And fvck the know it all haters. Like to see these twats do what you guys did.

If the old compass is a Ritchie, it might be eligible for their factory reconditioning program. It’s probably cheaper than the new compass.

UNACCEPTABLE! Kidding love you guys , keep killing it

You can get different pich props ab get a better rpm

Always good to see your wife put in some hard work and skill.

And inefficient.

They are LUGGING. That is a lot of load for that rpm level.

​@@TheBCninja I bet that if @Texas Speed see this video they already called him regarding constant full load at those RPMS.

And you are using Marine Plywood on your table?

Teak wood will Grey over time. That is normal.😅

Yeah you definitely want those engines singing 5000+ at WOT. Lugging them down like that is harmful

I was going to comment the same thing, bow is way too low and killing speed and economy

It's not a problem of trim tabs, but of lack of weight at the stern...the boat is built for heavy diesels.

​@valefur72 It has the wrong props. It's doing 10mph at 1000RPM. LOL!

Yep he trimmed it wrong pushed the bow down

Lift the tabs your plowing the bow

His bow is plowing because he is missing a few thousand lbs in the stern.

Never wear shoes on board on a yacht 😇🙏🏻

@@demagescod9657 Well yes, but he also seemed to have the trim tabs deployed by a lot. Which is the very opposite of what you want with too little relative weight in the rear, of course.

Trim tabs were definitely down lmao

These engines are definitely running way below their max. power and probably also max. torque rpm. I don't know the cam setup but I'd guess peak power will be above 4000 rpm for sure. Props with less pitch will definitely improve the boat's perfomance big time.

Yes, low RPM and high engine loading with the current prop. Equivalent to shifting your car into top gear and climbing a steep grade. The recipe for detonation and catastrophic failure.

Exactly! It’s so close, just needs some fine tuning!

How do you figure too large diameter though? Thats not necessarily the case if you ask me, its the gearing and the pitch.... You need blade area to handle the power transfer good enough after all.

Absolutely #1 rule no shors!!!! Deck shoes only!!!

No shoes!!!

Top Siders from Sperry

Hope he reads this post and follows your advise.

it's clearly geared to go downhill

Definitely the wrong props on there, he should be seeing double that RPM

Smaller diameter props with same/slightly higher pitch might increase efficiency too. The old props are probably for torky low reving motors. I dont think the torque curves are anywhere near a diesel motor on such a low rpm. People forget that torque and horsepower varies a lot on different rpms. Shouting out 1500hp measured at 6000rpm makes little sense when you have half that at 2500rpm.. When done properly you choose an optimum cam for the most torque at cruising speed rpm if overall efficiency is the most important factor.

On these boats a bigger diameter prop is in most configurations beter for efficiency and hole shot . I don’t know the gear ratio but it looks like hey needs to drop about 10 inches of pitch. Or change the gear ratio . Running this setup full trottle with to much pitch on the props can and will hurt the engines !

agreed with the comment here, you may want to talk to a motor shop about the correct props for these new motors

Amen brother- Boat needs to stay -So does Chelsea- she cleans way better than the boys, $10 bucks says she’s the perfectionist of the B is for Boat crew

Also- next spring - I’m hoping for the boat-a-con -

Pumped for you guys!!

All that wood needs a few coats of marine varnish. It will protect it all so much better.

I don't even own a boat and I want to see more

Agree, and the plastic might not be compatible with gas fumes long term. That said, a 3d printed prototype is great to make everything perfect before you spend machinist money!

a turned delrin part would be ideal.

they are fabricators. They can make it themselves. A solid block of UHMW and they can just cut it out. I am not a fan of 3D printed parts. I have had ones that i bought melt and self destruct.

Yeah this happens even with my portable Yamaha fuel tanks for my outboard powered boat. As they age the plastic breaks down a little and lets vapors & fluids out (near the fuel gauge/sender) if the tank is 100% full.

Sendcutsend wouldn’t be too expensive, and they already have a cad file for it

who would have thought??? 🤣

Agreed! Getting props though to reach WOT for those motors (5000-6000 rpm) would take a good bit of time to get that boat on plane- would you agree?

@@jackdaily3383 I haven't seen the dyno graph for those engines but I will guarantee you texas-speed has one. Those props should be pitched for right dead nuts in the middle of that camel hump. I will guarantee you it'll get on plane three times as fast as it does now. For some reason I'm thinking 6000 RPM as well. I'm sure those things can handle 8 but six is probably where they peak. What blows my mind here is all the money that was thrown around including given to Texas Speed yet no one questioned the tire size or the rear end gears of this boat.

He has transmissions though so need to account for that too. To elaborate he should prop the boat for the hull and plane speed he wants to run and should have gotten the trans' with the reduction ratio required to be in range for the ideal prop speed.

​@@mrjgueret100% this. There is no way he made it to peak torque at that low of RPM.

Yeah, it's weird that they had the solution and then immediately abandoned it. 😄 what they did worked but the drill worked first. Lol

This...those motors are being strained. They are not designed to have that much load at that low of an RPM. Definitely going to hurt the engines in the long run.

THIS. ^^

When these engines wear out like start banging rods out lugging them so hard he will be sponsored to get 2 new ones! Duh

AGREE….NEEDS REVS! 2600RPM is diesel revs

Yes, 3300-3600 is great cruising rpm on my twin 7.4L

IKR, it's rare to see all the little finishing touches done on BIFB, normally the projects are "complete" them they just vanish. This sort of final video is much more satisfying.

Even if only 10 minutes.

