Pump Blueprinting

[tnj4life]

Ive been blueprinting my pumps this winter on 2 of my skis over the winter, ive been bored (no pun intended). Ive gotta get the flex cable for my dremel to reach further back, I tore my other one up. My question is this, is this a worthwhile mod on a smaller pump? Can anyone tell a difference once done, im talking actually feeling the difference? Or is it a waist of time? If its not worth anything im going to just throw my skis back together and ride.

 

[Mark44]

Not worth the trouble and mess IMO. You will feel no difference.

Unless you just have nothing better to do with your time then have at it.

Mark44

 

[tnj4life]

Thats what I wanted to know. All those hours of grinding in vain. I did manage to drive my wife crazy while doing it so thats worth something, I done it in the house while she was trying to watch tv.

 

[Foximus]

only worth it on the small 550 and fx1 pumps.

or if your using a TBM big hub cone

 

[tnj4life]

only worth it on the small 550 and fx1 pumps.

or if your using a TBM big hub cone

One is a 550 pump on my 440/750 conversion ski. I have it halfway done so I guess i'll continue, That little pump does need all the help it can get. I just gotta come up with a flex cable for my dremel.

 

[Foximus]

well 440 pumps dont need it.... so if its a 440 750 conversion, your better getting a 550 pump. And you should need a flex bit, just a ton of sanding bits on a 1/8" bit.

 

[tnj4life]

I have a 550 pump on my 440. My dremel wont reach far enough back to get all the edges ground down. Ive been using a grinding stone bit with a coat of candle wax to keep the aluminum from sticking.

 

[Foximus]

you should have taken off the impeller so you can get at it from both ends.

Ditch the wax and stone, that will take FOREVER. Get 10-15 sanding drums.

 

[tnj4life]

Good points, i'll have to go dig out my impeller tool. The stone doesnt seem to be that slow. I may run a drum over it when Im done to make it smooth. Its not a professional job, but mainly taking down the raised edges and smoothing it out somewhat.

 

[Foximus]

If you do it nicely you can gain 2-4 mm in overall pump diameter from cutting the inside and outside walls. Theres lots of little secrets in 550 blue printing... =]

 

[tnj4life]

Hmmm secrets?? I bet 4mm would help that little pump flow better huh? I really dont think I have the patience to take 4mm off with a dremel! Does it work that much faster with the drums?

 

[Foximus]

Sanding drums seem to almost always work better than stone bits, you just need 10-20 of them as they burn through fast.. The main areas to deal with after you do all the grunt work is turning the 3 bolt bodies down the hub into smooth ramps. Also there are 2 recesses down the outside walls that you can take metal out of and open up the width there.


If you want to take it down fast youll have to get a nice 1/4" air dremel and porting bit.

 

[tnj4life]

I have a die grinder and some carbide porting bits. The biggest thing is keeping the aluminum from sticking to the bits. Does taking that much out help the cavitation issues some? Well the secrets are out now, how much do I owe you?

 

[Foximus]

LoL, taking it out deffinately helps unload the pump some. A built 750 motor can rip the veins out just from pump pressure alone if it revs to high, and making those areas flow better definitely help.

 

[tnj4life]

Not my 750, its a sad stock one with 110 per hole. I have managed to throw a sbn44 on it during winter.

 

[Foximus]

Ouch! Take that cylinder off for a hone and new rings before you do anything else!

 

[tnj4life]

Ive been running it like that for a while, I do need to hone and ring it. It was a nice 150 per hole motor when I bought it. I never checked for air leaks, well I learned the hard way. Bad crank seals and case seal. Now I try to check my motors somewhat often. Will rings/honing get me back close? I think my cylinders are bored to the max.

 

[Foximus]

I dunno, could be a headgasket.... but it would be good if you havnt had a rebuild in a while.

 

[tnj4life]

Your right foximus. Now that I got the impeller out im on the thick stuff and its taking forever! I gotta get the die grinder out tomorrow evening.

Got a ride review of that 550 you built with the 701 and big pump?

 

[Foximus]

Yea... ride review = AWEESOME


Its the most squirrely ski Ive ever riden. Nothing even comes close. its a good 30-35 lbs lighter than a fx1, even with a full gas tank.


I'm getting a TBM pump cone and it should be out of this world with this new motor im building (which for superjet standards is really nothing all that special)
I couldnt imagine it with a team scream or Jetworks motor.... Itd rip right out .