sundogz

That was found to be a limitation of the 2040 sized motor, not the pump. In particular the higher kv (>3500kv) motors on 3S will make more noise above 3/4 throttle, but not more speed - they just don't have the torque. But if you go to a 28mm (or larger) motor it will pump quite a bit more water!

willo jet

So what your saying is that the nitro engine should be fine for the jet unit ?? if not i can get a 40mm unit with rev bucket for 80 buks do not too worried.

Cheers

seehuusen

I say go for it mate, I can't imagine the nitro engine doesn't have the torque/HP that a 28mm motor has, which is what it boils down to

DRAGONFIRE81M

reailly your the first person to do this with this pump . i thought about it a few years back but didited to do it to a larger hull and useing the 28mm drive .

willo jet

Im half way threw the project so no point giving up !! lol

Well this pump is only 8mm smaller so...lol

No progress on the exhaust manifold haven't herd back from engineers yet lol

Ratrunner

only concern i might have is that the electric motors make 100% of available torque at zero rpm,
where the nitro motor has to get to high RPM before it makes any real torque at all.

this can be seen when a nitro tmaxx tries to pull an electric Emaxx.
the nitro one has more power available, but by the time it has made any significant power,
the electric one has pulled the nitro one very far backwards.

you might find that the motor has a tendance to stall as soon as it starts to suck water through the impeller.
some nitro boat owners that i know will even start the motor with the boat already in the water.
others just kinda throw to boat into the water, so it's not as much load on the prop hitting the water.

time will tell on how well this goes. i can't wait to see how this runs.
it will be very interesting to see.

Jason.

DRAGONFIRE81M

thats the tricky part . he wont know if the motor has anof power to turn the pump and get up to the rpm to make the power to stay going . has far as the stalling part . its going to need to be drict drive b/c of the cooling two as long as he uses the large flywheel on the motor he will be good . been there done that . my set up was a 31" hull with a 28mm drive and a ofna .32 motor .

if u like to see it heres a link http://www.youtube.com/watch?v=styk7GQaX1M&feature=plcp

what kinda manafold are u looking for

sundogz

Were you replying to me? All I know about Nitro motors is they are messy, noisy, slow off the line and smell as if they are harmful to the environment (no offense!). Where can you get a 40mm drive for $80?

willo jet

Thanks for the feedback it is all trail and error at this stage....

Im having a custom header made for me as im limited with room so its pretty much a16mm alu tube witch will conect too a 250mm stinger pipe.

As for starting the engine im looking at using a belt starter and ill proberly either start it in the water or by the edge with a slight bit of throtle applied too keep it running and pop it in the water ohh and it has a lager brass flywheel atm..

Cheers

DRAGONFIRE81M

yeah that large brass flywheel will keep it going when in the water . i bump the trottle trim on all my nitros it helps with starting

willo jet

yup i was going too trim the throttle up so i don't have too hold the tx and start the engine.

Well i cant do much atm till i get the exhaust manafold back so im going too tidy up the fiberglassing and look for a tx/rx.

What do you guys think about using a dogbone  from a nitro rc car as my drive shaft ? use the dogbone end in the flywheel and machine the other end to fit the new drive sleeve.

willo jet

Have a look at this bit of kiwi workmanship ! jettec.co.nz

And this guy here sells this unit and larger ones all nzd btw.

http://www.trademe.co.nz/toys-models...-477004540.htm

swervyn

well ive always found hobbyking good to deal with. they have tons and tons of stuff i dont need, but still seem to buy, postage is reasonable, prices are great, service is good! i had an order 2 days ago, they emailed me today to say one part was out of stock, so the whole order was on backorder, i sent msg on live support page saying credit will be fine so as not to hold up the rest of the order and recieved a reply and resolution within 30 minutes! pretty good service as far as im concerned! now if only they stocked 19mm impellers......

swervyn

some goodies here if anyone need spares:

http://stores.ebay.com.au/HobbyWonde...=p4634.c0.m322

http://www.ebay.com.au/itm/ws/eBayIS...m=400296677625

Wavekatcher

Maiden Voyage

I was able to get the 1st runs on my sons' NQD. The leak is fixed (for the most part), only get about a tablespoon of leakage for each run. I've got the 4800kv motor and 2S 2650mah 30c setup, not very fast, but lots of fun. I got 5 minutes on the 1st battery @ wot w/ 3.77 volts left per cell. 2nd run 4 minutes w/ 3.82 volts left per cell. (brand new batteries) The batteries were only slightly warm. Motor and esc (35amp seaking) were cool to touch.

Overall, I'm happy with the results. Thanks to everyone for the help!

seehuusen

well, I built the boat today And then I took it for its maiden voyage, man does it haul *****

seehuusen

woohoo, I just managed to get 2 of the last 8 from that eBay seller listed above, cheers for the link
and being from Australia, it should be a fast shipping time to QLD

willo jet

Ohhh wow thats good news !

I got a dogbone drive shaft today so on monday ill get into machining the new drive sleeve and still no exhaust manafold so ill go see the guy aswel.

willo jet

How is everyones boats going ?

Any pics yet martin ??

Well i gave the engineers at work the 90mm dogbone shaft and told him i want it shortened too 35mm with 10mm turned down too 3mm and 10mm of the sleeve drilled out to 3mm to accept the drive shaft so should have that in a day or so...

Cheers
Will

seehuusen

Hey guys,

willo jet

Martin,

Have you done the brass bush mod ?

seehuusen

I looked into it, and I've only seen hot prop shafts when the boat is out of water for extended amounts of time, on a fair bit of throttle... Even the stock motor will heat that little hole up Providing you back off the throttle when you are out of water, you'll probably find that it will last a fair while

littledvl

First time poster on here

I picked up a nqd jet awhile back, also ordered a 4800kv inrunner, and aseaking 60amp esc to go in it. I already had a hitec servo and a mr200rx to use for it.
Have had the stuff for a few weeks, finally got aroundto installing it all, hope to get a test run done tomorrow, gonna use sky lipos, 2s, 2200mah.

Hope it works, aif it does ill clean it all up and paint the hull, clean the wires up and such.

willo jet

Hi and welcome Littledvl hope this thread helps ya out !

Martin,

Well im trying too decide wether to do the mod or not or i might just buy a second jet unit just incase it craps out ! lol

seehuusen

well, what do you know... The copper tube I got is the exact inner diameter that it would work as a sleeve, but is copper an OK material to use?? Has anyone tried this before? Why is brass preferred?