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Bad Dog
09-01-2000, 08:08 AM
Well, yesterday was the day I finally got to test to see how fast my 18 would go. I borrowed the GPS from work and headed out on my local lake.

I could only get up to 55! Cripes that's slow. Had it trimmed up all the way wide open. Grrr.

I figure I can eek out a few more mph by cleaning and waxing the bottom again, but the engine runs good (350 Chevy Magnum, Alpha One drive), and I'm not much of an engine tinkerer anyway.

Just frustrated and thought I'd share.

Everyone have a good time at Lake Euf... (I'll catch it next year).

Bret

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Bret Pedigo
bret@emji.net

GEOO
09-01-2000, 08:22 AM
Bret,
How much power does your Magnum have? A 300hp should put you in the low 60's. GEOO

BERTRAM BOY
09-01-2000, 08:29 AM
Hey Bad Dog,
I wouldn't be too upset, 55 sounds like you're pretty much on target.(I know, we ALWAYS need to go faster!)My 18 will go 60 with just me in it and a 260hp 350. However, My X dimension is raised up 3 inches. It makes a tremendous difference at top end, but I give up something out of the hole. Hey, If you have a river in the area check your speed going down river It's usually good for 2,3 or 4 mph!!!
BERTRAM BOY

CDMA
09-01-2000, 09:09 AM
Cliff

How did you raise the x dimension? You have a Volvo right? Did you reglass the transom? the throttle is coming soon.

Chris

PaulO
09-01-2000, 11:19 AM
Sorry to hear you are dissapointed with your top speed however, thanks for being honest and giving others something real to compare with. I have said it before and everyone is probably tired of hearing it but, the exagerration does not help. If you are going to post top speeds (even if it is in the for-sale section) get them from GPS or radar. Can't tell you how many 70 plus boats are really high 50s boats once the GPS comes out. True 70 MPH boats of this type are rare.
PaulO

Craig
09-01-2000, 11:35 AM
Yea I recently tried out a "65 mph boat" that would only go 52... Its kind of funny how that works. In my experience a fairly consistent phenomenon.

Stan
09-01-2000, 12:13 PM
RE 1990 18 2+3

I bought this boat with no power...bought a 5.7 merc/alpha 1 Gen 2 ( somewhere around 225 hp )......after getting the kinks finally out..I can turn a 14 x 21 stainless steel to 53 mph @ 4250 rpm. Very dissapointed !!! I want 65 mph like everyone else says THEIR BOAT DOES !!!

Well.....now I know the REAL truth...while I still might be a little slower than the group as a whole, I'm not that far off the mark.

OK...that said....how do I get this boat to turn a 14 x 23 @ 5000 rpm...and get this mother up to 65 + MPH !!!!


Stan

RickR
09-01-2000, 01:43 PM
On a 18 Classic removing the hatch, air cleaner, cooler, anchor and wife should give you 3 or 4. (Depending on the size of your wife) http://www.donzi.net/ubb/biggrin.gif
If you really want to go fast I have a 454 Mag (385 Crank HP) in the For Sale section.

When I test drove my 22 in April the owner said she'd do 70. Funny thing my GPS said 61.2. Price came down $1000. http://www.donzi.net/ubb/wink.gif
I am up to 66.5 and the new prop is going on this afternoon.

Bertram Boy
A good tail wind helps too.


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RICKR
mailto:riggerb@aol.comriggerb@aol.com</A>



[This message has been edited by RickR (edited 09-01-2000).]

boxy
09-01-2000, 02:43 PM
Stan,.....12 mph.....$12,000.00.

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boxy
mailto:sboxma@sprint.casboxma@sprint.ca</A>
Smuggler's Cove
Ontario

Jamesbon
09-01-2000, 03:01 PM
It's all a matter of how much $$ you want to part with. On a budget, I would add smaller combustion chamber heads to raise the compression and maybe a hot roller cam. For more money, maybe a stroker or 400 ci small block. And for a lillle more, a big block.

RickR,
Is your 454 raw or fresh water cooled? Is it "strokeable" to a 502? Or does the 502 use a different block?

rayjay
09-01-2000, 04:32 PM
You can stroke a 454 with a 4.25 crank pretty easily, give 488 - 494 depending on bore. A 502 with same crank would become a 540. With a tall block there are even longer strokes and wider bores getting you up to and over 600 cubes without much trouble, just a few (lol) scheckels. All depends on how fast you can afford to go.

