Transom Weight Limits

[kwil]

That'll be why he has water coming out the bilge pump in that pic on flat calm day ?

Not quite, in the pic I am just putting the bucket away after washing all the mud off that we picked up whilst launching at our nice muddy Knott End slip.

Keith

[demondesmond]

Hey Keith I thought you had crew to swab the decks

[demondesmond]

Thanks to all who contributed I'm learning all the time (although I still don't know how to work out a transom weight limit.......)

[njensen]

I spent 4 years thinking about this issue, because i wanted more HP on my 4.7SR. I ended up simulating the "overweighted" transom by adding 45 kg of lead to my A-Frame. I got a little bit of chine walking at max speed.

The SR4.7 and SR5.4 has the same construction of the transom, and therefore i choose to believe it could physically carry the load of a 90 HP E-Tec (145 kg), since it's ok for the SR5.4.

Now i have had a 90 HP E-Tec on my SR4.7 for 1½ years (rated for 70HP).

The boat handles like a dream. I have never had any regrets. The E-Tec is awsome, and due to the steep hull on the SR i don't think the rated 70 HP gives it justice. 75 HP E-tec could have been fine, but the weight is the same as the 90 HP.

HP is not a problem, just use them wisely... weight is there no matter what... so simulate it....


Don't know about insurance issues in UK....so this is not a recommendation just facts on my 4 years of thinking about it.

[demondesmond]

njensen. It sounds like we have the same train of thought. I had spoken to my insurers some time ago and they were pretty relaxed about the possible engine change. In reality my 5m Destroyer is rated at 90HP anyway so Humber recon the power isn't an issue it is only the weight limit. I won't get a chance to get out for a couple of weeks but next trip I will be loading up the transom with the additional 35kg to see how she handles. After that who knows........ a contribution to the lifeboats or better still an etec 90HP

[njensen]

Originally Posted by demondesmond

njensen. It sounds like we have the same train of thought. I had spoken to my insurers some time ago and they were pretty relaxed about the possible engine change. In reality my 5m Destroyer is rated at 90HP anyway so Humber recon the power isn't an issue it is only the weight limit. I won't get a chance to get out for a couple of weeks but next trip I will be loading up the transom with the additional 35kg to see how she handles. After that who knows........ a contribution to the lifeboats or better still an etec 90HP

Remember to place it as far back as possible. 35 kg on the inside on the transom might not reflect the 35 kg of an engine hanging behind the transom.

Here is a picture of my test setup: (lead tubes tied to a-frame).

https://picasaweb.google.com/nikolaj...24303474855010

When the boat was load normally (2 persons in center) everything was good.
When i asked my friend to stand in the stern holding the a-frame, i got a bit of chine-walk.

however with my new engine, build-in 62L fueltank, new steering console, the chine-walk "problem" seems gone.

[demondesmond]

Wow njensen....you've got it all going on there. Took the liberty of having a look at the rest of your pics. Great job on the console by the way and I guess you're big into fishing.

Yep I'll get the weight as far back as possible when I get out next. Probably be a couple of weeks yet.

Des

[9D280]

....or join the Clamshell club and loose some KG!

[njensen]

Originally Posted by demondesmond

Wow njensen....you've got it all going on there. Took the liberty of having a look at the rest of your pics. Great job on the console by the way and I guess you're big into fishing.

Yep I'll get the weight as far back as possible when I get out next. Probably be a couple of weeks yet.

Des

I spend a lot of time doing that console/engine project. It was fun and cost a lot of money, but i also learned a lot. I also would have done a few things differently, if i were to start over agian.