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View Full Version : Replacing engine, what will fif?


Surfer
10-25-2012, 08:45 AM
Hi,

my 1995 MC ProStar 190 has got 2100 hours. This summer problems, first it seemed only head gasket problem, but now opening the engine, seems that I should replace bearings, some machinery work, cooling tunnels not in so good shape, etc.

Replacing the whole engine could be not much more expensive.

Any idea is there anything special in these MC marine engines? Or I can just pick up marine base engine and put the external parts from the old engine? The Indmar programmed EFI computer will fit? Special camshaft etc. in the engine??

The engine is Chevy 350, EFI, 1:1 transmission, 275 hp. This was the base option in 1995.

How about this? http://www.michiganmotorz.com/350ci-base-marine-engine-19871995-replacement-p-122.html

Of if you know a place to order a new engine that will fit?

Thanks a lot for any answers! :)

mikeg205
10-25-2012, 09:13 AM
The marine engines have different cams and a number of other parts to allow it to last under the loads a boat puts on an engine.

The ECM will have to retain it's harness and components to allow it to work. Tuning ECM to new installation will take expertise and software allowing changes to be flashed to its memory.

Contact this TT member http://www.mastercraft.com/teamtalk/showthread.php?t=33716&highlight=diesel+engine

maybe you could drop in a diesel...

Rossterman
10-25-2012, 09:45 AM
Other then stainless head gaskets, brass freeze plugs, and cam they are the same as a standard vortech engine. Engine castings, crank, rods, and pistons arent anything special. You could go with a direct marine replacement for a simple fix or buy something with more stout components from summit racing. They typically sell engines with 4bolt mains, steel cranks, forged pistons for slightly more than the marine basic replacement engine. Heres a couple to consider:

Gm vortech: http://www.summitracing.com/parts/nal-12530282/overview/

Or 383 stroker!: http://www.summitracing.com/parts/mll-bp3830ct1/overview/make/chevrolet

JimN
10-25-2012, 10:09 AM
The marine engines have different cams and a number of other parts to allow it to last under the loads a boat puts on an engine.

The ECM will have to retain it's harness and components to allow it to work. Tuning ECM to new installation will take expertise and software allowing changes to be flashed to its memory.

Contact this TT member http://www.mastercraft.com/teamtalk/showthread.php?t=33716&highlight=diesel+engine

maybe you could drop in a diesel...

Most engines just come off of the same assembly line as the car/truck engines and, while marine engines run at higher RPM for longer than cars, it's never as much of a load as tires hooking up with the road from a standstill unless the prop strikes an object. The ECM shouldn't need much tweaking unless a lot more air is being shoved in, although I do agree that the calibration should be specific to the hull/setup.

JimN
10-25-2012, 10:15 AM
Hi,

my 1995 MC ProStar 190 has got 2100 hours. This summer problems, first it seemed only head gasket problem, but now opening the engine, seems that I should replace bearings, some machinery work, cooling tunnels not in so good shape, etc.

Replacing the whole engine could be not much more expensive.

Any idea is there anything special in these MC marine engines? Or I can just pick up marine base engine and put the external parts from the old engine? The Indmar programmed EFI computer will fit? Special camshaft etc. in the engine??

The engine is Chevy 350, EFI, 1:1 transmission, 275 hp. This was the base option in 1995.

How about this? http://www.michiganmotorz.com/350ci-base-marine-engine-19871995-replacement-p-122.html

Of if you know a place to order a new engine that will fit?

Thanks a lot for any answers! :)

Call Jasper. I used their engines several times and they not only have a direct-replacement for your engine, they come with a 3 year warranty.

Yours doesn't have a special cam or anything else. First thing I would do is call a speed shop in your area to find out what they can do. It's likely that you could get the same thing for less that $2799. All of the accessories will bolt on and the harness goes on the same as your engine.

As long as you're not doing anything that's really custom, it won't be hard to re-power without a lot of screwing around.

I would recommend using a GM reman engine but they specifically state that marine use doesn't come with a warranty (maybe they changed that since I read their brochure).

Surfer
10-29-2012, 07:11 AM
Hi,

thanks for the answers!

