Restoring #151489 - building a faux cam carrera
- Steve Proctor
- 356 Fan
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- Joined: Fri Mar 28, 2008 12:15 am
- Location: Spring Hill, TN
Re: Restoring #151489 - building a faux cam carrera
Impressive innovation, design and implementation, Bill.
STP
Steve Proctor
Member Since 1977
VIN 84757
Steve Proctor
Member Since 1977
VIN 84757
- Bill Sargent
- 356 Fan
- Posts: 1147
- Joined: Thu Apr 10, 2008 11:03 am
- Tag: Faux-Cam
- Location: Seattle, Washington
Re: Restoring #151489 - building a faux cam carrera
Thanks Steve, but do not give us credit for implementation just yet. Right now things are still in the virtual world. Once we have a 3D print and confirm dimensions etc we will be a step closer.
The first task undertaken to modify the Okoren/Lager V drvie body was to design a new internal shaft to carry the pushrod distributor drive gear. On a factory 90 degree V drive the gear on the shaft is smaller in diameter than the bearings, but not so with the pushrod gear so we needed to design a new inner cap that would carry one of the bearings and oil seals. This sounds easy, but when you are in Beijing, China without parts to hand it is a little more difficult. Fortunately Gregory had both pushrod and 4 cam V drive parts, quality measurement tools and he send me at least 100 measurements. We also corresponded frequently via email and by voice over internet phone about the design. The photos below show the newly designed outer and inner end caps as well as the internal shaft. The internal shaft is sized to have the pushrod distributor drive gear interference fit as on the crank and use the large C clip from a push rod crank. Shoulders are built into the shaft for the bearings to rest against. At this stage we also changed the oiling system, placing the oil input so that it would spray on the shaft drive gear and the oil outlet so it was low on the bottom distributor shaft. Oil to the V drive will come off the dry sump pressure pump. Oil from the V drive will have a fitting to drain back into the 3rd piece. The next post will show how the unnecessary parts of the Okoren/Lager V driv body were removed and design started for a new mount frame. Thanks for following along!
The first task undertaken to modify the Okoren/Lager V drvie body was to design a new internal shaft to carry the pushrod distributor drive gear. On a factory 90 degree V drive the gear on the shaft is smaller in diameter than the bearings, but not so with the pushrod gear so we needed to design a new inner cap that would carry one of the bearings and oil seals. This sounds easy, but when you are in Beijing, China without parts to hand it is a little more difficult. Fortunately Gregory had both pushrod and 4 cam V drive parts, quality measurement tools and he send me at least 100 measurements. We also corresponded frequently via email and by voice over internet phone about the design. The photos below show the newly designed outer and inner end caps as well as the internal shaft. The internal shaft is sized to have the pushrod distributor drive gear interference fit as on the crank and use the large C clip from a push rod crank. Shoulders are built into the shaft for the bearings to rest against. At this stage we also changed the oiling system, placing the oil input so that it would spray on the shaft drive gear and the oil outlet so it was low on the bottom distributor shaft. Oil to the V drive will come off the dry sump pressure pump. Oil from the V drive will have a fitting to drain back into the 3rd piece. The next post will show how the unnecessary parts of the Okoren/Lager V driv body were removed and design started for a new mount frame. Thanks for following along!
Regards,
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
- Bill Sargent
- 356 Fan
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- Joined: Thu Apr 10, 2008 11:03 am
- Tag: Faux-Cam
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Re: Restoring #151489 - building a faux cam carrera
As you can see in the last post the Okoren/Lager design V drive body has a lot of material that is not needed for Gregory and my application. So the next step was to remove all the unnecessary parts of the V drive body that they needed to facilitate mounting on their integrated 3rd piece and to allow the integrated internal oiling. This sounds simple, but due to the way the original part was constructed in the CAD program it was necessary to almost completely rebuild the V drive body, while maintaining the internal geometry. Shots of this process are shown below. Getting to this point probably took about 24 hours of work.
The next post will show the start of the mount frame design process. Thanks for following along!
