Rocco

Prices for GM crate motors have come down. Last months Powerboat magazine had a good article about SB2 Nascar small blocks that Tyler Crokett was building for a Sunsation. I think any of these light, high reving small blocks would make a nice package in a sub 30 ft V bottom boat. The power to weight efficiency is getting in 2 stroke outboard territory ! The LS7 and the Nascar SB2 motors are dry sump motor that can spin some serious revs.
http://www.crateenginedepot.com/stor...ry_ID=2&Page=2

MTRiverrunner

I dont post here much, more of a lurker since I am not really an offshore boater. I had to chime in here since I am currently having a boat built with an LSA in it. The motors are redily available, as I have driven several LSA equipped boats already and my motor is on the way to my boat builder. These things are impressive to say the least, less than 500 lbs and way more power than the 8.1HO. I have been impressed so far with my test drives. They do burn A ton of fuel though, 40+ GPH at 4500 RPM (WOT) in a jet application. I bought mine for WAY less than the Raylar motor, fully marinized. I would of considered the Raylar motor, as I like the idea of more displacement, but I just couldnt afford it.

Raylar

Are the LSA engines you are running in these boats, closed cooling ? Since they are jets, I kinda doubt it. remember LSA engines as well as our LSM550's are all aluminum engines and as such are not designed to run raw water cooling! Even the GM leterature on these engines calls for closed cooling for the engine and oil cooler systems and with aluminum intercoolers they won't last on raw water long! Good luck doing so, we'll see how long they last in such applications in hard running hours.
Sure, it appears they are now available from GM Performance, heck GM has been making them faster than they can sell Cadillac CTS-V's to put them in!
These LSA engines only make 500 ft/lbs of torque in FULL BOOST not at part throttle so we'll also see how they last in cruising rpms where you noticed them drinking fuel like crazy, thats because they were in BOOST!
These 364 cubic inch engines will not get it done for normal size performance boats, especially deep-vees 24-28 foot types when they need to make 450ft/lbs plus torque at 3500-4000rpms for cruise! Trust me, if these engines had held up in Mercury's last three years of testing, Mercury would be selling them marinized and not their new 502 rpelacement!
But what hell do I know, I am just an LS marine engine manufacturer! You guys are the experts!

Best Regards,
Ray @ Raylar

shifter

We have been running a pair of LS7 427 smallbocks for over a year now at 650hp. Great engine. We are turning them hard, 6800 to 7400. This winter we are putting them up to 700hp. In the video you can hear a sound change, thats a shift.....

http://www.youtube.com/watch?v=MTH0PmLrx0U

pat W

Smarty

Sounds cool, looks cool, and most importantly it seems to be working based upon the race results, from the videos Rocco posted about your set-up on 11/4 in this thread. Who built your motors, would you disclose what it cost to get you those numbers (hp). Compression ratio?

I am an information sponge... (the transmissions and drives are interesting too, I realize that is your business, so post away, there may be a sales prospect lurking in this thread who does not know the benefits of your products..)

Thanks,

Stephen

Smarty

I understand Pepe and Jo Nunez (Pantera) have a 28' twin step boat; that size boat (easily-trailerable, fast, ...) to me would be a great pleasure boat application for these LS7 motors. I better get back to work so I can make the money to make my dreams come true!

MTRiverrunner

The motor that I have ordered and all the ones that I have seen are running closed cooling. I havent seen a motor go into a jet boat (at least the type that we run) without closed cooling for a long time.

The motor makes 545 ft lbs of torque at 4000 RPM and over 400 ft lbs from 1800 up, yes it is running in boost at WOT and burning lots of fuel. But at cruise (3000 rpm) it was burning 11-12 gph, about the same as an 8.1 in a similiar application. I have no idea how the motor will hold up (I am going to run it hard while it is still in warranty to make sure it is going to make it), but a lot of boats that I have been in have been running the 6L LY6 motors with Eaton superchargers. Those motors are holding up really well, and get excellent fuel economy.

When my boat builder put the first LSAs in a twin, some GM technicians came out to run the motors and get some data. The technicians had them run WOT for a sustained 5 minutes while monitoring all the engines parameters, and everything went fine, I am never going to run WOT for a full 5 minutes, but it is nice to know that the motor can take it. This is also the smoothest motor I have ever run. It is amazing how much less vibration and noise it makes than the 8.1.

Again, I think that the LSM550 looks like a sweet engine and I might of gone that way if it wasnt for the price, but for nearly half the cost I will have to take my chances with the LSA.

Brad Zastrow

Five minutes? I would hope they can last a lot longer than that. In the marine world we talk about hours and hours at WOT.
Some guys drive with a bungee cord on the throttles to hold them full open. LOL

Pismo10

Who did the motors for you?

Pismo10

Seems like the 454 LSX might be nice.