Q: must cylinder/exhaust connection be totally airtight ?

**Sun Jan 14, 2007 11:59 am » Post: #1 » Download Post**

Even with a gasket, some people also use silicone, but when using a flange there is no gasket between the flange and the pipe, so it won't be tight anyway ?
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**Sun Jan 14, 2007 5:04 pm » Post: #2 » Download Post**

Air tight is what you want. The gasket that goes between the flange and cylinder I put a little high temp silicon on. Also put a good bead around the flange where the pipe slides on. It just helps to keep the black guew from seeping out over time.
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**Sun Jan 14, 2007 5:10 pm » Post: #3 » Download Post**

I'm not so much concerned about black goo, as I never had any, but was more thinking about efficiency
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**Sun Jan 14, 2007 8:45 pm » Post: #4 » Download Post**

The flange in your post is the flange between silencer and tail (i think),not cylinder /header!
Q: must cylinder/exhaust connection be totally airtight ?

**Sun Jan 14, 2007 10:25 pm » Post: #5 » Download Post**

Nope, I think pbekkerh means the bolt on flange you use on race pipes, like these Tyga ones, you bolt the flange to the cylinder then attach the pipes to the flange with the springs (or not, it can't fall off once the frame bolt is in).

And as mentioned air tight is the aim, it's not the reality for the average sprung chamber.
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**Sun Jan 14, 2007 10:27 pm » Post: #6 » Download Post**

Nope

I'm just referring to the flange link in the first post Wink

**Sun Jan 14, 2007 10:33 pm » Post: #7 » Download Post**

Yes I know, but he doesn't mean the flange between silencer and pipe (that doesn't leak anyway, just bolt it up), he means the one between the cylinder and the pipe.
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**Sun Jan 14, 2007 10:35 pm » Post: #8 » Download Post**

the flange between silencer and pipe (that doesn't leak anyway)
Mine does Laughing

**Sun Jan 14, 2007 11:35 pm » Post: #9 » Download Post**

yes I did mean the "Tyga ones", sorry about the wrong link.

So, back to the question: Does it affect performance if the cylinder/flange/pipe connection isn't airtight ?
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**Mon Jan 15, 2007 1:04 am » Post: #10 » Download Post**

Yes, It will have an effect how big depends on the size of the leak. The goal is for all the exhaust to go through the chamber and silencer.
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**Mon Jan 15, 2007 12:25 pm » Post: #11 » Download Post**

Some of the exhaust gas pressure needs to bounce back from the pipe into the cylinder to prevent the incoming fuel / air mixture getting sucked striaght through the cylinder and out of the exhaust port.

Does that make sense?
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**Tue Jan 16, 2007 10:32 am » Post: #12 » Download Post**

Yes but in the end all spent gas should leave the exhaust via the endcan, not via any leak.
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**Tue Jan 16, 2007 1:04 pm » Post: #13 » Download Post**

(unless they're emmision testing you! Wink

)
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