Hell yea that boat can do a lot more it could do that with one of those motors

yea that thing needs changing gear ratio and props for gasoline engine. 2.5k rpm is to low. i converted my boat from gas to diesel it vent from 1:1.95 to 1:1.158 and prop from 21 to 17 pitch. now with 120hp diesel max speed is 24 miles crosing speed 15-18 and burning like 8 liters of diesel per houer.

I was about to say just this… those coarse brushes had to have left a grain in the deck

Life's too short for varnishing, especially cheap Ikea stuff. Back to the workshop and spray them with clear epoxy. They will last a lot longer as well.

NB epoxy isn't UV stable. Its good for water intrusion, but needs to be protected from UV by some sort of varnish or pigmented top coat.@@jean-pierredeclemy7032

He also should probably be using the proper plywood and other boards. Teak is a lot more expensive than regular wood but there's not much better for marine applications

Don't spray epoxy. It's terrible with UV exposure. Use spar urethane, or something else that's meant for the outdoors. Regardless, you'll likely need to retreat it every couple of years.

Yes, I was wrong, West System recommend a two pack polyurethane @@sfallier

Yep. 100% needs to happen

Ls boats can go past 4k easily. I'll have to check next time I'm out

I think for something like this yacht, 3000 is decent. He could gear it down a little more to get more speed out of it, but then at high throttle the engines would be revving too high at a cruise, and that would reduce the life expectancy of the engines and burn more fuel at cruise speed, I'd think. So not only is this going to extend the life of these LSX engines, its going to burn less fuel at cruising speed, since engines always burn more efficiently at lower rpm and WOT, lugging is the most efficient zone for an engine but too low of an rpm makes the engine useless and start to burn more fuel again. Generally, peak torque at WOT is the peak efficiency of the engine, its the point of the rpm band where an engine such as the Mazda SkyActiv-X is actually capable of its claimed 57% thermal efficiency, that drops when the rpm dips below peak torque and drops more so when it goes above. Of course, this also means that Chris has no equivalent "flank speed" to get extra speed by over-revving the engines with WOT, but for a yacht I believe that's just fine. Of course, I am not a boating person, I'm just using what I know of engine science and what little naval trivia I remember :P

He should be at above 7000, most likely... so yes "a bit" wrong...

@@Avetho 3000rpm is not good enough and I will tell you why: It lugs the engines a lot, he should be at 7000rpm or more with these engines at WOT. Lugging is not good, if not immediately the end of the world. These engines can cruise a 4-5k easily with the right stuff around them, so gearing down by a factor of more than 2, even 3 isnt a concern. Less fuel burn for lower revs isnt really true for boats in any meaningful way. He really need max allowed engine revs (above 7000rpm) to be WOT. that would surely mean a reasonable cruise of 30mph at say 4000 rpm.

@@GoldenCroc Ah, that makes sense, I'm still thinking in tyre diameters instead of prop pitch. Its like a certain amount of knots per rpm, right?

Think he had the trim too far down, made the front drop into the bow wave...

Yes! you dropped so much weight in the rear that you need to lighten the front, load the back, and change props to get the motors turning where they are efficient and make power.

Good post, much better than most here.

Those engines should be cruising at 3500. They are not the old diesels. 1500 is barely off idle for this setup.

Tabs don’t lift the bow, the tabs can only push bow down.

Correct, but he clearly states he used tabs to lower bow during high speed run which slowed him down considerably

He doesn't have big block engines, so your statement irrelevant.

@@charlieodom9107 It is, but not for the reason you might think. The engines got "big block" capacity, but RPM should be decided by max revs of the engine, likely over 7000 in this case.

You have a point, but its not about "big block" per se, its about the max rpm of the engine, thats where he should be at WOT, with these engines it over 7000 rpm most likely... I think from you post you are using standard engine "rules of thumb" but they are not really applicable here since its such an unusual case for engines and boat combination.

@@GoldenCroc no, completely wrong. Totally different engines, with totally different RPM ranges.

@@GoldenCroc Max RPM of these engines is certainly NOT over 7k, and NO Big Block engine has a max RPM over 6k. Most are around 5k. This engine is NOT a Big Block, should not be treated as such, and RPM should be based on a dyno graph, not some arbitrary number from a completely different engine.

Or a Cummins

or two duramaxs or two DT466e engines...two school buses...rebuild kits, done.

geared for diesel i suppose,

Probably those propellers are the original calculated for the lower RPMS and the massive torque of the Cummins diesels.

Even more, above 7000 I should think...

Have you checked the cam specs? I seen xe (energy) cams, xr (race) cams and xm (marine) cams. It happens that marine cams are desinged to develop maximum torque at lowest rpm possible. If you have race cam and it's always searching for air just to keep rpm needed to cruise, a marine cam will make a huge difference. A cam with such specs will minimise overlap, it should have a conservative duration and wide lobe separation angle. I don't like the dual plenum intake, but if the cam builds vacuum it should help to run smooth. Now that you know that, you may want to choose a set of propelers that will make trust at low rpm. The lower the engine needs to rev the less fuel it will consume. If you want to make a video about a before and after of these mods that would be so awesome. Also you could choose small injectors and adjust the tune so that they open for longer. If you don't have a turbo and won't rev it too high, there will be no need for big injectors and the increased duty cycle with the smaller injectors will help to have a better atomisation by decreasing the dropplets size. If you increase fuel line pressure that could help for that too. Finally, I would try to improve the ignition. If you can run with a lean mixture it will help to have good spark. If you go lean, choose colder plugs and keep it cool with a low temp marine thermostat.

propellers geared stupid long

Mostly dependent on the weight of the boat. Its as expected, pretty much.

That’s not bad for a boat of that size. Mine gets .75 mpg at 28mph

He should have keep it diesel