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2oodoor
02-18-2011, 10:02 AM
sitting here thinking how would a A20 serve as an inboard boat motor using a yamaha stern drive or any brand, Would need to see the drive coupling flywheel, and of course custom exhaust .. they already use GM inline fours for years now.
Aluminum head may be an issue, I think the chevys use ironhead vortec LT1. just kicking it around some....

w261w261
02-18-2011, 12:07 PM
The general problem with using direct transplants of road vehicles to boats, beyond the details, is that auto engines are not designed to be run at full throttle or close for extended periods.

2ndGenGuy
02-18-2011, 01:56 PM
What about those boats I see running blown big blocks and shit?

Another alternative would be one of those Honda boat engines that is basically an C35 or J35 or whatever inside a plastic case. :)

How about a 3.5 liter V6 putting out 225hp with VTEC!!!
http://marine.honda.com/Products/modeldetail/BF225

Seriously though, How different do you think they are from the car engines? I bet it's damn near the same engine they put in the Legend, just keeping the RPMs down which is why it only makes 225 instead of 300...

w261w261
02-18-2011, 07:02 PM
There's a lot of articles out there about the differences between marine engines and auto engines. People gripe regularly about the expense of marine parts over what seems to be the identical item in the auto realm. Maybe the markup is more because of the lower volume, but there are also differences.

I've been around muscle boats some, and at the high end the blown big blocks blinging with chrome are a really spectacular sight. They also don't last too long, and if they fail in spectacular fashion, you're looking at 40k to make them right. Oops!

But if you want spectacular, one guy had a boat with twin jet turbines out of a helicopter. This was probably 8 years ago, and he was capable of 180 on the Hudson river. Move the fuck over! At the dock, it stank of jet fumes. Reminded me of an airport.

Nowadays, they just had a shootout at I think Lake of the Ozarks. Guy went through the flying mile at over 200.

lostforawhile
02-18-2011, 07:41 PM
my dad tried this years ago with a subaru motor, the boat wouldn't go over 5 mph, you also need to remember about the water pump having to pull in water out of the drive and it going back out. Marine engines are designed to generate a lot of torque at low rpm, a direct drive engine like an A20 just isn't going to have it, when you see a V8 in a boat, it usually has a special cam set up to generate all it's torque at lower RPM, and you need a lot of torque, also remember the coast guard has specific rules about the engine needing a flame arrester, and the ignition has to be designed to be used in a boat, there are other things too, mainly due to preventing an onboard fire. Think of a marine engine being setup just like an aircraft engine, except instead of it operating in air as a fluid, it operates in water.

2ndGenGuy
02-18-2011, 10:05 PM
There's a lot of articles out there about the differences between marine engines and auto engines. People gripe regularly about the expense of marine parts over what seems to be the identical item in the auto realm. Maybe the markup is more because of the lower volume, but there are also differences.

I've been around muscle boats some, and at the high end the blown big blocks blinging with chrome are a really spectacular sight. They also don't last too long, and if they fail in spectacular fashion, you're looking at 40k to make them right. Oops!

But if you want spectacular, one guy had a boat with twin jet turbines out of a helicopter. This was probably 8 years ago, and he was capable of 180 on the Hudson river. Move the fuck over! At the dock, it stank of jet fumes. Reminded me of an airport.

Nowadays, they just had a shootout at I think Lake of the Ozarks. Guy went through the flying mile at over 200.

Holy fuck! And I thought 55mph seemed fast on the water! 180-200 must have been just insane if the water wasn't just glass... how often rivers aren't... :)

w261w261
02-19-2011, 06:43 AM
Up to about 100 it's like FASTER FASTER FASTER. After that, for me at least, it was too much. You should be wearing a helmet, and there's other traffic, wave action and the concern about your driver's skills. One little mistake and it's gonna really hurt. Like anything else, maybe you get used to it after awhile.

