Re: hull extension in progress with picks
Re: hull extension in progress with picks
The problem with aluminum blocks is that you should really use zincs inside the engine, even in fresh water. Of course, you could install a closed cooling system, but that's more weight and expense.
Oops, I think you need to consider what's more important to you.. whether you want a very high top speed or the ability to pull up skiiers and tow items. I think this boat is going to be pretty heavy too, so you'll want some serious boost for a good hole shot.
At the same HP rating, the BBC and stroker do not produce the same *output*. There's a big difference on their power bands, the graph of torque vs. time for each engine. Specifically the BBC will produce more torque near the low end of the power band and make its max HP at a lower RPM (HP = ((Torque * RPM) / 5252). The stroker can make the same HP, and as you've mentioned it's lighter, but it needs higher RPMs (by a lot) to make its full HP and you won't feel nearly as much seat of the pants power as the BBC at low RPMS, IE for hole shot or pulling things.
The racers use strokers because of how they drive their boats. They don't care about hole shot much, they just want light weight and good HP at high RPMs... which means a stroker is a good choice for them, especially since they don't mind rebuilding the engines often. High RPMs are killers for almost any engine parts... it's not that they're cheap/bad parts, it's that you're asking a lot from them. Generally, a lower RPM engine will last longer without a rebuild. Of course, since boats don't have transmissions, you'll probably have a lower top speed with a lower RPM engine than the high RPM boat, even if you have the same "HP" for the engine.
Keep in mind that the top speed of the racing boats is also dependent on the prop.. their props are for top speed and nothing else. So you won't get the same top speed as a race boat even if you have an identical engine unless you use the same prop, in which case you will have a garbage hole shot. Even then you have a different hull than most race boats, so you won't have their speed, period. While you have the race prop on, you'll hate driving the boat at any other speed than fast.
If you use a BBC engine, then you have a lot of torque available at the low end. You'll get a really nice hole shot as compared to the stroker, and you'll have a very responsive throttle because of the amount of water you can push quickly. You could put a high pitch (racing) prop on it and get a good amount of speed (and yet have a pretty good hole shot), or you could put a low pitch prop on and be able to jerk 4-5 skiiers out of the water at once
But, even with your BIG engine, you won't be as fast as some of the other boats, especially smaller or lighter ones. You won't match a race boat's top speed. You'll have the larger weight of the 454 over the 383.
One more thing... a stroker is usually "maxed" for non bolt on modifications, IE you can't do a lot more to it if you want more power, short of supercharging it or something similar, which won't buy you as much as you think for a boat. But a big block can be upgraded with performance parts and tuning just like a stroker was upgraded from an SBC. You've got somewhere to go if you want "more". You can pick from several (6-7?) generations of BBC if you want more HP too. The older ones are cheaper, the newer ones have incredible power.
So I recommend you figure out what you want to do with the boat, then that'll dictate your engine choice. It's easy to think of race engines as "the best" boat engines, but that's only true if you're racing...
Erik
