350 mpi swap from v6 carb

[Fun Times]

Re: 350 mpi swap from v6 carb

My only remaining issue now is the threaded hole next to the oil filter. If someone could help with that it'd be a great help. It's not the block drain as there is already a plug there. If its another drain hole ill pick up another plug and well...plug it up

Is this the empty hole you're asking about ?, http://forums.iboats.com/showthread.php?t=575028&p=3950410#post3950410

One of you're best bets in dealing with the ECM would be to call mefiburn and explain that you have a horizon 350 MAG bravo 3 MPI, mefi 3 ECM with an engine manufacture date of 06/29/2000 and that your going to an alpha drive standard cooling system. He may be able to help one way or another.

http://www.mefiburn.com/

I hope your doing this with the service manual #24 in hand? If so, for the vacuum hose routing diagram, look on page 5C-17.

The white wire could be coming out of the J2-9 pin of the ECM heading to the shift switch assembly and should be plugged into a jumper plug that looks something like this,
http://www.google.com/imgres?hl=en&...nw=55&start=0&ndsp=19&ved=1t:429,r:0,s:0,i:74

Or it's the white wire on the coil. I kind of remember the threads your talking about but don't remember the details of it. If it is the white coil wire, just keep in mind using that could set off a code 45 which could make it Rough Running, Poor Idle, Lack of Performance. This white wire goes to pin J1-2 Ignition Coil.

Let us know how you make out in the end.

 

[jdubslopro]

Re: 350 mpi swap from v6 carb

The hole is similar, but in a slightly different location. Mine is at about a 45 degree from the oil filter on the left side, between the filter and the freeze plug. I guess I'll fill it with oil and run water through it to see if anything leaks from it and go from there. On mercruiserparts.com the part number for the closed cooled 350 MAG shows a part number 991551, which turns out to be a 160 degree tstat. If this is wrong please lmk.
I have a service manual that I downloaded from maxumownersclub.com.
I was able to figure out the vac line when I was putting the wiring harness on, saw there was a vac port on the lower part of the throttle body.
I do have a 2 pin plug that ends in a jumper with a white wire. The two wires going to that plug are black and purple/yellow. I might be mistaken here, but I thought purple/yellow was +12v ignition? I haven't powered the motor up yet, but I'm going to prime the oil pump and probably do that today. First thing is to get it running on the stand and I will put it in the boat afterwards.

 

[jdubslopro]

Re: 350 mpi swap from v6 carb

Ok I did a google search for 350 mag mpi thermostat and came up with the same microfiche on several websites, but only one that showed the raw water cooling system thermostat part #. Appears that the closed system runs a 170 degree while the raw system runs 160. Will the extra 10 degrees really hurt anything if I put in the hotter tstat? I don't run in salt water, so salt precipitate is a non-issue for me. In the same respect, will 10 degrees really create a performance issue?

 

[QC]

Re: 350 mpi swap from v6 carb

Hopefully Fun Times or Don will reply soon. That is the ultimate question, and seems you have framed it properly

 

[Fun Times]

Re: 350 mpi swap from v6 carb

The hole is similar, but in a slightly different location. Mine is at about a 45 degree from the oil filter on the left side, between the filter and the freeze plug.

On mercruiserparts.com the part number for the closed cooled 350 MAG shows a part number 991551, which turns out to be a 160 degree tstat. If this is wrong please lmk.

I do have a 2 pin plug that ends in a jumper with a white wire. The two wires going to that plug are black and purple/yellow. I might be mistaken here, but I thought purple/yellow was +12v ignition?

Maybe if you could post a photo someone will recognize the hole for you? Since you now have MPI, See page 1B-42, c- Y-Fitting (Fuel Injected Only) d- Cylinder Block Drain Plug (Fuel Injected Only) e- Knock Sensor?

Yes, this closed cool system uses a 160. Looks like your going to try and use the closed cooling thermostat housing? You know if the other guy ends up using the closed cooling system on another engine, most likely he's going to need it and the hoses to it. Expensive mistake for him.

On some engine models the fuel mapping on the horizon closed cooling system the ECM is said to be different, But you will be happy to know this is not the case with your engine model ECM or wiring harness.

There is only one ECM part number 891895A01 Superceded From 861927T3 for all 350 MAGNUM MPI ALPHA/BRAVO (GEN+) ENGINE & 350 MAG MPI HORIZON & 350 MAG MPI HORIZON MIE.

So this means you are good to go with the ECM you have and you should be able to use your old alpha V6 shift cable plate assembly with the old shift switch and just plug into the jumper end and check shift adjustment.

Are you using the engine mounted sea water pump or using the alpha drive water pump?

