The Ghost

I use truck inner tubes because they are thicker material. As seen in the photo, you also have to remove the moulding on the joining line to get a good seal. I have mine out as I am replacing the seal.

Cheers

phillio35

thanks ghost i filled mine got the gasket from adam after i got the pump heres some pics of mine

kamipalms

quick update

The Ghost

Kamipalms
It's looking great, can't wait to see the video of it on the water.
Cheers

bermylizard

I am looking for a Jet drive for a 26cc CY engine in a 1000mm custom jet sprint hull I am designing. Plans will be available soon. For now I want to discuss Jet drives/pumps, build quality and thrusts ratings for the various jet drives available.

My research indicates Jettec NZ is the bees knees, but you pay for it $780 + delivery, and stock is hard to come by.
http://www.jettec.co.nz/#/shop/45634...Jettec/2208552

Then MHZ does two jets for 26cc engines , the Jet 4 and the Jet 52. Neither one comes with a grate.http://www.mhz-powerboats.com/category-11/category-22/

The MHZ Jet 52 is $380 + delivery with 120-240N static thrust.
The MHZ Jet 4 is $255 + delivery with 140N static thrust.

Then there is the HobbyKing XL pump for $392
http://www.hobbyking.com/hobbyking/s...e_X_Large.html
Apparently build quality is good in some areas or the pump (impeller, stator) and poor in others (housing). There is no performance data on the pump.

Some user thoughts/info on HK pumps can be found here:http://modeljetboat.com/forum/index....52.msg2547#new

Then there is Graupner Jet Propulsion Unit 5 (2347) not currently available but some have said the performance is okay.

Gravitix, I found today?
http://www.rcnz.com/Shop/Service/Detail/Product/6905

MHZ seems to be the only manufacturer to give thrust values. I want to see more technical details about the pumps. Perhaps users of the different pumps can offer some insight into the pumps performance? I heard that Jettec was 36% efficient compared to Graupner 18%, but have no details on the test procedure etc. Just numbers.

I am looking to build a review to help justify the cost and performance gains from one pump to the next.

If you own one of these pumps or other (with approx 50mm impellor for 26+cc engines) please drop a line to help.

How is the build quality?
What power pack do you have? (26cc modded or not etc.)
Have you measured static thrust? If so how much?
Is it reliable?

As the info comes together I will put in an easy and digestible form to help others make 'informed' purchases.

Thanks for your help,
Bermylizard

The Ghost

Bermylizard
The Jettec unit is a great unit, I am running with RCMK K30S out of the box, No problems with the jet unit. You say that stock is hard to come by, I have two and had no problem with delivery, within a week. Have not checked thrust as I have built the jet boats just to have fun.

Cheers

bermylizard

Thanks for your feedback.

I said that stock is hard to come by because the website says it is sold out. That said, it also says a few lines down that it is now available. So not sure what to believe. I'd like to be wrong and the pump available, but then I would also like to have the $1000NZD for the pump. =)

I am just trying to work out best bang for buck. Effectively i can acquire 2 MHZ pumps for the price of one Jettec pump, and that does not even consider import tax for the Jettec to the UK (if any). I am a firm believer that you get what you pay for. At the same time I would like to know what I am paying forin terms of performance and quality. Why should Ibuy the Jettec over the MHZ or other pump?

I also am having fun, but I check the thrust for fun, I must be a sad engineer =) Thanks again for your input, keep em coming.

Do you have any more specs? Top speed? max rpm? what ever you got, I would like to have it asI am building a spreadsheet that I populate based on information on the web (youtube videos and other forums), to try and simplify a decade of RC jet pump development.Does populating spreadsheets for fun make me really sad? Haha

Thanks again,

bermylizard

So here is the start of the table, can you help fill any sections in?
<colgroup><col width="110" span="9" style="mso-width-source:userset;mso-width-alt:4022; width:83pt" /> <col width="64" span="5" style="width:48pt" /> </colgroup>

