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Discussion in 'General' started by 4bait, Jan 15, 2010.
amazing work you doing mate, good luck with it! keen to see how she goes in the water!
This is my favourite project at the moment. Would love to build something like this one day!!! Keep up the good work!!
Wow this is a massive job. Be sure to make a video of it all going when it's finished.
Well heres a quick Video of it running. Still have heaps to do as I have only done enough wiring to make it start for a test.
Had it running for about 1 hour today the only real issue I have noticed so far is that the Starboard Exhaust manifold gets hot at the top much more than the port side and is almost to hot to touch.
Reason I think is that I have the outlets too big and the manifold is not filling all the way to the top, It will be an easy fix to weld the water outlet end up a little more to create a restriction.
At least now I know it is going to work and the next job will be to finish off the wiring and dashboard etc etc
YouTube - Holden Ecotec Motor first start up in boat
to be a wet blanket on this amazing conversion. There is a reason that marine engines tend to be diesel. They are less likely to burst into flame and those that are petrol are specifically designed to reduce the risk relative to the environment in which they are used. Insurance? GOOD LUCK
if thats the case then why to honda and yamaha still make petrol engines for boats, and im pretty sure they still have the petrol can sitting in the boat.
and when my family was racing boats im pretty sure it was a Blown Chev 454 Petrol motor?
and im also pretty sure that when u have insurance on something like a boat, it is a requirement to have a fire extinguisher on board, its just common sense anyways.
I must say,
awesome project mate, it looks like an awesome setup
Mate, I'm pretty sure that's just in the bigger boats, because they have the extra torque to push the absolutely massive weights, and the friction caused by water.
In the high performance boats, they're usually petrol motors. I know most ski-boats are petrol based V8s.
You are very wrong but partially correct if that makes sense.
I always have a giggle when this question comes up.
90% of marine inboard engines for the recreational boat owner are all petrol Mercruiser or Volvo penta's most of which all have the Chevy V8 or V6 or inline 4cyl in them. Only the very high end and commercial stuff run diesels. Many of the bigger inboards run twin big block Chevy V8 petrol’s
99.999% of all outboards are petrol
All vessels by law have to be equipped with fire extinguishers and the size is dependant on how much fuel the boat carries, mine holds 200 litres so I have to have a minimum 1kg extinguisher on board at all times.
All inboard boats also have what is called a bilge blower, this is turned on prior to starting the engine and it sucks out any fumes that may be trapped in the bilge, Some petrol boats including mine also have a bilge sniffer and this detects any vapour that maybe in the bilge and sounds an alarm if vapour is detected, they can also be wired so the engine will not crank.
Also most petrol boat engines have spark arrested alternators and sealed starter motors and this motor has had the mod done to both.
most petrol boats run a carby which is designed for marine use and they have an overflow back to the tank incase the carby floods, fuel injection doesnt have this problem
Underfloor fuel tanks have an air space between them and the engine compartment etc etc and the list goes on
Insurance is not an issue with petrol boats and as said 90% of them are petrol.
Yes there are risks but that goes with anything. Diesel still has the potential to go bang if the fuel to air ratio is ideal.
if the boat is well maintained and the preventative and warning measures are in place then the risk is minimal and no higher than anything else.
Hope this clears anything up
well well well Bohemian Wanderer seems the know it all comment has been blown out of the water "pardon the pun"
4bait absolutely amazing build mate, may I ask what is your background? mechanic, boilermaker etc cos the work you have done is top notch...I would be willing to pay money for that type of work.
The ecotec would be putting out around the 150hp mark (I guess) and weighs around 200kgs
The new mercruiser 3.0 4cyl is putting out 135hp at the prop but weighs 315kgs
4.3 6cyl is rated at 220hp and weighs 393kgs.
so effectively you have cut 100kgs of weight from your boat and given it more power.
I can't wait to see what kind of fuel consumption you get out of the old girl
The ecotec I believe is 170hp, The old motor was a 470 4cyl Mercruiser which was also 170 hp but it was 30 year old technology so a newer 170 hp V6 should perform heaps better.
It will definately have better torque, and yes I will have cut back on about 100 to 130 kg of weight.
This boat weighs over 2 tonne as it is so any weight loss is good, it used to sit very low in the rear end when at rest.
As for my history / background for the last 15 years I have been working at a local Golf Club that will be hosting the Aussy Masters this November and I look after all the machinery there, I am a 45yo qualified Mechanic "old school I guess", also a Qualified Green keeper, I have an electrical certificate, I own my own Lathe and Mill and do engineering on the side for other golf clubs and as a hobby, generally I will have a go at anything, fabrication is a big part of my current job and I am generally welding every day. I used to work for Garry and Warren Smith Holden, Honda, Suzuki and Jeep as a team leader/ workshop controller and trained apprentices during the years of VN to VS. I have also worked around ozz a few times, Also Ridden motor bikes around ozz and 4x4 around ozz and held many different mechanical positions at different places over the years.
I am also a moderator of a well know Victorian fishing/ boating site but not sure if I can advertise that here. There is a similar post to this on that site as well
if the wiki is right should be 193hp
Bit of help please
Trying to run the original Mercruiser Tacho and have connected it to the brown wire that normally sits inside the mudguard when the motor is in a car.