Along the way I found that the 6 year old PC I was running the Inventor CAD software on was not quite up to the task - with only the drive body and 3 parts I kept getting messages about RAM being 90% fill etc. So one unintended consequence of this project (isn't this how it always goes) was a new high end PC work station - latest Intel Core i7 Chip, 32 gig of ram, 3 x 3tb hard drives, outboard NAS for back up, water cooling etc and now the program flies! I built the PC myself and found that it was about 30% cheaper to purchase most of the major components (mother board, processor, ram) in the US even though the parts are made here in china. Apparently they are made in special duty free export zones. Places like Newegg in the US buy 10,000 of something so the cost is low. To be sold in China the part must have import duty, VAT at 17%, Transport etc paid and then Mr. Zhang at the computer market only buys 5 or 10, so he gets higher pricing. The middle class Chinese are not being well served by this type of pricing. The next post will show the start of the mount frame design process. Thanks for following along!
Regards,
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
- Bill Sargent
- 356 Fan
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- Joined: Thu Apr 10, 2008 11:03 am
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Re: Restoring #151489 - building a faux cam carrera
Once the V drive body was modified to something that I could build a mount frame off of we then started designing the mount frame. First step was to set up a plane in the model with points in space to represent the center points of the upper two studs on either side of the top of a 912 3rd piece. Gregory is using a 912 motor as the base for his project and it seemed logical to make a mount that fit in one plane. The plan for a 356 was to use spacers on the 3 studs that are at different elevations to the 4 on a 912. Our first thought was to make the mount frame an integral part of the V drive body. The progression of this first mount design is shown below.
UGLY! So back to the virtual drawing board. But it does get better. A lot better. Thanks for following along!
At this point I was still learning the software. Gregory and I both agreed that this design was not Porsche like and moreover just plain Regards,
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
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- 356 Fan
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Re: Restoring #151489 - building a faux cam carrera
Hello Bill, I'm no engineer, but .... the mount frame you are proposing seems too filmsy and will fracture as you suggest. Why not copy the original 2-ltr 4-cam mounting? Or, maybe I missed a previous discussion of this idea.
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- Bill Sargent
- 356 Fan
- Posts: 1147
- Joined: Thu Apr 10, 2008 11:03 am
- Tag: Faux-Cam
- Location: Seattle, Washington
Re: Restoring #151489 - building a faux cam carrera
Hi Brad,
Something like shown in the photos below? Did this over the last weekend. As I get to know the software better I am learning how to make the more complex shapes. Give me a few more posts and you will see the evolution of how I got here, as well as an alternate design for Gregory's use in a 904 replica. Thanks for following along.
Something like shown in the photos below? Did this over the last weekend. As I get to know the software better I am learning how to make the more complex shapes. Give me a few more posts and you will see the evolution of how I got here, as well as an alternate design for Gregory's use in a 904 replica. Thanks for following along.
Regards,
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
- Bill Sargent
- 356 Fan
- Posts: 1147
- Joined: Thu Apr 10, 2008 11:03 am
- Tag: Faux-Cam
- Location: Seattle, Washington
Re: Restoring #151489 - building a faux cam carrera
Here in LA now to attend the the open houses, Lit and swap meets. Thought all of you sitting in LA hotels needed some entertainment. Was in Seattle earlier this week meeting with the architect and city planning office for a house in the works. Also got to visit with Brad Green, Steve Terrien and Denny Akers. One can only take so much 4 cam machinery before a break is needed.
And this was just one of the garages. But I digress, back to the faux cam - looking at the photos before Brad's post, I scrapped design 1 and looked at a 904 V drive mount and set about making a more boxy mount that might look at home in a 904. By now I had figured out enough about the software that the mount frame was not too difficult. We chose to make it with 8mm wall thickness. It was at this point that we decided to make the mount frame a separate piece from the V drive body for the 904 application. First step was to design a way to mount the V drive body to the mount frame. I ended up with ears that extended beyond the body of the V drive such that when it is bolted to the frame dowel pins can be placed in the ears to positively locate the V drive on the frame. These will be drilled and installed for each application to ensure the V drive is centered on the crank.
The next step was to start designing the mount frame itself. This begins (as do all parts in this software) with a sketch on a plane that can be "extruded" or "revolved" in one way or another.
And here is the somewhat complete mount frame first version.
This process took a couple of days to complete. The sharp eyed among you will notice a problem with the photo directly above. Resolution of that is for the next post. I hope to see many of you in LA over the next few days. Then it is back to China - land of no Porsches older than 2005, air pollution and slow internet. Thanks for following along!Regards,
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
- Bill Sargent
- 356 Fan
- Posts: 1147
- Joined: Thu Apr 10, 2008 11:03 am
- Tag: Faux-Cam
- Location: Seattle, Washington
Re: Restoring #151489 - building a faux cam carrera
So in the last post I mentioned a problem. After posting Gregory several screen shots of the new mount frame we discussed clearance of the crank pulley with the mount frame and the dry sump oil pump immediately below. Even from the CAD file you could see that the 100mm crank pulley would interfere with the bottom of the mount frame.
