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esde Samba Member
Joined: October 20, 2007 Posts: 5966 Location: central rust belt
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Posted: Sat Jan 08, 2022 10:17 am Post subject: Oversize camshaft |
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I have seen some discussion about retrofitting a 36hp case for camshaft bearings, and the associated issues. Alternatively, what if a camshaft was made with an oversize journal, and the case was line bored to match? It's not ideal, but would be a way to breath some life into otherwise worn out cases. Heck, if you filtered the oil it would probably be a long lasting solution. Has this been done or considered? Maybe WW could be swayed to have some oversize camshaft blanks made? _________________ modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that. |
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[email protected] Samba Member
Joined: June 24, 2015 Posts: 719 Location: Rialto. CA
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Posted: Sat Jan 08, 2022 3:08 pm Post subject: Re: Oversize camshaft |
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esde wrote: |
I have seen some discussion about retrofitting a 36hp case for camshaft bearings, and the associated issues. Alternatively, what if a camshaft was made with an oversize journal, and the case was line bored to match? It's not ideal, but would be a way to breath some life into otherwise worn out cases. Heck, if you filtered the oil it would probably be a long lasting solution. Has this been done or considered? Maybe WW could be swayed to have some oversize camshaft blanks made? |
I think cam bearings would just fix that issue ...cam bearings would be a vary vary good thing in all 36hp cases .... |
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esde Samba Member
Joined: October 20, 2007 Posts: 5966 Location: central rust belt
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Posted: Sat Jan 08, 2022 5:54 pm Post subject: Re: Oversize camshaft |
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[email protected] wrote: |
I think cam bearings would just fix that issue ...cam bearings would be a vary vary good thing in all 36hp cases .... |
I would agree, but given the complexity, nobody has managed to do it consistently enough to make it an available service. Mr Okrasa has some posts from 2019 showing his progress (impressive) and her also mentions the cost of the tooling and complexity of making the bearings. If you skip the bearings, and remachine the cam tunnel to accept an oversize cam, you're eliminating the hardest parts. I wonder if webcam could hardweld the cam bearing journals to make them oversize? _________________ modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that. |
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[email protected] Samba Member
Joined: June 24, 2015 Posts: 719 Location: Rialto. CA
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Posted: Sat Jan 08, 2022 6:10 pm Post subject: Re: Oversize camshaft |
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I think if you over size it they would also have to make the thrust area on the cam also wider and the case would have to have the thrust area on the case machined as well .. |
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Tvättbjörn Samba Member
Joined: May 07, 2004 Posts: 1431 Location: SoCal
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Posted: Sat Jan 08, 2022 8:12 pm Post subject: Re: Oversize camshaft |
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How about welding up the cam bearing seat / case and machine it back to standard .?.
There was a company back in the 90's they did it to water cooled vw heads. |
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[email protected] Samba Member
Joined: June 24, 2015 Posts: 719 Location: Rialto. CA
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Posted: Sat Jan 08, 2022 8:17 pm Post subject: Re: Oversize camshaft |
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That can probly could be done ...but the fear of heating/welding the magnisium case to be welded can cause it warp...and than you would really have a problem there... |
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Tvättbjörn Samba Member
Joined: May 07, 2004 Posts: 1431 Location: SoCal
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Posted: Sat Jan 08, 2022 8:42 pm Post subject: Re: Oversize camshaft |
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that is why it is so important to pre-heat the case to the proper temperature before welding and cooling it down slowly also.
However, it would be smart to surface the case sealing surface and do alignbore for the crankshaft also.
