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454 upgrades, worth it?

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805HD

Regular Contributor
So I have my engine pulled apart, basically just trying to freshen it up. Bearings, rings, seals etc.

Been wondering what upgrades are out there that will offer a little more power that are worthwhile. Is there any point changing out to a mild cam? Intake manifold? Heads? Not trying to build a rocket ship but if any upgrades are ever going to be done. Now is the time to do it.

suggestions?!

boats a 1988 so I’m assuming the engine to be the same
Engine serial# B558933
454
alpha 1
through hull exhaust

thanks in advance
 
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Worth hopping up the engine yes, but if you are pushing a gen 1 alpha with a 454 I wouldn't put anymore power to it. Seems like they only ran a alpha behind a 454 for a handful of years with some issues. Typically they seem to hold up if you take it easy, so no real point in making more power unless you upgrade drive to a bravo.
 
Again, boats do not behave like cars. Dumping several thousand dollars into engine "performance" usually results in almost immeasurable "seat of the pants" gains.
If you increase the horsepower ten percent let's say, that might give you a knot or two better top speed. Worth it? You tell me.
What will help most is displacement. If you bump your 454 up to a 502, yes you'll have more power to swing a prop with more pitch. However, much depends on hull shape, cargo, weather and sea conditions, blah blah blah. You're constantly pushing the boat up out of the hole it makes in the water, so you reach a point where more power simply does nothing to make the boat go faster. This costs much more in fuel consumption too.
So ask yourself if it's money well spent or should those dollars go toward beer, suntan lotion, Ray Bans, Doritos, gas, etc.
 
You can certainly find ways to better the performance of the 454, just note that you may be on borrowed time with an Alpha drive behind a BBC engine.
 
Thanks for the responses guys. I hadn’t really thought about it but it’s true. With that alpha1 more power is probably not a good idea. The boat is a 23 foot cobalt, an old Condurre that is primarily on the river and in lakes. It’s plenty fast, was just throwing around the idea of it being a bit faster but considering the age of the boat and money invested already I wouldn’t want to gain power at the expense of a outdrive.

i think I’ll just leave her alone and enjoy as is.
 
805HD said:
Thanks for the responses guys. I hadn’t really thought about it but it’s true. With that alpha1 more power is probably not a good idea. The boat is a 23 foot cobalt, an old Condurre that is primarily on the river and in lakes. It’s plenty fast, was just throwing around the idea of it being a bit faster but considering the age of the boat and money invested already I wouldn’t want to gain power at the expense of a outdrive.

i think I’ll just leave her alone and enjoy as is.
Click to expand...

When Merc starting using 454's with Alpha's it was a vast improvement in overall performance. But soon it became apparent based on the upper gear cases coming apart that the increase in TORQUE was not good. They then installed/made available heavy duty gear sets and that helped but then in 1989 ish they released the Bravo 1 which simply solved the problem.

Merc had many higher horsepower engines in the 80's with alpha's but most if not all were small blocks. Back in the mid to late 80's they had many 320 hp fuel injected small block with alpha's that worked perfectly well but the lower torque produced was key.

I have worked on a few 80's 454/alpha's and they were a blast to drive but NO hole shots.........70+mph in 23 footer!!

If you were around back then Merc used the TR/S drives for big power high torque engines. Huge drives that weigh a ton and have no shifting capabilities and need a transmission. I think the drives weigh in around 150lbs + alone..................ugh!
 
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Ah, by they were the nicest stern drive setups ever made! Beautiful, smooth shifting without a CLUNK and no damn shift interrupter either!.

And--theoretically, the upper and lower gear cases COULD be the strongest design for the space allowed.

Jeff
 
the TRS drives were the only viable option if you had a big block torque monster and didn't want to spin a jet pump....

Anyhow, keep the 'peanut ports' on the heads....you really don't want the big rectangular ports.....
 
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