4.3 175hp

[MooseHootie]

is it so simple to just bolt on the 4 barrel intake and carburetor to make my engine 190 hp?

 

[Bondo]

Re: 4.3 175hp

Yep......

 

[Capt. T]

Re: 4.3 175hp

What about the cam? A marine mechanic who works on my boat told me its not worth the effort w/o changing cams.<br /><br />What's the general opinion: <br />w/o cam = good<br />w/ different cam = great<br /><br />Then of course how does a 4bbl compare to TBI?<br /><br />Since I was having the engine rebuilt (brain fade and freezing temps... ) at the time I should have insisted on new cam AND 4bbl oh well

 

[Capt. T]

Re: 4.3 175hp

Forgot to ask... what are the model #s for the carb and manifold?

 

[Walt T]

Re: 4.3 175hp

Don't worry about the cam, It'll be fine.<br />TBI is much better than carb any day.

 

[Lark40]

Re: 4.3 175hp

I looked up the parts numbers for the 1988 4.3 last year, and the only things different were the carb and manifold. Cam had the same number.

 

[Bondo]

Re: 4.3 175hp

Yep,<br />If in fact, We're talking about Mercruiser....<br />I find only 2 different cam #s... 1 for the Early motor,+ 1 for the motor with the counter-balance shaft(has an Extra gear to drive the shaft)......<br />The carb is the same right up thru... The Merc/Weber carb is The Exact Same carb as the Carter/Edelbrock..... 600cfms.... I bought a Carter Street/Strip Tuning kit,+ a Carter Rebuild kit.... <br />Exact Same Parts.....<br />Just Cheaper,+ Easier to Find.....<br />As far as Manifolds, There are 2..... 1 for the Pre-Vortec, with 12 bolts..... And the Vortec, with 8 bolt holes.... No amount of Drilling + Grinding will make 1 Fit the Other.... Vortec Intake Ports are .200" higher...<br /><br />I'll admit Any EFI will give you Better starts,+ Economy......<br />But, If you're looking for Power.....<br />Nothing Beats a 4bbl....<br />Especially if it's been Tuned & Tweeked

 

[bluewater19]

Re: 4.3 175hp

I did the swap on my 19ft bluewater. I bought a 4bbl setup off ebay. It gave me 4 mph on top end and better cruising economy. I have the holley setup off a volvo 4.3<br /> I also just bought a webber and vortec setup for my glastron. I am just waiting till my warranty is up in march to do that swap. I think on my 17footer it will be a real kick in the pants. I was told that the difference on the vortec motors is more noticable than on the pre vortec.

 

[Liquid_force]

Re: 4.3 175hp

Wow - extremely informative post.<br /><br />Just out of curiousity - on my '89 OMC 4.3 2 barrell anyone know about what I'd be looking at price-wise for a 4 barrel and manifold?

 

[Walt T]

Re: 4.3 175hp

You can probably find a used set on e bay. Overhauling the carburetor might run a couple hundred.

 

[Bondo]

Re: 4.3 175hp

Overhauling the carburetor might run a couple hundred.

Walt,<br />"The carb is the same right up thru... The Merc/Weber carb is The Exact Same carb as the Carter/Edelbrock..... 600cfms.... I bought a Carter Street/Strip Tuning kit,+ a Carter Rebuild kit".... <br />Aftermarket, I paid $25.00 for the Rebuild Kit....<br />And, $50.00 for the Street/Strip Tuning Kit....<br /><br />A Brand New Complete Edelbrock 600cfm, ele.choke, Marine Carb is Only $289.99......<br /><br />I suppose if you had to add Labor, It Could get that High.....<br />My labor is Free, to me, of course....

 

[Liquid_force]

Re: 4.3 175hp

Originally posted by bondo:<br />

<br />A Brand New Complete Edelbrock 600cfm, ele.choke, Marine Carb is Only $289.99......<br /><br />I suppose if you had to add Labor, It Could get that High.....<br />My labor is Free, to me, of course....

What about the manifold?

 

[bluewater19]

Re: 4.3 175hp

Check ebay,<br />Last winter I bought my 4bbl manifold with a holley on it for my 4.3 for 140+35 for shipping(cast iron is heavy!) You can get a new setup from edelbrock for 200 for the manifold and 289 for the carb. Check out www.summitracing.com You will also need thier calibration kit for the 4.3<br />I would just check out ebay they will have what you need. It just takes time.<br />I bought a brand new cast iron manifold for my 2003 voertec v-6 for 150.00 the seller was michagan motors. I was going to buy an edelbrock carb for mine but then I fornd a webber from a 1998 4.3 for 135.00<br />That is just my experince.<br />good luck

 

[bluewater19]

Re: 4.3 175hp

I was just cruising ebay and they have a 4bbl manifold for your boat. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2455397897&category=50442 I am in no way affiliated with the seller. But This is how I did mine.

 

[Liquid_force]

Re: 4.3 175hp

So a 97 vortec manifold will bolt right up to my '89 base model OMC ??

 

[denniz]

Re: 4.3 175hp

NO a Vortec will not bolt up.

 

[bluewater19]

Re: 4.3 175hp

You need a intake with 12 bolts on each side not 4 bolts on each side.

 

[bluewater19]

Re: 4.3 175hp

I just went back to my link and that is not a vortec intake. It might of come off a 1997 but that is a pre vortec motor. Count the # of bolt holes there are 12. I just did this on my 1991 bluewater and that is the kind of manifold it takes. It looks nothing like the manifold from my 2003 vortec motor. I know in the automotive 4.3's they changed heads in 1996 so the odds are that motor is a leftover that was put in a later model boat or had been replaced before.