Lots of work, but it could pay of if a lot of cases are being done. |
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Robert Chambers Samba Member
Joined: August 11, 2005 Posts: 216
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Posted: Thu Jan 20, 2022 7:20 pm Post subject: Re: Oversize camshaft |
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Could the camshaft be spray welded and remachined? Just a thought! _________________ '63 OG 117 Herbie Replica
'56 Euro Oval Deluxe
'52 Standard Zwitter
'63 OG 117 |
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Mr. Okrasa Original Old Speed
Joined: May 20, 2000 Posts: 726 Location: Eastside, Costa Mesa. So. Califas...Loco's ;-)
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Posted: Sat Jan 22, 2022 6:49 pm Post subject: Re: Oversize camshaft |
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Interesting that nobody has addressed the issue of machining the cam bore PROPERLY! Hard chroming, spray welding etc, etc. to oversize the camshaft for a larger diameter is very easy! What method are you going to use to properly bore the cam tunnel and have all the bores concentric AND.......Wait for it......maintain the proper distance / dims. from the crank and cam centerline in order to have correct cam backlash using -4 to +4 cam gears? _________________
See my Instagram: https://www.instagram.com/okrasa/
1959 VW Karmann Ghia Coupe / Bamboo-Green / Denzel 1300cc / OG. owner, paint
Denzel engine running. See this link: https://youtu.be/DgUlsQDTXTE
VW www.Okrasa.com
356 www.PreA356.com |
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esde Samba Member
Joined: October 20, 2007 Posts: 5966 Location: central rust belt
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Posted: Sun Jan 23, 2022 8:15 am Post subject: Re: Oversize camshaft |
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Mr. Okrasa wrote: |
Interesting that nobody has addressed the issue of machining the cam bore PROPERLY! Hard chroming, spray welding etc, etc. to oversize the camshaft for a larger diameter is very easy! What method are you going to use to properly bore the cam tunnel and have all the bores concentric AND.......Wait for it......maintain the proper distance / dims. from the crank and cam centerline in order to have correct cam backlash using -4 to +4 cam gears? |
I haven't haven't considered the details of this because honestly it's beyond my capability. My assumption is that if VW, Rimco, and yourself have successfully line bored the cam tunnel of a VW case, then it is possible for a competent machinist. And yes, to properly locating the bore one would need to know the range of cam gear sizes and how they relate to the crank/ cam centerline distance. My post was more to discuss the use of bearings/ or not use bearings and let the cam ride on the case as VW did originally. While not the ideal repair scenario, it does eliminate the stumbling block of finding/ making suitable bearings at a reasonable cost. I know you have considerable time doing R&D on this, but you said yourself that the cost and tooling setup was substantial.
https://www.thesamba.com/vw/forum/viewtopic.php?t=711196&highlight=
No doubt there are plenty of guys with worn early cases that would love a shot at some affordable repair. When you were making the tunnel boring fixture, did you ever consider simply going with an oversize camshaft journal? _________________ modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that. |
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Mr. Okrasa Original Old Speed
Joined: May 20, 2000 Posts: 726 Location: Eastside, Costa Mesa. So. Califas...Loco's ;-)
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Posted: Sun Jan 23, 2022 11:41 pm Post subject: Re: Oversize camshaft |
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If you just consider hard chroming, flame build up or ???, you still have to bore / ream the cam tunnel for the oversized cam journal. Since the camshaft bore wears more horizontally in the block, it's going to be oval shaped. Now the question is: How do you install an "oversized", round cam into an oval cam bore? Brings us back to boring the cam bore perfectly round regardless if you install cam brngs, make the bore "larger" for the oversized camshaft? The cam bore should be addressed first. The rest is easy peasy....
