4.3 Vortec Mercruiser intake question
 

OK, My intake manifold popped (two barrel 8 bolt 4.3). As long as I have
to replace it, I would like to explore a few higher HP options.
Ebay has a bunch of Throttle body fuel injection manifold for auto use for
sale. Could these be used in a marine application? What type of conversion
would have to be done( does it need an ECU etc)? How many HP would it buy
me??


--
John

WWW.Firewalk-NC.com

"Be the change you wish to see in others"

----Gandhi

I think the fuel injection would work if you can figure out where to put the
oxygen sensor. You can't put it in the exhaust where it would get wet from
the water pump output. You will definetly need an ECU. May have to have a
new EFI engine exhaust manifold.

I would save the money and install a 4 barrel intake and carb (make sure the
carb is marine) instead. That will give you more power and will be a lot
cheaper.

What is the boat and what year?

--
Tony
my boats and cars at http://t.thomas.home.mchsi.com
"John A" wrote in message
.com...

OK, My intake manifold popped (two barrel 8 bolt 4.3). As long as I have
to replace it, I would like to explore a few higher HP options.
Ebay has a bunch of Throttle body fuel injection manifold for auto use for
sale. Could these be used in a marine application? What type of
conversion
would have to be done( does it need an ECU etc)? How many HP would it buy
me??


--
John

WWW.Firewalk-NC.com

"Be the change you wish to see in others"

----Gandhi

I agree, EFI is way more work than you want to tackle.
Look for an aluminum 4 barrel intake and put a small holley or quadrajet on
it.

"tony thomas" wrote in message
news:mtzbe.17818$c24.1554@attbi_s72...
I think the fuel injection would work if you can figure out where to put
the oxygen sensor. You can't put it in the exhaust where it would get wet
from the water pump output. You will definetly need an ECU. May have to
have a new EFI engine exhaust manifold.

I would save the money and install a 4 barrel intake and carb (make sure
the carb is marine) instead. That will give you more power and will be a
lot cheaper.

What is the boat and what year?

--
Tony
my boats and cars at http://t.thomas.home.mchsi.com
"John A" wrote in message
.com...

OK, My intake manifold popped (two barrel 8 bolt 4.3). As long as I
have
to replace it, I would like to explore a few higher HP options.
Ebay has a bunch of Throttle body fuel injection manifold for auto use
for
sale. Could these be used in a marine application? What type of
conversion
would have to be done( does it need an ECU etc)? How many HP would it
buy
me??


--
John

WWW.Firewalk-NC.com

"Be the change you wish to see in others"

----Gandhi

Consider this: it takes 12-15 more HP just to gain 1mph!


"John A" wrote in message
.com...

OK, My intake manifold popped (two barrel 8 bolt 4.3). As long as I have
to replace it, I would like to explore a few higher HP options.
Ebay has a bunch of Throttle body fuel injection manifold for auto use for
sale. Could these be used in a marine application? What type of
conversion
would have to be done( does it need an ECU etc)? How many HP would it buy
me??


--
John

WWW.Firewalk-NC.com

"Be the change you wish to see in others"

----Gandhi

In article ,
says...


Problem is most 4 barrel auto intakes are designed to make the power
in a higher RPM range. You need a performance intake designed for your
boat application. If you know your typical 'Wide Open Throttle' rpm range
for your motor/boat/propeller combination, I would start with Victor Edelbrock,
and see if his company makes something suited to your purpose. You need
a 'dual plane', or else a single plane that has long narrow runners for
more boost at the lower end.



OK, My intake manifold popped (two barrel 8 bolt 4.3). As long as I have
to replace it, I would like to explore a few higher HP options.
Ebay has a bunch of Throttle body fuel injection manifold for auto use for
sale. Could these be used in a marine application? What type of conversion
would have to be done( does it need an ECU etc)? How many HP would it buy
me??


--
John

WWW.Firewalk-NC.com

"Be the change you wish to see in others"

----Gandhi

On Tue, 26 Apr 2005 16:34:53 GMT, "John A"
wrote:


OK, My intake manifold popped (two barrel 8 bolt 4.3). As long as I have
to replace it, I would like to explore a few higher HP options.

I put a super charger on my 4.3 as a kid. I ringed 700hp out of it,
and was the envy of all my class mates.

"tony thomas" wrote in message
news:mtzbe.17818$c24.1554@attbi_s72...
I think the fuel injection would work if you can figure out where to put
the
oxygen sensor. You can't put it in the exhaust where it would get wet
from
the water pump output. You will definetly need an ECU. May have to have
a
new EFI engine exhaust manifold.

I would save the money and install a 4 barrel intake and carb (make sure
the
carb is marine) instead. That will give you more power and will be a lot
cheaper.

What is the boat and what year?


After doing a lot of research came up with the following solution. Since I
need a manifold anyway I ordered a four barrel manifold from
MichiganMotorz.com (anyone have any experience with them?) they have by far
the best prices. I plan on adding an adapter plate from CFM-tech.com.
Using my existing carb and the adapter and 4 barrel manifold should add
about 15 hp. Not a lot but just maybe enough to get my fat butt out of the
water a little quicker when skiing.......
Chaparral 18 ft I/O 1997...

"harry.krause" wrote in message
...
On Tue, 26 Apr 2005 16:34:53 GMT, "John A"
wrote:


OK, My intake manifold popped (two barrel 8 bolt 4.3). As long as I
have
to replace it, I would like to explore a few higher HP options.

I put a super charger on my 4.3 as a kid. I ringed 700hp out of it,
and was the envy of all my class mates.

OK I'll bite - what kind of supercharger did you use? how much boost? how
long did the engine last before it blew?

Sorry, but you are not going to get 15hp by putting your original 2 barrel
carb on a 4 barrel intake.

"John A" wrote in message
. com...

"tony thomas" wrote in message
news:mtzbe.17818$c24.1554@attbi_s72...
I think the fuel injection would work if you can figure out where to put
the
oxygen sensor. You can't put it in the exhaust where it would get wet
from
the water pump output. You will definetly need an ECU. May have to have
a
new EFI engine exhaust manifold.

I would save the money and install a 4 barrel intake and carb (make sure
the
carb is marine) instead. That will give you more power and will be a lot
cheaper.

What is the boat and what year?


After doing a lot of research came up with the following solution. Since
I
need a manifold anyway I ordered a four barrel manifold from
MichiganMotorz.com (anyone have any experience with them?) they have by
far
the best prices. I plan on adding an adapter plate from CFM-tech.com.
Using my existing carb and the adapter and 4 barrel manifold should add
about 15 hp. Not a lot but just maybe enough to get my fat butt out of
the
water a little quicker when skiing.......
Chaparral 18 ft I/O 1997...