EMC 2017 353ci SBC

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GARY C
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Re: EMC 2017 353ci SBC

Post by GARY C » Mon Jan 15, 2018 4:23 pm

MadBill wrote:
Mon Jan 15, 2018 9:32 am
My drill I'd guess typically gets ~ 3-400 RPM (6-800 engine) once the pressure comes up and depending on clearances, temperature and viscosity, ~ 20-30 psi. I don't know the range of the resulting flow rates but my S.W.A.G. is it draws <0.10 hp. (I suppose I could use a corded drill and compare amps running free vs. under pressure, assume a number for efficiency and calculate the power demand, but that sounds too much like work! #-o
Wouldn't it rob more power at higher rpm?
It seems like it would be worse with HV HP due to trying to flow more oil than the cavity will allow.
It's possible to get full pressure on a primed engine with a cordless but would it achieve the volume needed?

I ran a 13.1 377 sbc solid roller engine on nitrous for 3 seasons with max psi of 45/48 range at 7500 to 8000 on the eighth mile with no oil related issues so I am not in favor of high oil pressure. :D

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Re: EMC 2017 353ci SBC

Post by MadBill » Mon Jan 15, 2018 9:20 pm

Yes it would take more power, especially with HV/HP
I think it might take more volume to pressurize a rotating engine, as more leakage/flow path average area would be in play.

randy331/CGT are the only ones I've heard of that have actually tested oil pump power demand, but they may well feel the data is a hard-earned secret.
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.

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Re: EMC 2017 353ci SBC

Post by randy331 » Mon Jan 15, 2018 10:58 pm

MadBill wrote:
Mon Jan 15, 2018 9:20 pm
Yes it would take more power, especially with HV/HP
I think it might take more volume to pressurize a rotating engine, as more leakage/flow path average area would be in play.

randy331/CGT are the only ones I've heard of that have actually tested oil pump power demand, but they may well feel the data is a hard-earned secret.
SekretZ :) ? I thought our group has been pretty open with what we did/learned on the EMC testing.

I can't give exact numbers off the top of my head cause I don't remember. I'd have to look up the pulls to know for sure and I don't even remember if the last few days worth of testing have been sent to me? And I've been on several more dyno sessions since then, so no way my mind can remember it.

But what we gained in power with the low volume/pressure pump I don't think is just power to drive the pump. Some more testing would be needed.
Like try the same tests with a very nice custom pan and lots of vacuum. It'd give some idea if/how much of the power gain is from windage etc and how much from pump drive only.

For the record, I'm currently building a 421 cube SBC for a truck pulling class that allows 472 cube big blocks. We need ALL the power we can get, and it's not getting a low pressure/low volume pump.

Randy

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Re: EMC 2017 353ci SBC

Post by Rick360 » Tue Jan 16, 2018 12:29 am

Looked at the dyno sheets and the avg power gain (3500-6800) was about 3-4hp (did couple of pulls). Low end of rpm range gained as much or more than the upper rpm range (explain that). The oil pressure went from 60-65psi on the std pump to 45-52psi with the low volume pump and low pressure spring.

When we tested the oil pumps on the test rig and drill I think we had the same pressure spring in each pump but don't remember for sure as that was 6 years ago. I do remember that there was no noticeable difference in amps in any mode that the pumps were tested.

Par for the course. Each test generates more questions than answers. :-k

I think the pressure difference was the reason for the HP gain. As others have said ... was it the reduction in pump load that gained the power or the reduced windage from lower oil flow. There are other ways to reduce oil flow that may be worth investigating.

Rick

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Re: EMC 2017 353ci SBC

Post by Warp Speed » Tue Jan 16, 2018 5:05 am

There can be a slight torque to turn difference between pressures, but most all the power gains with lower oil pressures, are based around oil control in the crankcase.

