Gaskets needed - straight pipe? - 328

You'll probably need at least one -- as one will most likely be stuck on the stock? cat and won't be able to be removed in a reuseable condition (on the stock parts, the two sides of each exhaust joint are not identical). For the same reason, if the other (also stuck)one is in decent shape, I try to reuse it just to save the hassle of getting it off . But I'd have two new ones on hand anyway just to ensure that I didn't have a delay in the project (for such a small$ part).

 

I'm suprised 2 would come with the Tubi straight pipe? When I got my X-ost exhaust and hyperflow cat I had 2 included with each item. They are the porcelain rings BTW.

Jeff

 

Your quickest source would be from one of our site sponsors. Like Ricambi or Nick's. Just check under "sponsors".

 

They're made of ceramic, like a donut. Flanges don't fit flush, the ceramic ring is what seals it. Use the sponsers the prev. poster rec.

Jeff

 

honestly any local parts source, napa, kragen etc.. will have exhaust donuts. they run about $2 per and are std. sizes. take the test pipe with you so they can measure it for you.

 

I bought exhaust donuts for my 328, they are different sizes..IIRC the cat donut is 4".....I got mine at FoD..

 

If they're anything like a 308 QV donut gasket, they're not ceramic! They're lead. I just re-attached my 'track-tube' after having it coated by Jet-Hot - the stock Ferrari pipe is approx. 72mm, and the donut gaskets are a tight fit. If the pipe has a heat-reflective coating on it, the dimensions may have changed and the stock gasket may not fit - mine didn't, and I attempted to file-down the inside of the ring to enlarge its diameter with no luck. Ferrari gaskets are somewhat fiberous, and split/crack apart under duress.

Fortunately, 72mm is VERY close to 3 inches - the standard diameter of diesel truck exhausts. I found a fresh lead donut gasket that fit perfectly for $12 at the nearest auto parts store. If the flange of the Cat/track tube allow for a single-tapered edge, the truck exhaust donut may be a better/cheaper solution - it either seals exhaust gasses when the spring-loaded bolts are torqued down, or it doesn't.

 

Yes, absoluetly not made from ceramic. That would have very poor sealing qualities and would be very brittle.

 

the material is either sintered metal or ceramic fiber composite, possibly why some posters are saying ceramic. ceramic fiber is used as insulation material in the heat shields as well.

 

Seems to be a ceramic coated metal on mine. Sorry, should have said ceramic coated, obviously ceramic only would be far to brittle.

Jeff

 

if they look white with brown spots it's not ceramic ,that's heat oxidation from the iron. much similar to what a cast iron manifolds look like after getting to hot.

 

I'm talking about the new ones supplied with the cat and exhaust, all white coating, no brown spots. They looked like a ceramic coated metal to me, sort of like a stove but not glossy.

Jeff

 

The job of the doughnuts is to deform as needed to compensate (seal) for slight mis-alignment/manufacturing tolerances. If they're made from a hard material it's not going to help. Maybe ceramic fiber bonded to a lead ring? Or maybe the melting point of lead is too low for that type of application??