Ah Damiler Engine Valves ?

[mgtaylor]

HELP !!!! Steph, Step in here for me will ya ?

I am trying to sort our some reference photos which have me confused?

I have read there were virtually not any outwardly differences between the AH Damiler 185/200/225 hp engines ?

I see photos of what I assume is the 185 hp Dmailer with one valve spring per clyinder.



BUt I have also right next to it seen what looks like a Damiler only it has TWO overhead valves springs per clyinder ? IS this a 200 or 225 hp Damiler ?

IS that one outward appearence difference ?

ANYONE HELP ?

[Taz]

mg- The 200 hp Austro-Daimler had two intake and two exhaust valves per cylinder, as I assume the 225 hp also did. A common horsepower increasing scheme with, in this case, a SOHC with four valves per cylinder with single intake and exhaust cam followers operating two valves each through single rocker arms.

Taz
Terry Phillips

200 hp Austro-Daimler 009 Valve Detail.jpg

[mgtaylor]

Terry '
THANKS !!! Mystery SOlved ! I thought that might be the case since they took a 185 hp and boosted it to 200 and 225 hp with DOHC ! Great THanks !

I thought is was a 185 but was confused it might be some other kinf of engine all together. THat makes sense !


Mike

[Dan_San_Abbott]

MGTaylor:
The Mercedes D.III engine had single rocker arms exiting the center of the cover on each side. I would like to see the lower crankcase to confirm my observation. The 180 Ps engine had the rocker arm emanating from the front of the rocker box cover on each side operating a single intake and exhaust valve. The Mercedes D.IV, 220 Ps 8 cylinder and the 260 Ps D.IVa had dual intake and exhaust valves with a "T" shaped rocker arm.
The photo shows a single intake and single exhaust valves. It is either a early Mercedes 160 Ps D.III or a D.IIIa 170 Ps engine.
Blue skies,
Dan-San

[Taz]

mg, Dan-San- Here is the rocker gear for the 180 hp Mercedes. Like Dan-San says, the rocker arms work off a shaft which passed through the outer edges of the small individual cam covers and the rocker arms were on the ends of the cam covers. Unfortunately I do not have the same detail on the D.III.

Taz
Terry Phillips



Mercedes 180 hp 04 8 bit Detail.jpg

[Koloman Mayrhofer]

hallo,
it is hard to notice the difference between the austro daimler series 17000 160 hp and the series 18 000 185hp as they are both two valve and have the rounded crankcase bottom. the series 19000 200 hp and series 23 000 225hp are also very simmilar in outside shape , both are 4 valve and have the more angular crankcase bottom.
in most cases identification on fotos can only be done by looking at the airplane type which they are installed and look at the files which engineversion was installed . not always successful as the mounting bolts was the same spacing on all four versions which made it possible that engines was installed at the field which should not be in following the books.

camshaft drive and magnetos are on all austro daimlers at the front and on german daimler at the rear.
austro daimler was completly independent from the german daimler company from around 1910 on. there was no technical or ownership connection between them from that time on.
ferdinand porsche was chief designer by austro daimler.

cheers
koloman mayrhofer

[Ransom E. Olds]

And all these Mercedes and A-D engines are SOHC whether they have two valves or four. About the only significant DOHC inline aero engine was the Napier Lion. Ransom

[Taz]

Koloman- Thanks for adding your considerable expertise to this discussion. I had to look up on British capture reports what you and Ransom knew from memory.

Ransom- All three of the engines illustrated in this thread are obviously SOHC, as you mentioned. The Mercedes aero engine had a tremendous impact on aircarft engine designers in WW-I, with a very large proportion fitting into the "Mercedes type" definition, including the Liberty engines.

Taz
Terry Phillips