Brand	Model	Req Power (Hp)	Static Thrust (N)	RPM	Impeller D (mm)	Impeller Blades	Impeller Pitch	Materials	Length	Height	Width	Mass	Shaft D
Jettec	Jet Unit	< 8	?	16000	55			Plastic/Composit	270	80	70	900	8
MHZ	Jet 4		140		49			Aluminium?	240	85		606	7
MHZ	Jet 52	3	120-240	16000	52			Aluminium?	210	80	81	670	8
Graupner	Jet 5 (2347)				49	5		Aluminium?	285	85	78	545	7
Hobby King	XL Jet Pump				53	4		Aluminium?	220	80	80		8
Gravitix	D50	>0.5			49	3,4,5		Plastic	265	85	76	270	6

sharpy22

hi guys jettec, to much , i like the hk, just starting my build to try pump

sharpy22

well tried the water pump in a cracker style hull ,works great tons of trust, but being flat, it kept losing contact with the water,pump awesome boat not so great,so im looking for a good used jet sprint hull to buy , any one know of one,let me know, thanx SHARPY

axsissti

building 1/8 hydro based on 92 tide with duel mhz jet 52 still working on power looking duel 6 cell lipo maybe motor totally up in the air

mickieb49

What size hull you after?
Dana makes a nice hull for Gas setups, or I can do a electric hull ?
Mick

axsissti

i got 2 1/8 scale framing kit from http://www.acutaboveboatworks.com/ in process of building 1 for water jets and 1 prop there about 44" long
'

axsissti

little behind in my project

swashdrive

Looks like u've bought another 2 of these knockoff hulls !
Who the dude doing this....name & shame man
I spent around 200hrs modelling and making this hull, theres some due's owed here !

The Ghost

Hi All,
Just to let every body know it looks like Adam at Jettec is no longer doing the jet drives as it looks like he has gone into full sized boats. All the 1/4 scale stuff has been removed from the website.

Cheers

swashdrive

Is this something Adam has told you or just something you've had a guess at ?
He is still buying jets off me, so i think if he was to stop i'd be the first to know, so i'd have to say proceed as normal jet boaters ! Jettec jets are still being pumped out !
Any info on those knockoff hulls yet ?

F1roddo

Have to agree with Ghost here, the Jettec website has no information on RC models or his Jettec jet drives. All his website shows, is info on his full size hulls and the different model range that he does. Looks like he may not be doing them anymore.

Cheers

F1roddo

I thought Swashdrive didn't make jet units anymore ? From the above statement, I guess this isn't the case, and it might explain why Jettec are so expensive.

Cheers

swashdrive

That is correct, i don't make em anymore...but i had a heap of mouldings lying around that i on-sold to Jettec,
who has made all the internal castings and assembled themselves,
that is were the real cost lies...the investment castings and also the lack of demand !
I hope this helps clear up any mis-understanding.

mickieb49

Ok, fair enough, but the question still begs, why doesn't he atleast list the jet units on his website? He certainly will not sell any units if everyone else thinks they are not available by not listing them?? Maybe i'm just a little simple minded here but that is what I was thinking....
Supply-demand.... no supply ( not listed) then certainly no demand, or is that what he wants?

swashdrive

Another possibility why adam has temp removed the jet is that for some time my CNC machining centre has
been out of action and as i finish machine the housings for jettec, this may be the reason why !
I really don't think he is walking away from this market fellas !

Cheers

The Ghost

Just got an email back from Adam(took a week) he is devoting his time to his full sized hulls. As has been said before, with out the items listed on a website the demand will drop and then what will happen.

Cheers

F1roddo

Well gotta say, that doesn't sound real promising for Jet boaters out there. I would imagine that if he is concentrating on the big boats, its now going to be hard to find a good quality jet unit.

Think Andrew is right, " As has been said before, with out the items listed on a website the demand will drop and then what will happen."

Cheers
Chris

mickieb49

Well Craig it seems like the demand is there, what about it? Scene you still have the tooling, how about getting back into manufacturing even if it is until Adam gets back into them? Hell, you could even just sell them under a different name if you wanted to be anonymous?