Stainless Manifolds/Risers?

[Shaun78]

Can you get stainless manifolds/risers? Wouldn't they be better? I know they make them for the high performance boats. I have a 7.4L MPI.

 

[Haut Medoc]

Re: Stainless Manifolds/Risers?

Yes you can, & they cost a fortune.....​

 

[imported_TheMan]

Re: Stainless Manifolds/Risers?

I was just looking at this the other day..
http://www.hitekmarine.com.au/

 

[Olds Eddie]

Re: Stainless Manifolds/Risers?

I bought a couple from IMCO marine and they are nice but expensive. I needed taller risers to help with reversion and theirs don't have the extra joint to leak that the mercs do with the riser extensions.

 

[Shaun78]

Re: Stainless Manifolds/Risers?

how much for the hitek manifolds/riser combo?

 

[wire2]

Re: Stainless Manifolds/Risers?

I made a set myself several years ago.

I had ss flanges cut from ?" plate, then tacked in 1-3/4" tube elbows, and placed 2" tube elbows over them. The collectors were tricky, I had 4 tubes inside 4 tubes, had to heat and pull them all together in the middle to form an "X" and weld. I continued with 3" tube inside 3?" tube elbows, turned back down at 25? and ended the inner tube 6" along.

I split them into a Y at the back of the engine with 1 path to the OMC mid drive, the other path thru hull with a butterfly valve to run quiet. It operates off engine vacuum through a dash switch.
It sounds like a stock car & goes like stink. (I also added an aluminum hi rise intake and 1.6:1 roller rockers) Planes in under 1 second.

Coolant water comes in at the bottom of all 4 outer pipes through ? ss tubes.

It cost under $150 for the elbows & tube but took me many hours of measuring, cutting, fitting, & tig welding. Then sanding & polishing.

And now that I've converted from OMC stringer to alpha gen 2, I'll have to redo the connection to the Merc Y pipe.

I'll try to find & post a picture.

 

[f_inscreenname]

Re: Stainless Manifolds/Risers?

HiTek's are awesome except for the shipping. Adds another $250.00 to the bill and if you have warranty work be prepared to ship them both ways and wait 4 months for them to return.

 

[wire2]

Re: My home made stainless headers

Re: My home made stainless headers

Both sides completed.

Bolted in & purring.

The chrome rocker covers aren't just for show, I needed tall ones to clear the roller rockers.

 

[HT32BSX115]

Re: Stainless Manifolds/Risers?

That is a REALLY nice job!!


Where were you when I had the OMC 460 King Kobra in my boat and needed manifolds for it.????

There ain't no manifolds available for them anymore (except the high dollar SS ones.....

 

[wire2]

Re: Stainless Manifolds/Risers?

One more thing, The oem manifolds and risers weighed 55 lbs per side, the headers are 16 lbs.
The oem cast iron manifold was 66 lbs, my Holley is 15.
I also have aluminum heads for it, will save another 50 lbs.

Now if only someone would invent a battery using aluminum or magnesium, instead of lead....

 

[wire2]

Re: Stainless Manifolds/Risers?

That is a REALLY nice job!!


Where were you when I had the OMC 460 King Kobra in my boat and needed manifolds for it.????

There ain't no manifolds available for them anymore (except the high dollar SS ones.....

Thanks, HT. I had considered doing them for custom applications but it takes a lot of time to make a pair because you're making 2 pair at a time.
Hence the high cost.

 

[dcg9381]

Re: My home made stainless headers

Re: My home made stainless headers

Those headers are beautiful.. Not everyone can TIG or has that level of fabrication skills.
I've wondered this myself, these things aren't that different from a set of "shorty" headers - I simply don't understand what makes them worth $1500-$2000, other than they're a lower volume business when compared to automotive..

 

[wire2]

Re: My home made stainless headers

Re: My home made stainless headers

Those headers are beautiful.. Not everyone can TIG or has that level of fabrication skills.
I've wondered this myself, these things aren't that different from a set of "shorty" headers - I simply don't understand what makes them worth $1500-$2000, other than they're a lower volume business when compared to automotive..

Thank you!

Yes, they're similar to shorties, but the double wall for water cooling is what complicates it, and takes so much time. You have to always have the inner wall extend ?" past the outer for access to weld the next piece on.
And when you get to the collector it gets really tricky, it's easy to paint yourself into a corner.

True, the lower volume bumps the price up also.

 

[180shabah]

Re: My home made stainless headers

Re: My home made stainless headers

Those headers are AWSOME!!

Do you have any pics showing how you did the collector?

 

[wire2]

Re: My home made stainless headers

Re: My home made stainless headers

Those headers are AWESOME!!

Do you have any pics showing how you did the collector?

Thanks!
Unfortunately, no. I forgot about the camera when the planning got a bit more intense.

If you're interested, I'll be happy to make some sketches and describe the steps.

 

[Boomyal]

Re: Stainless Manifolds/Risers?

And now that I've converted from OMC stringer to alpha gen 2, I'll have to redo the connection to the Merc Y pipe.

Nice job on those manis Wire, but if you are keeping the thru hull, wouldn't you just cap the Y pipes? How is the noise level on your system?

 

[Bondo]

Re: Stainless Manifolds/Risers?

Those headers are AWSOME!!

Ayuh,........ Very,... Very Impressive...... Truely a work of Art............

Do they run Dry all the way to the diverter,..??....

 

[wire2]

Re: Stainless Manifolds/Risers?

Nice job on those manis Wire, but if you are keeping the thru hull, wouldn't you just cap the Y pipes? How is the noise level on your system?

I believe, legally, here in Ontario, we're not supposed to run open exhaust within 1 Km (5/8 mi) of shore. But I regularly hear/see other boats traveling the channel with open headers on 1 and 2 V8's.
I find the drone of some 4 cyl I/O's far more obnoxious.
If I start it at the dock at 1500-2k rpm with the pipes open, all my neighbors know about it. It sounds sweet, but it is a bit loud, so I'll connect the Y pipe as well.

Ayuh,........ Very,... Very Impressive...... Truly a work of Art............

Do they run Dry all the way to the diverter,..??....

Thanks, Bondo.
The inner pipe ends 2-3 inches before the Y. The lower half is mostly blocked to force the water out the top and mix with the exhaust to keep everything cool. I can run hard for 30 minutes, stop and immediately put my hand anywhere on the pipes. It's maybe 120? - 130?.