true, once you cross over that power level, boosted is the only way to make it,,,,but makes my ass pucker thinking about keeping each cylinder equally happy when laying in the throttle lol

Why don't more use the LS7 (427) based LS motors? At least for a boat it would help with displacement. Seems a SC version would be a nice package.

I keep wondering how these would be if you just wanted light weight and smaller footprint as a replacement for HP 500's. For the ski boat world PCM says it will give you a 5 year warranty on them.

http://www.gmpowertrain.com/engines/...0Sheet.pdf?v=2

Joe you would love this, I seen one builder selling 650 HP 540 cu in motors. Shows the dyno run, long tube headers, no accessories even running a electric water pump.

Add water pumps, alternator, power steering pump, manifolds, wet exhaust,,,,,, I would like to see the numbers then.

I was thinking about the "no replacement for displacement" comment and remembered I had a graph of the dyno results from my old 509s (HP500s w/Marine Kinetics CAM w/AFR heads) to compare against Dennis' 416CI LS3 motors from Swap Shop. I added the numbers from his dyno sheet to compare.....

https://cimg2.ibsrv.net/gimg/www.off...547ceaaa3.jpeg

242LS, interesting graph. The torque and HP advantage from 4-5k is pretty decent on the 509. Looks like the 509 runs out of cam/valve train past 6K. But I would not think you would want to spin a BBC boat motor much past 6K anyway. Beyond that there is obviously so many many other factors than just displacement. There are some pretty cool comparisons of stuff like this on "motortrendondemand" specifically the engine masters series. You can watch them for free with advertisements. But I pay the $4 a month for the membership. There is so much content. I hardly even watch regular TV anymore.

John

Cool graph to compare.Thanks.

Speaking of 32 Sunsations vs engines Any of you guys remember Domscott from Speedwake days? Older nonstepped 32 Sunsation Dominator. 502's/fact rect heads other than springs and etc/ 741 cams/ lightning headers / small 174blowers/nose cones on the Bravo's and Sternjack's of all things ran just over 100.

Yes I met Scott may years ago at the Sunsation Rally. Think the boat was bright green and black. Your details sound right and yes he said it would run 100. Personally I didnt really buy it, but whatever. Like ive already said. The 509's in the Sunsation I had dynoed at 650hp(dyno headers, no accessories) and it did 92 as an average. You can do the math.

Thats also when/where I met Bailey with procharged 502's that I mentioned earlier.

John

I looked at those to and decided by the time they take over my BBC you are spining them pretty good.

I was thinking in a boosted application the 427 would be a nice base to start with. The link is to a boosted 6.2 that has pretty good low end TQ so I would think the 427 would do well. Mild's (Joe) boosted 454 do real well.

Thinking out loud, the LS offers variable cam timing, more modern design, and small weight/ size.

In anything over 30 I don't think it would matter but in something like my little boat I do think it would. Looking at the picture of the LS in the Sunny the distance between the headers were NICE. Does seem the cost is a issue.

Yes I remember him well from Sunsation's forum and the Sunsation rallies. The Sternjack's were a pucker factor 10. Boy knew no color other than lime green.

A true 100+ MPH Dominator was Dragonheart.

Yes the Dragonheart. That was the fastest Dominator back then. Not sure about now. My personnel experience is that low 90's can be pretty hairy with not alot of hull left in the water. I cant imagine going 110 or whatever it did! But I guess with more power one might be able to use less trim and have the boat be more settled.

John

well the lsa take-off's are running about $1200 on ebay from what im seeing lately,,,they were alot cheaper and plentiful when gm was replacing them under warranty. The reason for them being replaced thru gm was due to the spring isolator making noise, which everyone just installed a solid one.
So then you need the lid with heat exchanger brick, a new camaro zl1 is about $600, sometimes you can find the cts-v take offs from one that upgraded to the zl1 lid for a few hundred.
Then you need fuel rails for the lsa blower $285
To adapt the blower to a cathedral port head, you need the adapters which are about $175
Used take off injectors from a cts-v or zl1 should only be about $100
On ebay you can get front mount heat exchangers and pump for under $200 with all the hoses.
then to run your accessories, lets say on a truck, LSX innovations makes a real nice and simple setup to drive everything off one belt for $325
Thats about it really

almost at 10 posts!

This weekend i just swapped my original Merc 377 (6.2) out of my 2009 Pachanga for a new all aluminium GM crate 6.2 Supercharged LSA engine (556HP & 551TQ). Used original Merc bell housing with a Ram Clutches conversion flywheel ($300ish) & the original motor mounts with LS adapter mounts all in the factory holes into stringers. I'd add pictures but I'm too new I need more posts lol. Anyways all bolted up easy...

Still waiting on headers & a few other things to finish up. Or if your asking it is a GM Performance crate engine yes.

I have been looking at those motors, did you buy the marine version? Link to where you got it?

No I did not buy the marine version as the marine unit has the less desirable intercooler. The motors are identical from the block to crank, rods, pistons, cam, heads, etc... Only information i couldn't find out about is the head gaskets. I'm running a closed cooling system as I'd think most would on an Aluminium block so there will be no issues with raw water/salt corrosion.

are you going to run wet exhaust? If so, what is it?

Yes, CMI marine E-Top header

Custom Marine Inc. - It's All About Performance - Header Applications - LS E-Top Headers

A NA 680hp 6.2 liter would be a dog in a decent size boat and you better have dry headers on it with the amount of cam that would have. Need to make torque in the midrange, i dont think they really need it at 2500 because everyone turns at least 3000 just putting them on plane but to really accelerate need to make equivalent or better torque in the 3500-4500 rpm area than the 502 etc they are replacing. Might be able to match that at peak but not below there with wild cam timing. Boost is the answer I think, Im doing LSA topped 6.0s in my Donzi