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FREDO FREDO is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 72
Default 305 c.i.d. HP topic


"FREDO" wrote in message news:...

"Short Wave Sportfishing" wrote in message ...
On 2 Oct 2006 13:55:17 -0700, "usafhg"
wrote:

Well, first, I must confess I don't know too much about recreational
boating engines specifically. However, there is much in common between
car and boat engines.


I've been watching this thread and found it very interesting.

However, I think I've got to chime in here.

In a general sense, yes, there is a commonality between car and
inboard marine engines.

Specifically, they are two different animals entirely.

I can't remember who, but somebody made the point that marine engines
are designed to run full bore all the time which is a high stress
load. High performance car engines (retail, not race) are not
designed to handle the same stresses for long periods.

The main reason is gearing. Marine engines are generally direct drive
through a drive train with no external transfer of energy by changing
gear ratios. Automotive engines don't develop their horsepower in the
same power band as marine engines and use different ratio gears to
provide mechanical advantage.

I'm sure one can take the 305 and bump the power - we've done it here
at the house with my oldest son's '92 Camaro RS audio/visual
masterpiece show car - it's not hard to bump the horsepower.

It's how the horsepower is applied that makes the different. It's
more a question of now that I have the horsepower, what the hell do I
do with it with marine engines.

In the case of a boat, you are dealing with a prop rather than a drive
train with variable or changeable gearing. Applying the power is an
entirely different set of challenges.


My son is currently in the process of rebuilding a 305. He is going to order a 335 stroker rotating assembly for it from these guys. http://shop.enginekits.com/osb/itemdetails.cfm?ID=341 It should only cost around 600.00 or so.