FOSTER'S XF20

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jorgepease
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Re: FOSTER'S XF20

Post by jorgepease »

I just found that video (nice job on the video), thanks for sharing that.
I think I am going to add some spray rails after watching :)

Has anyone modified the tunnel on the XF20?

cali123
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Re: FOSTER'S XF20

Post by cali123 »

[quote]Has anyone modified the tunnel on the XF20?/quote] Do a search for timoub007 in this forum. He has some interesting and informative things to say about the XF20 tunnel.

Uncle D
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Re: FOSTER'S XF20

Post by Uncle D »

Glad you vented Brent. Fast and Shallow :D :D
cali123 wrote:
Has anyone modified the tunnel on the XF20?/quote] Do a search for timoub007 in this forum. He has some interesting and informative things to say about the XF20 tunnel.
I'm going with a cross between the two. I used the basic XF20 tunnel plans. I changed the exit by narrowing it a bit and the sides of the tunnel are at a 15 degree outward angle. I'm also going with a completely different vent system.

jorgepease
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Re: FOSTER'S XF20

Post by jorgepease »

I found the timoub007 thread. It's an interesting design he ended up with ... and the out angled walls is something like a flats cat. funny how different these two mentioned are, one tapers in, the other out but at least the idea of both is to compress the water.

I remember an old western movie which had these miners using water pressure to strip mine. They started with a really large diameter pipe and kept narrowing the pipe for about a hundred foot of drop. It exited a pipe about the size of a fire hose with a huge amount of pressure.

I hope you guys finish yours and test before I get to that point :) otherwise I will probably stick pretty close to the plan, maybe make the lines a little more gradual and rounded that is about it. I think a compression plate will take care of a lot of the blowout.

FOSTER
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Re: FOSTER'S XF20

Post by FOSTER »

One thing to add I didn't do the radius on my tunnel just strait up on the sides and 18" wide. I have no baffle and no vent valve.

Nice video Cali123!!! I haven't noticed that much spray coming from the side of my XF-20. I will try and video the hull running next set of off days.

I think with the tunnel vented the boat has a faster hole shot. I haven't noticed more draft in the hull unless it’s a 1/4" or less which is no big deal to me. I would also guess that it would allow the back of the boat to actually ride higher in the water without the suction on the bottom of the tunnel while underway (key word "guess"). I have noticed when in shallow water you can actually feel the back of the boat lift before the tunnel was vented. Haven't tried running the shallows with the tunnel vented yet.


I will try and video the water pattern coming out of the tunnel. It seems with the tunnel vented it has a better pattern to it.
Brent

FOSTER
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Re: FOSTER'S XF20

Post by FOSTER »

1 year and 100hrs and the boat still runs strong.

Image

Image
Brent

jorgepease
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Re: FOSTER'S XF20

Post by jorgepease »

Hope the boat is still running strong for you.

I am about to mount my Yamaha 70 on a 4 in jack plate and I was wondering … with the jack plate all the way down, where does the cavitation plate on yours line up? I keep reading it's supposed to line up with the top of the tunnel which means you have six more inches up, is that how yours is set up?

Thanks!

FOSTER
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Re: FOSTER'S XF20

Post by FOSTER »

Jorgepease, sorry just saw your post I will check it when I get back in May. I'm currently living in Japan.
Brent

jorgepease
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Re: FOSTER'S XF20

Post by jorgepease »

FOSTER wrote:Jorgepease, sorry just saw your post I will check it when I get back in May. I'm currently living in Japan.
No worries I got it. ))
my cav plate ended up about 1.5 inches below the top of a 6 inch round tunnel... that's with JP all the way down.


Thanks

Jorge

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