making custom headers ?
07-24-2009 | 08:01 AM
#1
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making custom headers ?
Im pretty new to boating,
but not new to engine building and fab work,
Ive made set of headers for drag cars turbo cars etc. motorcyles etc.
Im getting a Baja Force 235 with single 454 mag motor and it has from what I can tell is stock exhuast routed through the hull,
what are the differences between Marine exhaust and car exhaust,
Ive seen some headers on boats that look just like car headers without any water rails
then Ive seen them where they have water passages,
is the water necessary,
just curious as Im considering possibly making a set of headers for the boat but I want to know exactly what they have to be before I jump into it
but not new to engine building and fab work,
Ive made set of headers for drag cars turbo cars etc. motorcyles etc.
Im getting a Baja Force 235 with single 454 mag motor and it has from what I can tell is stock exhuast routed through the hull,
what are the differences between Marine exhaust and car exhaust,
Ive seen some headers on boats that look just like car headers without any water rails
then Ive seen them where they have water passages,
is the water necessary,
just curious as Im considering possibly making a set of headers for the boat but I want to know exactly what they have to be before I jump into it
07-24-2009 | 08:26 AM
#2
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From: KCMO
Don't try it!
You need the water in your app....because the motor is enclosed, you can't use the injected style of header. Even the pros have a hard time w/ Q-C on the annulus style header...you should give up on the idea. Take care, Dave
07-24-2009 | 08:33 AM
#3
21 and 42 footers
Joined: Sep 2004
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From: Richmond VA
Marine headers are water jacketed to reduce ENCLOSED engine compartment heat among other things. These things are essentially 2 sets of header pipes INSIDE each other. Exhaust through the inner tube, water passing through the outer tube. I'd love to see someone make them....and then tell me they don't cost a fortune to make!!! 
07-24-2009 | 08:42 AM
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okay thanks for the reply
so basically they are a set of tubes inside another set of tubes, and between the inner and outer there is water circulation through to cool them
yeah that does sound a little tough to fabricate
what about doing a log style header ?
could you run each primary to a log and then say like 2" primary to a 4" log then enclose the 4" log inside a 4.5" pipe and run the water between the 4" and 4.5" pipe
just looking for some ideas
like I said Im new to boating so please forgive me if some of the questions are not too intelligent
thanks for the replys
so basically they are a set of tubes inside another set of tubes, and between the inner and outer there is water circulation through to cool them
yeah that does sound a little tough to fabricate
what about doing a log style header ?
could you run each primary to a log and then say like 2" primary to a 4" log then enclose the 4" log inside a 4.5" pipe and run the water between the 4" and 4.5" pipe
just looking for some ideas
like I said Im new to boating so please forgive me if some of the questions are not too intelligent
thanks for the replys
07-24-2009 | 10:26 PM
#5
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You might could make it work... but if it cracks you're out an engine. I would go with a set of aftermarket manifolds from imco, stainless marine or emi if it were me... for the money and hassle... and performance will be good overall. the imco powerflows should make a little more power than the other two...