I've checked with RIMCO and they only have tooling for the later 40hp blocks on up. They cannot successfully bore the cam in a 36hp block for oversize cams or bearing inserts. If there are other machine shops that can do the work on 36hp cam bores or more important, where are those machine shops? We need to know who and where are they....
esde wrote: |
I haven't haven't considered the details of this because honestly it's beyond my capability. My assumption is that if VW, Rimco, and yourself have successfully line bored the cam tunnel of a VW case, then it is possible for a competent machinist. And yes, to properly locating the bore one would need to know the range of cam gear sizes and how they relate to the crank/ cam centerline distance. My post was more to discuss the use of bearings/ or not use bearings and let the cam ride on the case as VW did originally. While not the ideal repair scenario, it does eliminate the stumbling block of finding/ making suitable bearings at a reasonable cost. I know you have considerable time doing R&D on this, but you said yourself that the cost and tooling setup was substantial.
https://www.thesamba.com/vw/forum/viewtopic.php?t=711196&highlight=
No doubt there are plenty of guys with worn early cases that would love a shot at some affordable repair. When you were making the tunnel boring fixture, did you ever consider simply going with an oversize camshaft journal? |
_________________
See my Instagram: https://www.instagram.com/okrasa/
1959 VW Karmann Ghia Coupe / Bamboo-Green / Denzel 1300cc / OG. owner, paint
Denzel engine running. See this link: https://youtu.be/DgUlsQDTXTE
VW www.Okrasa.com
356 www.PreA356.com |
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[email protected] Samba Member
Joined: June 24, 2015 Posts: 719 Location: Rialto. CA
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Posted: Mon Jan 24, 2022 10:49 am Post subject: Re: Oversize camshaft |
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Mr. Okrasa wrote: |
If you just consider hard chroming, flame build up or ???, you still have to bore / ream the cam tunnel for the oversized cam journal. Since the camshaft bore wears more horizontally in the block, it's going to be oval shaped. Now the question is: How do you install an "oversized", round cam into an oval cam bore? Brings us back to boring the cam bore perfectly round regardless if you install cam brngs, make the bore "larger" for the oversized camshaft? The cam bore should be addressed first. The rest is easy peasy....
I've checked with RIMCO and they only have tooling for the later 40hp blocks on up. They cannot successfully bore the cam in a 36hp block for oversize cams or bearing inserts. If there are other machine shops that can do the work on 36hp cam bores or more important, where are those machine shops? We need to know who and where are they....
esde wrote: |
I haven't haven't considered the details of this because honestly it's beyond my capability. My assumption is that if VW, Rimco, and yourself have successfully line bored the cam tunnel of a VW case, then it is possible for a competent machinist. And yes, to properly locating the bore one would need to know the range of cam gear sizes and how they relate to the crank/ cam centerline distance. My post was more to discuss the use of bearings/ or not use bearings and let the cam ride on the case as VW did originally. While not the ideal repair scenario, it does eliminate the stumbling block of finding/ making suitable bearings at a reasonable cost. I know you have considerable time doing R&D on this, but you said yourself that the cost and tooling setup was substantial.
https://www.thesamba.com/vw/forum/viewtopic.php?t=711196&highlight=
No doubt there are plenty of guys with worn early cases that would love a shot at some affordable repair. When you were making the tunnel boring fixture, did you ever consider simply going with an oversize camshaft journal? |
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I thought you were doing bearings?? or had a shop machining the 36hp case for you...so you should give the folks here the info to that machine shop so the folks here can send out their cases to that shop who does your work ..🤙👍 |
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Mr. Okrasa Original Old Speed
Joined: May 20, 2000 Posts: 726 Location: Eastside, Costa Mesa. So. Califas...Loco's ;-)
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Posted: Mon Jan 24, 2022 11:22 am Post subject: Re: Oversize camshaft |
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The firm that did my camshaft bore work is overseas. They advertise on eBay: https://www.ebay.de/itm/173689132861?hash=item2870add73d:g:VNMAAOSwUWtcEg0G
This process alone is a little over $2,000. Add another $300 for surfacing the mating pieces so they are perfectly flat, add another $300 for shipping and now you are over $2,600. The last case that I had done (before COVID delays) took about 6 months. This person does excellent work! If you have a matching numbers block and this is the only available option for a worn cam bore, then you "step up" to the plate and pay.
