michael-tuttiett
Cadet
- Joined
- Dec 9, 2013
- Messages
- 13
Hi Guys
I have been referred to the prop forum here.. Wondering if you can all offer some advice.. I will try to give as much info as possible.
I have a 1994 Cobalt 200. They are quite a heavy boat for a 20 foot.
The engine was a 190hp 5.0 V8 Mercruiser with an Alpha 1 Gen 2, 1.65:1 gear ratio and running a 19" stainless steel prop. Performance was not too bad but I always said if I re power I want to increase the boogie...
two weeks ago we snapped a conrod. The engine is history.
I'm going to buy a long block and bolt my bits to it. My mechanic wants me to upgrade to a vortec engine.
I would like to get the 5.7 vortec (which will require new inlet manif. and carb - all good). This engine will have significantly more hp - in the range of 280hp.
What I have discovered is that merc 5.7s and the higher hp 5.0s came with a 1.5:1 (or 1.47) gear ratio. As mine was the baby baby V8, it came with 1.65:1 gear ratio.
my question is this: If I get this 5.7 vortec, will I need to re gear the drive to 1.5:1 or can I compensate with a higher pitch prop? I'm not afraid of the cost of re-gearing. I can buy an upper gear set with the 1.5 ratio. I also don't want to destroy my drive. I know the alpha 1 will take 300hp but I'm afraid over propping it will stress it.
My other engine options are:
5.7 non vortec (still recommended 1.5:1 ratio)
5.0 Vortec
5.0 non vortec.
All are the same price for the long blocks.
Can someone offer some advice or put me in the right direction.
I have been referred to the prop forum here.. Wondering if you can all offer some advice.. I will try to give as much info as possible.
I have a 1994 Cobalt 200. They are quite a heavy boat for a 20 foot.
The engine was a 190hp 5.0 V8 Mercruiser with an Alpha 1 Gen 2, 1.65:1 gear ratio and running a 19" stainless steel prop. Performance was not too bad but I always said if I re power I want to increase the boogie...
two weeks ago we snapped a conrod. The engine is history.
I'm going to buy a long block and bolt my bits to it. My mechanic wants me to upgrade to a vortec engine.
I would like to get the 5.7 vortec (which will require new inlet manif. and carb - all good). This engine will have significantly more hp - in the range of 280hp.
What I have discovered is that merc 5.7s and the higher hp 5.0s came with a 1.5:1 (or 1.47) gear ratio. As mine was the baby baby V8, it came with 1.65:1 gear ratio.
my question is this: If I get this 5.7 vortec, will I need to re gear the drive to 1.5:1 or can I compensate with a higher pitch prop? I'm not afraid of the cost of re-gearing. I can buy an upper gear set with the 1.5 ratio. I also don't want to destroy my drive. I know the alpha 1 will take 300hp but I'm afraid over propping it will stress it.
My other engine options are:
5.7 non vortec (still recommended 1.5:1 ratio)
5.0 Vortec
5.0 non vortec.
All are the same price for the long blocks.
Can someone offer some advice or put me in the right direction.
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