willisdaye
Member
Joined: September 2015
Posts: 41 
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Post by willisdaye on Feb 21, 2016 13:31:09 GMT -5
Thanks. So is removing the safety valve safe? I don't have a ton of experience with propane tanks and such. It's also an almost full tank...
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Post by smithy1 on Feb 21, 2016 13:42:01 GMT -5
On the oil subject in heavy truck motors the oil temp is kept to 110 - 118 degrees Celsius for efficiency. The turbos produce up to 40 psi pressure with oil this hot at about 230 Kpa. Any hotter and the oil losses its ability to protect components and any lower creates excessive lead on components due to viscosity. I try to keep my oil temp as low as possible....good oil circulation, plenty of oil capacity...whilst being pumped through a cooler with plenty of surface area and I rarely see temps above 70-75C even after several engine runs. We also like to keep pressures above 50-55psi if possible...The GT6041 thrust plate setup allows for high oil pressures but still allows for easy rotation for starting....unfortunately not all turbos have this feature. Even at 70+psi oil pressure the rotor turns easily with a flick of a finger. The lube system John built for my 6041 is working very well, I've made a few "modifications" to it to add a cooler with it's extra -10AN plumbing, check valve and a temp gauge etc. I never see pressures below 55psi even when oil is warm....when cold it's up at ~72 psi. John's systems are usually very simple....but they just work ...and are super reliable. If you over-engineer things by ~25-30%, there's always plenty of reserve if you need it. Smithy. |
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willisdaye
Member
Joined: September 2015
Posts: 41
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Post by willisdaye on Feb 24, 2016 15:26:15 GMT -5
So I found out that it's the nut on the propane cylinder that has the shutoff valve in it. Its max ouput is 200,000 btu/hr. If any more than that comes out at a time, it will shut off the flow. However, I can get a high flow nut that tops out at 400,000 btu/hr. Will this higher capacity be enough?
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Post by smithy1 on Feb 24, 2016 18:28:24 GMT -5
So I found out that it's the nut on the propane cylinder that has the shutoff valve in it. Its max ouput is 200,000 btu/hr. If any more than that comes out at a time, it will shut off the flow. However, I can get a high flow nut that tops out at 400,000 btu/hr. Will this higher capacity be enough? I'd be "Modifying" one to suit yourself....the tap/valve assembly may be all you need, It's hard to know exactly how much flow you'll need until you get your engine running. You shouldn't need a huge amount of flow for starting, just enough to keep the fire lit until the real fuel takes over. I've also got a flashback/check valve in the line for safety. Smithy. |
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ripcrow
Veteran Member
Joined: December 2015
Posts: 114
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Post by ripcrow on Feb 26, 2016 5:09:09 GMT -5
On the oil subject in heavy truck motors the oil temp is kept to 110 - 118 degrees Celsius for efficiency. The turbos produce up to 40 psi pressure with oil this hot at about 230 Kpa. Any hotter and the oil losses its ability to protect components and any lower creates excessive lead on components due to viscosity. I try to keep my oil temp as low as possible....good oil circulation, plenty of oil capacity...whilst being pumped through a cooler with plenty of surface area and I rarely see temps above 70-75C even after several engine runs. We also like to keep pressures above 50-55psi if possible...The GT6041 thrust plate setup allows for high oil pressures but still allows for easy rotation for starting....unfortunately not all turbos have this feature. Even at 70+psi oil pressure the rotor turns easily with a flick of a finger. The lube system John built for my 6041 is working very well, I've made a few "modifications" to it to add a cooler with it's extra -10AN plumbing, check valve and a temp gauge etc. I never see pressures below 55psi even when oil is warm....when cold it's up at ~72 psi. John's systems are usually very simple....but they just work ...and are super reliable. If you over-engineer things by ~25-30%, there's always plenty of reserve if you need it. Smithy. Smithy I think you missed my point. With modern heavy vehicle oil you can run it outside of accepted parameters. While the truck engine has a oil thermostat to maintain that 110-118 temp range for effiency and run lower pressure but higher flow rates to achieve the same protection. I agree more is better but using top quality oil allows a little lee way. |
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Post by smithy1 on Feb 28, 2016 16:53:24 GMT -5
Oh, I'm not arguing with you rip, I totally agree with you about the modern oils....I guess I'm just a bit anal about pressures, the hotter the oil the lower the pressure tends to become, all else being equal...I'm probably being a bit over-cautious but I've seen what happens to turbo bearings when the oil pressure isn't as it should be, once the bearings start to wear, the end is nigh!
As you're well aware, turbos need a goodly amount of pressure to keep the fluid "cushioning" in case the turbo balancing isn't optimal, plenty of flow is one thing but i like to see plenty of pressure as well...as long as I see ~55-60psi on my beast when the oil is warm/hot, I'm happy.
Cheers,
Smithy.
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Post by racket on Feb 28, 2016 20:58:48 GMT -5
The problem with having sump oil temp at elevated temps is when the extra 50 deg C is added as it passes through the turbocharger , the exit temp could be beyond the oils limit .
With 75 deg C for a turbo oil inlet temp its at a reasonable temperature out , our turbine temps are going to be hotter than a diesel truck exhaust temp in most cases, with probably more heat soakback along the shaft
Cheers
John
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Post by smithy1 on Feb 28, 2016 21:11:52 GMT -5
Spot on John, and hence why I like to keep it as low as possible....
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