430 Scuderia broken exhaust manifold head studs

Common problem for Scuderia and 16M according to my dealer. What is happening is the flanges on the exhaust manifold warp, causing the studs to stretch and break. Even before the studs break, you will often have the telltale sign of an exhaust leak at the flange from a ticking noise at cold start. It usually goes away as the car warms up. Under warranty they would simply replace the exhaust manifolds with new, but found the problem often recurred, necessitating another replacement. Their current solution is have the exhaust manifold flange ground flat, replace all the studs (since the unbroken ones may be stretched or weakened), use new gaskets, and reinstall. According to them, they have not had a car return for the same problem, so the flanges don't appear to continue to warp.

Most dealers continue to replace exhaust manifolds that leak at the flange with new ones. That is only a temporary fix at best.

 

The flaw is in the exhaust manifold flange.

 

It might be worth thinking about undercutting the last thread where it meets the plain section, that will reduce the stress point, you could just drop it in a lathe and use a parting blade with a rounded blade to make a U section

 

Just have the machine shop surface the header. Throw in new factory hardware, nuts, gaskets you will not have another failure. Don't over think this I've done dozens.

 

From the guy that did mine

 

See post #2 and #6 again, that is what Windsock told me, and FoS. I'm not sure how many different ways this can be restated.

"According to them, they have not had a car return for the same problem, so the flanges don't appear to continue to warp."

"...you will not have another failure. "

 

correct.

 

Is this an engine out procedure if the studs are broken ?

Would it be wise to do this as preventive maintenance for a car with some miles ?

I'm considering a higher mileage Scud as my next Ferrari.

 

Engine doesn't come out. You can't do the job as preventive maintenance...it requires the flange to warp first and is then ground flat. There is nothing to prevent this from happening. Wait until it happens, then fix it if it does.

 

Presumably changing to aftermarket headers would be preventative in a number of ways.

 

I did one set of aftermarket headers that a customer supplied. Worst nightmare I ever got suckered into. I should have gone with my first answer which was no but I let a longtime customer convince me to try. We had manifolds off three times in order to get them to fit right and then because of the lack of heat shielding it promptly melted and ruined the parking brake cables with in 500 miles. Customer sold the car.

 

^^430 headers are the ones that fail. Not so much the 360. Scud and challenge headers are are just 430 headers without the pre-cat so I can't see any flange warpage specific to the scud because the flange is the same flange as the 430. But hey maybe they warp too. Scud headers last better than the 430 because of the way the exhaust is supported further downstream.

 

But alas, the 430 Scuderia and 16M exhaust manifold flanges do warp...a lot. I know a few other Scuderia owners that experienced the same problem...and saw invoices for repairs while shopping for a car. Could be a bad batch of metal used in production...who knows? But it is what it is. Never heard of a oem F430 exhaust manifold flange warping.

I also know two 360 owners that had oem exhaust manifolds fail, I forgot in what manner, but not unheard of.

 

This ticking you mention... I recently noticed it after removing my S-Line exhaust. It goes away after a bit. I thought it may be low oil but that wasn’t the case. How would I inspect for this? It worries me now.


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Curious, how did he back out the studs?

 

Scuderia and 16m headers are not 430 headers. They have air injection ports and rails in them which makes them fit very differently and also get a great deal more heat as they use the air injection to create the after burn in the header rather then in the pre cat. This creates a very rapid increase in temperature on a cold header within the first 2 min and causes the warp and failure of the manifold studs.

 

I was aware of the air injection difference but thought that was only in effect for a very short time on cold start to bring the manifolds up to normal temp quicker. But I can see how heating something quicker could cause warping. I guess my challenge headers are the best of both worlds. No air injection and no pre cat.

 

Thank you windsock and 355. Just to clarify, would refacing scud headers also be a fix to the root cause?


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I does not correct the cause, it does seem to prevent a recurrence of warping and exhaust leak, which is the source of the ticking noise.