Go Back   TeamTalk > Maintenance Tips, How-tos and Refurbishing Topics > Engine / Drive Train

Reply
 
Thread Tools Display Modes
  #1  
Old 06-02-2009, 03:02 PM
MTBMAC MTBMAC is offline
TT Newbie
 
Join Date: Nov 2007
Boat: 1990 MasterCraft Tristar
Location: Northwest
Posts: 6
Thumbs down Engine Swap Questions

I am currently restoring a fankinstine of a boat. The current Enging that is in it is a GM 327. My questions are 1st, Can I swap it out with a 350? 2nd Will my current engine mounts line up? What about my current manifolds and other neccessary parts? and 3rd, Are there any differences between an Auto and Marine engine, other then the intake and exhaust manifolds?

Thanks for your help
Reply With Quote
  #2  
Old 06-02-2009, 04:15 PM
CantRepeat's Avatar
CantRepeat CantRepeat is online now
 
Join Date: Jul 2008
Boat: 06 X30
Location: Roll Tide!!
Posts: 8,382
The 327 you have should have all the same bolt holes as any 350.

The Carbs are different on the marine models as well.
__________________
Tim
Gone, surfing.
Reply With Quote
  #3  
Old 06-02-2009, 04:24 PM
rob935's Avatar
rob935 rob935 is offline
TT Enthusiast
 
Join Date: Jun 2006
Boat: 1993 prostar 190
Location: ireland
Posts: 158
Send a message via ICQ to rob935
marine engines are basically the same as auto engines but most of the ancillaries are marinised in order to last in tough damp and hot conditions, standard auto parts such as starter motors,alternators etc would burn out in no time at all so they may look the same but in reality are quite different .
__________________
nil satis nisi optimum
Reply With Quote
  #4  
Old 06-02-2009, 04:34 PM
bcampbe7 bcampbe7 is offline
MC Addict
 
Join Date: Jul 2004
Boat: Tubtime Tugboat
Location: In front of my PC
Posts: 5,268
Send a message via MSN to bcampbe7
Not only that but boat engine compartments tend to hold fuel vapors. Marine starters and alternators are built to reduce/eliminate the possibility of creating spark so that your boat doesn't go boom.
__________________
If my words don't make sense, try reading them backwards.
Reply With Quote
  #5  
Old 06-02-2009, 04:52 PM
flipper's Avatar
flipper flipper is offline
MC Addict
 
Join Date: Mar 2005
Boat: 1991 Prostar 190, fuel injected 302
Location: Under the radar
Posts: 5,083
Don't know for a fact, but I was told the valves are different also to withstand the heavy load and heat that a boat engine faces.
__________________
Lots of power is good, more is better, too much is just right.

'91 prostar 190
Reply With Quote
  #6  
Old 06-02-2009, 04:55 PM
denverd1's Avatar
denverd1 denverd1 is offline
TT Enthusiast
 
Join Date: Nov 2007
Boat: 1986 Tristar 220, 351W, 2000 lbs
Location: tx
Posts: 238
Flip, can you confirm that? Looks like I'll be tearing my 351W down again and I'd like to know the details on the valves. Blew a head gasket saturday...
Reply With Quote
  #7  
Old 06-02-2009, 04:57 PM
flipper's Avatar
flipper flipper is offline
MC Addict
 
Join Date: Mar 2005
Boat: 1991 Prostar 190, fuel injected 302
Location: Under the radar
Posts: 5,083
I can find out, or somebody that know a lot more than I ever will like Jim or engine nut may chime in.
__________________
Lots of power is good, more is better, too much is just right.

'91 prostar 190
Reply With Quote
  #8  
Old 06-02-2009, 06:44 PM
panshovel68's Avatar
panshovel68 panshovel68 is offline
TT Enthusiast
 
Join Date: Jan 2009
Boat: 1990 prostar190
Location: maryland
Posts: 186
You might as well get used to changing engines if your going to put a automotive engines in your boat! The heads and cams are usually different, different torque curve. Boats have a single gear trans. Do it right the first time and repower with a marine engine. If you could just slap a car engine in your boat, why would companies like PCM and Indmar be in buisness? I just repowerd a ps190. Took out the ford and put a PCM chevy in. It wasnt cheap but it was a plug and go operation. And I am more than satisfied with the turn out! I have no problem pulling three footers goin 40mph.
Reply With Quote
  #9  
Old 06-02-2009, 09:17 PM
CantRepeat's Avatar
CantRepeat CantRepeat is online now
 
Join Date: Jul 2008
Boat: 06 X30
Location: Roll Tide!!
Posts: 8,382
Quote:
Originally Posted by panshovel68 View Post
You might as well get used to changing engines if your going to put a automotive engines in your boat! The heads and cams are usually different, different torque curve. Boats have a single gear trans. Do it right the first time and repower with a marine engine. If you could just slap a car engine in your boat, why would companies like PCM and Indmar be in buisness? I just repowerd a ps190. Took out the ford and put a PCM chevy in. It wasnt cheap but it was a plug and go operation. And I am more than satisfied with the turn out! I have no problem pulling three footers goin 40mph.
That's not true by any measure. Indmar purchased those motors from Ford with factory cams, P40 heads and standard pistons. Other then the external parts they are automotive engines with automotive parts.

Indmar and PCM are in business because Ford and Chevy don't build boats.
__________________
Tim
Gone, surfing.
Reply With Quote
  #10  
Old 06-02-2009, 10:22 PM
panshovel68's Avatar
panshovel68 panshovel68 is offline
TT Enthusiast
 
Join Date: Jan 2009
Boat: 1990 prostar190
Location: maryland
Posts: 186
Quote:
Originally Posted by 92Maristar View Post
That's not true by any measure. Indmar purchased those motors from Ford with factory cams, P40 heads and standard pistons. Other then the external parts they are automotive engines with automotive parts.

Indmar and PCM are in business because Ford and Chevy don't build boats.
Well then put a car motor in your boat!

Besides duty cycle there are other important differences. A marine engine’s core plugs are corrosion resistant bronze. The camshaft is ground to different specifications, most often to maximize low end torque. Also, the camshaft profile is different. Valve overlap (the time when both intake and exhaust valve are open) is shortened to minimize the chance of water being sucked out of the exhaust and into the combustion chamber. Gaskets are premium quality for better sealing and corrosion resistance

Electrical, ignition, and fuel system components on Indmar engines are designed and manufactured to comply with U.S. Coast Guard rules and regulations to minimize risks of fire or explosion. Use of replacement electrical, ignition, or fuel system components, which do not comply with these rules and regulations, could result in a fire or explosion hazard and should be avoided. Also, many other components on Indmar engines are designed and manufactured differently from standard automotive parts. Marine engines operate at or near full-throttle for most of their lives. They are also expected to operate in both fresh and saltwater environments. These conditions require numerous special parts. Care should be exercised when replacing marine engine parts, as specifications are quite different from those of the standard automotive

The bottom line, an unmodified automotive engine is totally inappropriate for a boat motor. Its torque curve won’t meet the needs of a boat, its light-duty components won’t long survive the rigors of marine usage, and you risk blowing yourself out of the water. You decide




According to Indmar and Marine engine digest.
Although they may be the same heads and camshafts they are reworked. That is straight off Indmars website!

BTW I never knew Indmar and PCM build boats

Last edited by panshovel68; 06-02-2009 at 10:26 PM.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -4. The time now is 08:55 PM.