It would be nice if you could find an engine making 500-600 ft pounds of torque at 3,000 rpm and make a strong direct drive. Not a fan of the engine and I doubt the weight claim, but, it is not too far from 500lbft at 3200rpm. Most props can handle that if you kept the diameter down. Just saying. A...

With the 450 or so hp you think the engine is making (conservatively) the a 4 blade 80" R should work fine as long as its combined with the proper gear ratio to ensure your engine reaches the RPM it actually makes it's best power at. This is what JR is saying earlier. Likely your engine makes t...

Honestly looks unsafe to operate, let alone as a rescue machine. I know you probably worked hard on it, but, that's my take away from that short video. Is this machine meant to be a superior alternative to a standard airboat design? If so, can you list what areas it surpasses the traditional methods...

Russ, What do you think about a wider hull? I read somewhere he has less than 4’ of planing bottom. Wouldn’t such a narrow hull require more power than an 8’ hull to keep on a plane? Absolutely. Though I am unaware of way to add beam to a boat after the hull has been built. Excellent point for anyo...

swamper2 wrote:How do we lube the chain.

May not have to if use a modern chain. Ran ATV in Florida sand for years and years with zero lube. Adding lube killed their service life and ate up sprockets too.

I don't know what the owner is using, but, just a thought.

Add a 4th blade and switch to more gear, not less. A 2.68 with 4 blades will likely get what you need and not have to give up on anything. Sure, adding pitch will of course lower cruise rpm. But you will lose max thrust more than likely. Will you lose too much? Only you can say that. So, your plan i...

Congrats on getting your boat finished! Now, unfortunately, you are over estimating the amount of power your engine is producing by quite a bit. A 6.0 isn't going to make 500+hp at 5100 RPM. Let alone anywhere near 600. I would estimate in the 425 to 450 range at the crank but builds vary so your en...

Don't think the PCM actually cares about low pressure side. It's basically a lift pump for the high pressure pump on these engines.

Here's a few pics with a cracker in the back seat.

pedal is not an issue. Mine has been fully exposed since 2012 with plenty of time spent in some heavy rain both running and on the trailer. Works best with an in tank fuel pump. Can be the factory system that you use the FCM along with the PCM or just a standard 70 psi feed / return. I run factory s...

That exact prop, with a 4th blade instead of 3, 80 inches, 2.3 ratio was 12 degrees at tip @ 5200 rpm on my 122 ci engine when we tested it. I imagine your 502 with it's 388 extra inches should be able to achieve somewhere north of that. Given your using 3 instead of 4 blades. Maybe shoot for 15+ de...

very similar to the LTG 2.0 It's not similar to LTG at all. It is similar to LSJ. Use an LSJ solution or run an aftermarket EFI from any place that supports an LSJ and you will be set. Use that as your request to others for help so you get the right help. Again, nothing at all like an LTG. Forget t...

skinnypockets wrote:Russ, Thanks for the reply. Have you ever heard of Microsquirt?

Yes, been around for ages. Megasquirt / Micro squirt are all from same group.

Likely you can use since your engine is EFI. Just won't come with a harness.

It's an LK9 engine and very similar to an LSJ. Look for LSJ options and you are likely to get what you need. Being EFI makes your electronics (PCM) options a lot more varied as there are countless EFI systems these days. https://en.m.wikipedia.org/wiki/GM_Ecotec_engine#LK9 I think your power goals f...

You want a max rpm of 7k, but also want max HP at 7k too? This sounds terribad. Most of its use would then be way under the curve HP and then relying on a wimpy TQ curve. unless of course you intend to cruize at close to 7k. In that case, fuel wont last long and neither will the engine. Interesting...

Thanks for the input guys!! Russ that is one nice build! When I decide to start my build I’ll have more questions I’m sure. My build is going to based around reliability and fuel economy. I hunt in the swamps of Louisiana and we can be rough on boats down here, I need a boat that can take going ove...

If you keep the 2.4 naturally aspirated then it compares well to a 360. It will make more static thrust due to the longer and slower prop, but the difference isn't massive. I wouldn't even bother comparing them that way. So, if that's your plan, then think of the 2.4 ecotec as a good running 360 and...

If those numbers are of a test run on a fully rigged boat vs engine on a stand with a prop on it, then that's good numbers for sure. Would be nice to have someone post a video of that test since a 66 inch blade prop is darn short to produce that with. Can tell you are all smiles about how it perform...

So is that one of the key elements to making a DD work, making the blades shorter so that you can spin it past 3K RPM? I always thought 3K RPM was the limit. http://www.epi-eng.com/propeller_technology/selecting_a_propeller.htm It's fairly simple yet complicated at the same time. Like all things ai...

Old timers didnt run barges...lol And they ran light boats with aircraft engines, which is old technology that will do what you’re asking. Formula for success never changes. 6lbs of boat to 1hp and you will have an adequate performance experience. move that to 4lbs per 1hp and it's a do all machine...

So funny, this is exactly what a proper ecotec boat feels like and peoples reaction to is when they drive one. The ecotec makes a few hundred pounds more thrust though. Good to hear the LS DD is working well. I like the platform and hope to see more of it around. Always things that can be improved, ...

Since we are posting weights.... IMG_20190304_161440.jpg click picture and zoom in to barely see weight. it reads 454lb. full of oil, with ox drive, engine mounts, wire harness, ecm, catch can, radiator overflow tank, adapter plate and big turbo with steel center section. add 20 for radiator and mis...

Polaris GPS (android device, free, no network required)

Google Maps (no network or cell required if you download the maps for the area you run)

I have 16x8 Alumitech 3’ rake full deck over setup for bowfishing( lights, generator, front steer) 1/2 ploy bottom, its heavy. The boat and tandem axle aluminum trailer weight 4780lbs, 3/4 tank of gas. It has a 509 BBC edelbrock heads with sniper efi, roller rockers, ch-3 2.3to1 that about all i kn...

Consensus is get another 350 motor with a 2:1 for cheap and get on with it?

Yep, I agree. No messing with rigging or any other cans of worms when you go changing stuff.

Done and back to sliding.

I am sure the ecotec sales person will or would be devastated? LS engine comparison is far and away even more obvious which is better from a performance perspective.

I am not selling anything but knowledge.

Use it how you wish. Not meant any other way.