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Re: EMC 2017 353ci SBC

Post by mekilljoydammit » Tue Jan 16, 2018 9:06 am

MadBill wrote:
Mon Jan 15, 2018 9:20 pm
Yes it would take more power, especially with HV/HP
I think it might take more volume to pressurize a rotating engine, as more leakage/flow path average area would be in play.
Just to touch on this as someone who was an engineer in the R&D lab of an industrial bearing manufacturer for a few years... barring something like variable valve timing, and unless I'm not thinking of something with regards to lifter motion, it should actually be the opposite. If you think about a journal sitting in a bearing, the leakage area is one circle minus another... but at the tiny areas separations comes into play a lot, and the viscosity losses will be such that the journal sitting stationary in the bottom of the bearing will be flowing more than the journal suspended roughly in the middle of the bearing.

... well, as long as the viscosity is the same and it won't be because the rotating bearing will be heating up the oil, but the math to do even the bad approximations of fluid film bearings gets annoying quickly.

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Re: EMC 2017 353ci SBC

Post by Warp Speed » Tue Jan 16, 2018 10:20 am

mekilljoydammit wrote:
Tue Jan 16, 2018 9:06 am
MadBill wrote:
Mon Jan 15, 2018 9:20 pm
Yes it would take more power, especially with HV/HP
I think it might take more volume to pressurize a rotating engine, as more leakage/flow path average area would be in play.
Just to touch on this as someone who was an engineer in the R&D lab of an industrial bearing manufacturer for a few years... barring something like variable valve timing, and unless I'm not thinking of something with regards to lifter motion, it should actually be the opposite. If you think about a journal sitting in a bearing, the leakage area is one circle minus another... but at the tiny areas separations comes into play a lot, and the viscosity losses will be such that the journal sitting stationary in the bottom of the bearing will be flowing more than the journal suspended roughly in the middle of the bearing.

... well, as long as the viscosity is the same and it won't be because the rotating bearing will be heating up the oil, but the math to do even the bad approximations of fluid film bearings gets annoying quickly.
This would be true if running clearances remained the same as static, but they don't.

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Re: EMC 2017 353ci SBC

Post by mekilljoydammit » Tue Jan 16, 2018 10:40 am

Warp Speed wrote:
Tue Jan 16, 2018 10:20 am
mekilljoydammit wrote:
Tue Jan 16, 2018 9:06 am
MadBill wrote:
Mon Jan 15, 2018 9:20 pm
Yes it would take more power, especially with HV/HP
I think it might take more volume to pressurize a rotating engine, as more leakage/flow path average area would be in play.
Just to touch on this as someone who was an engineer in the R&D lab of an industrial bearing manufacturer for a few years... barring something like variable valve timing, and unless I'm not thinking of something with regards to lifter motion, it should actually be the opposite. If you think about a journal sitting in a bearing, the leakage area is one circle minus another... but at the tiny areas separations comes into play a lot, and the viscosity losses will be such that the journal sitting stationary in the bottom of the bearing will be flowing more than the journal suspended roughly in the middle of the bearing.

... well, as long as the viscosity is the same and it won't be because the rotating bearing will be heating up the oil, but the math to do even the bad approximations of fluid film bearings gets annoying quickly.
This would be true if running clearances remained the same as static, but they don't.
Not sure what exactly you're thinking of, but I think the biggest issue is going to be the bearing distorting from the various loads, at least on the rods. The whole thing is actually cool if you start running numbers because a bearing as heavily loaded as rod bearings won't actually work statically.

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Re: EMC 2017 353ci SBC

Post by randy331 » Tue Jan 16, 2018 10:50 am

Rick360 wrote:
Tue Jan 16, 2018 12:29 am
Low end of rpm range gained as much or more than the upper rpm range (explain that).
Less drag on back of the cam = less twist so the average position of the cam as a whole was more advanced ???

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Re: EMC 2017 353ci SBC

Post by Warp Speed » Tue Jan 16, 2018 11:09 am

mekilljoydammit wrote:
Tue Jan 16, 2018 10:40 am
Warp Speed wrote:
Tue Jan 16, 2018 10:20 am
mekilljoydammit wrote:
Tue Jan 16, 2018 9:06 am


Just to touch on this as someone who was an engineer in the R&D lab of an industrial bearing manufacturer for a few years... barring something like variable valve timing, and unless I'm not thinking of something with regards to lifter motion, it should actually be the opposite. If you think about a journal sitting in a bearing, the leakage area is one circle minus another... but at the tiny areas separations comes into play a lot, and the viscosity losses will be such that the journal sitting stationary in the bottom of the bearing will be flowing more than the journal suspended roughly in the middle of the bearing.