There should be 0v at that shift switch plug. I think there is a diode in that jumper, but not 100% sure. They have two part numbers for that plug, one for a white wire and the other for a black wire.

http://www.mercruiserparts.com/selectDocs.asp?doc_nbr=809488+99

 

[Fun Times]

Re: 350 mpi swap from v6 carb

Ok I did a google search for 350 mag mpi thermostat and came up with the same microfiche on several websites, but only one that showed the raw water cooling system thermostat part #. Appears that the closed system runs a 170 degree while the raw system runs 160. Will the extra 10 degrees really hurt anything if I put in the hotter tstat? I don't run in salt water, so salt precipitate is a non-issue for me. In the same respect, will 10 degrees really create a performance issue?

Service manual #24 shows the the closed cooling to be 160 as well.

Some CC engine models do run 170 while others do not. You really have to do your home work to know for sure between engine models.

Your CC T/housing should have part number 991551 in it,
http://www.iboats.com/Mercury-99155...gle-_-Mercury:OEM Parts:Google-_-991551_Broad

What is the serial number for your old V6?

 

[Tail_Gunner]

Re: 350 mpi swap from v6 carb

You do not have to worry about water temp above 120 degree's from there and above your off the enrichment mode for starting.

 

[jdubslopro]

Re: 350 mpi swap from v6 carb

The guy I bought the motor from kept everything for the closed cooling system, so he has all the necessary hoses/clamps. The only thing I'm going to need is an extra hose and some clamps, to connect the inlet hose to the fuel cooler and from the cooler to the t-stat housing. I am using everything original from the v6 including water pump, t-stat housing, alpha drive impeller and all hoses. I couldn't remove the brass elbow (water outlet) from the intake manifold and I didn't want to break it trying to remove it so I'm just going to cap that off.
Fun times, thanks for the great info. I do have a horizon cover that came with the engine, but when I look up the serial it comes back as just MAG MPI--the horizon numbers start later.

Damn this rain, was hoping to drop the motor in today after work...

 

[jdubslopro]

Re: 350 mpi swap from v6 carb

I don't remember exactly but I think the v6 was 0L0142 plus another digit or two, its a 98 vortec 2 bbl

 

[jdubslopro]

Re: 350 mpi swap from v6 carb

Oh and the threaded hole in the block is just an empty hole, I shined a flashlight and it stops about 3/4" in. The hole to the top right of the oil filter appears to almost be an inspection hole, it just goes to the back of the block. It's only about 7/16" so it wouldn't be any good to check the flywheel.

 

[Bondo]

Re: 350 mpi swap from v6 carb

Oh and the threaded hole in the block is just an empty hole, I shined a flashlight and it stops about 3/4" in. The hole to the top right of the oil filter appears to almost be an inspection hole, it just goes to the back of the block. It's only about 7/16" so it wouldn't be any good to check the flywheel.

Ayuh,.... 1 of those holes is where a clutch linkage arm would bolt to a standard pickup truck motor...

 

[Fun Times]

Re: 350 mpi swap from v6 carb

The only thing I'm going to need is an extra hose and some clamps, to connect the inlet hose to the fuel cooler and from the cooler to the t-stat housing.

I am using everything original from the v6 including water pump, t-stat housing, alpha drive impeller and all hoses.

Fun times, thanks for the great info. I do have a horizon cover that came with the engine, but when I look up the serial it comes back as just MAG MPI--the horizon numbers start later.

Good to hear you just need the two hoses that come from the power steering cooler to the cool fuel then to the t-stat housing. just a little over $100.00 more, not bad. Horizon, http://www.mercruiserparts.com/Show...r=4848&bnbr=140&bdesc=Standard+Cooling+System

4.3L ALPHA, http://www.mercruiserparts.com/Show...r=2694&bnbr=150&bdesc=Standard+Cooling+System

Also it's a good thing your using your old alpha t-stat housing, with alpha drive impeller because there is a differents between alpha & bravo styles t-stat housings. For some reason I was under the impression you still had the closed cooled t-stat housing and was wondering what temp the t-stat was so you could use it. In this case they were/are both 160*, so you're still good. To use the closed cooled t-stat housing or a bravo t-stat housing, you would need an engine mounted sea water pump to make it work right.

I also noticed mercruiserparts.com does not show your serial number range for the Horizon engine unless you went to the V-8 Inboard Engines under 350 MAG MPI HORIZON MIE to find your serial number range. They must have forgot to add it somehow, but your engine really is a Horizon engine. Just know the parts catalog link you're using is the correct one. Catalog part number 90-80948899!

 

[jdubslopro]

Re: 350 mpi swap from v6 carb

Thanks for that info about the motor, it'll make it easier to reference parts online and my local dealer. I think I'm just going to run my existing water line from the ps cooler right into the fuel cooler (cut it to length) or cut it to length and run it from the fuel cooler to the tstat housing, and just pick up some $2/foot water hose. I can't see spending $100 on the correct hoses when I can do the same thing for much less. It's looking like tomorrow might be the day for the install and hopefully the initial break-in procedure.

