Midas repaired my severely damaged y-pipe for free, and I was just installing it this evening when I saw that when I put my heat riser and donut on, the donut won't fit! Which should I use: the heat riser that does nothing, or the donut which does no more than sit in there and be an obstacle?

What are the ill effects of not having the donut in there, it goes exhaust manifold, riser, donut, y-pipe, but is it necessary to have the donut in there? The only thing I saw it doing was creating holes between it and the riser, so really, besides being a spacer, what was its real purpose?

Thanks!

G

 

Carbed cars had "heat-risers," TPI cars spacers. I don't recall either having a donut.

JamesC

 

I could have easily mixed this up. See, we had at one point 3 TPIed engines sitting in the back shed with random parts lying around. Now, we removed the exhaust stuff 3 years ago, and were just now putting it back on. This engine was carbed, and we knew there was a head riser (thank God for car paint overspray), but were still convinced there was a donut the acted as a spacer. Well, turns out there wasn't! And I still have two spare donuts!

Thanks James. MUCH appreciated.