Turbo engine vs Naturally aspirated

[TheOldHokie]

His particular application is a pump.

A sample pump to illustrate HP variance. Keep in mind this is PUMP input shaft HP not engine HP which will be significantly higher based on the type of drive and efficiency factor. He really needs to know what pump he wants to drive and how.

General TSF2421

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[Trash Panda]

A sample pump to illustrate HP variance. Keep in mind this is PUMP input shaft HP not engine HP which will be significantly higher based on the type of drive and efficiency factor. He really needs to know what pump he wants to drive and how.

General TSF2421

View attachment 173611 ​

Yep.

Pumps need more than just a simple horsepower target.

 

[SDT]

His particular application is a pump.

Agreed.

If you re-read the OP's original question you will find that he questions whether to choose the NA or turbo version of the Perkins engine in question. I answered his question based upon the information he provided. I did not attemp to answer questions not asked.

Given the information provided, either the NA or the boosted engine will suffice to power his pressure washer, originally powered by a 40 HP air cooled Kohler gasoline engine.

HP is HP.

 

[TheOldHokie]

Agreed.

If you re-read the OP's original question you will find that he questions whether to choose the NA or turbo version of the Perkins engine in question. I answered his question based upon the information he provided. I did not attemp to answer questions not asked.

Given the information provided, either the NA or the boosted engine will suffice to power his pressure washer, originally powered by a 40 HP air cooled Kohler gasoline engine.

HP is HP.

40 HP @ 3600 RPM. Do you think thats a direct drive and if not how does that change the HP comparisonz?

Dan

 

[SDT]

A sample pump to illustrate HP variance. Keep in mind this is PUMP input shaft HP not engine HP which will be significantly higher based on the type of drive and efficiency factor. He really needs to know what pump he wants to drive and how.

General TSF2421

View attachment 173611 ​

Agreed.

Still, as his device was originally powered by a 40 HP air cooled Kohler gasoline engine, either the NA or the boosted version will suffice.

 

[SDT]

40 HP @ 3600 RPM. Do you think thats a direct drive and if not how does that change the HP comparisonz?

Dan

I answered the OP's question based upon the information provided.

I have neither need nor desire to answer questions not asked.

 

[Trash Panda]

Agreed.

Still, as his device was originally powered by a 40 HP air cooled Kohler gasoline engine, either the NA or the boosted version will suffice.

If you ignore RPM requirements, it’s very possible that neither will suffice without modification to the drive between the engine and pump.

It’s not answering questions that weren’t asked, it’s helping the OP consider all the factors at play here.

 

[hagrid]

Agreed.

 

[TheOldHokie]

cz

I answered the OP's question based upon the information provided.

I have neither need nor desire to answer questions not asked.

He gave you that info:

Gas engine 40HP @ 3600 RPM.
Diesel engine 55HP @ 2400 RPM.


Just maybe its important to think about that and ask a couple questions if you want to give meaningful advice. You are an automotive design engineer and know how to do the calcs. The OP is not and is clearly lost.

Lets use his formula for HP and assume 3000 PSI @ 10 GPM

HP = 10 GPM X 3000 PSI / 1450 x 1.3 = 26.9 HP

Thats substantially less than his 37Hp@3600 RPM gas engine and half the 55HP@2400 RPM diesels.

Whats going on here? Simple question for Jason - 10 GPM at what pressure? Do you have a particular pump in mind?

Dan

 

[Floridaman]

[

You are missung something in your calculations. Your r diesel is going to run at 2/3 the speed of the gas engine. Have you considered what thats going to do to pump output volume (GPM)?

To get the same GPM out of the pump you will hsve to gear the diesel speed up by 1.33 which is going to eat torque and HP.

How about providing some basic pump data.

Desired flow = 10 GPM
Pump displacement = ???
Pump pressure = ???

Or better yet make and model of the pump.

Dan

I don’t believe anything is missing in the calculation. Yes I understand The diesel is going to run slower than what a gas engine runs.
These pumps depending on the manufacturer run at either 1450 RPMs or 1750, they are driven by v belts or poly chains. Homeowner aversions that have the pump directly attached to the engine. All ran at the speed of the engine, which is 3600 RPMs. In my situation because of the horsepower and torque, I will need a poly chain. At 2700 rpm, a 7” driver sprocket and a 11” sprocket on the pump will give me about 1715 rpm’s On the pump.
20 gpm/2500 psi at a 1.3 service factor calls for 45 gas horsepower

 

[TheOldHokie]

I don’t believe anything is missing in the calculation. Yes I understand The diesel is going to run slower than what a gas engine runs.
These pumps depending on the manufacturer run at either 1450 RPMs or 1750, they are driven by v belts or poly chains. Homeowner aversions that have the pump directly attached to the engine. All ran at the speed of the engine, which is 3600 RPMs. In my situation because of the horsepower and torque, I will need a poly chain. At 2700 rpm, a 7” driver sprocket and a 11” sprocket on the pump will give me about 1715 rpm’s On the pump.
20 gpm/2500 psi at a 1.3 service factor calls for 45 gas horsepower

Your on it. I thought you were looking for 10 GPM.

