OMC 4.3 Help

[SouthernWolf]

I have a 1987 19'Chapparal 195 XLC with a OMC 4.3 inboard with a cobra outdrive. What is the horsepower of a OMC 4.3?<br /><br /> Thanks<br />Don Spears

 

[DJ]

Re: OMC 4.3 Help

Don,<br /><br />I believe that vintage would be a 160 ( 2 bbl. carb.) and a 175 for a four bbl.<br /><br />I believe that was before the "Gen II" heads which bumped them up to 190 and 210.

 

[Lark40]

Re: OMC 4.3 Help

I just bought a 4.3 OMC boat myself last week.<br /><br />It is a 1987 Starcraft 22' Islander 2210V. An aluminum cuddy cabin. These boats are still made and come with 3.0, 4.3, or 5.0 engines.<br /><br />The seller told me that the "V" in the model was for the GM Vortec engine, and that this engine has 205 hp. It has a Rochester 2bbl carb and uses 93 octane gas (or 89 with retarded timing).<br /><br />I have been looking at various websites, but so far can't confirm or deny his horsepower statement. <br /><br />It is a nice running engine.

 

[wileecoyote]

Re: OMC 4.3 Help

Sorry to tell you, but in 1987 there was no such thing as a "vortec" engine. Not only is it not a Vortec(unless it's been replaced) It's not even a balance shaft motor. I don't know where the fellow you got it from got his info.

 

[moderator1]

Re: OMC 4.3 Help

Moving to I/O questions.

 

[tylerin]

Re: OMC 4.3 Help

I have a 4.3 cobra 2 barl rochester.I bought this bought brand new in 87 it was advertized as 205 hp

 

[Lark40]

Re: OMC 4.3 Help

Wow! This thread has come back from April, 2002.<br /><br />The previous owner of my boat also told me that the horsepower was 205.<br /><br />But, since then I've read several postings stating that the horsepower of my 1987 OMC 4.3 Cobra with 2-bbl carb is 175. So, I've accepted that is fact, and that he was wrong. <br /><br />Can you tell me what evidence you have (book/brochure/etc.) that tells you 205 hp?<br /><br />Thanks

 

[tylerin]

Re: OMC 4.3 Help

Yes I bought a Galaxie of California (I guess there is another one somewhere else) It came with a small maybe 20 page illustrated booklet which I'm searching for as we speak. It stated the motor specs (spark plugs, timing, gap, dwell and hp etc) on one page. I bought the boat because I liked my friends who had a 3.8 or 3.9 w/ older type stern (stringer I believe) w/ 185 hp and his boat beats mine every time we have raced. (a turtle race) In 87 Galaxie was using the 205 hp as a selling point.

 

[pra51]

Re: OMC 4.3 Help

I can tell you what is on the OMC sticker on the flame arrester cover of mine.It is a 1991 4.3lt<br />HO.The HO means it has a Holley 4 bbl.on it.The sticker on it says 205 hp.So therefore the 2 bbl.<br />version is less.I'm not saying it produces 205 hp but that's what the OMC sticker says.One manual I have list the 2 bbl.version as 175 hp.

 

[tylerin]

Re: OMC 4.3 Help

You mean I can bolt on 30hp

 

[pra51]

Re: OMC 4.3 Help

I don't know if there is a difference in the cam or not,all I can go by is what the sticker says.I did notice that there is a difference of wot max rpm of 200 rpm in manual on the 2 bbl.version and the 4 bbl.version.

 

[Lark40]

Re: OMC 4.3 Help

According to my parts book, the cam is the same, and the only parts I see as different are the manifold and carb.

 

[tylerin]

Re: OMC 4.3 Help

I know on 350 chevy the diff between a 4 bar and 2 bar are the heads The ports are differant sizes. The 4.3 is the same as a 350 - 2 cylinders. I would like to know how many horses I have but it won't change anything. I would like to know if the dealer that sold me the boat was BSing me. I never did like that guy. He could sell ice cream to an Eskimo

 

[Lark40]

Re: OMC 4.3 Help

The 1987 OMC 4.3 Cobra Parts Catalog shows the same part numbers for the cylinder heads for the 2-bbl and 4-bbl versions. Only the intake manifold and carb have different numbers.

 

[tylerin]

Re: OMC 4.3 Help

Lark40 I believe you,I believe your book, but I just don't understand why, if the 4 brl carb is 205 the 2 barl is only 175. Thats 30 hp. This is a Rochester we're talking about.