the pass side. This side I have no leaks at all. However with this being said, I have "some" metal stock that comes up at an angle on the drivers side V band connection, maybe this was done this way to allow installation? I am not sure.

The TA cross over comes with some thin graphite gaskets, which I used ultra copper on, fastened the vband back up, let her dry overnight. Drove yesterday still the same area leaking. So hell if I know. The leak sounds right in the cross over joint area. It's got to be there, I just need to figure out a way to seal it up. I am questioning that angle of stock that is sticking up out of the crossover now. Attached are pictures of the V band connections. I took pictures when I first received them, as I questioned if they were made correctly. Maybe they are, maybe they are not. One picture is with a gasket laid on top, one is without. That I cannot get a positive seal has me questioning this.

 

[Toby_Goodmk]

You are using the gaskets in the joints right? The graphite ones arent reusable. RJC has some alum ones that are.

For TA race headers?

 

[turbo nasty]

The flange faces might be distorted somehow now.