Need a intake Manifold for a 5.7L MPI Mag that isn't made anymore

[Seattlescarab]

I am looking for a intake manifold for a OK163243 5.7L Part Number is 807352A1 and no one has one and they don't make them anymore. Has anyone done a workaround? Will a later 807352A13 work with a little Mod? I have no idea where to go from here......

 

[Bondo]

Ayuh,.... Welcome Aboard,.... What exactly is wrong with the original manifold,..??

Have ya searched the used market,..?? craigslist, ebay,..??

 

[NHGuy]

That's cause you can use any 5.7 intake that fits your heads and carb. The mag uses a dual plane high rise intake, so that's my suggestion.

 

[Fun Times]

It's the MPI intake Plenum that would interfere with adding any old intake.

There were a few MPI intake designs by Merc before going to GM's new intake design for the MPI engines.
First it was named Mercuiser MPI intake then came the low Mercruiser MPI intake, http://www.mercruiserparts.com/bam/subassembly/31745/2691/110
Next came GM IAFM (GMEFI) intake which is a 2-piece and called a Long Runner intake with 75mm Throttle Body (80mm w/DTS), http://www.mercruiserparts.com/bam/subassembly/31747/7585/90

While there's two Merc names used, The intake design that the Scorpion uses is called Mercruiser MPI intake and they started using it around 96 - 98 on the 350 MAG's and Scorpions.. but the Black/Scorpions continued using the (non "low") Merc MPI intake also calling it Tunnel Ram in their selling pitch which now uses a 90-mm throttle body full time but did offer a 75 MM throttle body like noticed here, http://www.crowleymarine.com/mercury-outboard/parts/2350_150.cfm?mdl=OOFMNT

Merc also had/used a intake part number that ended in A2, http://www.crowleymarine.com/mercury-outboard/parts/2350_160.cfm?mdl=OOFMNT
Doing a search on EBay only using part number 807352A yields many including A2, http://www.ebay.com/sch/i.html?_fro...0.TRC0.H0.X807352A.TRS0&_nkw=807352A&_sacat=0 < But not your A1 needed.

350 Mag MPI

MH

1996?1997, 6MH, start Gen+, Bravo, start MerCruiser MPI intake

Black Scorpion	MH	1996?2002, 6MH, start Gen+, MerCruiser MPIintake, 0MH, start Toluca production	14 (356)
Black Scorpion	MN	2002?UP, MerCruiser MPI intake	14 (356)

^, Here is some more Scorpion and other engine intake design names to engine sizes info, https://www.perfprotech.com/blog/bo...-block-id-codes-small-block-v8-marine-engines

The following is just some informational notes:
The exclusive tunnel-ram intake manifold draws on racing technology for maximum power and exceptional throttle response.
Black Scorpions exclusive low-profile air intake system (Plenum) combines a massive 90 mm throttle body with the MerCruiser multiport fuel injection system to produce 365 ft torque. http://www.boattest.com/engine-review/MerCruiser/136_MX-6-2-Black-Scorpion-(330-hp)

The intake plenum gasket is the same part number between the Scorpion and 350 MAG, 27-807670 so you'll be fine there should you order one of the other part numbers available.

Or just go all out and add a supercharger.. https://whipplesuperchargers.com/index.php?dispatch=products.view&product_id=143

Maybe you could try contacting some of the sellers in EBay and get some photos to compare yours too.

Hope this helps you out some, good luck.

 

[Bt Doctur]

Or just put a carb on it and be done.

 

[NHGuy]

OOPs, not a carb. didn't pay attention.

 

[Yegboats]

When I looked up 807352a 1 part in merc it says to Order from seaway marine 800 332-0830 when I looked on their site it say's not available : / Maybe call them and ask if they can steer you in the direction of someone who may have one or offer a solution.

 

[Scott Danforth]

What's wrong with the original intake? Generally the intake outlasts the rest of the motor.

I would check ebay

 

[Seattlescarab]

So the original on the port motor is dissolved from salt water, the starboard is still fine but lack of rinse and no fresh water cooling have destroyed the port side (obviously they are the same). Seaway no longer has them, no luck on ebay, I will post a pic. I am fairly good online so this was a call out to someone who had one, an old motor with one etc. It would be a very expensive proposition to yank all the Injection stuff off and replace with carbs and different manifolds since its computer controlled.

 

[alldodge]

Are you rebuilding the motor(s) or is this a intake replace?

 

[Seattlescarab]

So it's a replace that was noticed over winter. I took a $1300 gamble this afternoon and purchased a new 807352A2 that was found on Ebay. After looking closely at the 807352A1 the subtle differences (fuel pressure regulator hose input) (MAP input on the A2) I think I can modify easily enough and make it work. Both volumes with the Vortec heads seem the same, they are the same years just MAG vs Scorpion. Anyway we will see what it looks like.

 

[Fun Times]

So it's a replace that was noticed over winter. I took a $1300 gamble this afternoon and purchased a new 807352A2 that was found on Ebay. After looking closely at the 807352A1 the subtle differences (fuel pressure regulator hose input) (MAP input on the A2) I think I can modify easily enough and make it work. Both volumes with the Vortec heads seem the same, they are the same years just MAG vs Scorpion. Anyway we will see what it looks like.

Please if possible, be sure to keep the topic updated as you go through the process of changing out the intakes... Good luck to you.

 

[Seattlescarab]

OK the eBay seller just refunded my money and cancelled the purchase. Apparently they don't have the part, which was a gamble. I am now stuck.......again

 

[Yegboats]

Is there any sort of casting number on the intake?

 

[Jay Curtis]

are you replacing it because the water passages are rotted out by the heads?
if so a good engine builder can usually weld and resurface those