So my original engine has got a cam, which is stardard in GM marine engine?
-> Indmar EFI computer is programmed for this.
Correct?

Rossterman, you meant in comparison to vortech car engine cam is different in marine engine?
JimN, yes I just need basic replacement, no customization.

If so, the GM base marine engine will do ok? Even the replacement has got a roller cam,
as the original engine has got flat tappet cam.
Ok, flat tappet cam is maybe an option, but roller cam would be better I understand; E.g. a bit more power.

The valve timings seem to be different with different cams, that is why I am wondering if the original EFI computer would do ok with roller cam?

I do not know EFI working principles yet so closely, and I am not able to tune EFI computer, and don't want to buy a new one.


Thanks!

Pasi

mikeg205
10-29-2012, 07:49 AM
Yours doesn't have a special cam or anything else. First thing I would do is call a speed shop in your area to find out what they can do. It's likely that you could get the same thing for less that $2799. All of the accessories will bolt on and the harness goes on the same as your engine.



Really? So Indmar basically took a 350 put on a marinized ECM-other electronics, marine exhaust manifold and riser, marine alternator,marine starter Johnson water pump, spark arrestor and added that 2 stage electric fuel pump?

The only reason I ask is because of all the other things I read about marine engines having different cams and other things to deal with engine load differences from road to marine use. This is great information. :D

JimN
10-29-2012, 08:34 AM
Hi,

thanks for the answers!

So my original engine has got a cam, which is stardard in GM marine engine?
-> Indmar EFI computer is programmed for this.
Correct?

Rossterman, you meant in comparison to vortech car engine cam is different in marine engine?
JimN, yes I just need basic replacement, no customization.

If so, the GM base marine engine will do ok? Even the replacement has got a roller cam,
as the original engine has got flat tappet cam.
Ok, flat tappet cam is maybe an option, but roller cam would be better I understand; E.g. a bit more power.

The valve timings seem to be different with different cams, that is why I am wondering if the original EFI computer would do ok with roller cam?

I do not know EFI working principles yet so closely, and I am not able to tune EFI computer, and don't want to buy a new one.


Thanks!

Pasi

If you call Jasper, they'll ask for some numbers that are on the block- they're usually in the rear and could be hidden by the transmission/bell housing. Sometimes, they're on the heads. Using this info, they can tell which engine you have. One easy way to tell if it's a Vortec or non-Vortec engine is by looking at how the intake manifold bolts go in- if they're perpendicular to the head/intake manifold mating surface, it's non-Vortec. The Vortec bolts go in vertically.

This info will also tell them which cam it has and, having replaced engines in MC boats of similar vintage to yours, they did get it right. All that was needed was to remove the accessories from the old engine and transfer them to the new engine. The roller cam isn't necessarily as different WRT valve timing just because it's a roller cam- it's because of a lot more than that. The air/exhaust characteristics of Vortec heads are different from non-Vortec and changing the cam allows more/faster intake and exhaust gas movement. If you get the same kind of block as the OEM, you won't need to make any changes to the calibration.

You can recover a bit of power by using roller rocker arms, too. This adds about 15 HP. Roller lifter/cam adds a similar amount and both allow more power because they add less resistance through friction. The intake manifold may be another place to look for more power but you might have to watch out for excessive height- some intake manifolds are a lot taller than what came with it, although you may be able to find a newer TBI manifold from an MC (a little better than the original TBI, but not a tremendous difference).

JimN
10-29-2012, 08:43 AM
Really? So Indmar basically took a 350 put on a marinized ECM-other electronics, marine exhaust manifold and riser, marine alternator,marine starter Johnson water pump, spark arrestor and added that 2 stage electric fuel pump?

The only reason I ask is because of all the other things I read about marine engines having different cams and other things to deal with engine load differences from road to marine use. This is great information. :D

It really depends on what was spec'd by the application designer. If a stock engine will work, there's really no reason to go beyond that and with the ability of MC/Indmar to customize the calibration, they're able to get the performance needed for each hull.

Surfer
10-29-2012, 09:43 AM
Hi,

JimN, thanks a lot!
Yes, the engine is non-Vortec.

