Toyota V8 Exhaust Pipes Length/Size

[EvilDrSomkid]

I would be happy to be your speed reader man. I want to see and have a ride in this beast.

[Topcroc]

Maybe we could all catch up over Christmas and do a second speed run

[SoCalChris]

the boat is FAST

at 2000 revs it does about 22 knots

at 3000 revs it does about 32 knots

have tried it over some stretches at 4000 revs, (the mill has still plenty to give, the pedal is not close to the floor at 4000),

then its really flying

dunno how fast, I only have a small handheld garmin GPS for hiking purposes,

and at that speed (4000 revs) I don't feel like taking my eyes off the road ahead

its so much crap in Chao Praya and hitting something hard at that speed could easily damage the bottom

haven't gone past 4000 yet

need somebody in the boat with me to call out or at least note down the speed,

or maybe hold the GPS in front of me

will install a proper boat speedo later this week, one which is GPS based and that gives speed over ground in knots

and the course over ground

it is great FUN to play around with it

Extrapolating from your current speeds and rpms data, I'd bet you could easily be over 40 knots at 4000rpms. That would then equate to around 45mph. It must be pretty darn exciting in that type of boat and sound very awesome as well.

I would be happy to be your speed reader man. I want to see and have a ride in this beast.

Put me into the queue at #2 please. As a suggestion, you should perform your speed runs very early in the morning when the water might be the smoothest (right after dawn). It'll be safer (relatively) and easier to spot the crap in the water.

Edited November 10, 2012 by SoCalChris

[mogandave]

Reset your GPS before you start and it will record your top speed, yes?

[mogandave]

Take a couple guys with you though that you cam move around the boat to trim it out.

[melvinmelvin]

Relieved your still at it, you have been quiet for some time.

Glad it is going so well for you.

Any chance of some current pix, sure other would like to see it finished.

I'll try to sort out some pics and post them, am not great at taking snaps,

but will have a go at it.

[melvinmelvin]

Reset your GPS before you start and it will record your top speed, yes?

yes, I suppose so, but I now have a proper GPS based boat speedo halfway installed,

guess that will do the job.

[melvinmelvin]

Take a couple guys with you though that you cam move around the boat to trim it out.

yes, I have also been thinking along those lines.

right now I have the 130 liters of 95 in jerry cans in the boat, aswell as a rather heavy 2nd battery,

and the 6 cushions aswell as a comprehensive tool kit in the boat.

Guess thats about 250 extra kilo.

Its really noticeable.

The boat is very weight sensitive.

Its a bit sluggish now. Have to reach about 3200 rpm before it planes out, when planing I can't go below 2800,

then it will sink down.

(before it planed at 2000 and I could reduce to 1800)

Discussed this with the mechanic. I suggested moving some of the jerry cans forward since most of the weight is in the aft

section of the boat.

He insisted that that would be a very bad idea and he said keep the weight where it is,

you must just increase the rpms, shifting weight around would only result in the boat having

its longitudinal centre of gravity in the wrong spot and it will not float nicely, when still and when planing.

Guess he knows what he talks about, he has designed longtails for such boats for years and years.

On the longtail, just in front of and above the screw there is a "trim tab" like fin, the Thais call it ski,

same word as ski in English.

Its really the size and angle and distance from the screw of this ski that pretty much determines the power

needed for planing at any given load trim of the boat.

He says my ski is just about perfect.

[melvinmelvin]

sure can look / see/ go for a ride.

I guess I'll ned another week or two for fixing a bunch of smaller things.

I'll try and do some photoshots.

[melvinmelvin]

yesterday; 40 knots at 3800 rpm

have the canopy up, don't fancy going above 4000 with the canopy up

the camera has just been put on charging

[melvinmelvin]

pics

[melvinmelvin]

sorry, I'm lousy with a camera, take two pics every 3 years

summary;

boat match weight for touring is about 900 kilo, all stash included

8.9 meters long (the boat itself)

the longtail extends 175 inches behind the transom

present screw; 2 blades, 12 in ch diameter, 22 inch pitch

speeds;

22 knots at 2000 rpm

32 knots at 3000 rpm

40 knots at 3800 rpm

max mill power is 260/270 hp at 5400 rpm

FAST

and fun

(and LOUD)

[seedy]

Very nice job.

Loud and fast - what more could you want !

[funcat]

I have 2 questions:

1.Maneuverability...how do you turn this beast?

2.Canopy...does it flap a lot at speed?

....but looks good...

[transam]

pics

Careful, it might ''take off'' at 50mph eh.

[mogandave]

Do you have a good fuel flow meter?

[Crossy]

Why do you have sausages drying on the sides?

Seriously, nice looking beast, now all we need is video of her in action.

[melvinmelvin]

I have 2 questions:

1.Maneuverability...how do you turn this beast?

2.Canopy...does it flap a lot at speed?

....but looks good...

I have 2 questions:

1.Maneuverability...how do you turn this beast?

2.Canopy...does it flap a lot at speed?

....but looks good...

yes, it flaps at speed, but not a lot, it is quite strongly tightened up

not easy to drive, they do not manouver well,

and as you can see the klong where it sleeps ain't large.

the turning radius is huge at speed,

weight shifting in the boat helps a lot to reduce the radius,

everyone moving to the right / left etc.

turning in close quarters ain't too bad,

you raise the shaft so that only 30-40 % of the screw is in the water

then whip the water at say 1000/1500 rpms

then it turns nicely without much moving backwards or forward

[melvinmelvin]

Do you have a good fuel flow meter?

no, I don't

(not a bad one either)

[melvinmelvin]

I have 2 questions:

1.Maneuverability...how do you turn this beast?

