"Fat Boy" 12/118 thrust engine

[racket]

Hi Ron

LOL.............understand, and guilty as well :-)

The pressure switch www.ebay.com.au/itm/162616805688 for the water injection finally arrived in the mail so I can progress with cobbling something together , I'll have it set to start pumping once past ~1.5 Bar P2 .

Cheers
John

[racket]

Hi Guys

Bit of an update .

The waterpump and ancillories are fitted and tested , the pressure switch for the pump activates at ~1.45 Bar P2 and is wired from the fuel pump , no fuel no water , the pump isolator switch and relay are seperate cicuit .

The 3/8"X 1/16" WT stainless tube for the ~3" dia spray ring manifold arrived this morning so spent the day making it up .

The ring is situated just downstream of the P4t pitot and thermocouple pickups , spray holes are 25 X 1.1mm dia and squirting roughly radially, went through 8 drills getting them drilled, hard bits in the stainless ;-)

Will do some actual flow testing of the system tomorrow to find out if I've got my 5 lpm .

A couple of pics of the roughly assembled unit , will tidy things up after testing , the usual stuffups making the ring mount , had the 4 holes and screw threads nicely aligned before TIGing the mount to the ring stem , only to weld it on 180 degrees out despite marking it ,bummer ..... large clearance holes for the screws now :-(





Cheers
John

[finiteparts]

John,

I think you might want to put a check valve in the line to keep the Pt4 gas from back flowing into you water pump/reservoir. Just a thought.

- Chris

[racket]

Hi Chris

Yep , that'll be one of the checks today , hopefully the pump valve/s will act as a check valve as well , theres only several psi of static pressure to cope with in the jetpipe , the equivalent of 10-15 feet head of water , initially I had problems getting the pump to pump until I primed and fiddled a bit , I think a valve was stuck from the couple of years the pump has been sitting in my shed cupboard.

This is the type of pump I'm using www.ebay.com/itm/High-Pressure-Diaphragm-12v-Dc-Self-Priming-Pump-Water-100w-Abs-160-Psi-8l-Min/323580749913?hash=item4b56ea6859:g:KjsAAOSw~bhcBTL5

Cheers
John

[racket]

Hi Chris

Pump checked and its valves held back 30 psi of air over the water in the delivery line , so thats one less thing to worry about .

Flow at ~5 psi delivery pressure was ~6 LPM , so even with a bit of interstage static pressure I should be OK for my 5 LPM , the manifold flowed 16 LPM when connected to the household mains pressure .

The pump only flowed ~6.5 LPM of water through the delivery tubing even with the spray manifold removed , so I'm a tad wary of their claimed 8LPM , maybe with a head of water feeding the pump .

Cheers
John

[racket]

A pic of the manifold spraying

[azwood]

How come you went for a ring and not just a nozzle

[racket]

Hi Aaron

6 lpm = 360 lph =~95 US GPH , thats a huge nozzle ....... not easy to come by, plus I'd still have to mount it somehow , and besides , this setup has been used in our afterburners for years with good results.

Nozzles generally need more pressure than my 5 psi to get atomisation size down when expelled from a single large oriface , I've got 25 orifii with hot high speed gases doing the atomisation for me , image each of those 1.1mm dia oriface is like a carby main jet and my hot exhaust gases are the inlet airflow through the carb .............carbs have been working like this for forever :-)

Cheers
John

[azwood]

I've got a 1.2 nozzle somewhere I might test that with the 8gpm pump I have.had the kart fired up on the weekend with a few mates thair haha they hadn't seen one before they looked shocked

[pitciblackscotland]

Dec 1, 2019 22:19:10 GMT -5 racket said:

Hi Aaron

6 lpm = 360 lph =~95 US GPH , thats a huge nozzle ....... not easy to come by, plus I'd still have to mount it somehow , and besides , this setup has been used in our afterburners for years with good results.

Nozzles generally need more pressure than my 5 psi to get atomisation size down when expelled from a single large oriface , I've got 25 orifii with hot high speed gases doing the atomisation for me , image each of those 1.1mm dia oriface is like a carby main jet and my hot exhaust gases are the inlet airflow through the carb .............carbs have been working like this for forever :-)

Cheers
John

Hi John, LOL something like these nozzles which was out of a ship engine

Cheers,
Mark.

[racket]

Hi Aaron

Yeh , first timers get a little uneasy when a homemade turbine engine fires up and shocks them with the noise and energy coming from it , even the toughest of them take a cautionary step backwards :-)

Thankfully I don't need to get full vapourisation of all the water , unlike an afterburner , so if a few small droplets hit the turbine wheel it won't matter .

Cheers
Joh

[racket]

Hi Mark

LOL......You been on Ebay again ?

They're a serious size

Cheers
John

[pitciblackscotland]

Dec 2, 2019 2:50:36 GMT -5 racket said:

Hi Mark

LOL......You been on Ebay again ?

They're a serious size

Cheers
John

Hi John,
Yeah one of many ebay bargains i got over the years.

Cheers,
Mark.

[azwood]

Dec 2, 2019 2:49:26 GMT -5 racket said:

Hi Aaron

Yeh , first timers get a little uneasy when a homemade turbine engine fires up and shocks them with the noise and energy coming from it , even the toughest of them take a cautionary step backwards :-)

Thankfully I don't need to get full vapourisation of all the water , unlike an afterburner , so if a few small droplets hit the turbine wheel it won't matter .

Cheers
Joh

Yep a mate who is the size of a toilet block and scared of nobody ran for cover it was priceless

[htevo80]

Hi John
I was admiring your water injection work and I was curious how you bend the steel tupeing into a circle. I'm working on my after burner and it would be a big help. Thank you
Gavin