2oodoor
02-19-2011, 06:04 PM
ive been in cars and trucks , especially pre 80 vehiclse without overdrive lock up torque converters, that zing along for hours on end at over 3600 rpm just crusiing down the highway..
I am aware of all the special needs of marine inboards, hell they use a GM 4.3 v6 in a lot of them, gee what kind of POS motor is that, fact is it isnt , it is a great motor or else it wouldnt have been chosen to use. So is 302 ford , 305 and 350 chevy, 455 olds, 151 pontiac and hell even Yanmar diesels like they use in dozens of applications from mowers, to generators etc.. . just have a good bottom end build.
A20 would serve just fine I think, but there would be better choices Im sure. so.. wouldnt it be cool to do one?
I am about to gain a lot of knowledge about the topic, since its someting Ive always wanted to know more about.l

w261w261
02-19-2011, 07:30 PM
I'd say throw a couple of em in a old fiberglass junk boat and have at it. Might cost you something for the outdrives but maybe you can find a couple of old Bravo 1's. They're cheap because they're POS anyway. Could be a fine way to lose a year of your life.

lostforawhile
02-19-2011, 07:47 PM
ive been in cars and trucks , especially pre 80 vehiclse without overdrive lock up torque converters, that zing along for hours on end at over 3600 rpm just crusiing down the highway..
I am aware of all the special needs of marine inboards, hell they use a GM 4.3 v6 in a lot of them, gee what kind of POS motor is that, fact is it isnt , it is a great motor or else it wouldnt have been chosen to use. So is 302 ford , 305 and 350 chevy, 455 olds, 151 pontiac and hell even Yanmar diesels like they use in dozens of applications from mowers, to generators etc.. . just have a good bottom end build.
A20 would serve just fine I think, but there would be better choices Im sure. so.. wouldnt it be cool to do one?
I am about to gain a lot of knowledge about the topic, since its someting Ive always wanted to know more about.l

the big difference is a v8 will generate it's torque without having to use as much gearing, with a smaller engine, a lot of the torque at the wheels is created by using a numerically lower final drive and higher rpm, even in fifth gear it's still gear reduction because of the final drive, it's never truely 1-1, with a direct drive you don't have any kind of gear reduction and can't create enough torque to move the boat, belive me i've been there, was there for an entire project like this from day one, to failure. the engine was killing itself trying to move the boat over 5 MPH, it actually blew up, and we had to use paddles to get back to shore, oh it was named POS 2, POS 1 was one of my step brothers cars

Hazwan
02-21-2011, 06:43 AM
What about those boats I see running blown big blocks and shit?

Another alternative would be one of those Honda boat engines that is basically an C35 or J35 or whatever inside a plastic case. :)

How about a 3.5 liter V6 putting out 225hp with VTEC!!!
http://marine.honda.com/Products/modeldetail/BF225

Seriously though, How different do you think they are from the car engines? I bet it's damn near the same engine they put in the Legend, just keeping the RPMs down which is why it only makes 225 instead of 300...

http://marine.honda.com/content/images/models/action/bf225_safeboat.jpg

VTECH JUST KICKED IN YO!!1

2oodoor
02-21-2011, 11:32 AM
I'd say throw a couple of em in a old fiberglass junk boat and have at it. Might cost you something for the outdrives but maybe you can find a couple of old Bravo 1's. They're cheap because they're POS anyway. Could be a fine way to lose a year of your life.

FLMAO true

2oodoor
02-21-2011, 11:33 AM
http://marine.honda.com/content/images/models/action/bf225_safeboat.jpg

VTECH JUST KICKED IN YO!!1

thsoe ARE V TECH and sweet outboards, wish I could afford one or duece :tongue:

2ndGenGuy
02-21-2011, 01:41 PM
Aren't there gear reduction drives for boat engines? The A20 stock seems to make peak torque pretty low compared to most 4 bangers. I imagine you could run it about 3500-4000RPM and it would cruise along nicely.

lostforawhile
02-21-2011, 02:08 PM
http://www.marineenginedigest.com/specialreports/marinevauto.htm

2oodoor
02-21-2011, 04:32 PM
:blah:
http://www.marineenginedigest.com/specialreports/marinevauto.htm

doesnt really say much I didnt know, of course, you missed my point in that A20 isnt too far off from being capable of marine app. Of course it wouldnt be dropped right in out of a car, just like a chevy v8 wouldnt. You can indeed use a targetmaster chevy crate motor in boats.. of course it would need to be HD, and USCG equipment attached such as anode bullshit and spark suckers etc.. :blah: humor me just a tad bit cuz.. lol

like 261 says though it would be a year of my life I wouldnt get back, geez a whole year I could be riding in a 300 hp volkswagon powered fan jetboat...:tongue:

I would consider such and endeavor if I had a bunch of resources around to do it already, like junkyard wars ya know.. and of course I would post a thread here on it.
LOL I am looking for a flame arrester breather for a weber 38 though.... seriously

also anybody know of some good forums for inboards, I need to know if I can use a car harmonic balancer on this four banger GM, apparently it was some sort of magnetized generator it has wire coils in it and rubber isolators, all which are coming apart and making vibration. It is no longer used for what ever that stuff is in there for... converted to marine alternator.

