Pietenpol-List: Re: Engines/horse power.

An archive of the Matronics Pietenpol Listserve.
Locked
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Engines/horse power.

Post by matronics »

Original Posted By: jkahn(at)picasso.dehavilland.ca (John Kahn)
Thanksto John for the Model A info..Aspiration was a problem..I talked to a Ford group that stopped at the nearby park, yesterday..The B cam will increase power, but runs lean at higher rpm.A downdraft carb is needed, one fellow said..I'm still curious about the actual valve timing and duration, overlap,etc.4.22:1 compression might ust run on kerosene! Rich________________________________________________________________________________
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Engines/horse power.

Post by matronics »

Original Posted By:> "Richard F. Rapp"
> From Steve(at)byu.edu Mon Apr 20 11:03:12 1998> Date: Mon, 20 Apr 1998 07:57:59 -0700 (PDT)
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Engines/horse power.

Post by matronics »

Original Posted By: "McNarry, John"
The disscussion about suitable engines has always been interesting. I'm sure the Model A was choosen because of its ability to swing a large prop at the right speed. It is still a good choice and with some scrounging they are available. Some specsbore 3 7/8" Stroke 4 1/4" 200.5 cu.in. 40 bhp @ 2200 rpm. Compression Ratio 4.22:1 Crank bearings 1.625" mains. Rear 3" long center and front 2".Crankpins 1.500"Some useful formulas HP = Torque X rpm / 5252Torque = HP X 5252/ RPMRPM = HP X 5252 /TorqueComp Ratio= Clearance Vol. + Cylinder Vol. / Cl. Vol.Clearance Vol.= Displ. Vol. / Cl Vol. -15252 comes from the engine torque being measured in foot pounds and the distance the engine moves the load in one revolution 6.28 feet. the unit of horsepower 33000 foot pounds/minute.The calculations of power required to get a stock Piet to climb at 300 ft/min is 33 horsepower. A good runnung A would have 7 extra HP!The biggest draw back to increased HP from an A or B block is the breathing problems inherent in the Flathead design. Hope this helps. John McNarry________________________________________________________________________________
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Engines/horse power.

Post by matronics »

Original Posted By: "Richard F. Rapp"
Subject: Pietenpol-List: Re: Engines/horse power.The disscussion about suitable engines has always been interesting. I'm sure the Model A was choosen because of its ability to swing a large prop at the right speed. It is still a good choice and with some scrounging they are available. Some specsbore 3 7/8" Stroke 4 1/4" 200.5 cu.in. 40 bhp @ 2200 rpm. Compression Ratio 4.22:1 Crank bearings 1.625" mains. Rear 3" long center and front 2".Crankpins 1.500"Some useful formulas HP = Torque X rpm / 5252Torque = HP X 5252/ RPMRPM = HP X 5252 /TorqueComp Ratio= Clearance Vol. + Cylinder Vol. / Cl. Vol.Clearance Vol.= Displ. Vol. / Cl Vol. -15252 comes from the engine torque being measured in foot pounds and the distance the engine moves the load in one revolution 6.28 feet. the unit of horsepower 33000 foot pounds/minute.The calculations of power required to get a stock Piet to climb at 300 ft/min is 33 horsepower. A good runnung A would have 7 extra HP!The biggest draw back to increased HP from an A or B block is the breathing problems inherent in the Flathead design. Hope this helps. John McNarry________________________________________________________________________________
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Engines/horse power.

Post by matronics »

Original Posted By: "Richard F. Rapp"
________________________________________________________________________________
Locked