OMC Repower

metro3pilot

Seaman Apprentice
Joined
Aug 12, 2007
Messages
40
I have an 87 Omc Cobra 4.3 L , 2 bbl, 175 HP

while at Lake Powell last week my engine started to idle rough, changed octane same thing and on the last day it sounded like it had an exhaust leak and lost the hole shot but would plane out with about 3 mph less on the top end got it home and did a compression check and I have 2 dead cylinders, it's not burning any oil, but has zero compression on 1 and 3 with serious damage to plugs from detonation so I figured the pistons are probably gone as well

I can have the engine rebuilt and tuned up to 210 HP with a 4bbl.

my question is this : what advantage can I expect from that 35 HP with the same outdrive gearing and prop ...should I run a higher pitch prop ? or possible save some cash and have it rebuilt to 175 HP with the 2 bbl
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,083
Re: OMC Repower

Ayuh,.......

Bolt on a set of Vortec heads, with that 4bbl.+ you'll be in the 215/220hp area,.....

Then you'll need a Couple inches of Prop to keep up........
 

JCF350

Lieutenant Junior Grade
Joined
Oct 21, 2007
Messages
1,149
Re: OMC Repower

If 175hp was enough to meet your needs then stay with the 175 version.
Otherwise it's "how fast do you want to spend?":)
 
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