Ok, I might ask for price of roller rocker arms for the base engine, if it is an option and maybe for newer TBI manifold. But MC did this type of engine only 1995 - 1997, after that MPI?

So EFI computer just "puts gas in", when crackshaft position sensor says so? When and how fast the valve is opening, fully open, closing and closed, does not matter?
Craph for roller cam vent opening is more rectangular, as flat tapped cam craph is more parabolic, as in time vs. vent opening x-y scale.


BR,

Pasi

JimN
10-29-2012, 10:10 AM
Hi,

JimN, thanks a lot!
Yes, the engine is non-Vortec.

Ok, I might ask for price of roller rocker arms for the base engine, if it is an option and maybe for newer TBI manifold. But MC did this type of engine only 1995 - 1997, after that MPI?

So EFI computer just "puts gas in", when crackshaft position sensor says so? When and how fast the valve is opening, fully open, closing and closed, does not matter?
Craph for roller cam vent opening is more rectangular, as flat tapped cam craph is more parabolic, as in time vs. vent opening x-y scale.


BR, Pasi

They won't have the same intake MC put(s) on the newer TBI and the one used on the Vortec won't work because of the way the bolts go in.

TBI engines, especially from the '90s, don't have a crank position sensor, they use the can on the distributor shaft and, unlike crank sensors, that doesn't tell the ECM which direction it's turning. The ECM uses the MAP sensor to detect engine load (uses barometric pressure and engine-induced vacuum relativee to RPM and throttle position), TPS detects idle throttle position (</= 2%) run throttle position (>2%) and fast throttle position changes (delta >20) for acceleration enrichment or deceleration enleanment, and coolant temoerature to determine whether to add or remove fuel when it compares its state, relative to the fuel mapping tables in the program. These run rich enough that changing the lobe shape won't cause the engine to experience problems unless it's run really hard and something is outside of the normal ranges.

Surfer
10-29-2012, 11:51 AM
Hi,

so driving for barefoot, there is a slight change of experience problems with roller cam and original EFI computer? Ok, nothing should be out of normal range, except the cam (the not original roller cam was included in your reasoning). Also cooler air temp. in Finland, but this EFI does not straigth take that into account?

Or, as you said rich enough; If we know the max. output of the original EFI, we could calculate what is the base GM engine's max. requirement?
Or are these specifications publicly available? Something should exist at least.


BR,

Pasi

JimN
10-29-2012, 12:06 PM
Hi,

so driving for barefoot, there is a slight change of experience problems with roller cam and original EFI computer? Ok, nothing should be out of normal range, except the cam (the not original roller cam was included in your reasoning). Also cooler air temp. in Finland, but this EFI does not straigth take that into account?

Or, as you said rich enough; If we know the max. output of the original EFI, we could calculate what is the base GM engine's max. requirement?
Or are these specifications publicly available? Something should exist at least.


BR,

Pasi

The intake air temp isn't monitored on older models. The only time I saw people having problems barefooting with a TBI engine was when they had small feet and were relatively heavy. With cooler air temp, the extra power wouldn't hurt (it's always nice to have a little extra)- what is the elevation where you'll be skiing?

Rossterman
10-29-2012, 09:05 PM
Hi,

thanks for the answers!



Rossterman, you meant in comparison to vortech car engine cam is different in marine engine?
JimN, yes I just need basic replacement, no customization.

If so, the GM base marine engine will do ok? Even the replacement has got a roller cam,
as the original engine has got flat tappet cam.
Ok, flat tappet cam is maybe an option, but roller cam would be better I understand; E.g. a bit more power.

The valve timings seem to be different with different cams, that is why I am wondering if the original EFI computer would do ok with roller cam?

I do not know EFI working principles yet so closely, and I am not able to tune EFI computer, and don't want to buy a new one.


Thanks!

