Sprint Cat40 twin

[Rumdog]

Yeah baby! The Sprintcat is a sweeeet kitty! Turns on a dime !!!

[runzwithsizorz]

I applaud your innovations to the stinger roller bearings, I too, am working on something similar. However, I fail to understand the use of a reservoir, for without some sort of back pressure I doubt it could possibly, auto/gravitationally feed, regardless of oil viscosity.

[millzee]

any video comming??

[drwayne]

I applaud your innovations to the stinger roller bearings, I too, am working on something similar. However, I fail to understand the use of a reservoir, for without some sort of back pressure I doubt it could possibly, auto/gravitationally feed, regardless of oil viscosity.

chuckle. Oh yee of little faith.

60cc canister drained after 45 minutes of onwater time.. outlets closed with IV bag clipsl when boat returned for battery change.
I use light machine oil 15-20W.

[Fluid]

I fail to understand the use of a reservoir, for without some sort of back pressure I doubt it could possibly, auto/gravitationally feed, regardless of oil viscosity.

These are commonly used on gas boats in the US and have worked on hundreds of boats for years. The gassers generally use thicker oil than the Doc did too. A few do use pipe pressure to force feed but most do not. Proven technology.






.

[drwayne]

You are going to LOVE this boat. I'd mount the stingers a tad higher than your mock up position though.

with stingers as per mounted photo post #14 it hoots.. 7 min run time 2x6S1P45C5000 on X447

Also, I am anxious to see how it handles with the long rudder bracket. I used a very short bracket and it worked great.

re: rudder further back.. 6" behind transom... 1" behind prop trailing edges ... turns on a dime, gives change....

[runzwithsizorz]

Well now, don't I look/feel silly, but you know what they say about dumb questions. Good info, and thankz for the additional picz, Fluid. It's back to the drawing board for me. Doc, do you have bearings on either side of the oil feeds, or just a single bearing? Does the oil drain toward the prop, and/or the transom? Does the cable get any oil/lube? 80cc's an hour, on this side of the pond the EPA would throw my azz in jail, and charge me to drain the lake. Would a higher oil weight drain less, and still provide lubrication? "water lines from rear", rear where? hull, transom, or rudder? Are you satisfied with flow, and temps? Can you see the water exit from your near vertical outlets as you do a low level flyby? (if so, cool). It's a visual I'm also trying to attain, but a flat deck doesn't make it easy.
Sorry to be such a pest Doc, but this old dog is in need of a new trick. Cheerz!

[drwayne]

Well now, don't I look/feel silly, but you know what they say about dumb questions. Good info, and thankz for the additional picz, Fluid. It's back to the drawing board for me. Doc, do you have bearings on either side of the oil feeds, or just a single bearing? Does the oil drain toward the prop, and/or the transom? Does the cable get any oil/lube? 80cc's an hour, on this side of the pond the EPA would throw my azz in jail, and charge me to drain the lake. Would a higher oil weight drain less, and still provide lubrication? "water lines from rear", rear where? hull, transom, or rudder? Are you satisfied with flow, and temps? Can you see the water exit from your near vertical outlets as you do a low level flyby? (if so, cool). It's a visual I'm also trying to attain, but a flat deck doesn't make it easy.
Sorry to be such a pest Doc, but this old dog is in need of a new trick. Cheerz!

Hi
60cc ... yes, flow too fast
15-20W was convenient at time...
feed enters 0.25 ahead the 2 bearings and flows through..natural reservoir between the 2 still holding oil when disassembled later same day.
Hughey 3/16 flex have stub shaft of 2.75" .. .. I have 1.25" between bearing centers.. 1.5" of stub inside stinger ..1.25 out rear ..
I run teflon lined tube in hull to motor.. I use a thin graphite based motorcycle chainspray lube on the shaft flex.
Temps? .. but sure was slippery ...

why?
3/16 roller bearing spec sheets said grease <10k .. oil <35k rpm .. this setup runs ~40k ..
previous hydro roller setup with grease.. when pensioned off.. had grease/carbon nodules 'welded' to rollers + cage.. not very smooth ..
Considered oiler at top the flex .. to feed through .. flow needed at stinger concerned me about 'blow back'.. so opted for local feed.
Will work until someone points out why not !
cheers

W
ergo .. this oils bearings, not flex as is the usual ( as in Jay's pic above )

[drwayne]

Here she is.
First run on largish open water

http://www.youtube.com/watch?v=LDCCtrJOBBs

[runzwithsizorz]

You know what they say Doc, any landing you can walk away from,---- is a good landing.

[Rich]

These are commonly used on gas boats in the US and have worked on hundreds of boats for years. The gassers generally use thicker oil than the Doc did too. A few do use pipe pressure to force feed but most do not. Proven technology.






.

Thanks Fluid for the pics! I was looking for ideas for my MM...