Author Topic: cvx 18 top speeds (Read 11371 times)

california special · « **on:** June 02, 2014, 08:07:49 AM »

What is everyones top speed in a cvz/cvx 18? what motor, what prop, what apox hp?

still_fishin · « **Reply #1 on:** June 02, 2014, 09:29:53 AM »

63 mph, Turbo 3 blade 23 pitch, 260hp.

dorelse · « **Reply #2 on:** June 02, 2014, 10:05:31 AM »

55 mph, Piranha 4 blade 22p, 210hp. (CVZ-18)

I'm sure I'll be the slowest!

still_fishin · « **Reply #3 on:** June 02, 2014, 12:00:43 PM »

We can all go slower!

fireman24mn · « **Reply #4 on:** June 02, 2014, 02:49:01 PM »

My 18 was at 60.3mph with a 4 blade Rev 4 21P Guessing the HP at 290 it was a 302 small block Ford. It was by far the fastest prop I ever ran. My boat still had the original floor and the strakes were pretty beat up though. Thinking with a new floor and no water logged foam it would of been closer to 65.

carlsoncvx18 · « **Reply #5 on:** June 02, 2014, 04:39:06 PM »

68 laserII 23pitch at 5000rpm not sure of hp maybe somewhere around 330hp

Diamond Chad · « **Reply #6 on:** June 02, 2014, 04:47:57 PM »

58 at 4800 rpm, 21 pitch 3 blade mirage. 260hp. Online prop slippage calculator shows thats about 10% slippage, which is about right. Same calulator says will hit 63 with a 23". You have to know your outdrive gear ratio, my Alpha One is a 1.5:1

Diamond Chad · « **Reply #7 on:** June 02, 2014, 05:29:25 PM »

http://www.mercuryracing.com/propellers/propslipcalculator.php

Plugcheck · « **Reply #8 on:** June 02, 2014, 05:32:37 PM »

My CVZ has clocked about 25 feet in four months moving around the shop, does that count? Previous record was about 8mph with the bow vertical enough to rip my seat from the rotted floor, followed closely with a 5mph hot pass pushing the 16ss with a rope back to the dock. No records yet, but I'm considering some prop changes may help.

CVX Fever · « **Reply #9 on:** June 03, 2014, 10:05:00 AM »

Stock 228 MerCruiser(305/4 bbl) - 57 MPH @ 4000 RPM turning a 22P Enertia

Jerry · « **Reply #10 on:** June 03, 2014, 10:39:23 AM »

This one might do the same thing, I just like the way it works when you change things.

http://www.csgnetwork.com/marinepropcalc.html

David CVX-16 · « **Reply #11 on:** June 03, 2014, 10:54:23 AM »

Using Jerry's calulator, I get 5.5 percentage slip with my CVX-16.

2 to 1 lower unit gear ratio
5,500 RPM
23" pitch
56.6 MPH GPS

Diamond Chad · « **Reply #12 on:** June 03, 2014, 11:53:30 AM »

Seems to be using the same formula, with my numbers it came up with 0.09328571 and the other one came up with 9% for my 18.

Grinder · « **Reply #13 on:** June 03, 2014, 11:55:12 AM »

Stock 305 4BBL, 21P Laser II 57.7. I have not checked since before the thru hulls were added. May be a bit faster now.

CVX Fever · « **Reply #14 on:** June 03, 2014, 05:29:51 PM »

Shaun yours must run a little stronger than mine used to.

I got 56 MPH running a Laser II 21P at about 4500 RPM. Anything bigger than a 21P is too much prop w/305. Mine was a slug out of the hole with the 22P Enertia and a 23P Laser II.

OleRed · « **Reply #15 on:** June 03, 2014, 10:47:38 PM »

the prop calculators have never been right with the props I run on these boats, just kinda general, sometimes, but sometimes right on with popular props, not lab props, just type in ... 23 pitch prop, 1.5 ratio, 5200 rpm and see what you get, then ask how many of you has ridden n my scimitar at 73 / 75 mph the prop calculators say it won't go that fast.
it's just general, no block for rake, prop diamater, cupping, design, or labbed props.
anything less than 0.10% prop slip is good, cruising at 2800 rpm, 34 mph is showing my boat
.07 and some calculators don't even show that, it's about the props, weight of the boats, length, water temp, climate temp, not the calculators, run what works for you and your boat.
Fast is better

california special · « **Reply #16 on:** June 05, 2014, 07:52:10 AM »

5.7 bored 60 over. 63mph 20 pitch powertech

kert0307 · « **Reply #17 on:** June 05, 2014, 08:11:40 AM »

I bet that motor was screaming at 63 with a 20 pitch prop!

CVX Fever · « **Reply #18 on:** June 05, 2014, 12:04:17 PM »

Its nice to see an RPM reading. Prop pitch & speed don't tell the whole story.

california special · « **Reply #19 on:** June 06, 2014, 06:33:56 AM »

i think its around 5100 rpms. i have a 23 mirage to try but i have a feeling i wont get the speed. rpms = speed with my motor