Parts Catalog Accessories Catalog Tech Info Tech Forums
 
  Search our site:    
 Cart  | Project List | Order Status | Help    
  We salute a legendary member of the community.
Thank you for selflessly sharing your wisdom with us...
Go Back   Pelican Parts Technical BBS > 1- Porsche Technical Forums > Porsche 911 Technical Forum

Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Sep 2005
Location: So. Cal.
Posts: 7,362
Evolution of the 4 Cam (Fuhrmann) Motor

I am fascinated by this crazy-complex engine - not that I'll ever own one. We know it was designed by Fuhrmann based on (either) his own or some Italians' research. It was produced from the mid 50's to the mid 60's, and I suppose ultimately replaced by the 901 motor.

Was the 901 an evolution of the 547 ? It did have overhead cams.

But the 4 cam was DOHC and gear driven. So where did the design for 901 originate?

And really where I am headed here is, were there ever any plans for another iteration of the 547 beyond the 2.0L 587? Say, something after the 1600GS? Surely Fuhrmann had more plans - wouldn't it be great to know where he would have headed next, had he not been elbowed out by Piech? A Turbo? Larger displacement? I think I read they made it produce up to 195 hp from 2 liters in 65 - that's pretty impressive, even if it was very complex.
__________________
David

1972 911T/S MFI Survivor

Last edited by daepp; 08-22-2011 at 02:42 PM..
Old 08-22-2011, 02:34 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #1 (permalink)
Registered User
 
Join Date: Sep 2005
Location: So. Cal.
Posts: 7,362
A few photos of my own and from the interwebs...





The crank comes apart instead of the rods!!!


At the factory


At the factory too



__________________
David

1972 911T/S MFI Survivor
Old 08-22-2011, 02:37 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #2 (permalink)
Registered User
 
Join Date: Sep 2005
Location: So. Cal.
Posts: 7,362
Seems to be some dispute over this one. Did Fuhrmann get the idea from this supposed Italian flat four 4 cam?

From The Samba
__________________
David

1972 911T/S MFI Survivor
Old 08-22-2011, 02:38 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Sep 2005
Location: So. Cal.
Posts: 7,362


Who needs an engine stand???

__________________
David

1972 911T/S MFI Survivor
Old 08-22-2011, 02:39 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #4 (permalink)
Capitalist and Patriot
 
911Freak's Avatar
 
Join Date: Sep 2006
Location: West Los Angeles
Posts: 1,824
Love it! Thanks for posting...

btw- I was trying to figure out the twin plug configuration; did the plugs enter the head at different points in the head (asymmetrical) ??

Looking forward to adding fresh pics to my Fuhrmann folder
__________________
'81 911SC RoW Targa (lot's of goodies)
'07 Lexus IS 250
'84 633 csi (turbo charged-sold)
'68 912 Targa (sold)
"Dream it, Believe it, Decide it, DO it "
Old 08-22-2011, 03:09 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #5 (permalink)
Max Sluiter
 
Flieger's Avatar
 
Join Date: Mar 2006
Location: So Cal
Posts: 18,390
Garage
You guys need to read Excellence Was Expected. The info is out there, but it would take Grady to be able to summarize and not leave anything important out.
__________________
911S
1971 chassis, 2.7RS spec MFI engine, suspension mods, lightened

Suspension by Rebel Racing, Serviced by TLG Auto, Brakes by PMB Performance
http://www.flickr.com/photos/max_911_fahrer/
Old 08-22-2011, 06:16 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #6 (permalink)
Registered User
 
tazzieman's Avatar
 
Join Date: Oct 2009
Location: Tasmania
Posts: 1,298
Garage
I don't have access to the "Bible" , but Paul Frere's "Porsche 911 story" states
Quote:
The most important decision of all was probably taken when Ferry (now professor) Porsche opted to forget about pushrods and to go ahead with the development of a completely new six-cylinder engine with an overhead camshaft for each bank of cylinders. refinement was the main reason for having six cylinders , while the overhead camshafts were dictated by the requirement of a lower noise level, of a higher specific power output and consequently high crankshaft speed , and with an eye to future developments , both for road use and for racing purposes.
Next paragragh discusses how there was a lot of thought given to how the shafts were to be driven - shaft and bevel was too noisy , toothed rubber belt too risky (at the time) and chain drive. Given problems with other chain driven cars (Jaguar) , Porsche insisted on the best quality chains in the world and hydraulic tensioners.

Obviously there were many other considerations in developing the 901 , but you need to read the books!

