Shortround6
Major General
This data is from a 1960/61 edition of "Aircraft Engines of the World" by Wilkinson. I don't know when the first Porsche aircraft engine was developed/marketed.
These appear to be flat four cylinder engines derived from the current Porsche 356 car engine and having a common ancestry with the VW engine.
5 models are listed, the 678/1, 678/3, 678/3A, 678/4 and the 701.1.
ALL share a common power section and differ in starter and drive arrangements and some have cooling fans. Carburetors also vary considerably.
The 678/3A appears to be one of the simpler versions with direct drive, electric start and 2 Bing 6/24 horizontal carbs.
Bore: 82.5mm
Stroke: 74MM
Disp: 1.6 liter/96.5 cu in
CR: 7.5:1
Weight 85 KG/187lbs
T-O power 52hp/3200rom/sea level
normal power 50hp/3150rpm/sea level
cruising power 40hp/2950rpm/sea level
The 678/3 used a manual starter.
The 678/1 used a 2.12:1 reduction gear to the propeller and a Pallas Zenith 32 NDIZF dual choke downdraft carb.
Weight went to 106kg/234lbs. Prop turned 2120rpm for take-off.
T-0 power was 65hp/4500rpm/sea level
max cont power 55hp/4200rpm/sea level
Cruising power 50hp/4080rpm/sea level
The 702/1 was similar to the 678/1 but arranged for vertical mounting, had a fan for cooling and manual starter.
The 678/4 raised the compression to 9.0:1 and used a pair of Pallas Zenith 36 NDIZF dual choke downdraft carbs. Used a fan for cooling (looking much like the fan housing familiar to owners of old VWs) and used 1.98:1 reduction gear with a prop flange ( what they planned to put it in with that fan I don't know, auto gyros?) and a prop speed at take-off of 2325rpm.
Weight was 112KG/247lbs
T-O power 75hp/4600rpm/sea level
Normal power 70hp/4500rpm/sea level
cruising power 60hp/4270rpm/sea level
The 1962/63 edition drops all but the 678/4 and adds the 702/4 which is pretty much a vertical version of the 678/4 without the reduction gear with power down 2-3hp.
I have no idea if these engines ever flew or what they were installed in.
A 1986/87 edition of "Jane's" has a small write up of the Porsche PFM 3200 aircraft engine which says it is the first Porsche engine since 1955 designed for aircraft use ( standard 911S engines being used in Aircraft Industries Skyship blimps). As may be guessed by the designation it is a 3200cc ( 3164cc/193 cu in) engine. It was rated at 212HP for take-off and max cont at sea level at 5300rpm. and had a 0.455 reduction gear to the prop.
It was well equipped with proportional speed fan cooling, two 24 v alternators, tow vacuum pumps and a drive for a hydraulic pump. It had a dry sump for acrobatic use. Unfortunately it weighed 200kg (441lbs) but that may be with the accessories.
Flight development was started in a Cessna Skylane in Aug 1943 and completed Sept 1984 by the LBA and in Aug 1985 by the FAA. A pilot production batch pf 50 engines was supposed to have been started in Aug 1985.
That is the only information I have at this time.
These appear to be flat four cylinder engines derived from the current Porsche 356 car engine and having a common ancestry with the VW engine.
5 models are listed, the 678/1, 678/3, 678/3A, 678/4 and the 701.1.
ALL share a common power section and differ in starter and drive arrangements and some have cooling fans. Carburetors also vary considerably.
The 678/3A appears to be one of the simpler versions with direct drive, electric start and 2 Bing 6/24 horizontal carbs.
Bore: 82.5mm
Stroke: 74MM
Disp: 1.6 liter/96.5 cu in
CR: 7.5:1
Weight 85 KG/187lbs
T-O power 52hp/3200rom/sea level
normal power 50hp/3150rpm/sea level
cruising power 40hp/2950rpm/sea level
The 678/3 used a manual starter.
The 678/1 used a 2.12:1 reduction gear to the propeller and a Pallas Zenith 32 NDIZF dual choke downdraft carb.
Weight went to 106kg/234lbs. Prop turned 2120rpm for take-off.
T-0 power was 65hp/4500rpm/sea level
max cont power 55hp/4200rpm/sea level
Cruising power 50hp/4080rpm/sea level
The 702/1 was similar to the 678/1 but arranged for vertical mounting, had a fan for cooling and manual starter.
The 678/4 raised the compression to 9.0:1 and used a pair of Pallas Zenith 36 NDIZF dual choke downdraft carbs. Used a fan for cooling (looking much like the fan housing familiar to owners of old VWs) and used 1.98:1 reduction gear with a prop flange ( what they planned to put it in with that fan I don't know, auto gyros?) and a prop speed at take-off of 2325rpm.
Weight was 112KG/247lbs
T-O power 75hp/4600rpm/sea level
Normal power 70hp/4500rpm/sea level
cruising power 60hp/4270rpm/sea level
The 1962/63 edition drops all but the 678/4 and adds the 702/4 which is pretty much a vertical version of the 678/4 without the reduction gear with power down 2-3hp.
I have no idea if these engines ever flew or what they were installed in.
A 1986/87 edition of "Jane's" has a small write up of the Porsche PFM 3200 aircraft engine which says it is the first Porsche engine since 1955 designed for aircraft use ( standard 911S engines being used in Aircraft Industries Skyship blimps). As may be guessed by the designation it is a 3200cc ( 3164cc/193 cu in) engine. It was rated at 212HP for take-off and max cont at sea level at 5300rpm. and had a 0.455 reduction gear to the prop.
It was well equipped with proportional speed fan cooling, two 24 v alternators, tow vacuum pumps and a drive for a hydraulic pump. It had a dry sump for acrobatic use. Unfortunately it weighed 200kg (441lbs) but that may be with the accessories.
Flight development was started in a Cessna Skylane in Aug 1943 and completed Sept 1984 by the LBA and in Aug 1985 by the FAA. A pilot production batch pf 50 engines was supposed to have been started in Aug 1985.
That is the only information I have at this time.
