Engine height v top speed

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Engine height v top speed

Рет қаралды 9,365

Performance Tinnys Down Under

4 ай бұрын

I did a vid on how much speed you gain from raising your outboard

Пікірлер: 29

@baenkt 3 ай бұрын

Great test! I've experimented with moving the engine to the side, as well as up. If you look at the engine cowling you'll se how you start turning the engine slightly at high speeds. By shifting the engine about 10cm (i see another test 😊) away from you the gearcase can run more straight and clean through the water. I gained anout 5% in fuel economy and maybe 3% top speed. To test and not have to drill new holes i built a little hole mover out of three layers of plywood glued up with polyester and csm between the layers. Would love to see someone else try it out! 5% off on your fuel bill for some scrapps of ply is a pretty sweet deal 😂😂

@growlith6969 4 ай бұрын

I seem to recall that the locals here in the states running speed boats would use a special low water pickup foot with a chopper prop to get the most speed.

@drifter9425 3 ай бұрын

Here in the bayous of south Louisiana its all about speed for efficiency I set it for top edge of prop to be even with bottom of hull Went from 48mph where it was originally set by dealer to 52mph raising to top edge of prop

@tairua1 4 ай бұрын

Excellent testing, I look forward to the surface running props, keep an eye on water pressure as you lift the motor.

@drifter9425 3 ай бұрын

That little boat hauls arse man nice

@douger1517 4 ай бұрын

Love your work, recent subscriber…can you show prop height in relation to bottom of hull.

@merc625 4 ай бұрын

Hi mate the string line in the video is level with the bottom of the hull. That’s as low as I could run my motor and raised it from there

@douger1517 4 ай бұрын

Wow..most tinnies have the cavitation plate an inch below the hull line. Do you know how far your cavitation plate is above your hull at best performance as at worst it’s about 2 inches above already.

@merc625 4 ай бұрын

About another 2 inches higher than what it is in the video is pretty much optimal for when I’m fishing

@joehozzy2616 3 ай бұрын

Hi, is that a kapten boat collar on the rear of the tinny? Can you just order foam pieces, or only the entire kit? Thanks

@merc625 3 ай бұрын

I bought it off a guy on marketplace I just glued it on with quality silicon. It’s been on there roughly 3 years and still going good

@bruceborchardt5708 4 ай бұрын

Are you trimming the motor to the same angle on each run?

@merc625 4 ай бұрын

Yeah I was trimming as far as I could with out the prop blowing out

@kizzjd9578 4 ай бұрын

My tinny gets 25 knots about that height but as soon as i lift it over 20mm, (been up to 50mm higher) (4” setback), it porpoises. I get 28knots with it high but it just bounces as soon as i hit 20knots. Any ideas why? 3.5m quintrex and 25hp 2023 yamaha 4 stroke. 10x10 stainless srt3 prop. Centre of prop inline with bottom of boat at the highest and fastest position.

@merc625 4 ай бұрын

Hi mate I haven’t really played with any Yamahas. When you start raising your motor your prop loses some bite. Sometimes cupping will help, if not you may have to get a prop that’s designed to run a bit higher or one with more diameter to cope with the extra engine height. I have personally found the permatrim helped mine with porpoising when I have the motor jacked up. Is your cav plate above the water surface when you have it jacked up

@joshwilliams9248 3 ай бұрын

Trim tabs may help.

@kizzjd9578 3 ай бұрын

@@merc625 yea vent plate is above the hull. Its on a cmc trim tilt jackplate so its higher and further back than usual. I dropped it back down to the lowest position and it doesnt porpoise at wot anymore but my top speed is 24-25 knots, going higher makes it porpoise which sucks. Cant really fit trim tabs onto 1.6mm ally either.

@merc625 3 ай бұрын

@@kizzjd9578 the porpoising will be from the prop losing grip. Dose your prop have any cup on it? If not, cupping will help it a lot.

@kizzjd9578 3 ай бұрын

@@merc625 yes, srt3 powertech prop

@evilnev 3 ай бұрын

hi , is this a standard outboard?

@merc625 2 ай бұрын

Yes a stock 2005 mercury 60hp with ccms reeds

@FrankRommerts-dr4yp 3 ай бұрын

It’s not height but weight, my Piranha used to be faster with a Yamaha 140 V4 than with a Mercury 175 V6

@officialWWM 3 ай бұрын

You don’t need an engine crane to lift that little motor 😂

@merc625 2 ай бұрын

I dunno mate it weighs about a 100kg😂

@officialWWM 2 ай бұрын

@@merc625 do you even lift? 😂

@davorfsunjich5209 4 ай бұрын

u trying reach 100 kmh.?

@merc625 4 ай бұрын

Hi mate, I’m just trying to show other guys that want to get there tinnys going some pointers I’ve cracked 101 in it with 22 cleaver

@davorfsunjich5209 4 ай бұрын

@@merc625 crazy mate. keep going. found your channel few days ago and im impressed at these speeds. i started looking for new boat and new motor having currently 3.9 meters elan401 boat with 8 hp going 32 kmh max. cant even imagine how u feel at these speeds lol, maybe i will take 60r in future with stable decent boat to work and fast. what boat is this and is that stable at heavier speeds

@merc625 4 ай бұрын

It’s a 4.25 stessl edge tracker slimline It’s pretty stable to around 85/90kph