Great topic , the old mechanical noises of the past will never return - and I always love the old pics!
__________________
'78 911 SC '81 924
'81 928S with 5.0 hybrid
'85 944 '73 Landrover
"They run best being run close to the ‘limit’ and done so regularly" - Grady
Old 08-22-2011, 08:16 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #7 (permalink)
Registered User
 
deathpunk dan's Avatar
 
Join Date: Jul 2005
Location: southern RI USA
Posts: 1,477
One or more of my 911 books discusses how 901 prototypes were fitted with 2 liter 4 cam engines during development/when the six was still in the design phase.

As most of you know, one of their performance benchmarks was to equal or best the 130 hp 4 cam, but be less noisy and high maintenance.

There is a gentleman in my neck of the woods with a beautiful 356 Carrera 2. At a show 2 years ago I was just sort of hanging around his car, hoping he'd fire it up. At one point he turned to me and said 'do you know what this is?'.

Yes, sir.
__________________
Sepia brown 1971 911T.
Old 08-23-2011, 04:39 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #8 (permalink)
Registered User
 
Join Date: Sep 2005
Location: So. Cal.
Posts: 7,362
That book is wicked expensive!
__________________
David

1972 911T/S MFI Survivor
Old 08-23-2011, 08:37 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #9 (permalink)
Registered User
 
Join Date: Sep 2005
Location: So. Cal.
Posts: 7,362
This guy knows how to drive his 4 Cam!


__________________
David

1972 911T/S MFI Survivor
Old 08-23-2011, 08:45 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #10 (permalink)
Max Sluiter
 
Flieger's Avatar
 
Join Date: Mar 2006
Location: So Cal
Posts: 18,390
Garage
Quote:
Originally Posted by DAEpperson View Post
That book is wicked expensive!
I have an early edition- 1st? It is black and a single book with the Porsche crest on it. You might be able to find one like that used for a better price. It covers more than I really wanted to know- like the 928. The newer eds go into GT3 and such.
__________________
911S
1971 chassis, 2.7RS spec MFI engine, suspension mods, lightened

Suspension by Rebel Racing, Serviced by TLG Auto, Brakes by PMB Performance
http://www.flickr.com/photos/max_911_fahrer/
Old 08-23-2011, 09:39 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #11 (permalink)
Registered User
 
kodioneill's Avatar
 
Join Date: Feb 2007
Location: upstate new york
Posts: 3,019
Garage
Quote:
Originally Posted by DAEpperson View Post
A few photos of my own and from the interwebs...





The crank comes apart instead of the rods!!!


At the factory


At the factory too



What are the hoses that run in and out of the tranny and starter motor?
__________________
1974 sahara beige 911 targa
1982 chiffon 911sc
1985 prussian blue metallic carrera
Old 08-23-2011, 10:54 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #12 (permalink)
 
Now Available for Ordering:   101 Projects For Your BMW 3 Series 1982-2000  [more info]
Registered User
 
Grady Clay's Avatar
 
Join Date: Dec 2003
Location: Arapahoe County, Colorado, USA
Posts: 9,032
Here is a fun thread:
What kind of engine do I have?


This is an early Spyder engine.
The transmission breather hose goes to a ‘separator’ box (red arrow) and then outside.
It is not connected to the starter.
The other hose (above the flywheel) is the crankcase breather and goes over to the dry-sump tank (just like a 911).

Note the tach drive on the flywheel end of the intake camshaft (yellow arrow).









This is the real bruit.
This is a 587/3 904 engine with ~210 hp.
Note the front engine mount like a 911 (coincidently, the 901 fits in the engine bay).
You can also tell it is for a 904 by the rounded (violet arrow) exhaust valve covers to clear the chassis (Carrera 2 587/1 and 587/2 were square (yellow arrow) like the intake covers).
The 2-liter has the cam flywheels inside the valve covers.

Note the 46IDA Webers and the exhaust going toward the transmission.




I’ll post more later.

BTW, the 3-volume Ludvigsen Excellence 2nd Ed. (not 3rd ) is regularly available for very low cost on Amazon.
It has all the early (pre-2003?) info the same.
Every Porsche enthusiast should own this and read it cover-to-cover.

Best,
Grady
__________________
ANSWER PRICE LIST (as seen in someone's shop)
Answers - - - - - - - - - - - - - - - - $0.75
Answers (requiring thought) - - - - $1.25
Answers (correct) - - - - - - - - - - $12.50
Old 08-23-2011, 11:23 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #13 (permalink)
závodník 'X'
 
intakexhaust's Avatar
 
Join Date: Sep 2010
Posts: 3,980
Garage
4 cam resurection

Nice pics of the crankshaft. I'll add that the multi piece crank, made by Hirth, was a weak area. Because of this, its odd to say this engine has greater longevity by running at high revs, meaning no lugging.

