Cracked Manifold

[OwenGT3]

Hi,

Thought I would just share this with you. It's not so much a technical problem as i can fix it, just something else to do! The exhaust note was sounding metallic, so I had a look in the engine bay with her running, when I notice a hole where there should be a hole. It was the weld cracking on the end head mount bracket. Who ever made the exhaust didn't really consider the stresses put on that mount, and welded it straignt to the exahst pipe without any extra strengthening around the area, so a nice crack has appeared from vibrations. My exhaust flaming the other night perhaps didn't help matters!

Still easily fixed, hopefully I won't have to take it off, and luckily I have a mig welder. I'm going to remove the boot tomorrow night, jack up the n/s rear and remove the wheel, this will give me maximum access to the area. Then I will cut of the old mount, repair the crack and grind nice and flat. I will then proceed to make a new mount, may even make it clamped on so it doesn't crack the pipe again. I must stress my manifold is a 4-2-1 banana set up, not the cast lump.

Here's the damage. Luckily I have a dremel with a flexi extension to get in tight spots like this!

Owen.

Edited July 30, 2007 by OwenGT3

[Vulcan Grey]

I would remove the manifold IMO.

I wouldn't want any loose slag balls going into the turbo at 120,000rpm!

I can remove my manifold in under an hr these days.

[OwenGT3]

Hi,

I'm removing it and repairing it this afternoon, it's only been on the car two months poor design who ever made it. Also going to modify the set up so it doesn't do it again.

Owen.

Edited July 31, 2007 by OwenGT3

[OwenGT3]

Hi,

Well I've had a busy afternoon and evening. Started removing the exhaust manifold about 2.30pm, finally got it off at 5pm. What was the main sticking point was the bolts to the turbo. The bolts were welded to the manifold, but the nuts and threads were really bad and the nuts didn't want to come off! One nut sheared off, another I had to grind the bolt off the manifold, one actually came undone and the last one I had to grind with a Dremel and chisel it off, this last one took the longest.

So with the manifold finally off I was able to repair it. While I was at it I cleaned up and redid some of the welds, which weren't that good I fitted a piece of L angle to the flanges to keep them all level before welding. as you can see the hole ended up quite large, too big to just reweld, so I ended up plating it. there was a hair line crack so I welded that first before plating the hole. I removed the bolts from the flange and have left them off, fitting bolts in with two lots of spring washers so it shouldn't work loose. I will keep an eye on them, but they should be alright.

With everything repaired I have managed to get it fitted back on this evening, just got to make a new support bracket tomorrow evening and fit. This will consist of a U clamp and some angle, so should be a lot stronger support, and as it's not welded should not cause any cracks again.

Hopefully that will be job done.

Owen.

[Simon350S]

Hey mate...

Looks good....

Who made the manifold originally??

Simon

[Kato]

Can't remember seeing one like that before! Any info on it?

[matk]

Sorry to be a pessimist, but quite a few people have weld repaired manifolds only to see them fall apart again. The problem involves the constant hot and cold cycling it experiences with consequent expansion and shrinking. That's going to put a high load on your weld joints.

If it were me I'd buy one of the new uprated manifolds from SJ Sportscars and start again with a new one. I know it's expensive but I fear you're going to be breaking the Dremel out again otherwise in the near future.................

[Simon350S]

Looks like a modified N/A manifold with the tail end of the pipe replaced to align with the Turbo....???

Is this right???

Simon

[Loose Cannon]

If it were me I'd buy one of the new uprated manifolds from SJ Sportscars and start again with a new one.

Sorry Owen but was thinking the same thing. I'm sure I saw written somewhere that banana headers do diddly squat on turbocharged engines too, any pulse gains being obliterated by the turbo (which is the bit to uprate).

[OwenGT3]

Hi,

Well the manifold was on the car when I got it, but I don't know who made it and where its from. I don't totally agree with what matk is saying about welds on manifolds. I've had a few cars with branch manifolds, even made a few myself for kit cars, but I've never had one crack on me or known of one cracking in 17 years of the motor trade.

My hole was not down to poor welding, ok it wasn't great, but it cracked due to the stress put on it. The mount welded on the pipe how it was, was not going to cope with the stress and vibrations. The bracket was too small, it was badly made and located on the manifold wrong.

I have made my support bracket this evening and now fitted it. Also got the correct size bolts for the turbo and fitted them. I have triangulated my support bracket, so it's not going anywhere! didn't quite finish the car tonight. so it's still on the stands, and I haven't started it up yet. I still need to do one final check that all bolts are tight, perhaps checked them a hundred times already, but thats how I am.

I'll keep with this manifold until it totally gives up, then I'll buy one, it runs very well with it.

Owen.

Some images of the new bracket fitted.

[Paul93Lotus]

Is that manifold made of steel? All these doom sayers need to remember that the stockers are cast iron, and welding cast iron is usually only successful if you preheat the ENTIRE part in an oven, weld with the part heated extremely hot, then a very slow cool down over night.

Now mild steel is a completely different scenario.

Edited August 2, 2007 by Paul93Lotus

[OwenGT3]

Hi,

Yeah, it's a proper mild steal branch manifold. I've done all types of welding in my time, Gas, Mig, Tig, Arc and spot, also different metals, mild steel, stainless, aluminium and cast iron so I'm famililar with most aspects of the materials and the welding process, and why things break.

The reason it broke was stress. I will post an image of the bracket when I have one.

Owen.

Edited August 2, 2007 by OwenGT3

[dmckenna]

The last time the manifold was replaced on this car to my knowledge was in 2005 by Steve Williams, that was a brand new one but nothing to say the 'inbetween' owner hadn't had a problem and had it repaired/replaced too

[matk]

Owen

You may well be right, I certainly hope so. I'm no expert here, but if you search all the manifold experiences on this forum you'll see what I mean. The problem is potentially Esprit specific because of the proximity of the manifold to the turbo.

[OwenGT3]

Hi,

Finished job tonight, checked nuts and bolts, all tight. Got the car ready and went for a blast in it, seems to be no problems (touch wood).

Owen.

[OwenGT3]

Can't remember seeing one like that before! Any info on it?

Hi,

I've asked the person who I bought the car off, and he has said he made it. He does work at Aston, so has some engineering skills, must have the means to bend pipes as well. But does need to improve his welding skills!

Owen