The calvulation tells you HP at the pump. You are stepping down with a belt drive so you pick up torque so You dont need 45 HP st the motor.

Dan

 

[Russell King]

One other concern with either one but more so with the turbo is the exhaust temperature. If you will be directing the exhaust upwards then tree and structure damage or fire could be a concern. I believe the turbo exhaust will be much hotter than the naturally aspirated engine.

If I remember correctly there is significant discussion about all that in this thread where a member produces turbo kits to put onto the L2501 tractors.

L2501 Turbo: A Journey Defined - The tractor, The comparison, The modification, The results...

^^^^^ Indeed it does! The factory pump provides more than enough fuel for the Turbo Kit. However, OEM components do fail, especially on older/high hour tractors. One of our customers has had to replace his faulty lift pump on an L3240 tractor. Definitely something to keep in mind. Mike...

www.orangetractortalks.com

 

[Trash Panda]

One other concern with either one but more so with the turbo is the exhaust temperature. If you will be directing the exhaust upwards then tree and structure damage or fire could be a concern. I believe the turbo exhaust will be much hotter than the naturally aspirated engine.

If I remember correctly there is significant discussion about all that in this thread where a member produces turbo kits to put onto the L2501 tractors.

L2501 Turbo: A Journey Defined - The tractor, The comparison, The modification, The results...

^^^^^ Indeed it does! The factory pump provides more than enough fuel for the Turbo Kit. However, OEM components do fail, especially on older/high hour tractors. One of our customers has had to replace his faulty lift pump on an L3240 tractor. Definitely something to keep in mind. Mike...

www.orangetractortalks.com

You would have to get that exhaust absolutely stuffed up into some flammable material for that to be a concern.

Even on our big 12L turbo diesel powered utility trucks, the exhaust gas temperature even 5’ from the stack is hardly noticeable.

 

[Russell King]

I only mention that since I have seen some damage to trees and structures from exhaust blowing up onto them while the exhaust was sitting static like on a backhoe or a rock saw trencher.

I assume a pressure washer on a trailer would be parked for the complete time frame of the job so guessing it would be running 4 to 6 hours in one position.

 

[Floridaman]

Your on it. I thought you were looking for 10 GPM.

The calvulation tells you HP at the pump. You are stepping down with a belt drive so you pick up torque so You dont need 45 HP st the motor.

Dan

sorry, I’m not tracking.

 

[Floridaman]

One other concern with either one but more so with the turbo is the exhaust temperature. If you will be directing the exhaust upwards then tree and structure damage or fire could be a concern. I believe the turbo exhaust will be much hotter than the naturally aspirated engine.

If I remember correctly there is significant discussion about all that in this thread where a member produces turbo kits to put onto the L2501 tractors.

L2501 Turbo: A Journey Defined - The tractor, The comparison, The modification, The results...

^^^^^ Indeed it does! The factory pump provides more than enough fuel for the Turbo Kit. However, OEM components do fail, especially on older/high hour tractors. One of our customers has had to replace his faulty lift pump on an L3240 tractor. Definitely something to keep in mind. Mike...

www.orangetractortalks.com

This is not a concern for me. I park on the edge of the roadway. The cab of my truck sits taller than my trailer, and I have yet to scrape the cab with any trees limbs hanging in that low.

 

[TheOldHokie]

I don’t believe anything is missing in the calculation. Yes I understand The diesel is going to run slower than what a gas engine runs.
These pumps depending on the manufacturer run at either 1450 RPMs or 1750, they are driven by v belts or poly chains. Homeowner aversions that have the pump directly attached to the engine. All ran at the speed of the engine, which is 3600 RPMs. In my situation because of the horsepower and torque, I will need a poly chain. At 2700 rpm, a 7” driver sprocket and a 11” sprocket on the pump will give me about 1715 rpm’s On the pump.
20 gpm/2500 psi at a 1.3 service factor calls for 45 gas horsepower

I got to thinking sbout my last post and decided to sanity check it

45HP @1715 RPM = 138 lb-ft of torque
45 HP @ 2700 RPM = 88 lb-ft of torque
Your 11:7 reduction drive boosts that to 138 lb-ft

So obviously the belt drive ratio is a wash when you do the calcs. I may have known that at some point but... Mea Culpa


Dan

 

[Floridaman]

Here’s a data sheet for one of the pumps that I’ve been looking at