Thought some might like to see these pics of a 1957 sunroof coupe 4 cam survivor now into restoration. (Please refrain asking further of it. Thank you)











Old 08-23-2011, 11:57 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #14 (permalink)
Registered User
 
kach22i's Avatar
 
Join Date: Mar 2004
Location: Michigan
Posts: 25,648
Garage
Nice video, I could not get my little computer speakers to go loud enough.

I have a book or two on these engines, they went into some very nice cars.
__________________
1977 911S Targa 2.7L (CIS) Silver/Black
1998 Chevy S-10 4x4 Pick-Up Truck, Sportside Bed
1990 Zebra Tracker died on Safari, RIP 2009
1989 modified Scat II HP Hovercraft
George, Architect & Business Owner
Old 08-23-2011, 12:04 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #15 (permalink)
Registered User
 
Join Date: Sep 2005
Location: So. Cal.
Posts: 7,362
I know I am showing my ignorance here, but why was it necessary to have flywheels on the camshafts? Aren't flywheels just used to maintain the engine's momentum between firings?
__________________
David

1972 911T/S MFI Survivor
Old 08-23-2011, 12:19 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #16 (permalink)
Registered User
 
tazzieman's Avatar
 
Join Date: Oct 2009
Location: Tasmania
Posts: 1,298
Garage
Quote:
Originally Posted by Grady Clay View Post
BTW, the 3-volume Ludvigsen Excellence 2nd Ed. (not 3rd ) is regularly available for very low cost on Amazon.
It has all the early (pre-2003?) info the same.
Every Porsche enthusiast should own this and read it cover-to-cover.

Best,
Grady
Well finally I decided to splash out on this ; 30% off from Amazon. You can't have too many books and this is the one to have, by all accounts. Won't even have to use the secret account as my wife and I do not question each other's library expenses!
__________________
'78 911 SC '81 924
'81 928S with 5.0 hybrid
'85 944 '73 Landrover
"They run best being run close to the ‘limit’ and done so regularly" - Grady
Old 08-23-2011, 04:08 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #17 (permalink)
Max Sluiter
 
Flieger's Avatar
 
Join Date: Mar 2006
Location: So Cal
Posts: 18,390
Garage
Quote:
Originally Posted by DAEpperson View Post
I know I am showing my ignorance here, but why was it necessary to have flywheels on the camshafts? Aren't flywheels just used to maintain the engine's momentum between firings?
The cam flywheels were timed to counteract the harmonic torsional vibrations at high revs that would cause the timing to drift on early engines, reducing power and longevity.
__________________
911S
1971 chassis, 2.7RS spec MFI engine, suspension mods, lightened

Suspension by Rebel Racing, Serviced by TLG Auto, Brakes by PMB Performance
http://www.flickr.com/photos/max_911_fahrer/
Old 08-23-2011, 05:32 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #18 (permalink)
Registered User
 
Join Date: Sep 2005
Location: So. Cal.
Posts: 7,362
Quote:
Originally Posted by Flieger View Post
The cam flywheels were timed to counteract the harmonic torsional vibrations at high revs that would cause the timing to drift on early engines, reducing power and longevity.
Amazing!

Why wasn't this a problem with the 901? Does distributor advance counter this problem?

I now I need to step up and buy the books, but what was Fuhrmann's background? I'm guessing he had to have been involved in WWII. Also, did all research on the 587 stop with the 901 - it would be very interesting to know where he wanted to go next!
__________________
David

1972 911T/S MFI Survivor
Old 08-23-2011, 06:52 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #19 (permalink)
Max Sluiter
 
Flieger's Avatar
 
Join Date: Mar 2006
Location: So Cal
Posts: 18,390
Garage
Fuhrmann's first project out of engineering school was the 4-cam engine, IIRC.

Hans Metzger designed the 901. He wrote his PhD dissertation on the 912 (917) engine as I understand.
__________________
911S
1971 chassis, 2.7RS spec MFI engine, suspension mods, lightened

Suspension by Rebel Racing, Serviced by TLG Auto, Brakes by PMB Performance
http://www.flickr.com/photos/max_911_fahrer/
Old 08-23-2011, 06:56 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #20 (permalink)
Old 08-23-2011, 06:56 PM
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 03:05 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.