Michael1

HaxbySpeed, that's a beautiful old Chris Craft. What kind of speed are they getting out of it now?

Michael

bdubs

Haxbyspeed, NICE! Can you give a more detailed comparison of the LS swaps you have done? How does the boat handle, speed, acceleration, fuel consumption, and any other details you want to add?

I plan to put a pair in my next boat.

Thanks

Wasted Income

Thanks Bor...that rig of yours looks like it's going to be a WHOLE bunch of fun! By the looks of that exhaust piping, adding a couple turbos to that thing down the road should be snap. What hull is that?

Haxby...thank you as well. You are living my dream...lol. Your last post is exactly what I was looking for when I started this 11 page long thread...where are the LS motors in the marine world, who is using them, what kind of results are they seeing. I really appreciate it.

What hull was the 496 swapped out for the LSA? How does it run in comparison....you implied that it runs quite a bit better, haha. If the 496 in my Sunsation lets loose...I'm planning for the same thing....but it will be a "Poor Man's LSA" aka junkyard block, forged bottom end, good heads, boost, and a Megasquirt.

HaxbySpeed

One of the most noticeable differences is how smooth they are. They run like sewing machines but still have a great exhaust note. In white water jet boats I've swapped them for big blocks and small blocks, if you try to lug them like an old 454 they get chitty gas mileage and the performance isn't great. If you let them turn some more rpm they work great. The cylinder heads are killer but the engines are still relatively small so you need to let them rev to get the benefits of all that extra airflow potential. The 496 to LSA swap was in a 24 Baja. It picked up almost 10mph over a 496 HO. I don't know if the 496 combo was optimized but there was no denying the performance increase. That one was a 550hp version, we've got them turned up to 600 now. Check out the torque on the dyno sheet below. This one had a very low rev limit to try and keep things under control when the pump unloads in the white water but it's still making almost 550hp.

Wasted, a 408" 6.0 stroker is the best bang for the buck. Wiseco/K1 has an excellent quality rotator and with the stock untouched cathedral port heads and the stock truck intake it'll make an easy 600hp with only 5-6lbs boost. Call Bob Madara for the cam. You can go the DIY megasquirt route or just get a Holley HP ecm with plug and play harness. It'll run the stock coil packs, dbw or cable, and plug into all the factory sensors.

On the Blackfin we're running electronic controls and Livorsi Vantage view digital gauges. All plug and play

Wasted Income

Very cool!! That is encouraging, regarding the 496 to LSA swap. 10 mph increase on a boat is nothing to sneeze at. I am certain that I could have gotten more speed out of my LS jet boat had I experimented with impellers. I was only spinning the engine about 5200 at WOT. I would have liked to get it up around 6000 or so. I ran a GM 0411 PCM and tuned it with EFI Live and it worked flawlessly for me. I'm just starting to experiment with Megasquirt MS3x on my turbocharged LQ4 in my hot-rod...but the Holley HP stuff looks very attractive as well. Again the GM pcm has been working great, but the added features such as electronic boost control, progressive water/meth control, 2 step, wideband closed loop control, real time flashing without a roadrunner, etc are all interesting.

Do you have any pics of the LSA in that 24 outlaw? Would love to see them.

bor

Hi waste ,the hull is a 21 Phantom from the UK there normal outboards which I convert to inboard ,bought it as a unrigged hull but a few years old after looking at the stringers and transom wood found out that it was all done wrong so started to redone the whole hull on the inside also separated the both halves to start over it was a HELL of a job but the finish is awesome !









hope that the blackhawk drive will do it good on the hull and come close to triple digits ,but I think the acceleration would be the biggest event whit the duo props .

Nice too see that there quite a bit ls engines know in the marine !



TQ is in NM !!

bdubs

Bor, that 21 Phantom is going to fly. What are the specs on that LS engine? It's making gobs of torque.

HaxbySpeed

Nice! 550ft lbs and 557hp with a nice flat curve.

regalman4925

this thread has my attnetion! i have been looking into lsx swaps in the 2 cars i am building, now i am even more tempted to build a boosted lsx for the boat . can we get more info on what people are runnign for exahust, computers and harnesses and what you are using to program them. i know it was mentioned on one above. also keep in mind MSD has a conversion kit for around 700 bucks to switch a lsx to carb

Wasted Income

Regalman, when I started doing my swap 3 years ago, there was NOTHING out there for LS water jacketed exhaust, with the exception of the ski-boat manifolds. There were some nice logs available in Australia, but no distributors in the US. I contacted stainless marine, CMI, IMCO, etc to see what was available for LS exhaust...and was met with a collective "there is no market". Looks to have changed in the past few years.

I ended up finding a set of Ford 351 wet logs and modifying them to fit my engine. Had to drill a couple holes in the cylinder heads, and had to do some welding on the manifold ports to close them up a bit, but overall they worked great. Here's a pic of the ford manifold with the LS gasket layed over it for reference.







As for engine control, I mentioned that I tuned it myself with EFI Live, and Bdubs and I re-worked a factory 2500HD harness. It looks worse than it really was.