This was easily solved by making a cut out on the bottom of the mount frame. This also solved another problem as the crank pulley does not have a lot of space between it and the dry sump oil pump. So the cut out was also needed to allow the fan belt to be changed.
At this point you will note that the corners of the mount frame are cut out to allow for a small flange where the case studs would come thru and have a nut installed to secure both the mount frame and the 3rd piece to the case. This was done with a 356 installation in mind. I then remembered that Gregory was using his motor in a 904 and the V drive mount frame needed to be a part of the front motor mount. We decided to beef up the mount frame by making the corners solid and using longer studs in the case that would go all the way thru the mount frame and the steel plate motor mount cross bar. The idea is to have the nut on the longer studs secure the motor mount, V drive mount frame and the 3rd piece to the case. There will be a cut out in the motor mount cross bar for the V drive to sit directly on the mount frame.
In the next post we will look at the start to design a 356 version of the mount frame that looks more like the stock "bowl" shaped V drive as shown in the first photo in the previous post (or the screen shorts in response to Brad Ripley's question). Thanks for following along!Regards,
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
- Bill Sargent
- 356 Fan
- Posts: 1147
- Joined: Thu Apr 10, 2008 11:03 am
- Tag: Faux-Cam
- Location: Seattle, Washington
Re: Restoring #151489 - building a faux cam carrera
At this stage we decided that Gregory would take the design to a CNC machine shop to discuss if there were problem areas in the design that might be difficult to machine. We also decided to share the design with Gary Okoren and confirm that he was OK with us proceeding to make our prototype – after all this was Gary and Al’s design to begin with. I sent information on the design to Gary and Gregory contacted him on the phone. Gary again was happy to see us pursue our design.
The machinability check is ongoing and we may need to make some changes based on feedback received. Once we have that feedback incorporated we will first make a 3 D plastic print and test fit parts to ensure clearances etc. So far the only difficult part to source will be the internally splined shaft that will carry the distributor drive gear in the V drive body. The shaft will start out at 45 mm diameter with the same DIN spec internal spline as on a stock V drive. Best quote so far is about $400 each for 7 pieces. The external splined shaft can be had for about $180/meter. Once the 3D print confirms the design we will make any necessary changes and then have a prototype machined in aluminum.
While Gregory was checking “machinability” I also started thinking about a different mount frame design for use in a 356 that would look more like the factory 90 degree V drive. Note the conical shape of the factory drive body that goes around the crank pulley and attaches to the case. This cone is cut away on top to allow the fan belt to go up to the generator. I used the factory V drive design as my guide and you can see from the photos below that this is still a work in progress. I have not quite mastered how to make a true cone shape in the software and instead have a rounded bulb, but you get the idea. I am not sure at this point if the round mount frame will be one part with the V drive body or separate. The current thought is to have flat mount ears coming off the perimeter of the round mount frame to allow mounting to the push rod case studs.
The next post will show how the design got to the current state that was shown in my post to Brad Ripley a few back. The redesign so far has taken between 150 to 200 hours spread over the last 14 months. The only portion of the original Okoren/Lager V drive design retained was the geometry and design of the distributor receiving tubes and the bore where the distributor drive gear is fitted. Thanks for following along!
The machinability check is ongoing and we may need to make some changes based on feedback received. Once we have that feedback incorporated we will first make a 3 D plastic print and test fit parts to ensure clearances etc. So far the only difficult part to source will be the internally splined shaft that will carry the distributor drive gear in the V drive body. The shaft will start out at 45 mm diameter with the same DIN spec internal spline as on a stock V drive. Best quote so far is about $400 each for 7 pieces. The external splined shaft can be had for about $180/meter. Once the 3D print confirms the design we will make any necessary changes and then have a prototype machined in aluminum.
While Gregory was checking “machinability” I also started thinking about a different mount frame design for use in a 356 that would look more like the factory 90 degree V drive. Note the conical shape of the factory drive body that goes around the crank pulley and attaches to the case. This cone is cut away on top to allow the fan belt to go up to the generator. I used the factory V drive design as my guide and you can see from the photos below that this is still a work in progress. I have not quite mastered how to make a true cone shape in the software and instead have a rounded bulb, but you get the idea. I am not sure at this point if the round mount frame will be one part with the V drive body or separate. The current thought is to have flat mount ears coming off the perimeter of the round mount frame to allow mounting to the push rod case studs.
