question regarding header & tuned pipe

[wgalligan]

BUT GRAY....   Yours is an educated guess!

> Without actually being privy to what these guys are using resin wise, but 
> experienced in identifying cured resins, I would venture to say the the ES 
> pipe is an aromatic amine cured epoxy that is made by Shell Chemical , 
> 8500 series. It is a liquid that cures at a temperature about 200-250 F 
> then can be post cured to give a glass transition temperature (Tg) of 
> about 350F.  This means at 350F the resin goes from the hard glassy state 
> to a more "rubbery" state. The Tg is usually when there is little to no 
> structural capability, but these temperatures do not necessarily damage 
> the resin. When over exposed to temperature above the Tg like the 425-450F 
> exhaust, the resin will break down.   The Bolly appears to be a 
> Bismaleimide resin which is a room temp semisolid resin that has a Tg of 
> 425-450 hence better header exhaust resistance.  The leaking of the pipe 
> is most likely a result of the wet-layup manufacturing method used, 
> leaving pinholes. Bolly's also have a kevlar outer layer which absorbs 
> water which gases off during cure creating pinholes. 
> And then there is the chance I am guessing wrong......
> 
> 
> 
> 
> 
> Gray Fowler
> Principal Chemical Engineer
> Composites Engineering
> 
> 
> 
> 
> s.vannostrand at kodak.com
> Sent by: discussion-request at nsrca.org
> 03/25/2003 12:47 PM
> Please respond to discussion
> 
>  
>         To:     discussion at nsrca.org
>         cc: 
>         Subject:        Re: question regarding header & tuned pipe
> 
> 
> 
> Bolly mufflers use a very different kind of resin that is more temp 
> resistent than the ES pipes.  It will become brittle over time, but will 
> not ablate.  Bolly's also eventually leak like a seive over their length 
> eventually. 
> 
> --Lance 
> 
> 
> 
> 
> Ron Lockhart <ronlock at comcast.net> 
> Sent by: discussion-request at nsrca.org 
> 03/25/2003 10:11 AM 
> Please respond to discussion 
>         
>         To:        discussion at nsrca.org 
>         cc:         
>         Subject:        Re: question regarding header & tuned pipe
> 
> 
> 
> Lance,
> 
> Would you know, is the end of the pipe being exposed to exhaust 
> gas a concern with the Bolly pipes & mufflers?
> 
> TIA   Ron Lockhart
> 
> ----- Original Message -----
> From: s.vannostrand at kodak.com
> Date: Tuesday, March 25, 2003 10:52 am
> Subject: Re: question regarding header & tuned pipe
> 
> > Every change in backpressure, due to the expansion chamber or 
> > header change will cause a wave reflection, however, the effects of 
> > necking down from 7/8 to the approx 3/4" OS pipe will not be much. 
> The bigger problem is that if the pipe is composite (CF) you will 
> ablate the pipe input and ruin the pipe.  I've seen 3 of these for 
> repair.  The hot exhaust gasses can not be allowed to contact the end 
> of the fibers and resin for most resins.  ES pipes fail in this 
> fashion.  Some people have been successful in using a squishy coupler 
> (like the Macs grey) but this is not a reliable setup for most people. 
> > 
> > The Mintor carbon fiber pipe (I have a N.I B. one for sale for 
> > $160 including shipping) uses an aluminum inlet to prevent this.  I 
> > also have a Macs to OS adapter made from aluminum for $12.
> > 
> > -Lance
> 
> 
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> 
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