avon 5,4 , anti caviation plate

mike-stgt · 07 February 2008, 21:41

Hi there,
on saturday i have to renew my engine plate .
I want to use a 85HP Evinrude on the boat.
Does someone has experience how much is the best distance between keel
and caviation plate? How much is the orginal measure from keel to top of engine plate? Ist the engine plate usually open on top, behind the alluminum
stripe and not closed with epoxy?
Thanks for your ideas

Mike

mike-stgt · 07 February 2008, 22:19

Sorry, my engine plate means the transom.

Nos4r2 · 07 February 2008, 23:08

Have you got any pictures of your boat?

I find that the anti cavitation plate needs to be as far below the V of the keel as possible for a standard long shaft engine. Mount the engine as low as possible and if need be you can move it up one bolt.

9D280 · 08 February 2008, 09:46

Mike,

Sounds like you are totally replacing the entire trasom (engine plate)? if so , seal it, and seal it well! Even if you are just replacing the metal bit that the engine sits against, seal it and seal it well!!! (but make sure it's dry inside first)

Water in the transom / floor is the favourite failure for old SRs......

mike-stgt · 08 February 2008, 17:51

Hi there,
i bought the rib 2 weeks ago in Italy, because it was not as far for me to transport it as from England.

It was converted to fix a short shaft engine and i have bought a 85HP V4 Evinrude longshaft and repair the transom this weekend.
I know , the normal measure for the transom is 20"to use longshaft, that means 50,8 cm.
The caviation plate has to be 2-4cm under the keel to prevent from caviation.
The keel of the searider is very deep and so i am looking for experience, how
deep the caviation plate must be in this case.

I sanded the transom and shall glue it with epoxy . I was only wondering, that the transom was not closed at the top, but only painted wood.

Greetings from Stuttgart
Mike

Locozodiac · 09 February 2008, 01:05

Quote:

Originally Posted by mike-stgt

Hi there,
on saturday i have to renew my engine plate .
I want to use a 85HP Evinrude on the boat.
Does someone has experience how much is the best distance between keel
and caviation plate? How much is the orginal measure from keel to top of engine plate? Ist the engine plate usually open on top, behind the alluminum
stripe and not closed with epoxy?
Thanks for your ideas

Mike

Hi

This is a standard information, don't know if this distances can be applied to your rib.

Happy Boating

Nos4r2 · 09 February 2008, 01:51

Quote:

Originally Posted by mike-stgt

Hi there,
i bought the rib 2 weeks ago in Italy, because it was not as far for me to transport it as from England.

It was converted to fix a short shaft engine and i have bought a 85HP V4 Evinrude longshaft and repair the transom this weekend.
I know , the normal measure for the transom is 20"to use longshaft, that means 50,8 cm.
The caviation plate has to be 2-4cm under the keel to prevent from caviation.
The keel of the searider is very deep and so i am looking for experience, how
deep the caviation plate must be in this case.

Mine is level with the keel and I can drop one hole on the engine bolts.The propeller will probably grip better with the anticavitation plate 2 cm below the keel-your V4 Evinrude will be a nice torquey motor and you will need the grip.

Quote:

Originally Posted by mike-stgt

I sanded the transom and shall glue it with epoxy . I was only wondering, that the transom was not closed at the top, but only painted wood.

The transom should be closed at the top-Avon use a 3mm aluminium strip. Avon weren't good at sealing them properly-but sealing it will be a good idea.

Chris · 09 February 2008, 08:23

Is having the anti ventilation plate below the keel necessary? I have mine set 2 inches above to get the best combination of grip and performance?

Or is this a SeaRider thing

Chris

Nos4r2 · 09 February 2008, 10:39

Quote:

Originally Posted by Chris

Is having the anti ventilation plate below the keel necessary? I have mine set 2 inches above to get the best combination of grip and performance?

Or is this a SeaRider thing

Chris

It appears to be a Searider thing.I do wonder if having the plate above the keel is maybe an Osprey thing though. It's higher than most have it as far as I know.

mike-stgt · 09 February 2008, 20:48

Hi there,
it is not a special thing to seariders, but normally the caviation plate is zero
with the keel to 50mm below keel. I only thought it should be the maximum of 50mm below, because the searider has a sharp V .
I try it with a transom high of 50cm , so i can adjust it lower or higher as
it improves riding.

avonsearider.nl · 09 February 2008, 22:42

Hello Mike,

Nice to see the picture's of your new Searider!

From the Dutch Avon Searider Club some ""official" Avon Searider Manual Instructions.

Engine Mounting:

Consult Your Manual for detailed instructions on egine mounting and peration.

The type of engines suitable for a 5.4 searider are longshaft as opposed to shortcraft. With the engine in position, the cavitation plate should be near level with the keel at the transom.

Single engines will need to be offset on the transome 25 mm( 1 inch) to starboard from the centre of the boat. This is to counter the centrifugal effect the engine has on the boat which can cause handling difficulties.

All holes drilled through the transom must be sealed to prevent water penetrating into the grain of the plywood.

Our Club experiance is as the adviced in the manual instuctions.

Average transom Hight SR5.4:is 52,5 CM

Yes to seal the plywood under the alu- strip is very important!

(In our opinion this habit is the only weak point on a Searider has !)

If it had't had this it wouldt last for ever.... (poor Avon sales mangers, nobody wouldt need a new one!!)

Also take precautions if you mount pieces (console etc.) to your floor.

C-ya @ www.avonsearider.nl

Greetings from the Netherlands,

Klaas Watze