lostforawhile
02-21-2011, 05:06 PM
:blah:

doesnt really say much I didnt know, of course, you missed my point in that A20 isnt too far off from being capable of marine app. Of course it wouldnt be dropped right in out of a car, just like a chevy v8 wouldnt. You can indeed use a targetmaster chevy crate motor in boats.. of course it would need to be HD, and USCG equipment attached such as anode bullshit and spark suckers etc.. :blah: humor me just a tad bit cuz.. lol

like 261 says though it would be a year of my life I wouldnt get back, geez a whole year I could be riding in a 300 hp volkswagon powered fan jetboat...:tongue:

I would consider such and endeavor if I had a bunch of resources around to do it already, like junkyard wars ya know.. and of course I would post a thread here on it.
LOL I am looking for a flame arrester breather for a weber 38 though.... seriously

also anybody know of some good forums for inboards, I need to know if I can use a car harmonic balancer on this four banger GM, apparently it was some sort of magnetized generator it has wire coils in it and rubber isolators, all which are coming apart and making vibration. It is no longer used for what ever that stuff is in there for... converted to marine alternator.
I have your flame arrester USCG approved, I can't remember the type of opening the webber has at the top, the overflow also has to vent into the barrel of the carb also. this one is made for a single barrel holley, I could adapt it if needed.

2oodoor
02-22-2011, 04:20 PM
i will get you a pic of the base of the current unit..

Ok update, turns out the motor I have is not a GM based engine at all. From trying to find out on the web if I could replace the harmonic balancer with a regular automotive (this one has a stator and winding in it to serve as a charging system, was bypassed and uses a one wire GM altnernator) because Im trying to eliminate some vibration.
This is a Ford 460 cut in half basically, aluminum block made by Mercruiser, but the head can be any 460 head. I also ran across some wierd forced induction racers of 4 cyl (hey Stevensimmons, pay attention) that have bought these from marine salvage yards and turn them into racers, dragsters mostly. Evidently they bolt up to GM tranmissions with very little modification.
Well anyway my news is, I think I can remove the balancer and gut out all the windings and magnets bs and reinstall it. Then I may go on to make a neoprene isolator for the upper motor mount.
And yeah, Im thinking about using a 38 weber as a carb.. Trying to get more response to plain out this boat sooner, its a bird watcher as it is. yah I know about trim and weight transfer but still, nothing responds like a weber hammer down.

1813mdw
02-27-2011, 06:15 PM
sitting here thinking how would a A20 serve as an inboard boat motor using a yamaha stern drive or any brand, Would need to see the drive coupling flywheel, and of course custom exhaust .. they already use GM inline fours for years now.
Aluminum head may be an issue, I think the chevys use ironhead vortec LT1. just kicking it around some....

if you are talking about the "iron duke" gm 4cyl, the only real difference between that and the "4tech"(used on alot of mid-late 80's cars) was the forged stroker crank. they used aluminum and castiron heads. i think the a20 would be great in this application if you could tune it for low end torque only

2oodoor
07-07-2012, 05:10 PM
"two of the happiest days in a man's life are 1) the day he buys a boat 2) the day he sells his boat"

Im pleased it's gone. I struggled to find time to mess with it, i learned quite a bit, i recouped most of what I paid, a good day was had.

Bluntman
07-08-2012, 08:30 PM
Old thread but check out some of these crazy set ups. LOL I saw these on travel channel or something so I just googled....http://www.google.com/search?q=bangkok+boats+with+car+engine+pics&hl=en&client=firefox-a&hs=a2l&rls=org.mozilla:en-US:official&channel=np&prmd=imvns&source=lnms&sa=X&ei=kFz6T6_QBIjc2gXQ_ZWBBw&ved=0CA8Q_AUoAA&biw=800&bih=398

POS carb
07-20-2012, 02:50 PM
am I the only one who has thought about having a boat motor in my car? I love the sound.

But on a serious note, an inboard A20 would work as long as you get the prop correct. You should run synthetic oil and set up an oil cooler and I bet my life it would work, it's all about efficiency and your prop needs to be matched to the motor's powerband. Also, weight needs to be considered, you're not going to move a 30' boat with 100 hp, but on a small boat a pair of A20s would be pretty cool.
And as for the torque argument, there are few 2.0L motors that can make the torque ours can

lostforawhile
07-20-2012, 08:18 PM
am I the only one who has thought about having a boat motor in my car? I love the sound.