2.Canopy...does it flap a lot at speed?

....but looks good...

re turn,

an alternative to whipping water is quite simply to use the longtail as a paddle,

up -- swing --- down --- swing etc

works fine if your engine/driveshaft/steering rod is reasonably balanced,

if not this way of turning is VERY hard work

[melvinmelvin]

am now in the process of registering the boat and getting number and ownership document (tabiian ruua)

have run into some obstacles in that process,

I have a Thai skippers licence for yachts, but they (Marine Dept) also require a Engineer Class 2 licence, hmm

the boat is 8.9 meters long

they have a regulation that says boats less than 10 m LOA can have maximum 4 cylinders and 175 hp

doesn't match well with a 1UZ V8

uncertain how I will sort this out

they try to be helpfull though, have pointed to some shortcuts in order to offer me the Engineer Class 2 license.

[VocalNeal]

am now in the process of registering the boat and getting number and ownership document (tabiian ruua)

have run into some obstacles in that process,

I have a Thai skippers licence for yachts, but they (Marine Dept) also require a Engineer Class 2 licence, hmm

the boat is 8.9 meters long

they have a regulation that says boats less than 10 m LOA can have maximum 4 cylinders and 175 hp

doesn't match well with a 1UZ V8

uncertain how I will sort this out

they try to be helpfull though, have pointed to some shortcuts in order to offer me the Engineer Class 2 license.

Melvin,

Do you have a skeg on the propshaft? I've seen some do. That might help with maneuverability or at least turning. Or maybe a high tech drop down tiller for those tight places?

Silly? An auxiliary jet ski pump with left and right thrusters?

[mogandave]

the boat is 8.9 meters long

they have a regulation that says boats less than 10 m LOA can have maximum 4 cylinders and 175 hp

doesn't match well with a 1UZ V8

uncertain how I will sort this out

How about adding a bow-sprig or figure-head?

[melvinmelvin]

am now in the process of registering the boat and getting number and ownership document (tabiian ruua)

have run into some obstacles in that process,

I have a Thai skippers licence for yachts, but they (Marine Dept) also require a Engineer Class 2 licence, hmm

the boat is 8.9 meters long

they have a regulation that says boats less than 10 m LOA can have maximum 4 cylinders and 175 hp

doesn't match well with a 1UZ V8

uncertain how I will sort this out

they try to be helpfull though, have pointed to some shortcuts in order to offer me the Engineer Class 2 license.

Melvin,

Do you have a skeg on the propshaft? I've seen some do. That might help with maneuverability or at least turning. Or maybe a high tech drop down tiller for those tight places?

Silly? An auxiliary jet ski pump with left and right thrusters?

yes I have, that skeg is called fish tail (haeng bpla) in Thai, its main purpose is to protect the screw from hitting the bottom

in shallow waters.

and also, the ski, that I mentioned earlier, is welded to the fish tail

turning at low speed or when still is no problem.

sharp turns at speed are close to impossible

[melvinmelvin]

the boat is 8.9 meters long

they have a regulation that says boats less than 10 m LOA can have maximum 4 cylinders and 175 hp

doesn't match well with a 1UZ V8

uncertain how I will sort this out

How about adding a bow-sprig or figure-head?

I was playing with various ideas yesterday, and ended up with making a new and longer nose and thread it onto the bow,

just for a couple of days until the surveyor has measured the boat and then remove it.

he will of course see and understand what I have done, that doesn't matter, they want to help

but there are limits to what they can neglect

went to Nakhon Pathom today and talked it over with my chang ruua (the chap that built the boat)

he and his assistant concluded it would be easier and quicker to extend the stern,

he can quickly extend it make it look as if some spoilers are added.

[melvinmelvin]

now a lot less sluggish to drive,

have consumed about 60 liters of the 100 I had in jerry cans

now cruising at 20 knots at 2000 rpm, however, the ski effect is not full at that speed so must

press the longtail/screw down by using my right thigh, but it does not require a lot of power to do that,

hence, not painfull as it was before.

[melvinmelvin]

Took the boat out of the water last Saturday, the bottom was fairly dirty after 1 year in the water.

Will launch it and install the engine again towards the end of the week I guess.

Then will address the Tabian Ruaa challenge.

I.e. extending the transom by 1.10 meters by means of some spoiler look alike stuff and

then see what the Marine Dept will say to that.

If more then 4 cylinders (Thai rules says pistons) and/or more than 170 hp the boat must measure 10 meters,

today it measures 8.9 meters.

[monty]

Thanks for the update!

Was kind of missing this thread...

[melvinmelvin]

have discussed this 8.9 meter versys 10.0 meters with several people,

all boat wrights/builders insist that extending the stern by means of spoiler lookalikes would be best and easiest

(also I don't really want to extend the bow, extending the transom will result in the total length

from tip of bow to the end of the drive shaft will remain the same.)

8.9m + the current driveshaft adds up to about 43 ', which is more than long enough

don't need another 4 '

have sketched what I am thinking to the Marine Dept surveyor, he is not enthusiastic,

my plan includes extension of the side decks (doll boards?) together with the transom extension

he has a different view than I regarding how to measure LOA (Length Over All).

however, the guy is open to talks

and he respects my university education in nautical matters

anyway, I have found a series of LOA related images on www that supports my view on how to measure LOA

will have them printed and bring 'em along next time he comes to do the survey

[seedy]

Thanks for the update!

Was kind of missing this thread...

Me too !