Exhaust manifold damage

XR4Ti / Sierra / Sierra Cosworth Discussions - Questions, problem resolution, general talk, technical tips and modifications.
Merkur Club web site
User avatar
andyofcolumbusmerkur
Level 7
Level 7
Posts: 1217
Joined: Mon Jul 15, 2013 7:58 pm
Location: NE Ohio

Re: Exhaust manifold damage

Post by andyofcolumbusmerkur »

Looks like that wastegate is almost 500 bucks. Another option would be to bolt up something like this "ultimate internal" unit.
https://www.atpturbo.com/mm5/merchant.m ... y_Code=WGT
Image
Image
You do not pick Merkur, Merkur picks you.
StratosSpawn
Newbie
Newbie
Posts: 12
Joined: Wed Aug 17, 2016 4:36 pm
Location: Wilton, NY

Re: Exhaust manifold damage

Post by StratosSpawn »

Thanks everyone so far for the great replies and ideas! Over the weekend I managed to get things started as far as tearing things apart to get a better idea of what needs to be done.
I contacted both Stinger Performance and TiAL Sport, and while Stinger does not believe that the tubular manifold is theirs (which I'm not 100% sure that it is either, but have no way of knowing for certain apart from the bit of information that I'm getting from the person emailing me), the TiAL Sport guys didn't have the serial number from the valve in their database but after reviewing some photos the rep believes that it is indeed an authentic TiAL Sport wastegate. The downside with the wastegate, however, is that the center support seems to have gotten bent after falling down and getting stuck under the car. I was unable to push open the discharge port before noticing that it was not perfectly aligned. TiAL Sport is willing to actually RMA the unit, and when they get it back they will disassemble it to evaluate the actual damage and then provide an estimate to fix it. The rep did say that the F46 model is one of the older models that runs over $500, so if the repair were to approach that level they would just recommend replacing it with a new unit, either the same model, or a newer style that fits in a smaller area, flows better, opens faster and uses V band exhaust connections (which would obviously require a bit of rework) for even less than the F46 model.
While tearing things apart, I did discover that the exhaust side of the turbo is only a 4 bolt flange, and the downpipe does appear to have been cut and reworked to have a slightly smaller diameter pipe and flange that mates to the 4 bolt connection of the turbo.
Part of me is thinking that it would be smarter just to rework the system by getting a different exhaust manifold that allows the turbo to sit lower down in the engine bay, closer to stock position, which would allow me to not worry about the spark plug wires getting overheated and failing as they have since I've owned the car.
So I've just got to remove the oil drain line from the bottom side of the turbo, and then I can remove the whole turbo and get the exhaust manifold off. I know you guys all love pictures as you are able to get a much better idea of what's going on and what's being talked about, so here are some more:

The nice bend in the wastegate:
Image
Image

The flange that was coming off of the exhaust manifold (looks like it may have been repaired once or twice :wink:) :
Image
Image

And the exhaust side of the turbo showing the 4 bolt mounting flange:
Image

Almost forgot to mention that the TiAL Sport rep recommends that the discharge from the wastegate actually feeds back in to the exhaust rather than just discharging out completely, however, he did state that if a recirculating discharge tube can't be made (due to space, bends, etc) that they recommend that the discharge tube be as short as possible and to provide support to the tube to reduce vibrations. I'm pretty sure the 12-18" long tube hanging down without any support except for what was at the wastegate probably didn't help in any way to alleviate stress on the welds (probably the original ones and the ones that were repaired after the originals probably failed).
john keefe
Level 6
Level 6
Posts: 933
Joined: Sat Sep 02, 2006 1:13 pm
Location: Campbell, CA

Re: Exhaust manifold damage

Post by john keefe »

Some of those mig welds look, ah, basic. Probably DIY repairs to the original damage... hard to tell if they just couldn't get penetration, poor prep, or figured it was enough to glob a ton on to hold it together. Shame about the wastegate.

I still don't think it's a Stinger, because of the angle of the blow-off tube, though the entire setup probably ran great when new until weaknesses started showing up. Needed better bracing and damping.

Does anyone know if Bob's Log-style headers are still available? IIRC the stock E6's weak point was cracking between 2-3 webbing, but I'm not sure if welding worked for long with that iron mix. Pretty sure the cracking issue was that it wasn't originally designed to hang a lot of weight under those kind of oscillations/vibrations, though it would seem to be more than adequate if you ran a strong buttress under the flange to the low block on the block. Did anyone remedy that by adding more webbing/bracing between the pipes?

I know guys here are/were running some serious HP with their improvements, and probably a lot of early discussions about what does and doesn't work as a turbo exhaust manifold. Definitely can find that kind of discussion at TurboFord.org, if you can put up with the arguing and paper-racers vs. doers...

Personally, I like the looks of the center-mount, high turbo better than the stock rearward position (probably inspired by the Cosworth setups), but its in the way of basic servicing, and generates a lot of heat up high on the motor. OTOH, in the stock XR's I've had, the low-back position always played havoc on the stock battery and wiring; the heat cause fumes to wick from the battery, which wicks into the main harness wiring. I eventually learned that was one of the first things I checked for "mysterious" symptoms.

As I mentioned before, Ford/Cosworth abandoned the tubular exhaust idea for a pretty robust, durable, 2-piece cast iron to make it work for production and racing, and even then added bracing/reinforcement through the years (albeit detuning it by inserting baffling). I remember reading some quotes about RS/RS500's in 12/24hr. races where cast exhaust manifold was so hot that at night they didn't need extra lighting to service the engine in the pits... not that we get our systems that hot in normal use, but a couple hundred repeated on/off hot/cold cycling can't be good for thin tube headers with inadequate bracing.
MarkM
Level 6
Level 6
Posts: 916
Joined: Wed Mar 17, 2004 11:59 pm
Location: Richmond, VA

Re: Exhaust manifold damage

Post by MarkM »

I don't think Bob is making his log header anymore. They turn up used occasionally, and now and then you see someone that's made their own.

RE: the cracking factory manifold, I think you're thinking of the E3 and not the E6. I don't recall hearing anything about E6s having cracking issues. XRs came with the E3 originally and I don't know when they switched to the E6. Based on the part number, you'd think 1986, but I'm not sure that's right in the XR's case.

http://forums.merkurclub.net/forum/view ... hp?t=31175
Mark
my8950
Level 7
Level 7
Posts: 1231
Joined: Wed Jan 19, 2005 11:07 pm
Location: Detroit

Re: Exhaust manifold damage

Post by my8950 »

MarkM wrote: Fri Sep 17, 2021 1:10 am I don't think Bob is making his log header anymore. They turn up used occasionally, and now and then you see someone that's made their own.

RE: the cracking factory manifold, I think you're thinking of the E3 and not the E6. I don't recall hearing anything about E6s having cracking issues. XRs came with the E3 originally and I don't know when they switched to the E6. Based on the part number, you'd think 1986, but I'm not sure that's right in the XR's case.

http://forums.merkurclub.net/forum/view ... hp?t=31175
E6's crack too, I've got a pile of about 10 of them. I'd still recommend the original poster go with one, or the Gnari as I mentioned early on. The Gnari may be the better way to go, maybe they've improved on the design of the original. I guess if it was me, I would go with one to try it out. They're out there, and I haven't seen/heard any bad about them, also available with external WG access.
Post Reply