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[lleksam]

Hi
can any one please give me any advise I am building a Riva aquarama 860mm long 1/10 scale, I decided to go with a single jet drive and ordered (not arrived yet) a Graupner 2340 jet and a tornado 600 750Kv in runner motor to drive it, on looking at  size of jet and full size drawings i have of model I don't think jet outlet will be near water line may be a bit above. My question is can I place jet a few inches forward and "pipe" "duct" the outlet and put steering, jets - buckets on the end of extension tube? or could I put a "Y" in and make it twin outlet one each side and put steering on both?

Thanks

Steve

[knoby]

Anything is possible, but ducting the jet will reduce the power.
Why do you need to lower the jet outlet, is it just for scale appearance?
The jet will work with the outlet above the waterline, as its not the water stream pushing against the lake water that provides the propulsion, its Newton's law of motion ' to every action there is an equal & opposite reaction'
Or to put it in simple terms, if you chuck something out the back of the boat it will push it forwards.

Cheers Glenn

[lleksam]

thank you for reply, i realised about newtons law but for some reason i thought it had to exit below waterline my full size Glastron jet did I'm sure, But i do remember in the dark recesses of mind someting about that, the extension i was thinking of was a polished stainless tube with a off set in it, but if i don't need it why go to all that effort


Steve

[aslo44]

Hi Steve, I had a Virgin Atlantic Challenger not long ago and the reversing buckets sat just proud of the waterline
with the jets just below waterline. I would've thought if the jets were shooting into mid air (instead of the water )
you might loose "some" power. there are people on here with more knowlidge than me though so get a few Ideas
before you actually decide what to do and also have a look at other jet propelled boats . Hope this helps Alan.

[lleksam]

Hi Steve, I had a Virgin Atlantic Challenger not long ago and the reversing buckets sat just proud of the waterline
with the jets just below waterline. I would've thought if the jets were shooting into mid air (instead of the water )
you might loose "some" power. there are people on here with more knowlidge than me though so get a few Ideas
before you actually decide what to do and also have a look at other jet propelled boats . Hope this helps Alan.

Jet came today mmmmm, will come out about middle of back end and will possibly fill back end of boat, think this jet is a little on large size, looks like TIG welder will be comming out, a little electric glue on some stainless works wonders

Steve

[grasshopper]

Once a water jet sets off from rest the efflux is usually above the waterline anyway - the whole principle is as Knoby said -

Newtons law, the third one I think, 'to every action there is an equal and opposite reaction'

[lleksam]

Once a water jet sets off from rest the efflux is usually above the waterline anyway - the whole principle is as Knoby said -

Newtons law, the third one I think, 'to every action there is an equal and opposite reaction'

Point taken I think it will just look awfull, and I think bu size of this jet, you dont want to be standing behind it when you open throttle, (for those of us that can walk on water) or standing on slip way could get very wet


Steve

[lleksam]

a few pictures of jet on full size drawing, bull dog clips not compulsory



Steve

[MikeA]

why have you gone with a jet instead of propeller? im not sure is that motor big enough to run that pump?

[lleksam]

why have you gone with a jet instead of propeller? im not sure is that motor big enough to run that pump?

Hi Mike
see It is big enough, .... where i work we habe a 3/4 acre ornamental lake but there are areas of underwater weed, i thought it might be better there, and i used to have a full size glastron jet,
motor is a tornado 600w 750kv in runner, i can get another identical if i decide to go for twin props, and stick with origional drawings, may be able to talk to cornwall models and return jet, It is a lot larger than i expected or even visualised

Steve

[MikeA]

see if you can swap it for the graupner mini jet its 110 milimeters

[hopeitfloats]

on one of the original jet units (and i'm talking full size here) made by bill hamilton, the performance was increased by quite a lot when he moved the outlet from below waterline to above.

[essex2visuvesi]

can you not shave a little off the bottom of the white inlet moulding to bring the whole unit down a little?

[lleksam]

see if you can swap it for the graupner mini jet its 110 milimeters

How about this its some where between mini jet and "The Beast" http://www.jet-drive.de/index.php?option=com_virtuemart&page=shop.product_details&flypage=shop.flypage&product_id=17&Itemid=17

can you not shave a little off the bottom of the white inlet moulding to bring the whole unit down a little?

I think its just too big overall, and would more than ruin overall look if boat

Steve

[MikeA]

yer that looks good too

[lleksam]

Hi
Ordered http://www.jet-drive.de/index.php?page=shop.product_details&flypage=shop.flypage&product_id=9&category_id=4&manufacturer_id=0&option=com_virtuemart&Itemid=17  this one today along with a    
Turnigy B36-50-09 1500kv Inrunner to drive it, I have the water cooling jacket for it, decision made, time to carry on with hull, will take a few pictures as soon as i get shed insulated and a bench back in there

Steve