A bored out 400 gives you 406 cubes, and with 6" rods and appropriate pistons, both of which are available for just little more than than regular rods and pistons, you would have a good power plant. There are even kits to get a small block out to 434. But it's just not going to have as much power as a big block. Old addage, there's no replacement for displacement. rayjay

BERTRAM BOY
09-01-2000, 10:35 PM
Well,I'm glad Paul O. brought the subject of "REAL" speed up. When I said My 18 would go 60, I didn't mean that it goes in the 60's, I mean't that using my handheld GPS and going down river that It goes 60.3 mph
Chris,I have a Volvo 290 drive. The engine and drive was already raised when I bought the boat. The transom wasn't re-glassed there is a big aluminum plate that the drive is mounted on. I'll e-mail you the pics, because I'm not sure how to post them.
BERTRAM BOY

Owen
09-02-2000, 02:30 AM
http://albums.photopoint.com/j/View?u=943763&a=4289178&p=27492236

and she's a fine boat at that!

So like, if you're running at WOT, can you sort of hold the GPS over your head behind you, key the speed reading and then swoosh the unit as far forward as you can reach......will it, like,
read 62.3 MPH?

Seriously, whats the fuss. We're already sitting on a speck of dirt thats going 19 miles a sec round the Sun and once you get to 12 million miles a minute its all pretty much a wash.



[This message has been edited by Owen (edited 09-02-2000).]

harbormaster
09-02-2000, 05:39 AM
Hey Owen,
Could YOU email me the pictures of Bertram Boy's boat? I have asked him in the past to email me photos for HIS registry page, but he still hasn't. I figured I would have better luck with you.

Scot V
Harbormaster with an attitude

[This message has been edited by harbormaster (edited 09-02-2000).]

[This message has been edited by harbormaster (edited 09-02-2000).]

BERTRAM BOY
09-02-2000, 09:36 AM
Hey Pain in the !@#$% Harbormaster ( ooops, was that out loud?).
But seriously that was one of the pics that I sent you , and you told me the quality was poor( which it obviously is ) It's just been raining here so much that I haven't had a good day for photos. Really, I didn't forget about you.realy I didn't....
BERTRAM BOY

P.S. Thanks Owen

[This message has been edited by BERTRAM BOY (edited 09-02-2000).]

RickR
09-02-2000, 11:48 AM
Jamesbon
My For Sale 454 has an open cooling system. I would upgrade the 454 but I don't think I can get the power I want and still retain the Silent Choice (that pesky cam reversion problem).
66.7 2wp(two way pass)in the 22 http://www.donzi.net/ubb/biggrin.gif
Lets get together week after next and have a cold one. Big Sarasota Pass?

Stromer are you game?

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RICKR
mailto:riggerb@aol.comriggerb@aol.com</A>

harbormaster
09-02-2000, 11:49 AM
Oh Good. I see I got the point across.

You should move to Texas where it doesn't rain. Its a sunny day here. Did I mention its 107 degrees?

And its MR. PAIN IN THE ASS TO YOU.

Scot V
(Pain in the Ass)
Harbormaster

Owen
09-02-2000, 05:44 PM
Bad Dog,
Waxing your bottom will actually slow you down.
I don't want to give bad info here cause I forgot what grit sandpaper you should use, but sanding the wot speed wetted surface so its alittle dull will break the vacuum effect water has on a perfectly smooth hull and give you a tiny boost. I think it was 400 to 650 grit, but I'd wait till the others chime in.

Hey CMDA, think you could run the idea of a thru hull air injection system on the forward edge of the wetted surface of a planing hull by one of your professors and see what he/she thinks? I'm thinking 200 psi thru hundreds of tiny holes right in the wetted contact patch. Match the psi with the weight of the boat and you're pretty much a hover-craft at that point.

[This message has been edited by Owen (edited 09-10-2000).]

wbateman
09-02-2000, 07:05 PM
Hey y'all. Lake E was great today!!! My 16 did GPS 50.5 today at 4800 with 4.3 V6 HO OMC
The dist conversion appears to be working. No more dropping Cyl.
Forest did 65 with his 16, 302.

Crazy Horse
09-03-2000, 01:20 AM
Harbormaster...My slant on things is the reason that you never got a pic of Bertram Boys boat is cuz it does not exist http://www.donzi.net/ubb/smile.gif
Best,
Crazy Horse

harbormaster
09-03-2000, 01:22 AM
Well I wasn't going to say anything but....

BERTRAM BOY
09-03-2000, 09:30 AM
Okay......
So now it's pain in the !@#$% Harbormaster and pain in the!@#$% Crazy Horse.... Who's next?
BERTRAM BOY

P.S. Excuse me, I meant "Mr." Pain in the ass Harbormaster!!!!