The next post will show how the design got to the current state that was shown in my post to Brad Ripley a few back. The redesign so far has taken between 150 to 200 hours spread over the last 14 months. The only portion of the original Okoren/Lager V drive design retained was the geometry and design of the distributor receiving tubes and the bore where the distributor drive gear is fitted. Thanks for following along!
Regards,
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
- Bill Sargent
- 356 Fan
- Posts: 1147
- Joined: Thu Apr 10, 2008 11:03 am
- Tag: Faux-Cam
- Location: Seattle, Washington
Re: Restoring #151489 - building a faux cam carrera
In the last post I was starting to build a more "356" looking V drive body and mount frame. It took some time to learn how to make a "revolve" in the software, but once I mastered that things went fairly quickly.
Mounting the V drive body to the mount frame is by allen bolts starting from inside the mount frame into threaded holes on the V drive body.
At this point the combination of the V drive body and the 356 style mount frame are looking a lot better, as the screen shot below shows.
The next post will take you through the process of repairing the various problems this version has. Thanks for following along!Regards,
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
- Bill Sargent
- 356 Fan
- Posts: 1147
- Joined: Thu Apr 10, 2008 11:03 am
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Re: Restoring #151489 - building a faux cam carrera
And now here is how the various problems on the "gen 1" 356 style V drive got resolved.
And this is pretty much where we are today. There is one more slight change to be made that you can see in the third photo above. The radius between the mount ear and the drive body on the small horizontal plane is too tight - need a much larger curve to prevent cracks.
Coming closer to get the parts printed for dimension checks. Thanks for following along!Regards,
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
- Bill Sargent
- 356 Fan
- Posts: 1147
- Joined: Thu Apr 10, 2008 11:03 am
- Tag: Faux-Cam
- Location: Seattle, Washington
Re: Restoring #151489 - building a faux cam carrera
In yesterday's post I mentioned a small clean up needed - adding a larger radius fillet in a corner. The screen shot below shows what was needed.
Next step is a printed prototype for dimensional checks. Thanks for following along.
I also noticed something about our design compared to the factory 4 cam V drive that I should have noticed long ago. The factory V drive has the distributors mounted 180 degrees out to the shaft compared to our design. See comparison photos below:
I mentioned this to Gregory and his explanation makes sense: All the 4 cylinder Porsche distributors turn clockwise (as viewed looking down on the top of the rotor). The Okoren/Lager design mimics the regular pushrod design - i.e. gear teeth “pushing" towards the distributor rotor. The Carrera 90 degree design has the gear teeth “pulling” away from the rotor. Therefore the gear drive teeth are “backwards” compared to a pushrod distributor (actually to the shaft in the 3rd piece) to ensure the distributors still turn clockwise. The Carrera steep V design has two gears on the internal shaft, one with “regular” teeth and one with backwards teeth so both distributors still go clockwise. In any event if we find the distributors turn the wrong way an early 911 turbo distributor crank drive gear is identical to the 356 gear but has teeth in the opposite direction.Next step is a printed prototype for dimensional checks. Thanks for following along.
Regards,
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
- Bill Sargent
- 356 Fan
- Posts: 1147
- Joined: Thu Apr 10, 2008 11:03 am
- Tag: Faux-Cam
- Location: Seattle, Washington
Re: Restoring #151489 - building a faux cam carrera
Now that the V drive design is ready for printing I can take a break from design work. Last week Nigel in the UK send me some photos of the intake manifold and cam box set up. Casting and machining of the first run is in progress and they look great. I will let the photos below do the talking.
That's it for now. More when we get the print of the V drive. Thanks for following along.Regards,
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works
- Sven Sivertson
- 356 Fan
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Re: Restoring #151489 - building a faux cam carrera
The beauty of a 4 cam and dependability of push rods and modern electronics.
This project is awesome.
This project is awesome.
- John Brooks
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Re: Restoring #151489 - building a faux cam carrera
At the NW bull Session with a real 2.0 engine, Saturday 26 July.
John Brooks
62 Roadster
66 912
84 Cab
getting pushed around in porsches since 1965
62 Roadster
66 912
84 Cab
getting pushed around in porsches since 1965