But on a serious note, an inboard A20 would work as long as you get the prop correct. You should run synthetic oil and set up an oil cooler and I bet my life it would work, it's all about efficiency and your prop needs to be matched to the motor's powerband. Also, weight needs to be considered, you're not going to move a 30' boat with 100 hp, but on a small boat a pair of A20s would be pretty cool.
And as for the torque argument, there are few 2.0L motors that can make the torque ours can

it already got tried, 100 hp Subaru motor moved the boat 2 knots with it going full out at maximum rpm, went about 100 yards before it overheated, then we had to switch to manual paddle power to get back to shore, was maby a 15 foot boat

Vanilla Sky
07-20-2012, 10:06 PM
Sounds like inadequate cooling to me. I've seen car 350 blocks used in boats many times. There's really nothing special about them.

lostforawhile
07-20-2012, 10:53 PM
Sounds like inadequate cooling to me. I've seen car 350 blocks used in boats many times. There's really nothing special about them.

it was pulling water through the pump in the drive and putting it back out like it was supposed to, I think the difference is in the torque of the V8, it's pretty easy to build a v8 with not much horsepower but a ton of torque low down in the rpm range, the 302 in my towncar is setup like that factory, not much horsepower but a bunch of torque down low to move it's weight and to tow your motor home behind it, you need everything an engines got down low as most props are designed to operate at low rpm, if they spin too fast they cavitate

Vanilla Sky
07-20-2012, 10:56 PM
There are plenty of 4 cylinder, high HP, comparatively low torque engines bolted to the back of boats. I mean, the Coast Guard has plenty of them. It sounds like you weren't pumping enough water to cool the engine.

lostforawhile
07-20-2012, 11:03 PM
There are plenty of 4 cylinder, high HP, comparatively low torque engines bolted to the back of boats. I mean, the Coast Guard has plenty of them. It sounds like you weren't pumping enough water to cool the engine.
it didn't have enough torque to move the boat anyway, boat made a one way trip to Ohio, failed miserably, and got sold for a couple of hundred bucks up there

Vanilla Sky
07-20-2012, 11:07 PM
Which engine was it?

2oodoor
07-21-2012, 04:01 AM
The Mercruiser 470 aka 3.7 liter had an aluminum block that at one time was branded by Ford motorsports as a race engine but Mercury marine couldn't agree on patent issues i bElieve. The head was a Ford part though. They sound like a beast out of th water! ThEre is info on the web where its used in cars bt it's like Amc wih all the cross brand mixing of parts lol

POS carb
07-21-2012, 04:55 AM
What about a jet drive?
One of my buddies had a boat with two Yamaha 1000cc bike motors and jet drives, it moved well, it could go 50mph

lostforawhile
07-21-2012, 06:19 AM
What about a jet drive?
One of my buddies had a boat with two Yamaha 1000cc bike motors and jet drives, it moved well, it could go 50mph

jet drive is a better option, you don't have the narrow rpm window that the prop operates in,

2oodoor
07-21-2012, 08:38 AM
Lol then there's fan boats, it's hard to beat a big jugged vw air cooled motor or a small block chevy for those... But a 190 to 250 HP A20a3 would be intresting:cool:

lostforawhile
07-21-2012, 10:50 AM
Lol then there's fan boats, it's hard to beat a big jugged vw air cooled motor or a small block chevy for those... But a 190 to 250 HP A20a3 would be intresting:cool:

better to use an aircraft motor that can no longer be certified, a lot of the ones I've seen are running lycoming 4's or even 6s designed specially to turn the prop, easier to adapt over then the VW engines, but operate basically the same way, what I would like to see is one of the small rotax aircraft 4s on a small bass boat with a pusher prop, small and lightweight and plenty of power for the prop, I've seen the rotax engines turbocharged in boat applications and they can produce more power then a lycoming 4 and hardly weigh anything, the aircraft engines can develop issues that make them unairworthy so they get repaired and used for non aircraft applications, since they are already designed to have a prop attached, etc, you simply turn them backwards, and use a pusher prop, magneto and all self contained, and if you are building your own boat, you can often get the motor mount assemblies from aircraft salvage yards, often they get sold from wrecks and you can straighten them out and fix them yourself