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 Post subject: Amphicar?
PostPosted: July 16, 2016, 3:27 pm 
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Got the inspiration from another thread here, and as my own is still in the 3d modeling phase, I could yet try it. It would require a transmission with a PTO, which I have, a SM465, but the better choice would be a ZF S5-42 or -47, due to the aluminum case and the overdrive. But the cost of going Ford versus the extra gear, and the weight savings of the case versus the weight of the extra gear, you decide. I have a 2.41:1 gearset for the axle I plan to use, so I wouldn't need an overdrive, plus I still end up with 4 useable forward ratios. Just a matter of choosing an engine or trying to adapt the 465 to the 3.4L I plan to use. Probably someone on Pirate4x4.com has shown how, probably really cheaply. I had a spare bellhousing for a 3.4, dunno if I still do, but if so, it could happen.
So, the big problem is getting it to float, at a probable fully-loaded weight near 2500#? Anyone sure what that would require, beyond displacing enough water? I was already planning a full bellypan, fully welded, and speed in the water isn't a big need, it will never try the English Channel.
Using a 465 means the PTO can go on either side, so under the passenger's left knee means it need not add width nor height to the car. But it makes me think an IRS wiser than a solid axle, and a TBird 8.8" differential assembly offers 2.47:1 as a possibility.
If we can make it float, I can make it go.
Anyone wanna help?


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 Post subject: Re: Amphicar?
PostPosted: July 16, 2016, 3:49 pm 
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Yeah, can't help with sealing. Seems like boots from an IRS could be adapted for the seals, and you could put the whole suspension outside the hull, but what do I know? I'm just replying because this is insanely cool. We used to have a guy drive down the public access next to my grandparent's cottage, and "drive" across the lake (about two miles of open water). Still think that was the coolest car I ever saw, even though it was not a great boat or car. I hope you go for it.

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 Post subject: Re: Amphicar?
PostPosted: July 16, 2016, 8:14 pm 
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https://www.youtube.com/watch?v=YVjo6YOT3Zg

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 Post subject: Re: Amphicar?
PostPosted: July 17, 2016, 12:42 am 
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Yeah, seen that, it references the Gibbs Aquada, which resembles a Miata


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 Post subject: Re: Amphicar?
PostPosted: July 17, 2016, 10:03 am 
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I went through all this with Das Boot. See Jan. 28, 2015 post. Rotary seals are available. If you keep the speeds low, pressures on the seals aren't too bad. B.F. Goodrich won't guarantee them for this use, though.


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 Post subject: Re: Amphicar?
PostPosted: July 17, 2016, 10:19 am 
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I'm familiar with industrial PTOs and transfer cases, if I do this it will be PTO, so I started looking into outboard drives. None of it seems difficult, the main issue is the floatation.


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 Post subject: Re: Amphicar?
PostPosted: July 17, 2016, 11:23 am 
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Found the info on the SM465 to 3.4L, Centerforce makes the clutch disc, it runs $110, the rest is just taking the 3.4 bellhousing to get bored out to 5.125", then it all bolts together.
Since the 465 has PTO provisions already, I can just get a used PTO from an old dump truck, then SixStates can provide new shaft rod that isn't bent, new u-joints for used yokes off said dump truck, and weld a yoke to whatever shaft the propeller requires. Route that shaft under the passenger side axle tube, then a u-joint there so I can raise the prop off the road. A few bearings to keep the shafts and joints running where intended, the whole deal could be $500, certainly no more than a grand.
Probably needed the Camaro drive shaft shortened anyway, also have the driveshafts that went with the 465, so a splice is nothing extra for cost, just a matter of which yoke gets welded to which tube.
For gearing, in overdrive the 3.4L Camaro was 2.25:1 with the standard 3.23:1 axle, and 2.38:1 with the optional 3.42:1 performance axle ratio, I have both 2.29:1 and 2.41:1 gear sets for this axle, and there was a rare 2.26:1 gear that can go in the Ford 8.8" if I go IRS, so no problems with fuel mileage. There was also a 2.14:1 ratio for my axle, if I want taller gearing.
Camaros that used the 3.4 with a T5 manual used a 3.23:1 axle only, with a 3.75:1 first and a 0.72:1 fifth. The SM465 has a 6.55:1 first, so this still works. You can do the multiplications if you like. To me. This would be a parking lot gear, second is 3.58:1, much more useful even with the taller rear, because of lighter car and maybe shorter tires.


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 Post subject: Re: Amphicar?
PostPosted: July 17, 2016, 12:14 pm 
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Assuming a stock 3.4, a 465, a 2.41:1, and 225/50R16s on 8s, it puts the HP peak in third at 80 MPH, which is great for around here, and puts red line at 25 in first, 45 in second, and 95 in third. Cruising at 65 MPH gives 2200 RPM. And at idle in first is just 3 MPH, great for keeping the brakes cool when entering cold water. You wouldn't want them hot, you'd want to park for an hour first.


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 Post subject: Re: Amphicar?
PostPosted: July 18, 2016, 1:29 pm 
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you may want to investigate two separate throttle controls as well, as your standard gas pedal would get quite obnoxious for any amount of time on the water.

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 Post subject: Re: Amphicar?
PostPosted: July 21, 2016, 1:46 pm 
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Location: Norfolk - UK
Dave1976 wrote:
...speed in the water isn't a big need, it will never try the English Channel.

Why bother messing around with complicated transmissions with power take-offs, then?

Why not think about a separate electric motor (electric outboards weigh next to nothing), or just use the driven wheels (possibly with some sort of additional 'paddle wheel' attachment sandwiched between the wheel and the hub, to aid efficiency)?

For inspiration, although it weighed a LOT less than your projected 2,500lbs:

Image

Image

Image

Or at the other end of the cost-complexity spectrum:

http://jalopnik.com/5291181/scamander-rrv-the-homer-comes-to-life

http://www.evo.co.uk/videos/planetevovideos/283690/peter_wheelers_scamander_on_video.html


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 Post subject: Re: Amphicar?
PostPosted: July 21, 2016, 2:35 pm 
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Gotta love that rear camber control.

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 Post subject: Re: Amphicar?
PostPosted: July 21, 2016, 6:31 pm 
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I suspect that when you were steering all four wheels hydraulically (presumably so that all four wheels could end up pointing in different directions unless the system was perfectly bled), with your feet, that would have been fairly low down the list of things you were worrying about, handling-wise. :D


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 Post subject: Re: Amphicar?
PostPosted: July 22, 2016, 10:27 am 
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Very cool, but not remotely suited to canyon roads at high speeds.


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 Post subject: Re: Amphicar?
PostPosted: July 25, 2016, 1:35 pm 
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Ok, I have the V6 bellhousing from an '83-'92 Camaro 2.8L, which will bolt right up to my 3.4L, and it already has dual sets of bosses for attaching a transmission, so I'll be trying to attach my SM465 to it. Pics when I do. Maybe tonight.


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 Post subject: Re: Amphicar?
PostPosted: July 25, 2016, 2:29 pm 
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The "correct" holes aren't drilled / tapped, I don't have enough correct bolts anyway, and the input bearing retainer needs turned down, but the 465 does bolt up, I got pics for later, and the PTO part could happen, freeing up my 4L60E for something else.


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