 

[jdubslopro]

Re: 350 mpi swap from v6 carb

Dropped the motor in tonight...kinda. Right now the rear mounts are bolted to keep the motor from shifting...but the front mounts are off by about 4" or so. Is there anyone who knows exactly how far forward I have to move the aluminum mounting plates that attach to the stringers? I'm hoping I can just mark where they are now and move them forward the exact amount the need to go, then drop the motor back down and bolt it all up.
Poor oversight on my part, wish I had thought about that before trying to put the motor in. It was too much work to take it back out, hence why I put the two rear bolts in and have it resting on the stringer mounts in front.

 

[Bondo]

Re: 350 mpi swap from v6 carb

Dropped the motor in tonight...kinda. Right now the rear mounts are bolted to keep the motor from shifting...but the front mounts are off by about 4" or so. Is there anyone who knows exactly how far forward I have to move the aluminum mounting plates that attach to the stringers? I'm hoping I can just mark where they are now and move them forward the exact amount the need to go, then drop the motor back down and bolt it all up.
Poor oversight on my part, wish I had thought about that before trying to put the motor in. It was too much work to take it back out, hence why I put the two rear bolts in and have it resting on the stringer mounts in front.

Ayuh,.... What I do is, mount the motor on the rear mounts, 'n on the hook,...

Then insert the alignment bar, 'n align the motor, on the rear mounts, 'n crane,...

When the motor is perfectly aligned, That's where the front motor mounts need to be built up too...

 

[jdubslopro]

Re: 350 mpi swap from v6 carb

So I should remove the mounting plates, attach the front mounts to them, adjust the level according to how the tool lines up, mark the locations for the mounting plates on the stringers, remove the mounting bolts, lift the engine, install the mounting plates in their new correct position, then drop the engine back down and bolt it all up, recheck alignment?

Sounds like it'll take some time, but I'm hoping to have the tool for tomorrow and its supposed to be sunny and 80 degrees.

One final item. I've read conflicting stories (on this forum and others) about regearing and the necessity/non-essentiality of doing so in regards to this engine setup. I know that these engines (5.7) are supposed to mate to either an alpha with a 1.5:1 (1.47:1) or bravo drive, but will it do any damage being mated to my 1.62:1? I know I'm right on the upper threshold of power capability in regards to the alpha drive at 300hp, but the only reason I can see for needing to regear is if I can't match a prop to get it within its specified operating range. I'm hoping a 23p will get me where I need to be. I intend to break in the motor at low rpms with a 19p prop and I have a 21p I can swap out for once I do the initial oil change and start working the upper rpm range.

 

[Tail_Gunner]

Re: 350 mpi swap from v6 carb

Gearing will be no problem. When your running make notes of what the old prop does and it should be easy to adjust up..23 sounds right

 

[jdubslopro]

Re: 350 mpi swap from v6 carb

Ok guys the swap is complete except for one injector...I broke it during install ($140, ouch!). I went through the trouble of reversing the throttle operating direction, only to discover that it changed it to the wrong way! So I put it back where it originally was, seems like it works great. It sometimes sticks when being put into "reverse" but it could just be the cable end in the gimble housing (outdrive is still off).
I bought a pair of exhaust elbows from someone on Craigslist and they seem like they fit really well, except the couplers didn't reach all the way to the risers. I had to loosen every clamp and pull the elbows a little out of the y-pipe coupler. Is there a different part that has a longer top part of the elbow? I think it was part number 14478 on the elbow I have. I was thinking I could just get a section of exhaust hosing cut to the right length, but at $100/foot that might not be the most financially responsible way to attack that problem.

 

[jdubslopro]

Re: 350 mpi swap from v6 carb

I'll also note that the y-pipe is not circular but elliptical. The elbow is elliptical on the bottom and round on the top. And when I'm referring to elbow I don't mean the one on top of the exhaust manifold.

 

[Fun Times]

Re: 350 mpi swap from v6 carb

Here is the exhaust system for your new 350, V8 for comparison's sake,
http://www.mercruiserparts.com/Show...4.png&inbr=4848&bnbr=280&bdesc=Exhaust+System
http://www.mercruiserparts.com/selectDocs.asp?doc_nbr=809488+99

Here is the exhaust system for your old V6 for comparison's sake,
http://www.mercruiserparts.com/Show...c=Exhaust+System(Use+With+Two+Piece+Manifold)
http://www.mercruiserparts.com/selectDocs.asp?doc_nbr=809969+98

Did either engine use/have exhaust risers?