Chaparral 300 with twin 5.0Gi and SX

Looking at a boat,

the Chaparral 300 is about 9,500# it has twin 5.0Gi and sx drive. Will i be miserable with those. I think they are rated 250hp each?.

I currently have a old Chap 278 with twin 4.3 and Alpha one. And it plane pretty quickly.

I have 3 kids + the Lady!

Thanks!

Re: Chaparral 300 with twin 5.0Gi and SX

My father had a 2001 Chap Signature 300 with twin 5.0EFIs (Mercruiser rated them at 240hp) with Bravo 2 drives. It performed well. He later broke one of the B2 drives and converted it to B3s. It performed GREAT after that. He LOVED it.
It would NOT plane on one engine with the B2 drive, however. Not sure if he ever tried it with the B3, but I doubt it planed on one engine that way either.

He pretty consistantly got 1.5mpg when cruising at 25mph.

Re: Chaparral 300 with twin 5.0Gi and SX

Are b2 equivalent of sx drive?

Re: Chaparral 300 with twin 5.0Gi and SX

eleblanc said:

Are b2 equivalent of sx drive?

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Essentially yes. Both are single screw as opposed to V-P DP and Merc B3, which have dual, counter-rotating props

Re: Chaparral 300 with twin 5.0Gi and SX

TilliamWe said:

He pretty consistantly got 1.5mpg when cruising at 25mph.

Click to expand...

With the b2 or b3?

Re: Chaparral 300 with twin 5.0Gi and SX

We had a 30' Sportcraft flybridge with twin 5.0 liter engines with 270 VP drives. It was a fast boat and we on occasion pulled skiers. It was fast out of the hole and ran 35+ WOT.

I think you would be happy with the engines and drives and the fuel economy.

We now have a 32' (see avitar) with VP sx drives and 5.7 engines (250hp). It is a bit faster, but at 12,000 # it is slow out of the hole (i.e. no skiers).

erie_guy
Port Clinton, OH

Re: Chaparral 300 with twin 5.0Gi and SX

I have a 293 Cobalt with 5.0 Gi's and duoprop drives. I believe the dry weight is around 8900. She is a low 50 mph boat. I usually cruise at around 3200 rpm and 30 knots. That's where she seems to be the happiest. This boat planes out almost as fast as my '94 252 bowrider with the single 7.4.

I was also concerned about the power, but was told by numerous people who know more than I do that it wouldn't be an issue. The appear to be correct as I have no complaints about power or speed.

Re: Chaparral 300 with twin 5.0Gi and SX

eleblanc said:

With the b2 or b3?

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With the B3s, mostly.

B2 is a single prop drive that has a "huge" lower unit allowing it to turn props up to 22" ( I think 22, at least 20") in diameter. So for a cruiser, it's superior to a VP SX, because it has more blade area. But the props for a B2 are very expensive.

You aren't going to run 50mph, though. Think 45 top speed on a great day. 42 more likely.

For the boat you are looking at, I am sure the VP SXs are fine, but if it had DPs you'd have absolutely NO worries.

Re: Chaparral 300 with twin 5.0Gi and SX

Sorry for all the questions, i'm kinda new to the boat world and all the mechanics and different engine and drives. But from what i understand a SX drive would be a upgraded Alpha drive? Or something between a Alpha and B2.

I ain't going to be driving that thing flat out. as long as i can cruise easily fully loaded somewhere between 30-33 mph and get decent fuel consumption i'll be happy. I guess a B3 would provide higher cruise speed at same consumption?

TilliamWe said:

With the B3s, mostly.

B2 is a single prop drive that has a "huge" lower unit allowing it to turn props up to 22" ( I think 22, at least 20") in diameter. So for a cruiser, it's superior to a VP SX, because it has more blade area. But the props for a B2 are very expensive.

You aren't going to run 50mph, though. Think 45 top speed on a great day. 42 more likely.

For the boat you are looking at, I am sure the VP SXs are fine, but if it had DPs you'd have absolutely NO worries.

Click to expand...

Re: Chaparral 300 with twin 5.0Gi and SX

An Alpha One is the simplest drive out there. It uses a dog clutch (which is to say that it just clunks into gear) in the lower unit of the drive. All VPs and all Mercruiser Bravo Searies have a cone clutch, that shifts in the upper unit of the outdrive. They shift smoother and can handle more weight and power.
So a VP SX drive is like a Bravo 1. Good all around drive. Bravo 2 was specifically aimed at "BIG OL' HEAVY CRUISERS". Large diameter props = equal lots of blade surface = lots of prop thrust to get the big boats moving. It has fallen out of favor in the past 10 years due to the Bravo 3. The Bravo 3 has the counter rotating propellers, like a VP DuoProp (DP for short). It does most all things better than a single prop outdrive. It's just a lot more expensive to buy, and propset changes are even higher priced ($1200+ for brand new props, $600 for used on Ebay, maybe a little less, if you're lucky), with much more limited options.
You will not "easily" cruise at 33mph loaded in the boat you described. Most boats in that size range "cruise" in the mid to upper 20s. And that's not a bad thing.