360 Exhaust Manifold leak...

Uh oh. I hope this isn't the start of 360 exhaust issues like the 355's.

Check e-bay, FML and the FerrariAds here for parts.

 

The Ferrari Market Letter just had an article on this subject written by Dave Helms. The consenses appears to be that if this problem develops, you do not want to use the OEM replacement. You should check into a Tubi or some other aftermarket header.

Dale

 

Tubi baby! At least something good will come from this!

 

See my post #51 and caution about driving your 360 with manifold leaks. Send your manifolds to QV London to have them repaired. QV London replaces the tube with 305 stainless not the crap Ferrari uses. You may have a cylinder running hot as I suspect I did:
http://ferrarichat.com/forum/showthread.php?t=17439&highlight=manifold

 

noah i have never heard of a 360 with this problem like the 355 my guess is that ferrari rectifyed this problem after the 355 headache.

I think its more like the gasket is bad especially if your shop tryed to fix the problem and did not use a new gasket maybe they just put the old one back on. Anyway i have contacted a friend and he can get you a manifold for 1,500 dollars you said that your shop you deal with wants to charge yo 6 gs that is ubsurd and i would stop usiing there service now.

I would go get a second opinion simply say to them I think my gasket is bad on the left maniforld can you look at it. If there reply is not the gasket its the whole manifold then call me and i will get you a used manifold from a challenge car. Good Luck and tell frank to go take a hike

 

I know of one other 1999 360 US spec. left side manifold cracking and being replaced under warranty. Mine on a 2000 360Modena failed because of the precats inside the manifold, the manifold itself are intact with no leaks, cracks or compromise.

 

Did you ever do the leak down on yours?

 

I don't have my exhaust back from QV yet. they did a material search to try to find 315 or 321 because those materials have better corrosion resistance. the 315 hoverever is all they could find in the same size with a .15 wall and supposedly is less ductile so it may thin the wall thickness in forming. for this reason I went with the 305 they offer as standard.

I intend to borrow and interoral camera from a dentist friend to inspect the valve seat on the cylindar I suspect was running hot and was the one where the burn-through occurred. If the seat looks ok I'll put every thing back together and attempt to discover if that cylindar was truly running hotter than the others - It it still is with the new pipes and Hyperflow exhaust, I'll replace the fuel injector at that location.

I did a flow test of my production CATs and they seemed to flow fine with little pressure drop. I did this with a leaf blower some PVC and a 15 psi dial pressure guage. Unfortunately the compressor was forced in to compressor stall by both my suspected Good and bad OEM CATS so I have no definitive conclusion where the OEM CATS contributed to my problem. I suspect they do not - but I'm installing the Hyperflows anyway just as insurance.

I'll let you all know what finally results.

 

See prior posts on manifold cracks statistics.

I had a dentist with his special glasses inspect the valves from the cylindar where the manifold burn-through occurred. He discovered a small chip from the contour missing .5mm x .5mm on the I.D. of the mating surface of the seat on the valve. He saw a similar protrusion and uneven surface at the corresponding location on the head. I don't know whether this protrusion on the head at this seat location was simple carbon build up to fill the void of the missing chip on the valve. There are 4 exhaust valves (open)exposed. None of the other surfaces he observed exhibited any other irregularity. He didn't have the ability to see the mating surfaces. It would seem however a valve replacement is almost a certainty sooner or later. I need an expert mechanic to view this and confirm the next stage of activity.

 

DAmn noah
you shouldn't have raced me back at Tobay. lol

Its not that hard if you do it yourself with after market parts. I helped a friend replace his muffler in his 360. Just nuts and bolts.

Best of luck
Lamarossa