BERTRAM BOY
09-03-2000, 09:35 AM
So Madpoodle,
About the Ryborunner, did it have a sepparate compressor or was it able to run one off the engine?
BERTRAM BOY

Blewbyu
09-03-2000, 06:40 PM
Owen-To get air injection you want the air to BLOW.In a Hoover craft-it SUCKS.........
My 18 does 73 and I'm stickin' to it!
If I GPS or radar-I'll find out how fast it really is-don't wanna know!It's fast enuf now to make me "pull vinyl" when it gets too loose!That has to be 73.

Owen
09-04-2000, 12:15 AM
So like, if you take a hoover and, and bolt it to the deck and like point the sucking end towards the bow and like turn it on, would you get 73.01 MPH?

Owen
09-04-2000, 11:14 PM
"Infamous Venturi Effect?" What did the Venturi Effect ever do to you? http://www.donzi.net/ubb/smile.gif

I understand the stepped hull effect - did you know they were first used in 1927 in Chinese suicide torpedo boats? Basicly runabouts with seaplane floats slapped on; its TTTTRRRRRUUUUUEEEEE!

But I've never heard of a direct air injection system. I think I'll get a demo boat to the patent office, post haste.

So what does all this have to do with getting Classic Donzis to go alittle faster?
Not a god damn thing, but it was the inspiration for this next idea.

Oky, you really want to know a speed secret.


Shave your HEAD! Thats right, all that useless shagg cause'n drag.
So whip out the gillette happy razors and wax that chrome dome. Good for at least a tenth of a
mile per hour. And the Chicks Dig It.






[This message has been edited by Owen (edited 09-04-2000).]

GEOO
09-05-2000, 07:30 AM
Scott, I took the Rybo Runner for a test ride back in 1988. Great running boat.
Thanks for the hair drag idea. I'll save my hair and use a swim cap.

Owen, Thanks, I forgot about my bottom. So, I sanded the bottom paint last night with 80 to take out lumps & sags; then 120 grit to smoother it out. I'll post the results as soon as the water calms. 25knot NE 3-5 foot I'm not going out today http://www.donzi.net/ubb/frown.gif GEOO

[This message has been edited by GEOO (edited 09-05-2000).]

[This message has been edited by GEOO (edited 09-05-2000).]

PaulO
09-05-2000, 11:19 AM
I don't know about speed gains but, If you sand your bottom, you will probably not slide around on the seat as much!
PaulO

Owen, I hate to admit that I have had a thought similar to one of yours but, I have been working on the idea of air injection for some time now. Looking for a proper hull I can mangle.
PaulO

Bad Dog
09-05-2000, 04:14 PM
I shave my head anyway for other sports since it reduces wind resistance for baskeball and the like.

I'm not sure that will help me much on speed, although now that I think about it my passenger had a lot of hair...

Bret

------------------
Bret Pedigo
bret@emji.net

Blewbyu
09-09-2000, 08:00 PM
Owen-Think about it......whaddya think CDMA's prof/s will say when you tell 'em your Hoover craft has a "planning" hull?
2.Jasper must be close to California?Time and Space is big down there......but like planning is really a GOOD thing!

oldLenny
09-09-2000, 08:12 PM
Paulo...What are you thinking about?...I like the idea. Is this like some sort of shark thing/gills on the deck ahead of the windshield traversing through a rectangular tunnel to the underside of the hull to release and ventilate or am I out to lunch? The nice thing about this idea is when taking on a large wave/swamping it would merely go back to where it belongs. What are your thoughts? As well, if you ventilate around the vacinity (spelling?)of the wetted
surface while at high speed and/or planing, it will drive the bow down will it not? CDMA, you should know, (or at least soon) Just ahead of the wetted surface would push the bow up and not cause some sort of "new steering characteristic from HELL." Thoughts anyone...

Owen
09-10-2000, 04:27 AM
After a lengthy consideration of the ventilation induction idea; about two seconds, I think it would only work with counter rotating twins in a deep-vee design. A single screw will just want to roll over. But hey I started the search. Here's around where I'm looking. http://patents.uspto.gov/cgi-bin/ifetch4?ENG+PATBIB-1976-2000+0+989463+0+3+91572+OF+12+18+1+ventilation+AND +hull

[This message has been edited by Owen (edited 09-10-2000).]

PaulO
09-11-2000, 08:37 AM
Lenny,
Cool idea about funneling the air from the deck area. I was hoping to start out by playing with shapes and placement of the vents in the hull ( you may be right that the bow will come down with ventilation at the forward edge of the wetted surface). My thought was to see if you could get a venturi effect between the air and water and "suck" air into the ports without assistance. If not, force it with a blower. If it added any benefit, you could install valves for "tuning" the hull.
Just some thoughts.
PaulO