Confused about engines - Is a 5.8 Pro Boss = GT40

[dba4life]

Hi,

Recently purchased a 94 Sport Nautique. On the plastic engine cover it lists it as a 5.8 Pro Boss PCM. It has EFI. Is this a GT40 engine? If not what are the differences? Also does anyone know the actual HP of this engine?

Thanks to whoever can set me straight

Kevin

[SprintCar39]

Kevin, The Pro Boss is NOT a GT-40. The GT-40 has 310 HP and the Pro Boss has 300 HP. They both use the same heads and block but have different fuel delivery systems. Hope that answers your questions. Eric

[mdboats]

Hi guys,

In 94 PCM fuel injected motor was a throttle body Holley with Pro Tech ignition. This motor was rated at 310hp and when running correctly was the most awesome Ford produced by PCM (in production). The bad news is the Pro Tech ignition parts are running scarce and consumers are paying a premium price to get them. The Holley throttle body on this unit is equal to a 900cfm Holley carb and this motor could perform

In 95 PCM introduced the GT 40 as Mid Ohio said same block and heads with a Ford multiport fuel delivery system and Ford electronics. Not the same stuff you find in Ford car, yet Ford product. Injectors are different. Another note is the FCC unit was not introduced until 96 so 95s will not have a fuel control cell.

The term GT 40 refers to heads. GT 40 heads have 3 ribs as you look at the side of them. Non GT 40 heads have 2 ribs.

Hope this helps.

Mark Q

[SprintCar39]

Here is what the 1994 Correct Craft Brochure had to say about the Pro Boss:
In 1990, Correct Craft and PCM introduced Pro Tec - The first electronic engine management system programmed specifically for water ski towboats. Pro Tec's computer module provides engine protection and optimum performance - quicker throttle response, faster acceleration, greater top end and increased fuel efficiency. In 1992, Pro Tec was teamed with PCM's 5.8 high output engine to create Pro Boss - the most phenomenal high output inboard on the market. Thanks to the performance advantages of the Pro Tec, the Pro Boss is rated at more than 300 horsepower. For 1994, PCM has developed the first Ford engine based electronic fuel injection system designed for marine use. The Pro Tec Electronic Fuel Injection features improved cold starts and quicker throttle response. And because every EFI system requires an engine management system in order to function, Pro Tec brings increased speed and more horsepower to the table. Now Nautique owners have the option of a carbureted engine, a carbureted engine with an engine management system, or an engine management system with electronic fuel injection. With Correct Craft the choice is yours.

[dba4life]

So when someone says "The GT40 is the best marine engine ever built" - Do I basically have a GT40 and fit in that category? If it isn't a GT40 it seems awful close? Or am I off base.

Thanks for all the detailed and quick responses. Great info to know.

Kevin

[darrel409]

It is the same motor/heads just a different fuel delivery system. GT40 has multi-port fuel injection , to each cylinder. Yours is throttle body and injects from the intake manifold simaler to a carb but has the advantage of enriching fuel for quick cold starts...as said above. Its 300 HP ..."its awful close"

[dba4life]

Very cool - Thanks for the responses on this.

In 94 PCM fuel injected motor was a throttle body Holley with Pro Tech ignition. This motor was rated at 310hp and when running correctly was the most awesome Ford produced by PCM (in production). The bad news is the Pro Tech ignition parts are running scarce and consumers are paying a premium price to get them. The Holley throttle body on this unit is equal to a 900cfm Holley carb and this motor could perform

I have this Pro Tech ign and throttle body injection on my 94 5.8 Pro Boss. Should I do something now to get these scare ignition parts - or just wait until there is a problem?

Thoughts?

Kevin

[gtxragtop]

Kevin, The Pro Boss is NOT a GT-40. The GT-40 has 310 HP and the Pro Boss has 300 HP. They both use the same heads and block but have different fuel delivery systems. Hope that answers your questions. Eric

I beg to differ on your statement. Here is a new GT-40 Pro boss and it looks just like my 96.
http://www.donzi.net/forums/showthre...gine-Brand-New

[TRBenj]

I beg to differ on your statement. Here is a new GT-40 Pro boss and it looks just like my 96.
http://www.donzi.net/forums/showthre...gine-Brand-New

No, he is (mostly) correct.

All HO 351w's made by PCM (1992-2002) featured GT40 heads and were given the moniker of "Pro Boss". This includes the carb'd version, TBI version and Multiport version.

Only the Multiport was given the moniker of "GT40", in addition to the "Pro Boss" moniker (as seen in your picture). In other words, a GT40 is a Pro Boss, but not all Pro Bosses are GT40's. Make sense?

In 95 PCM introduced the GT 40 as Mid Ohio said same block and heads with a Ford multiport fuel delivery system and Ford electronics. Not the same stuff you find in Ford car, yet Ford product. Injectors are different.

The term GT 40 refers to heads. GT 40 heads have 3 ribs as you look at the side of them. Non GT 40 heads have 2 ribs.

Mark, I mostly agree with you, but a few clarifications:

-The injectors used in the GT40's were common Ford parts bin 24 lb injectors... though I couldnt tell you specifically which automotive application they were used in.

-Not all non-GT40 heads have 2 bars... though I believe you're correct if you meant "all non-HO 351w PCM Ford heads". Obviously there are other Ford factory heads that have other markings (GT40p heads have 4 bars, for example).

[Sandro]

HI

I have 1994 Ski Nautique with PCM 351 5.8HO Pro Tech. As I understood from this discussion, the engine that I have is Pro Boss with 310HP right..? Or is there another ways to identify it visually..?

[mf01]

The Carbed version was around 280hp. The TBI version is 310+hp.

[DanielC]

If your engine has an intake manifold that looks like the manifold in the link above, you have a GT-40 engine.
If your engine looks like it has a carburetor, it has throttle body fuel injection, and is NOT a GT-40.

[Lewy2001]

HI

I have 1994 Ski Nautique with PCM 351 5.8HO Pro Tech. As I understood from this discussion, the engine that I have is Pro Boss with 310HP right..? Or is there another ways to identify it visually..?

The GT40 was not available till 1995 so you have the Pro Boss with Protec in a 1994.

[Sandro]

If your engine has an intake manifold that looks like the manifold in the link above, you have a GT-40 engine.
If your engine looks like it has a carburetor, it has throttle body fuel injection, and is NOT a GT-40.

Thats how my engine looks like:



There is no GT40 ro ProBooss signs. Just Pro Tech Injection. Thats why I dont really understand what type is this engine.. It says that it has electronic fuel injection.

[swc5150]

You have an early TBI version; a predecesor to the GT-40 MPI. It's a nice engine, that was an early answer to MC going standard EFI in '94, after releasing the MPI LT1 in '93. PCM and Mercruiser had to play catch up for year or two, as MC really jumped out to an early lead with EFI.

http://correctcraftfan.com/reference...ex.asp?page=04