Crank to Cam dimension on 616 engine.

[Ibrahim Kuzu]

Is there any factory blue print of 616 engine showing center of the crank to center of the cam
dimension ( measurement ) with plus and minus.
Thank you,
IK

[Albert Tiedemann]

Is there any factory blue print of 616 engine showing center of the crank to center of the cam
dimension ( measurement ) with plus and minus.
Thank you,
IK

Good luck on getting the authenticated dimensioning requested. Folks close enough to be "well connected" will keep this kind of information closer to the vest than their skin and often hide behind the armor of intellectual property. Your best chance is to measure up a few crankcases with a co-ordinate measuring machine and average the result for the dimension. Since this dimension represents the center distance of the timing gear set. it will be a basic one for the gear set which is likely produced at the nominal values without profile shifting. Errors in center distance manufacturing are made up by fitting camshaft gears whose generated running pitch diameters differ by .01 mm. Early manuals say that this .01 difference applies to the gear pitch radius. Although the difference is small in either case, you just keep fitting gears with different numbers until you measure the correct backlash. The numbers stamped into the cam gear, -2, -1, 0, +1 +2 represent a deviation from the the basic dimension. So, the plus /minus or tolerance on the basic dimension could be .02 or .01 depending on what manual that you read. Moreover, the gear set is likely produced at a standard module. I am not sure how to pull up the math symbols for equal to or greater than and equal to or less than, but if you let * represent the former and ** represent the latter a standard set of modules, m with increment, i might be inferred from metric thread pitch gauges as follows:

.35* m **.55; i = .05
.60* m **.90; i = .10
1.00* m **1.375; i = .125
1.50* m **2.75; i = .25
3.00* m **4.50; i =.5

Calculating the center distance using the number of teeth on the gear set, 26/52 and one of the above modules and comparing with an average of measured values might hone you in on "the distance" requested.

[Ibrahim Kuzu]

Ab,
Thank you for a great detail info .

We get from center of crankshaft to center of the Cam shaft 95.576mm
in our measurements...
I like to see if any factory blue print out there to give us plus and minus tolerances and to see
if we are 100% in our measurements with factory....
IK

[Larry Coreth]

Ab,

If you open up "Character Map" you will find most any mathematical symbol or other character you could possibly think of
there which you can copy & paste to suit. It also for some characters gives you a keyboard short cut for that symbol which will be useful in the future but does not work in this posting window (use MS-Word , Excel, etc.)
Ex. >, >=, ±


Ibrahim,

May I suggest you measure the CL to CL of the crank to cam distance on the case as opposed to the 3rd piece. The 3rd piece is not machined tightly to that dimension since the connection to the oil pump gear is a slot and a loose one at that !

Just for interest sake why do you need that dimension and/or the design tolerance therefor ?
"Curious minds want to know" ! 8)

[Craig Richter]

Yeah, another "curious mind" would like to know. You must be planing to cast some trick new front cover for your beautiful "looks like a Carrera"?

[Ibrahim Kuzu]

May I suggest you measure the CL to CL of the crank to cam distance on the case as opposed to the 3rd piece. The 3rd piece is not machined tightly to that dimension since the connection to the oil pump gear is a slot and a loose one at that !
-------------------
Larry,
Thanks,
We did from crank case...but not laser read ,did it old fashion with caliper...I want to be 100% before machining (which is little long way)

The twin dist,full follow oil filter new timing cover designed for bolt on the Carrera gen stand (so we do not weld blocks on the case any more)
Please see the solid works drawing from computer screen..

Craig,
Yes, you are correct...Long time spend in designing ,still working on but coming to end slowly....Please see the picture...
IK

[Craig Richter]

Ibrahim,
I should have read your earlier postings so I would have known your plans. You are doing some really fun stuff, as is Bill Sargent. Glen too, with his project, John Wilhoit with his stroker motors, and of course the magical Clifford. On and on. It's wonderful the different paths our hobby keeps taking. A lot more resources being thrown into 356 development these days than any of us ever envisioned back in the day! Keep at it...

[Ibrahim Kuzu]

Craig,
Thank you for the good words....As progress continues ,will post pictures of the engine.
Hopefully trying to get one ready for the Los Angeles Lit meet.....We will see....
Now days as you noticed in other posting ,doing testing new design under the Carrera cooling shroud aluminum oil cooler.
IK

[Jacques Lefriant]

Hi Ibrham
The distance should be the same as Type I. VW either 36 or 40hp. When we manufactured replacement gears we used 95.68 as the centerline distance the pitch angle was 23.5deg and the Pa 20 and the Mod 2.25. We did not have access to any factory information and we then manufactured the gears to give the same dimensions as stock gears when measured with a .144" ball.
cheers
j
If you are making third pieces i would reverse engineer from the two dowel holes.

[Ibrahim Kuzu]

Hi Jacques,
Thank you for the info...We are close....It would be great if there was a machinist blue print of 616 engine out there...
I red few info on the distance from crankshaft to camshaft center.....even factory was not 100% on the aimed measurement
so they used different numbered cam gears 1,2,3, + and 1,2,3,- and the 0 degree cam gear as we know.

When the new timing cover casting done , than I will be digging in more in other area precision measurements....There are always more things to do than we think in the beginning....
IK

[Larry Coreth]

Ibrahim,

If you think about it, no measurement or machining dimension is perfect or exact. With todays equipment manufacture machining can be done more exactly than 50 years ago. Hence the factory did what was and still is common, which is to allow for the machining inaccuracy by designing in an adjustment to suit. No doubt it was more expedient to account for the tighter requirements of the cam gear tooth clearance with different size gears than to try to machine the crank to cam center lines to the necessary tolerance of the gear clearance required.

BTW if you use a too small of a pitch dia. gear (too much clearance) the gear will self destruct (chew the teeth right up) in no time, 100 miles or so. I have the evidence to show for my error !

[Ibrahim Kuzu]

"If you think about it, no measurement or machining dimension is perfect or exact. With todays equipment manufacture machining can be done more exactly than 50 years ago."

Larry,
Thank you for the note...That is what my aim is to take advantage todays technology and try to get the best measurement between Crank C
To Cam C.....So All working in perfect harmony....

Will have to take it to one hr away shop the case and the timing cover in future to read by high tech coordinate measuring machine ...
see what is the difference with our measurement...maybe do few cases and timing covers to see where the dimensions going...

I also have other idea to leave some material on the crank and cam area and make a jig to machine these both dimension
after bolting all together Our new twin dist.full flow oil filter timing cover on each engine case and machine it from flywheel side
both dimensions, For this need to build two perfect jigs...
IK

[Jacques Lefriant]

Hi Larry
Your cam gear wear is counter intuitive most wear i have seen is the result of too little clearance.
j

[Jacques Lefriant]

Hi Ibraham
If you are making timing covers why don't you use a stand alone oil pump like the early 3 piece engines.
j

[Craig Richter]

Great idea J, then he can use VW pump. There are many really good racing VW pumps available, both single-stage and dry-sump. One less wheel to re-invent, but tach drive could be tricky.