Crank to Cam dimension on 616 engine.

356 Porsche-related discussions and questions.
Message
Author
User avatar
Jan Balder
356 Fan
Posts: 320
Joined: Tue Oct 21, 2008 4:21 pm
Location: Netherlands

Re: Crank to Cam dimension on 616 engine.

#61 Post by Jan Balder »

Ibrahim,

I wish you luck with your projects !

To add to the confusion, I measured the crank to camshaft centerline distance on a prime case with electronic calipers the best I could and found it to be 95,53 mm. @ 25ºC. (95,52 mm. @ 20ºC)


( I know, never trust your professional, brand-new, waterproof Mitutoyo electronic calipers, always use micrometers. :))

Jan.
Last edited by Jan Balder on Mon Sep 15, 2014 8:58 am, edited 2 times in total.
Jan Balder

User avatar
Ibrahim Kuzu
356 Fan
Posts: 830
Joined: Wed Mar 26, 2008 8:15 am

Re: Crank to Cam dimension on 616 engine.

#62 Post by Ibrahim Kuzu »

Jan,
Thank you. Very much appreciate it.
Also thank you for the crank to cam center line measurement.
Best Health and Wishes,
Ibrahim Kuzu

User avatar
Juha Vane
356 Fan
Posts: 303
Joined: Tue Jul 01, 2008 3:06 pm
Location: Sumiainen, Finland

Re: Crank to Cam dimension on 616 engine.

#63 Post by Juha Vane »

My engine case need to be line bored and now I really wonder what to do when
crankshaft and camshaft cc distance is not very clear.

Found these different distances in this topic:
95,50
95.576
95,68

Could somebody please tell me what is the correct distance so I could inform
the machine shop.
KTF,

Juha Vane
Finland

'59 308
'63 356
'85 911

User avatar
Jacques Lefriant
356 Fan
Posts: 4607
Joined: Mon Dec 06, 2010 1:50 pm
Location: Washoe county NV

Re: Crank to Cam dimension on 616 engine.

#64 Post by Jacques Lefriant »

Hi Ibraham
By my good fortune i have the print 539.01.147(21 jun 1954 release date) the original third piece It was supplied to Fletcher Aviation to build engines under license. the distance on the print from crank to oil pump center is 109.378 +.025 (pretty tight dimension). I also have the print 546.05.101(22 jun 1954) cam gear that has 16 gear dimensions on it in German but i will have to get my gear guy to explain it to me unless Ab wants to chime in. if you multiply 127.504(Teilkreis) by .75=95.628(Achsabstand) then you might have to allow for backlash?
BTW Juha that is why they make different gear sizes.
j
 

User avatar
Juha Vane
356 Fan
Posts: 303
Joined: Tue Jul 01, 2008 3:06 pm
Location: Sumiainen, Finland

Re: Crank to Cam dimension on 616 engine.

#65 Post by Juha Vane »

Hi Jacques,

The reason I’m looking for this distance is that he who will line bore
my block would not increase/decrease the camshaft to crankshaft center to center.
Do I understand right that the nominal achsabstand is this 95,628mm and then with
the +/- gears is correct backlash achieved?
KTF,

Juha Vane
Finland

'59 308
'63 356
'85 911

User avatar
Ibrahim Kuzu
356 Fan
Posts: 830
Joined: Wed Mar 26, 2008 8:15 am

Re: Crank to Cam dimension on 616 engine.

#66 Post by Ibrahim Kuzu »

Hi Jacques,
Could not get this dimension you mentioned from blue print "from crank to oil pump center is 109.378 +.025 (pretty tight dimension)"

Can you explain. There is huge difference from 95.628 to 109.378

This new Timing cover was much more work than we thought
Our pattern maker part time working old fashion way on it took long time, but hopefully end result will be nice.
Took these pictures last time visit to his shop,he was finishing the some area core boxes..
IK
Attachments
20171024_091329_resized.jpg
20171024_091323_resized.jpg

User avatar
Jacques Lefriant
356 Fan
Posts: 4607
Joined: Mon Dec 06, 2010 1:50 pm
Location: Washoe county NV

Re: Crank to Cam dimension on 616 engine.

#67 Post by Jacques Lefriant »

Hi Ibraham the nominal center distance on a VW oil pump is 28 ergo 109.38-14.=105.38
j
 

User avatar
Joris Koning
356 Fan
Posts: 2505
Joined: Thu Mar 27, 2008 12:38 pm
Location: Netherlands

Re: Crank to Cam dimension on 616 engine.

#68 Post by Joris Koning »

Juha Vane wrote:Hi Jacques,

The reason I’m looking for this distance is that he who will line bore
my block would not increase/decrease the camshaft to crankshaft center to center.
Do I understand right that the nominal achsabstand is this 95,628mm and then with
the +/- gears is correct backlash achieved?
This is a big problem with 4-cams where lay shaft and crank gear availability is poor. I will leave it to Jacques who knows much more about this than me to elaborate.
'56 Coupe
'57 Coupe
'59 Cab 
'60 Coupe

User avatar
Jacques Lefriant
356 Fan
Posts: 4607
Joined: Mon Dec 06, 2010 1:50 pm
Location: Washoe county NV

Re: Crank to Cam dimension on 616 engine.

#69 Post by Jacques Lefriant »

Hi Joris
the impression i get is the repair of cases that require a line bore is problematic. theoretically you can achieve a set dimension but not with the equipment that is found in automotive machine shops. the time required to set up the job with precision machines is not economical since they are usually used to make many parts so the setup is a factor on a small run especially on a one off. you could have a dedicated fixture that would do the job but i doubt that anyone would take the effort and expense to do it. i just had a gear shop make some different size gears for the roller crank but we made them off of samples and the angle/module may be off. also we made them the old fashion way with a hob cutter and if we wanted to make them perfect they would have to be ground instead of hobbled. to complicate the matter further even thought the cam to crank distance is pretty consistent there seems to be at least 2 different matched pairs produced they must be different as to some of the gear dimensions to achieve the same centers so it is hard to get the fit correct if you the gears were made differently.
j
 

Post Reply