SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: foxfury on February 26, 2011, 11:42:11 AM

Title: BBC exhaust issues
Post by: foxfury on February 26, 2011, 11:42:11 AM: I am having an issue with my exhaust on my 81 miller with 454. My logs are a standard 3 1/2 where my transoms are 2 9/16. Anybody have any ideas on how to enlarge the transoms without spending to much $?
Title: BBC exhaust issues
Post by: lbhsbz on February 26, 2011, 01:36:43 PM: Buy or make larger tips. Or, if you want to be ghetto about it, find someone like me to machine up some sleeves to press over the existing tips and make them 3 1/2 OD. How big are the flanges that bolt to the transom? Probably not enough room to sleeve them. best to find new tips I think,
Title: Re: BBC exhaust issues
Post by: ka0tyk on February 26, 2011, 04:00:31 PM: by the time u get someone to weld up some alum or stainless in a 2 7/8" (not 9/16) to a 3 1/2" you couldve just bought new ones. =)

http://www.cpperformance.com/c-468-trumpet-style-tips.aspx (http://www.cpperformance.com/c-468-trumpet-style-tips.aspx)

3 1/2" trumpets are $80. done deal.

or go big and go stainless

http://www.cpperformance.com/p-12583-3-standard-straight-cut-exhaust-tip.aspx (http://www.cpperformance.com/p-12583-3-standard-straight-cut-exhaust-tip.aspx)
Title: Re: BBC exhaust issues
Post by: NORDIC454 on February 28, 2011, 09:14:02 AM: Right now you can buy 4" stainless tips in straight or slash cut, from CP for $79. Then adapt them to your original size exhaust like im going to today, with reducers. Ill post pics later today

http://www.cpperformance.com/sales/2011/feb-21-tips.html (http://www.cpperformance.com/sales/2011/feb-21-tips.html)
Title: Re: BBC exhaust issues
Post by: Your Mom on February 28, 2011, 10:14:59 AM: Just slide a small piece of exhaust hose over what you have(will act as a spacer)and then the thickness of the outside will match your snails. Then just get 3 1/2 exhaust hose to go over the whole thing...
Title: Re: BBC exhaust issues
Post by: ka0tyk on February 28, 2011, 01:22:15 PM: Quote from: NORDIC454 on February 28, 2011, 09:14:02 AM
Right now you can buy 4" stainless tips in straight or slash cut, from CP for $79. Then adapt them to your original size exhaust like im going to today, with reducers. Ill post pics later today

http://www.cpperformance.com/sales/2011/feb-21-tips.html (http://www.cpperformance.com/sales/2011/feb-21-tips.html)

curious how you're going to adapt. i was looking at new tips and asked cpperf if they would have the 3" exhaust on sale and they said no. its like $40 more for less... plus the 4" has slide in mufflers.
Title: Re: BBC exhaust issues
Post by: NORDIC454 on February 28, 2011, 05:02:06 PM: My original plan was to use 4x3 reducers, and run with my original 3" hose, and jump up to hit the 4". but now that i have the tips installed, i dont have alot of room. So I am now going to run it in 4" hose, with somesort of sleeve over my 3" log exit, to make it 4" diameter