However I can't make it work the Mercruiser tacho.
The brown wire is good all the way back to the DFI module. The genuine GM manual it says that this wire is for I/P tacho's (I guess I/P stands for independent or something).
Now I am curious will this wire run a standard aftermarket Tacho? When I put the same motor in the Hilux I used an adapter to convert the signal but this may have just been to run a 4cyl Toyota tacho can't remember.
I would like to run the Mercruiser tacho if I can especially since I just made up a new dash panel for it to fit in.
If I have to replace the Tacho then I will need to make another new dash Grrrr.
Also another concern is that the motor will run with the oil pressure switch disconnected, I assumed that since the fuel pump runs through the oil pressure switch that the motor should not run while it disconnected? I have double checked the relays and wiring etc and all is good
Have also checked our stock VR and also the Ute and they both also run when disconnected so now I’m a little confused as I thought the oil pressure switch was a fail safe to cut the fuel pump.
oil pressure switch is a backup for running in limp home mode and if the rest of the pump circuit fails relay etc .the tacho can be a problem if its made for a 12v signal lots of aftermarket ones have trouble working on the v6 does it move at all then cut out when the revs come up or nothing at all
It does nothing at all. Have even tried changing it between 4,6 and 8 cylinders just to get a response from it.
is there any particular type of tacho that work well on these?
the hole I have is 3.5 inch or about 90mm and prefer to find one that doesn't go over about 7000rpm. boat will be set to around 4200rpm full throttle.
All the ones I have seen have those stupid shift lights and wanky stuff on them, as if people don't know when to change gears and need a stupid light to tell them when to change, not only that but there are no gears in a boat LOL.
I would be looking for something old school.
the shift lights are detachable, and autometer sell some without them, and they look old school to
did the tacho work with the last engine.ide maybe try earth the tacho negative to the engine directly and see if it has a better time also try the green spout at the dfi .sometimes you need to run a 10k or 480 ohm resistor or similar inline yo get them to red over certian revs thats why i asked if it moved at all i can find out the exact resistor value if need be
yeh it worked fine on the last motor but it was an old 12 volt ignition with coil and points set up not electronic.
I have just purchased a new Tacho off Ebay coming from New Zealand.
It's the correct diameter for the hole, is all black face with no extra Gizzmo's on it so will see how it goes when it gets here.
might keep playing with the other one in the meantime.
Ok with the boat motors they need what is called an interrupt switch, which basically kills the motor momentary by shorting the coil to ground. This is to take load of the prop so it will return to neutral.
Without the interrupt it is very hard to get the gears to go back to neutral. To achieve this I have wired up a switch to the gear selector cable so that when activated it triggers a relay and cuts power to 3 injectors. This drops the RPM briefly to about 300rpm and is just enough to take the load of the prop and get the thing into neutral. The switch and mechanism is off the original engine and it simply just shorted the coil to earth hence the reason I needed a relay in the circuit to operate it on the ecotec engine. They are designed to work only when disengaging gears and not engaging
Heres a pic of the water proof box I put in for the computer and stuff for those who are interested.
I used an Ice box so it is also insulated from heat and cold and it is tucked up under the transom behind the rear seat.
I have a little bit of Glass work to tidy it all up a bit more.
Ok so the BOM got it wrong and the predicted 30-knot winds and 3 meter waves didn’t arrive.
So I finally got to do my water test and I must say I was very happy with the results.
First off I had an old 19p 3 blade prop on and found the thing didn’t have enough thrust to steer the boat properly at idle, Which is strange because the old motor had a 4 blade 17p so their must be a slight gear ratio change there.
With the 3 blade prop it still went well under high revs but it did want to rev higher than I liked, also hole shot was awesome, in fact too awesome LOL.
Piece of advice don’t try this without securing everything in the boat first LOL, I went from Idle to full throttle and everything that wasn’t tied or bolted down in the front of the boat ended up in the rear of the boat in a milli second LOL
Given that I headed back to the ramp and swapped the 19 p prop for a 21 p 3 blade prop and headed back out again.
This was heaps better, Hole shot as expected was down a little from before but still pretty good and WOT at around 4700 rpm doing 65kph 35 knots. This is a 10kph improvement from the old engine and I think there is still heaps of room for more improvement.
I’m Still running the standard Holden computer chip at this stage as it gives me a starting point to change things, but over all I think the standard tune is pretty good and fairly well suited to the boat.
Exhaust manifolds at full noise stayed nice and cold and basically everything did what it should be doing.
I think the prop may have a slight slippage in the bush as the motor seemed to intermitantly rev slightly higher for no reason and the prop nut was loose when I got back home.
I would also like to make the whole thing a bit quieter and will be putting some extra sound deadener foam in the engine bay, It is better than the old 470 motor for noise but again there is room for improvement.
Why do cars run pretty silent at 3000rpm and boats sound like a rocket ship LOL,
Here is a bit of video looking over the transom while under way Please excuse the shoddy camera work as it is hard to shoot video and drive a boat at the same time LOL, (Lucky there isn't a law against it yet)
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