Intake manifold, 350 GM

[rickasbury]

My intake manifold may need to be replaced. We have a rinker 270 with a 350 mpi, 2006.
The boat has a dingy package which means underneath the rear bow seating, the bottom of the compartment is molded to accept the dingy motor for storage- rinker vented the compartment over the 350 motor so water was constantly sitting on the back end of the intake, right where the rotor goes through the block. At some point I will have to replace it. Sooner the better..on the rinker forum someone just replaced theirs, best deal he found was 1200 bucks. Why would this not be a standard gm intake, what would be "marine" on an intake manifold? I went through this when I had to replace the power steering pump. The reservoir is
Merc, but the pump itself is a Saginaw pump for 45 bucks- I think the merc with the reservoir was over 500. Thoughts?

 

[Bt Doctur]

redirect the drains around the motor to preserve it. No one ever said boat engineers were the sharpest knife in the draw
a shame because I have a TBI v8 manifold

 

[rickasbury]

redirect the drains around the motor to preserve it. No one ever said boat engineers were the sharpest knife in the draw
a shame because I have a TBI v8 manifold

My thought process is this is a 350 GM motor adapted for marine. Mine is closed cooling which is even more like a land
based motor. Maybe bearings are more HD, or maybe it's just a modified marine application. I'm going to do more digging, I will put my buddy Chat on it and see what worm holes I find. If they are the same I'm sure I could find a used one for a couple hundred vs 1200!

 

[Lou C]

Is it MPI or a carb? Carb cast iron Vortec intakes can be bought new for a lot less than 1200!
If all it has is external rust just wire brush it, clean with acetone and coat with rust converter and then paint. The cast iron is very thick & not likely to rust thru.

 

[rickasbury]

Looks like a big no way but I thought it was worth a look.

 

[rickasbury]

Is it MPI or a carb? Carb cast iron Vortec intakes can be bought new for a lot less than 1200!
If all it has is external rust just wire brush it, clean with acetone and coat with rust converter and then paint. The cast iron is very thick & not likely to rust thru.

That's good news- I need to get back to tge boat and address this for sure.we are mpi 2006.

 

[Lou C]

Pick up one they are heavy cast iron. Mine has had salt water running inside it (raw water cooling) for at least 25 years and it hasn’t rusted through yet!!!

 

[Bondo]

My intake manifold may need to be replaced. We have a rinker 270 with a 350 mpi, 2006.
The boat has a dingy package which means underneath the rear bow seating, the bottom of the compartment is molded to accept the dingy motor for storage- rinker vented the compartment over the 350 motor so water was constantly sitting on the back end of the intake, right where the rotor goes through the block. At some point I will have to replace it. Sooner the better..on the rinker forum someone just replaced theirs, best deal he found was 1200 bucks. Why would this not be a standard gm intake, what would be "marine" on an intake manifold? I went through this when I had to replace the power steering pump. The reservoir is
Merc, but the pump itself is a Saginaw pump for 45 bucks- I think the merc with the reservoir was over 500. Thoughts?

Ayuh,..... You, 'n yer boat will be better served by redesigning the storage locker the O/B motor sits in, to move the water drips directly to the bilge, so it doesn't drip onto the main engine,....
Then do as Lou says, 'n repaint the intake manifold,.....
Bein' a Mpi, a new one won't be cheap, 'n I doubt there's anything wrong with the current one,....

 

[Scott06]

My intake manifold may need to be replaced. We have a rinker 270 with a 350 mpi, 2006.
The boat has a dingy package which means underneath the rear bow seating, the bottom of the compartment is molded to accept the dingy motor for storage- rinker vented the compartment over the 350 motor so water was constantly sitting on the back end of the intake, right where the rotor goes through the block. At some point I will have to replace it. Sooner the better..on the rinker forum someone just replaced theirs, best deal he found was 1200 bucks. Why would this not be a standard gm intake, what would be "marine" on an intake manifold? I went through this when I had to replace the power steering pump. The reservoir is
Merc, but the pump itself is a Saginaw pump for 45 bucks- I think the merc with the reservoir was over 500. Thoughts?

not sure if you need only the upper or as others have said may not be rotten yet

https://www.ebay.com/itm/156639899434?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&mkscid=101&itemid=156639899434&targetid=2450593697471&device=c&mktype=pla&googleloc=9007369&poi=&campaignid=24192622954&mkgroupid=196851590342&rlsatarget=aud-1412318123216:pla-2450593697471&abcId=10813841&merchantid=5086385101&gad_source=1&gad_campaignid=24192622954&gbraid=0AAAAAD_QDh_mfKJw_42Ftx603hMnsitPN&gclid=EAIaIQobChMIvOmEtLjJlwMVltufCR3elxCtEAQYASABEgI8fPD_BwE

complete off a VP which is the same chit

https://www.ebay.com/itm/198630012266?_trkparms=itmf%3D1%26aid%3D1110006%26rkt%3D12%26pid%3D101875%26mech%3D1%26algv%3DSimVIDwebV4WithContextualRankerV42_18SignInOut%26pmt%3D1%26amclksrc%3DITM%26sd%3D156639899434%26sid%3DAQALAAAAEPpz4fWY1DNd58pFl7UxwoM%3D%26itm%3D198630012266%26noa%3D0%26plcampt%3D0%3A150780735012%26algo%3DHOMESPLICE.SIM%26brand%3DVolvo+Penta%26asc%3D345455%26ao%3D1%26rk%3D4%26mehot%3Dnone%26lsid%3D100%26meid%3Dc09e7c887456497d83657ef988addf12%26pg%3D2332490&_trksid=p2332490.c101875.m1851&itmprp=cksum%3A198630012266c09e7c887456497d83657ef988addf12%7Cenc%3AAQALAAABIPublsLHMrwa19e7ruMkC3MA1bD5ySgze%252B0f4QBr6mVMH3bgGFjLCZSScvtNoNg5mDjAm05yApoh7QUriUcQgG8dUgwOthB7AkC516OGUdtgHdoVLD1xoDkUR2ywBbGTJnTQ73gpUQ%252FwdK8zEFGrER3UMH6TzX%252BWiKVHwFWPqC4zMOgA4TyKutEMXIT1MzNEVvKhjWzKMyY30LG1VB4KjnrF72DCdAnwEyIQyGmwQjMG%252FeBBat6omOqMD2ZzQSNXXFYaTFRsVQIeYlywTZ2fUBl6irtlBDbt%252FjTPYr%252BvxMJ0%252BreS%252FO2vmYbdahgVfePDIBRYLl%252BE47%252BCKfhOTyXCpGBFs8HJ6GjvODu59OGHgknrEK2co5wqogeZyuhtTK2tgQ%253D%253D%7Campid%3APL_CLK%7Cclp%3A2332490&itmmeta=01M5DG81BFYX6GY143P879KMT1

 

[Scott Danforth]

The MPI intake is expensive.