Anyone ever seen a double bellcrank?

356 Porsche-related discussions and questions.
Message
Author
Steve Kram
356 Fan
Posts: 127
Joined: Sat Apr 12, 2014 4:12 pm
Location: Los Angeles, CA

Anyone ever seen a double bellcrank?

#1 Post by Steve Kram »

Looking at the back of a friends engine shroud I saw a double bellcrank?
Any one ever seen this before? It looks factory installed.
Attachments
Double Bellcrank - .jpg

User avatar
Ron LaDow
356 Fan
Posts: 8092
Joined: Wed Mar 26, 2008 11:45 am
Location: San Francisco

Re: Anyone ever seen a double bellcrank?

#2 Post by Ron LaDow »

Steve,
Is that a 912 fan shroud? I do not recognize it as any 356 version I've seen.
Oh, and per out discussion, you might use this opportunity to find when the single-flapper air channels changed to doubles.
Ron LaDow
www.precisionmatters.biz

User avatar
Phil Planck
356 Fan
Posts: 2030
Joined: Wed Mar 26, 2008 7:21 pm
Location: NE Michigan, lower penn.

Re: Anyone ever seen a double bellcrank?

#3 Post by Phil Planck »

Steve
That throttle bar with bellcrank was used on 68, 69 912s as an emmision device. It connected to a electro-mechanical vacuum valve next to the oil filter.
Phil Planck

User avatar
Mike Wilson
Classifieds Monitor
Posts: 11490
Joined: Tue Apr 15, 2008 4:37 pm
Location: SW Los Angeles

Re: Anyone ever seen a double bellcrank?

#4 Post by Mike Wilson »

Excellent info! Would that be the emissions device seen on the 912 engine currently offered for sale in the classified ads?

Mike
Mike Wilson
Lomita, CA
'63 B coupe

User avatar
Phil Planck
356 Fan
Posts: 2030
Joined: Wed Mar 26, 2008 7:21 pm
Location: NE Michigan, lower penn.

Re: Anyone ever seen a double bellcrank?

#5 Post by Phil Planck »

Mike
Yes, that's it.
Phil Planck

User avatar
Mike Wilson
Classifieds Monitor
Posts: 11490
Joined: Tue Apr 15, 2008 4:37 pm
Location: SW Los Angeles

Re: Anyone ever seen a double bellcrank?

#6 Post by Mike Wilson »

Adding another microchip to my brain board. Thanks!

Mike
Mike Wilson
Lomita, CA
'63 B coupe

User avatar
Vic Skirmants
Registry Hall of Fame
Posts: 9278
Joined: Tue Oct 27, 2009 5:02 pm
Location: SE Michigan
Contact:

Re: Anyone ever seen a double bellcrank?

#7 Post by Vic Skirmants »

I have NEVER seen one like that. The 912 used an extra part on the throttle crossbar. NEVER seen the double fitting on the fan shroud! Maybe industrial engine?? Definitely NOT 356 nor 912.

User avatar
Mike Wilson
Classifieds Monitor
Posts: 11490
Joined: Tue Apr 15, 2008 4:37 pm
Location: SW Los Angeles

Re: Anyone ever seen a double bellcrank?

#8 Post by Mike Wilson »

I just checked the 911/912 PET. Page 170, 1969, 912, illustration 202-40.
Special throttle crossbar (linkage) #616.108.028.01
Vacuum unit #901.113.309.00

The bracket for the vacuum unit attaches to the rear of the fan shroud. It looks like the holes match the ones for the oil filter canister and coil brackets.

Used in conjunction with the vacuum advance distributor.

Mike
Mike Wilson
Lomita, CA
'63 B coupe

User avatar
Martin Benade
356 Fan
Posts: 12179
Joined: Wed Nov 23, 2011 10:52 am
Location: Cleveland, Ohio

Re: Anyone ever seen a double bellcrank?

#9 Post by Martin Benade »

So you are saying that the vacuum unit, etc is not related to the extra belcrank pivot, right?
Cleveland Ohio
62 Cabriolet
56 VW
02 IS 300
04 Sienna

User avatar
Mike Wilson
Classifieds Monitor
Posts: 11490
Joined: Tue Apr 15, 2008 4:37 pm
Location: SW Los Angeles

Re: Anyone ever seen a double bellcrank?

#10 Post by Mike Wilson »

Unfortunately, I couldn't find an illustration of the rear of the fan shroud. On the diagram for the vacuum set up on a 911, it shows a linkage going downward which might connect to the extra bell crank pivot.

This will be one of those things to look for at a Porsche event on a '69 912 or perhaps one of our members can shed futher light.

Mike
Mike Wilson
Lomita, CA
'63 B coupe

User avatar
Phil Planck
356 Fan
Posts: 2030
Joined: Wed Mar 26, 2008 7:21 pm
Location: NE Michigan, lower penn.

Re: Anyone ever seen a double bellcrank?

#11 Post by Phil Planck »

The extra pivot bracket, as Vic stated and Ron obseved, is not 356 or 912
Phil Planck

User avatar
Neil M. Fennessey
356 Fan
Posts: 275
Joined: Wed Mar 26, 2008 9:20 am

Re: Anyone ever seen a double bellcrank?

#12 Post by Neil M. Fennessey »

Here's the front face (forward facing) of a '68 912 fan shroud belonging to 401(k): an Oct. 1967 delivery to Springfield, MA. Note the modified throttle cross-linkage bar. That extra lever is used to operate the vacuum retard dash-pot mounted atop the shroud.
IMG_0031.JPG

Here are a couple of photos showing 401(k)'s vacuum retard dashpot.
IMG_0033.JPG
IMG_0021.JPG
And yes, that's a rust hole in the rear sheet metal to the left of the Rost Off can. We know how to make 'em rusty in Massachusetts. And we own stock in Rost Off.
Back to the Ivory Tower I go!
 - Neil
'67 912/356D (Ol' Blue)
'82 HP 34C

User avatar
Martin Benade
356 Fan
Posts: 12179
Joined: Wed Nov 23, 2011 10:52 am
Location: Cleveland, Ohio

Re: Anyone ever seen a double bellcrank?

#13 Post by Martin Benade »

Actually not vacuum retard, it's a throttle positioner, slightly opens the throttles during over-run. Slightly lessens engine braking and emissions.
Cleveland Ohio
62 Cabriolet
56 VW
02 IS 300
04 Sienna

User avatar
Mike Wilson
Classifieds Monitor
Posts: 11490
Joined: Tue Apr 15, 2008 4:37 pm
Location: SW Los Angeles

Re: Anyone ever seen a double bellcrank?

#14 Post by Mike Wilson »

Neil: are there two bell crank brackets?

Mike
Mike Wilson
Lomita, CA
'63 B coupe

Brad Ripley
356 Fan
Posts: 4205
Joined: Tue Mar 25, 2008 9:28 pm

Re: Anyone ever seen a double bellcrank?

#15 Post by Brad Ripley »

Here's a close up of the bracket in question -- the one on the left side. As Vic suggested, I volt for the idea that it might be one of the industrial engine fan housings -- there were four different ones of those -- but I have no photos to check. How is the engine stamped for type number?

Industrial - boat - aircraft type numbers:
616/13
729/1
678/1
616/18
729/2
678/3
678/3-A
678/4
Attachments
FanShroud pivot bkt.jpg
FanShroud pivot bkt.jpg (17.2 KiB) Viewed 1457 times

Post Reply