Calling all Channel island 22 owners!

Ive tried a couple, but get varied answers from each one. I also cant really fill the form in as well as id like to get it more accurate as i have no idea what she is capable of. It could be anything from the 11/12kts im getting to the 18/19kts the people with the 140's say theyve had.
Id hope for around 15. 15 or above would make me a happy camper.
 
I think the rule of thumb for outboards is 1" pitch change gives 500rpm change in max revs. Don't know how this transfers to low speed diesels. My understanding is a D4 max revs are 2500, first thing to check is you can get max revs in neutral. If you can't then you need to adjust the stop. If you can get max in neutral but not when in gear, assuming a clean hull you need to check the prop for damage, if it is ok then you need to change it.
 
gordmac said:
I think the rule of thumb for outboards is 1" pitch change gives 500rpm change in max revs. Don't know how this transfers to low speed diesels. My understanding is a D4 max revs are 2500, first thing to check is you can get max revs in neutral. If you can't then you need to adjust the stop. If you can get max in neutral but not when in gear, assuming a clean hull you need to check the prop for damage, if it is ok then you need to change it.
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I can't swear to it but i think you are wrong about 1 inch pitch gives 500rpm change for outboards, my understanding is about half that, more like 200rpm per 1 inch pitch.
 
Davy_S said:
I can't swear to it but i think you are wrong about 1 inch pitch gives 500rpm change for outboards, my understanding is about half that, more like 200rpm per 1 inch pitch.
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Props are a Black Art!
I'm no expert by a long way but I believe the calcs/figures above will relate in a different manner to the CI 22 as a semi displacement shaft driven vessel as opposed to an out board
My CI 22 with a 140 turbo Mermaid made 19.75 knots
This was after a complete rebuild
I mean a Complete rebuild from stem to stern!
Too much to list here
However I did try a 4 bladed prop but reverted to a 3
'Aquapoise' I had it made/ tuned by Castle Marine in Caernarfon
It was a long time ago so I dont think they would have a record
They have a great 'prop Calc' facility on their web sight by the way
The Yard that fitted the prop and did loads of work on the boat for me is still going
I must visit them. Well 'Him' really!
An old fashioned boat builder on the Menai Strait
Wouldn't be suprised if somewhere in His desk at the end of the Shed he still has a little book with that kinda detail pencilled in somewhere!
There are still old fashioned boat building tools in the 'shed' that look like Spanish Inquisition Torture gadgetts to me!
My Man still does some work, if He likes the cut of yer jib etc etc!
I will go there over the next few days and have a cup of tea
That said I might die, I think the cups are due to be washed in 2020!
Ref some remarks about the CI 22's being 'twitchy' at WOT
I altered the rudder and the steering pump
I had too many turns on the Helm initially
So I bought a steering pump with different gearing
Five and half turns in total
The origional had almost 12!
Plus I altered the rudder
Did away with the 'leading Edge'
So more 'rudder' was aft
In that there was not the piece of blade forward of the rudder shaft
Hope that makes sense
This calmed everything down at high speed and made for more control when berthing
I think the prop was 15X 13 but memory escapes me
It was 20 or more years ago in my defence!
I do remember at 19kts ish She was doing 2200/2300 RPM
At 1900 to 2000 She cruised between 14/ 16 kts
I remember a trip of about 55 miles from the IOM to the mouth of the Strait (Anglesey) took 4 hours 35 mins once
I think I got the Tide right too that day!
Yes I will visit my old mate the boat builder pretty soon
Flipflop 1982 needs answers too I think!
How are you 'Flipper'!:D
So I will reply asap
If I survive the the Cuppa!
:encouragement::nonchalance:
 
I was selling a boat with an inboard diesel, never had a problem with the engine (until the day I had a buyer) took the boat out and would not reach normal revs and was chucking black smoke out.
It turned out that a fishing net had wrapped itself around the propeller, perhaps worth checking.
 
Davy_S said:
I can't swear to it but i think you are wrong about 1 inch pitch gives 500rpm change for outboards, my understanding is about half that, more like 200rpm per 1 inch pitch.
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I wasn't sure as I have inboard diesels not an outboard, on reflection 200rpm is probably more accurate.
 
Checked with the Boatyard and Builder chap who helped me sort my Channel Island out
Drive was 1 to 1 IE 'direct' the Prop was 14 X 13
140 turbo gave max at 19.5 kts and cruised at 12/14 kts at about 2000 to 2001 rpm
Flat outthe steering was not twitchy
In a strong following sea though, lots of activity on the helm
Hope this helps!!!
 
Hey Kawasaki, sorry been out of it with flu and work for a while.
Surprised you had a 14x13 as others on the forum have said the turbo4 runs best with a 15x13.5 prop but thanks for the info.
Ive also seen a few 85hp on the interweb claiming 15kts top speed, and may even go and seatest one to see if its just B/S or not as it seems quite high!
I got onto a few firms in the end, clements marine being the most helpful and reccommending a 14x11 or 15x10 to allow the turbo to fully boost.
The prop i had on was a 14x13 when i removed it a while back. this weekend managed to pick up a barely used 14x11 on ebay for £23! Which obviously i dont mind paying for and testing at that price!
Going to collect tomorrow and hopefully will fit some point in the next 2 weeks.
Il report back what happened in regards to speed increase.

Lutefiskgeorge how have you faired in getting info?

Rich, il also give you a bell for a chat when ive sorted all that out. Ive got a mountain of work to catch up on at the mo. Xx
 
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