5.0 OMC Carb Swap Question

arileyosu

Recruit
Joined
Apr 1, 2011
Messages
4
Hey all,
I am looking for a little advice here. I have a 1992 Four Winns 190 Horizon with the 5.0 OMC. The model number on the motor(502BPRAMH) tells me that it is the standard output model, but Four Winns says that they only put the high output version in that boat(according to the brochure). Looking at my handy-dandy OMC service manual, the only major differences I can tell in the standard and high output motors is that the HO has a little bit bigger 2bbl carb at 490CFM instead of 300CFM and the firing order is different. All other specs, that I can tell are identical. I found a remanufactured HO carb for $250. In the opinion of the iboats elders, is it worth the money to swap to the HO carb? Will I notice any difference on a carb alone? Let me know if there is any other pertinent information that I have left out that may lend itself to a more accurate interpretation. Thanks in advance.

**All other aspects of the boat/motor/drive are original**
 

etracer68

Ensign
Joined
Oct 11, 2009
Messages
906
Re: 5.0 OMC Carb Swap Question

The firing order should be the same, on all small block chevys. As far as the carb goes, the intake man may be differant. Im sure someone else may know if the carbs are the only thing differant on the two motors.
 

arileyosu

Recruit
Joined
Apr 1, 2011
Messages
4
Re: 5.0 OMC Carb Swap Question

This is a Ford 302. I don't have a HO motor to reference so my only source of information is the OMC factory service manual. The firing order is the same for the 5.0L HO and the 5.8L(1-3-7-2-6-5-4-8) of that model year but different for the 5.0L standard(1-5-4-2-6-3-7-8). Timing and fuel requirements, distributor specs, spark plugs, pcv valves are all the same. (Again according to the manual.)
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Re: 5.0 OMC Carb Swap Question

That is a sizeable CFM jump, and the new carb may need different tuning if the engine is not demanding extra flow now. What exactly are you wanting to accomplish? Does your engine stop pulling at a certain RPM now?
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,524
Re: 5.0 OMC Carb Swap Question

In the opinion of the iboats elders, is it worth the money to swap to the HO carb? Will I notice any difference on a carb alone?

No, 'n Nope....
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Re: 5.0 OMC Carb Swap Question

And, Yes, what he (Bond-o) said... ;)

There is more behind the HO than just CFM.
 

arileyosu

Recruit
Joined
Apr 1, 2011
Messages
4
Re: 5.0 OMC Carb Swap Question

Thanks, that's the answer I was looking for. I just wanted to make sure I wasn't missing any easy horsepower.
 
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