Exhaust manifold whistle

**Tins** · 25th May 2017, 09:55 PM

Originally Posted by land864

So $775 all up
Does the ceramic coating improve performance ?
Good point on the underbonnet Temperature
I reckon I kept cooking the second battery in my old
D2 because of the exhaust being next to it
I even had a special twin skin heat shield made up

Performance?? No. Longevity of the repair? Yes.
The underbonnet temp thing cannot be over emphasised.
I have my old manifold here. It will get machined, it will get the holes, all but the middle ones, drilled to 10 mm,
it will get coated properly. Folk talk of dewebbing. I don't know about that. Then it will be put back on.
People talk about bigger studs, at least on the outer ports. There are many threads on here weighing the pros and cons.
In the end, it's up to you. Just don't ignore it, as it will hurt more later on.

Move the second battery. There's a bloke on here, Carl somebody ( sorry Carl, I just can't bring it up now ) who makes a battery tray that replaces your one, that takes two batteries side by side. Then you can use the one that cooks to hold something else, like a compressor.

**clintooo** · 25th May 2017, 11:35 PM

what did you find was the best technique for removing the studs?

I was thinking warm head would help with some expansion of the head to perhaps ease out the bolts. I was going to go the double nut method to wind them out rather than a stud extractor or welding a nut onto the stud.

I was also thinking of using freeze n release. But I wasnt sure if you could use that on a warm head. Although I guess warm ali head and freeze the bolts would help. but just not sure how localised the cooling will be and if I will damage the head in anyway? I will continue to hit the nuts with penetrant over the next week. But I guess that is probably not going to penetrate down the stud.

**land864** · 26th May 2017, 11:54 AM

Thanks John and all

**Tins** · 26th May 2017, 12:08 PM

Originally Posted by clintooo

what did you find was the best technique for removing the studs?

I was thinking warm head would help with some expansion of the head to perhaps ease out the bolts. I was going to go the double nut method to wind them out rather than a stud extractor or welding a nut onto the stud.

I was also thinking of using freeze n release. But I wasnt sure if you could use that on a warm head. Although I guess warm ali head and freeze the bolts would help. but just not sure how localised the cooling will be and if I will damage the head in anyway? I will continue to hit the nuts with penetrant over the next week. But I guess that is probably not going to penetrate down the stud.

The double nut method works if they aren't frozen in. I was told to try and wind them in a little first. I had very little trouble, except for the broken one, which caused no end of dramas, which is why I recommend getting it done BEFORE it breaks. If I ever get another TD5 car, it will be the first thing I get done, and it will get done as soon as I can organise it.

Oh, on a different note. Don't get tempted to get on of those shiny stainless manifolds off Fleabay. They don't fit, at least not on a Disco. Ask me how I know....

Tombie · 26th May 2017, 01:39 PM

They don't last either.. they crack and fail.
Allisport tried multiple permutations before going a cast version.

**rick130** · 26th May 2017, 05:08 PM

So do we elongate the end couple of holes or just drill them out?
My die grinders and compressor are about 8 hours away....

**rangieman** · 26th May 2017, 06:17 PM

Originally Posted by rick130

So do we elongate the end couple of holes or just drill them out?
My die grinders and compressor are about 8 hours away....

I drilled all mine bar the centre 2

Tombie · 26th May 2017, 06:58 PM

For the record - good Ceramic coating, slotted webbing, standard size holes and stock studs...

10 years tuned right up without a problem... towing 3,000kg in 40c regularly etc as well.

**PhilipA** · 26th May 2017, 08:41 PM

Ditto with ceramic inside and out, elongated holes and ends 10 mm, completely removed webbing, remap, Mercedes studs with Belleville washers.

About 5000Km now including towing up the Alpine Way NSW (steep) for 20Km and several +700C excursions, although now keep it under 700C with Serck intercooler.
Regards Philip A.

**twr7cx** · 27th May 2017, 07:13 AM

Originally Posted by johntins

Performance?? No.

You are correct, there is no performance benefit in terms of the motor having more power or torque, etc, but I found there is an indirect benefit of performance once my ceramic manifold was fitted. As it significantly reduced the EGT I was able to give more throttle, or throttle for longer, on some of the hills resulting in the vehicle traveling up faster or quicker. That's a performance benefit side effect. There's a hill on the highway on my way home from work or the city each day, previously I would have to back right off about 85% of the way up due to EGT getting too high, now I can leave the vehicle on cruise control at 110km/h and even when I hit the peak EGT is still low enough not to be a concern. Same pyro probe and gauge fitted at the same location on the manifold.

Originally Posted by PhilipA

with Belleville washers.

Where did the washers come from?

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