This is the reason that I'm looking into making my own tooling so I can do this process here in the USA and keep the cost to a very minimum. I'm up to my elbows in engine builds right now "but one day", I will get around to make the tooling.
I built the engine, a 1952 type 527 / 1500cc for a Porsche Pre-A Split Windshield Cabriolet. See You Tube video of engine running....Cheers
Click on link and view in "Full Screen" mode, turn up volume: https://www.youtube.com/watch?v=I7QVBWVzQ_4
Quote: |
I thought you were doing bearings?? or had a shop machining the 36hp case for you...so you should give the folks here the info to that machine shop so the folks here can send out their cases to that shop who does your work ..🤙👍 |
_________________
See my Instagram: https://www.instagram.com/okrasa/
1959 VW Karmann Ghia Coupe / Bamboo-Green / Denzel 1300cc / OG. owner, paint
Denzel engine running. See this link: https://youtu.be/DgUlsQDTXTE
VW www.Okrasa.com
356 www.PreA356.com |
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RWK Samba Member
Joined: June 24, 2009 Posts: 1348 Location: S.W. MI
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Posted: Mon Jan 24, 2022 8:19 pm Post subject: Re: Oversize camshaft |
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Mr Okrasa, go to Practical Machinist, PM AlfaGTA or view his post, he does custom/restoration engine work, 1 offs, original rare engine repair, ect. I know he's done Porsche stuff, in his post's, he's in CA.
We have similar machine's, Deckel universal tool mills and share in that community. He would most likely bore direct vs. a stand alone boring bar, similar to how it was done originally, the Deckel can be used like a horizontal boring mill, the way deep holes are done in industry. You would have to provide the crank to cam bore center distance, or he could reverse engineer it, I believe its a very doable job, lots of set up and screwing around to make a cutter, and a simple cut.
https://www.practicalmachinist.com/vb/deckel-maho-aciera-abene-mills/ _________________ 73 Type 181
63 Type 113
63 Type 261- 428 071
62 Type 241-378 025 178 530 |
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RWK Samba Member
Joined: June 24, 2009 Posts: 1348 Location: S.W. MI
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esde Samba Member
Joined: October 20, 2007 Posts: 5966 Location: central rust belt
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Posted: Tue Jan 25, 2022 6:03 am Post subject: Re: Oversize camshaft |
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I spoke with Rimco about this several years ago when I was having them install new bushings in my Port-o-tool line bore guides. At the time, they said that if bearings for the 36hp case existed, they would have pursued making a fixture to bore the cam tunnel. They said that yes it would be expensive to make the case guides, but once it was done the operation would be similar setup to line boring the crank.
RWK, that machine is amazing. It's incredible that he was able to make a rigid cut that far into the case. What market/ purpose were the Deckel machine originally intended for? _________________ modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that. |
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RWK Samba Member
Joined: June 24, 2009 Posts: 1348 Location: S.W. MI
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Posted: Tue Jan 25, 2022 8:49 am Post subject: Re: Oversize camshaft |
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esde, precision toolmaking, the German BP, they make several sizes in the FP series the one shown link is a 3 or 4, I have a FP3, they had optical scales that you would read thu a built in magnifying glass on their rotary tables, gage block stops and holders for precision locating before DROs. Probably a dozen accessories and attachments, tilting rotary tables, slotting heads, spiral milling, dividing heads ect. considered a universal mill. common throughout the world, copied by many other foreign company's, La Blonde/Makino copied it some what and put CNC on their's in the 80's. _________________ 73 Type 181
63 Type 113
63 Type 261- 428 071
62 Type 241-378 025 178 530 |
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PEPPE Samba Member
Joined: August 24, 2003 Posts: 1068 Location: Roma Italy
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Posted: Wed Mar 09, 2022 7:52 am Post subject: Re: Oversize camshaft |
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does someone recognised which is the brand and model of the bearing used on the porsche block machined in germany? the aluminium colored bearings looks factory production bearings readapted for different application. |
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