How many HP needed for #4 blower?

[rhino1]

Replacing an engine and considering anything, including LP burning engines. The question is.... how many HP is needed to turn a #4 blower & a pump? Is a 20 HP engine enough, or do I need a 24? Does it matter if it is air-cooled or water-cooled?

Thanks for any advice in advance.

 

[Jay D]

18hp is the min. I have seen, a EZ and a Judson. I tried to run a 16 briggs on a 45 roots and it went from 3600 no load to 2950 with a load. That being said if you can get a good deal on a 18-25hp kohler I'd buy it. Water cooled are great but can be expensive but Aircooled are just fine and simple to setup. Are you replacing one or building a machine?

 

[Farenheit251]

I have a 25 Kohler and use all of it. I think I heard each inch of additional lift is 2 Hp. I've seen alot of machines using only a 20 HP but seemed like they were usually running a leaky vac relief set at 12 hg.

 

[Shawn Forsythe]

Horsepower capability of an engine at resline itself is not a good absolute measure when describing the power necessary to turn a given blower at speed.

What is important is the requisite torque needed at the particular RPM the blower will be run, and under what load condition.

That being said, an 18 hp engine will suffice in "most' cases, but is at the side of minimum even where it does work. A more comfortable service factor is achieved using a 20-22 hp for most of the engines out there used at near full load on a 4M blower.

 

[steve g]

I run a bridgepoint saber with an 18hp briggs 3cp and a 3-6 blower. I would not want any less power, when the motor does blow one day I think I will repower the machine with a 20hp motor. a 22hp motor would be the minimum I would run with a #4 blower

 

[bob vawter]

Shawn...which senerio would be best...


Continuese 90% draw on a 25HP motor
OR
continuese 15 or 20% draw on a 185HP motor

Which motor will last longest?

NEVERMIND....we all know the more HP the better....'specially if it's usin'...


LESS GASOLINE!

 

[Dolly Llama]

Shawn...which senerio would be best...


Continuese 90% draw on a 25HP motor
OR
continuese 15 or 20% draw on a 185HP motor

Which motor will last longest?

NEVERMIND....we all know the more HP the better....'specially if it's usin'...


LESS GASOLINE!

Bob, whether one is a direct drive proponent like you, or a slide-in proponent like me, I'm sure we can ALL agree there are virtues to DDs
However, GAS USE ain't one of 'em.

You're the only one that buys '83 church vans and pulls the electronics and fuel injection and makes a FrankenbOb engine.
That you "claim" gets .8GPH
Everyone else is using close to or 3 times that


..L.T.A.

 

[bob vawter]

"FrankenbOb engine"

LOL..that was great.....accurate but still great!

 

[Larry Cobb]

Rhino1;

It depends on the engine manufacturer.

We ran 20 HP Hondas with very good RPM loss.

Kohler also does a good job.

Other engines showed over excessive RPM drop (2X) at full vacuum.

Larry

 

[bob vawter]

All i'm trying to say is.....that it is BETTER to use only 10% of an engines power, rather than than 90% ......this crap ain't rocket science.......

however I DID stay at a Holiday Inn last nite!

 

[rhino1]

Thanks for all sharing your advice/opinions. I went with a 24 HP Honda, air-cooled, just to be sure I had enough power.