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Post by racket on May 3, 2016 0:32:02 GMT -5
Hi Andy 25 psi is a tad low . Warm oil will flow quicker so more needs to be pressurised so load may go up . Turbo drain oil won't be going very fast when cold but the quantity will increase substantially when warmed Don't know about what happens when its spinning , too many other things to concentrate on , as long as the pressure stays high I don't care too much. Power steering pumps need internal mods to be 100% satisfactory . The Shurflo model 8000-643-236 with buna seals works OK legacy.shurflo.com/pages/new_industrial/industrial/agriculture/doc_sum/8000-643-236.html but only for smaller engines as the demand from a big engine running warm oil will be too much . Cheers John |
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steamn51
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Joined: March 2016
Posts: 14
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Post by steamn51 on May 3, 2016 4:00:03 GMT -5
Hi John
Thanks for your input, will reconsider the options, gone this far I dont want to destroy turbo.
Cheers
Andy
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Post by smithy1 on May 3, 2016 15:15:13 GMT -5
Hi Andy,
As John mentions, 25psi is just too low, especially when cold....when warm this will drop off substantially. Don't overthink things too much, the oil supply system for most turbos is simple really. As long as the supply has enough volume and pressure.... and the drain has enough capacity to get back to tank easily it will work.
A small-ish turbo like the one you have doesn't need much in the way of volume but the supply pressure must be adequate to keep your turbo alive, I'd suggest something around 40-45psi and above when warm.
The oil system on my big GT6041 which John designed has ~70psi when cold and drops to ~55-60psi when warm, (~80-90C), after a couple of consecutive runs.
When warm, the drain back to tank will be fast flowing and possibly aerated or foaming so there needs to be a "diffuser" of sorts in the top of the tank to help this foaming oil to dissipate.
I can drop by one day and we can have a look at what, if anything, you may need to change etc...
Cheers,
Smithy.
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steamn51
Member
Joined: March 2016
Posts: 14
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Post by steamn51 on May 3, 2016 20:14:23 GMT -5
Thanks buddy, I need top check battery voltage as maybe this is effecting the 12v motor above 25psi.
Are you at Bankstown airport?
Cheers
Andy
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Post by smithy1 on May 3, 2016 21:26:13 GMT -5
Thanks buddy, I need top check battery voltage as maybe this is effecting the 12v motor above 25psi. Are you at Bankstown airport? Cheers Andy I have a proper battery "Drop load tester" if it helps.?? Do you know how many amps the 12v motor is pulling? Used to be at Bankstown Airport when I was with Hawker De-Havilland some years ago, I now work for another aircraft engine maintenance/overhaul company in Chester Hill, so not too far away. I drive past Bankstown Airport every day on the way home from work. Cheers, Smithy. |
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steamn51
Member
Joined: March 2016
Posts: 14
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Post by steamn51 on Jul 13, 2016 4:58:14 GMT -5
Hi gents I took the geared 12v pump which couldn't pump the correct pressure and made a new shaft and bearing housing so it could be direct drive of 240v motor. I mounted a bypass valve as suggested and now find the oil pressure as high as 100psi. The return form turbo has good flow. The gauge starts to flutter at no bypass which looks around 100psi its the hard to get it to stabilise at say 50psi. I guess this means its a goer, I will just recheck it before ignition. Cheers Andy  |
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Post by smithy1 on Jul 13, 2016 18:24:48 GMT -5
Hi Andy,
100psi is probably getting a bit high, but still should be usable and may well drop off a bit when the oil is warm, it may also make the turbo a bit hard to turn and possibly cause issues during engine start...most of our pumps have relief valves and can be adjusted via shims or screw/spring adjustment to get the desired pressure.
Cheers,
Smithy.
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steamn51
Member
Joined: March 2016
Posts: 14
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Post by steamn51 on Jul 15, 2016 22:26:52 GMT -5
Hi Smithy
Just been fiddling and it seems good at 50 psi.
At first the 240 motor is quiet and seems to be loaded and after a few minutes it speeds up, may be this is due to the airation of the oil.
Anyway looks like pump issue is solved.
Theres a video of you kart next to a mx track, Appin?
Cheers
Andy
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Post by smithy1 on Jul 17, 2016 14:35:30 GMT -5
Hi Smithy Just been fiddling and it seems good at 50 psi. At first the 240 motor is quiet and seems to be loaded and after a few minutes it speeds up, may be this is due to the airation of the oil. Anyway looks like pump issue is solved. Theres a video of you kart next to a mx track, Appin? Cheers Andy 50 psi is near perfect.. ;-) Yep, that vid was taken at Appin MX track, just up the road from my place, I have a good mate who works there..! It was just after the new A/B pipe was fitted....doing a little "testing". Cheers, Smithy. |
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turbo
Member
Joined: June 2016
Posts: 11 
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Post by turbo on Oct 2, 2016 1:34:10 GMT -5
Hi Andy A synthetic 5W-40 oil will do the job nicely All the best with the spoolup :-) You mention that its a T3T4 unit , hopefully the compressor inducer isn't bigger than the turbine exducer as you might have difficulties getting it to run . Cheers John Hi my fist build was a t3 t4 started and ran OK only problem I had was that my combustion chamber was too small and I wrecked a number of turbines.My current unit is a t4 turbine with at5 compressor ,a good sized combustion chamber it starts well and idle well ,with 6 bar fuel pressure I get 2 bar boost , I was using automatic transmission oil and used air impingement for starting. |
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