C2 muffler drain hole

[Andries ter Hennepe]

Should one drill a hole (and if so, where and what diameter?) in the mufflers to get rid of condensationwater build-up? Thank you for your input.

[Joe C.]

Re: C2 muffler drain hole

Andries:

The hole is always at the muffler's lowest point, and usually about .060" diameter. This will create a small exhaust leak, but shouldn't be objectionable. It will, of course, compromise the "originality". I wouldn't do it unless absolutely necessary. A better alternative would be to drive the car until the condensate is completely evaporated. This is a better approach for the entire exhaust system, as well as the engine's crankcase.

Joe

[Joe L.]

Re: C2 muffler drain hole

Andries-----

Eliminate the heat riser (or, wire it open) and about 95% of the benefit of the added drain hole "goes away".

[Andries ter Hennepe]

Re: C2 muffler drain hole

A thank you to both Joes. But before I take out the drill, could you explain the reason why Joe Lucia? I already changed my heat riser with a FI unit (no valve). Is this more or less what you are referring to?

[Joe C.]

Re: C2 muffler drain hole

Andries:

Yes, it is good that you did that. Heat risers tend to be problemmatic in that they eventually rust, and later seize in the closed or part closed position. This results in excess heat build up in the engine, poor performance, detonation. It also results in premature corrosion of the right side exhaust pipe/muffler because the lack of hot exhaust gas retards condensate evaporation. Only recommend using the valve for winter driving, if applicable. Most midyear owners no longer use their cars for winter duty.

Joe

[Joe L.]

Re: C2 muffler drain hole

Andries----

Yes, changing to the FI spacer is what I was talking about. Left side Corvette mufflers usually last a LONG time; the right side is the one that usually rots out rather quickly. That's because the heat riser allows condensation to build up in the right side muffler. By eliminating the heat riser you have "2 left side mufflers". Exhaust gasses pretty much purge the condenstaion from BOTH mufflers when there is no heat riser present. There still might be some benefit to drilling the drain holes, but most of the benefit is lost if the heat riser has been eliminated.

[Timothy B.]

Re: C2 muffler drain hole

I purchased a Allens aluminized exhaust for my 63 at Carlisle this year and Mike Allen told me to use tennis balls or something to block the exhaust tips after running the car. He said much of the condensation occurs after the pipes get hot and cool air enters after shut down. I know the real solution is not to run the engine without fully warming to get the pipes hot enough to evaporate condensation but it can't hurt to try.

[Patrick H.]

Re: C2 muffler drain hole

So what happens when you forget to remove the tennis ball? Is it like the "banana-in-the-tailpipe" trick in "Beverly Hills Cop"?

Patrick

[Gerard F.]

A potato works better per "Columbo" *NM*