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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Nova Eona on July 04, 2021, 09:04:46 AM

Title: 4104 Exhaust Manifold
Post by: Nova Eona on July 04, 2021, 09:04:46 AM
Hey all, trying to track down a source for a 4104 6-71 split exhaust manifold, I've got a cracked ear on mine.  Already tried Luke and J&R Diesel to no avail, anyone else have a source or a spare manifold lying around they'd be willing to part with?

Plan B is to get it welded, but if I can get ahold of a replacement all the better.

Also, for the record of anyone else going down this road in the future, 4104s do have non-standard exhaust manifolds.  Getting to them is easy at least, provided your conversion doesn't cover the plate - it's held in by quarter-turn spring screws, so they're unlikely to strip out.
Title: Re: 4104 Exhaust Manifold
Post by: luvrbus on July 04, 2021, 09:46:43 AM
Try PC Industries in Afton WY have the casting number ready,some 6v71 and 3-71 had the same manifolds,PC matched one for me before
Title: Re: 4104 Exhaust Manifold
Post by: Nova Eona on July 04, 2021, 10:21:08 AM
Quote from: luvrbus on July 04, 2021, 09:46:43 AM
Try PC Industries in Afton WY have the casting number ready,some 6v71 and 3-71 had the same manifolds,PC matched one for me before

Thanks, I'll check them out!  Follow-up question; does anyone have the casting number for this application?  Not sure I can get mine without pulling it, and I'd rather not pull it until I have a replacement in hand (or am resorting to welding).
Title: Re: 4104 Exhaust Manifold
Post by: Van on July 04, 2021, 10:36:29 AM
Try Diesel Pro https://dieselpro.com/detroit-diesel-parts/671-engine-2-valve.html
Or PC Industries https://www.powerlinecomponents.com/catalog/il71_catalog_menu.htm
Title: Re: 4104 Exhaust Manifold
Post by: Nova Eona on July 04, 2021, 02:48:39 PM
Quote from: Van on July 04, 2021, 10:36:29 AM
Try Diesel Pro https://dieselpro.com/detroit-diesel-parts/671-engine-2-valve.html
Or PC Industries https://www.powerlinecomponents.com/catalog/il71_catalog_menu.htm

Sadly each only have the 'standard' Detroit manifolds, neither carries the 4104-specific variant which outputs down instead of to the side.
Title: Re: 4104 Exhaust Manifold
Post by: luvrbus on July 04, 2021, 03:03:36 PM
You can flip a Detroit manifold for up or down for out put 
Title: Re: 4104 Exhaust Manifold
Post by: dtcerrato on July 04, 2021, 03:57:19 PM
When you say split manifold are you referring to dual exhaust manifolds? I may have a single exhaust manifold for 4104 I can part with.
Title: Re: 4104 Exhaust Manifold
Post by: Nova Eona on July 04, 2021, 06:42:52 PM
Quote from: dtcerrato on July 04, 2021, 03:57:19 PM
When you say split manifold are you referring to dual exhaust manifolds? I may have a single exhaust manifold for 4104 I can part with.

I am indeed - one manifold per exhaust, like pictured below (stolen pic from elsewhere on here).  Good to know on the single, but I think I could only go that route if I come up entirely dry on replacing or repairing my current setup as then I'd be looking at replacing the entire exhaust system as well.

Also below is a pic of the common manifolds I've seen elsewhere - the standard three-port manifold exits to the wrong side, so I don't see a way to make one of those work without some major reengineering.
Title: Re: 4104 Exhaust Manifold
Post by: dtcerrato on July 04, 2021, 07:17:20 PM
@Nova Eona
Mine would be the one illustrated.
Title: Re: 4104 Exhaust Manifold
Post by: dtcerrato on July 04, 2021, 07:25:39 PM
@Nova Eona
I took a closer look at the photo you posted of the dual exhaust manifolds with the egr taps. Ironically that is my set up as we replaced the oem single manifold with dual manifolds.
Title: Re: 4104 Exhaust Manifold
Post by: gmnut55 on July 05, 2021, 05:21:15 PM
.Bob, I have two of them and the mufflers and tailpipes.  And also the complete single exhaust with the mufflers one on top of the other email gmnut55@hotmail.com
Title: Re: 4104 Exhaust Manifold
Post by: gmnut55 on July 05, 2021, 05:22:59 PM
O and Bob ,I'm headed your way Wednesday