... well, as long as the viscosity is the same and it won't be because the rotating bearing will be heating up the oil, but the math to do even the bad approximations of fluid film bearings gets annoying quickly.
This would be true if running clearances remained the same as static, but they don't.
Not sure what exactly you're thinking of, but I think the biggest issue is going to be the bearing distorting from the various loads, at least on the rods. The whole thing is actually cool if you start running numbers because a bearing as heavily loaded as rod bearings won't actually work statically.
Main clearances, and their distortion under load has a far greater impact on dynamic flow.

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Re: EMC 2017 353ci SBC

Post by mekilljoydammit » Tue Jan 16, 2018 11:18 am

Warp Speed wrote:
Tue Jan 16, 2018 11:09 am
mekilljoydammit wrote:
Tue Jan 16, 2018 10:40 am
Warp Speed wrote:
Tue Jan 16, 2018 10:20 am


This would be true if running clearances remained the same as static, but they don't.
Not sure what exactly you're thinking of, but I think the biggest issue is going to be the bearing distorting from the various loads, at least on the rods. The whole thing is actually cool if you start running numbers because a bearing as heavily loaded as rod bearings won't actually work statically.
Main clearances, and their distortion under load has a far greater impact on dynamic flow.
Oh, whoops, yeah, you're right. Things on the industrial stuff are typically heavy enough sections they can be thought of as rigid - I didn't think of that deviation from "normal" too.

Wish I had access to a dyno mule and all the data acquisition and sensors I had from that job though, might be interesting to see how much of a difference it actually is.

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Re: EMC 2017 353ci SBC

Post by zums » Tue Jan 16, 2018 7:49 pm

randy331 wrote:
Tue Jan 16, 2018 10:50 am
Rick360 wrote:
Tue Jan 16, 2018 12:29 am
Low end of rpm range gained as much or more than the upper rpm range (explain that).
Less drag on back of the cam = less twist so the average position of the cam as a whole was more advanced ???

Randy
Curious, did you measure that, ive never detected much wind up on a cast flat with typical spring pressures{ 380 open}, solid roller with springs for rpm different story- low and high rpm gain on the pump is interesting, maybe low is drive and high windage, when you amp tested, was the "leak" the same and bypass spring installed length and piston the same
Tom

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Re: EMC 2017 353ci SBC

Post by randy331 » Tue Jan 16, 2018 8:12 pm

zums wrote:
Tue Jan 16, 2018 7:49 pm
Curious, did you measure that, ive never detected much wind up on a cast flat with typical spring pressures{ 380 open}, solid roller with springs for rpm different story- low and high rpm gain on the pump is interesting, maybe low is drive and high windage,
I didn't measure twist, it's just speculation as to why it gained at the bottom end too.
zums wrote:
Tue Jan 16, 2018 7:49 pm
when you amp tested, was the "leak" the same and bypass spring installed length and piston the same
I think same spring, but it's been 6 years now like Rick said. It was done on a little jig Rick made that has a valve you can regulate flow or shut it and dead head it for a peak pressure reading.

I'm sure the power difference to drive the pumps would be very small.

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Re: EMC 2017 353ci SBC

Post by zums » Tue Jan 16, 2018 8:34 pm

Gonna put that engine in anything?
Tom

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Re: EMC 2017 353ci SBC

Post by cjperformance » Tue Jan 16, 2018 8:45 pm

Warp Speed wrote:
Tue Jan 16, 2018 5:05 am
There can be a slight torque to turn difference between pressures, but most all the power gains with lower oil pressures, are based around oil control in the crankcase.
Warp, have you seen the exact same engine and oil run at differing oil pressures AND measured the oil flow difference between the different pressures?
Craig.

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