Pasi

Roller cam in the vortech truck could be the same as marine as i have never seen anyone publish the lift and duration numbers of either. I suspect they are identical but cant prove. You will get more power using the roller cam vortech motor as much superior cylinder heads to non vortech motors and the roller cam has better performance with quicker opening/closing ramps

Surfer
10-30-2012, 06:05 AM
The intake air temp isn't monitored on older models. The only time I saw people having problems barefooting with a TBI engine was when they had small feet and were relatively heavy. With cooler air temp, the extra power wouldn't hurt (it's always nice to have a little extra)- what is the elevation where you'll be skiing?


Hi,

my barefooting driving is rarely 38 mph (US nautical miles), more likely in 35 -36 mph range at the highest.
By the way the old engine (ca. 2100 h) still this summer took close to 38 mph, before it broke down.

Cooler air is more packed, i.e. more oxygen in smaller space, you get more power then actually?

Maybe with TBI, high revs and constant resistance for the engine with previously described barefooter causes something? Though I understand no major problems.

My altitude where I normally ski would be ca. 102 feet above sea level. Occasionally at around 246 feet.


BR,

Pasi

JimN
10-30-2012, 10:37 AM
Hi,

my barefooting driving is rarely 38 mph (US nautical miles), more likely in 35 -36 mph range at the highest.
By the way the old engine (ca. 2100 h) still this summer took close to 38 mph, before it broke down.

Cooler air is more packed, i.e. more oxygen in smaller space, you get more power then actually?

Maybe with TBI, high revs and constant resistance for the engine with previously described barefooter causes something? Though I understand no major problems.

My altitude where I normally ski would be ca. 102 feet above sea level. Occasionally at around 246 feet.


BR,

Pasi

It's less a matter of more power and more about whether the air/fuel ratio is correct and while using an intake air temperature is more accurate, these run just fine in cooler weather. The first thing that happens when the key is turned on is the ECM uses the MAP sensor to check the barometric pressure. You should be fine.

Surfer
10-31-2012, 05:25 AM
Hi,

any estimate, how much base engine with roller parts and new intake manifold would increase fuel consumption? Likely to be not less consumption.
I mean more hp, vents longer time open, but less friction, newer engine. + / - = 0?


BR,

Pasi

Rossterman
10-31-2012, 08:21 AM
Dont think you will see much change. Tbi predator engine is essentially what you would have and they are very good on gas. Better combustion and less friction with roller cam and rockers = better fuel economy.

Surfer
10-31-2012, 10:35 AM
Hi,

any idea what exactly is the ECM on this original engine?
Maybe some codes on the ECM will tell.

I have replaced that many years ago, as the original broke itself, had to order a new one from MC UK.

The boat with original ECM had starting problems with warm engine since new, I experienced that a couple of times, but not anymore after replacing the ECM.


BR,

Pasi

Surfer
11-01-2012, 05:44 AM
Hi,

Roger from Michigan Motorz told me not to take an engine with a roller cam.

"TBI 5.7L engines and the ECMs are very finicky and do not like any changes or modifications. We know from experience." The engine might not run properly.

Surfer
02-14-2013, 05:20 PM
Hi,

anyone knows which one is the exact replacement base engine for my boat? Listing below.
My MC is 1995 TBI, with 275 hp. Did Indmar use cam upgrade engine option, or TBI gives extra 15 hp on the first engine on the list?
S/N's are the same on each.
2 or 4 bolt main, I guess that is what decides this?
The list is what First Mate marine engines offer.


BR,

Pasi




88-95
1 Piece rear main seal. Valve covers bolt down center. 2 bolt main.
Has metal timing cover. Flat tappet. Works for carburated or fuel
injected. 12 Bolt intake.
260 5.7L
350 CID
V-8 548, 526,
148, 638
– – GM350LC GM350RC GM350LCT GM350RCT

88-94 1 Piece rear main seal. Valve covers bolt down center. 4 bolt main.
Has a metal timing cover.
260 5.7L
350 CID
V-8 548, 526,
148, 638
SGM350LCF SGM350RCF GM350LCF GM350RCF GM350LCFT GM350RCFT

88-94 1 Piece rear main seal. Valve covers bolt down center. 4 bolt main.
This is a cam upgrade. Has a metal
timing cover.
275 5.7L
350 CID
V-8 548, 526,
148, 638
– – GM350LCFHO – GM350LCFHOT –