|
|
| Author |
Message |
Doc
Guru
Joined: 14 Oct 2002
Posts: 4968
Location: Working in Silicon Valley, USA
|
|
Post subject:
(Tue Jan 03, 2012 1:19 pm)
|
 |
|
|
| Quote: |
...I think I have the gear hobbing issue resolved, am waiting to hear back from 3 different sources now to see what kind of quantities they want to have to do it. I can tackle your castings once I get that sorted out. |
That is great news...
Careful if dealing with gear "hobbing" shops, I talked to 3 shops in my area and all of them said "sure, no problem, bring us the work".
The story changed when I showed-up at their door with parts in hand.
What I learned is that the center gear location on our long cam shaft, with 2 cam lobes right next to the gear, requires a special "worm hob", along with a special hobbing machine.
I did not look into the option of machining the gear profile on a CNC lathe, using special "live tooling".
DD
|
|
| Back to top |
|
emsvitil
Supercharged
Joined: 12 May 2005
Posts: 4714
Location: So California
|
|
Post subject:
(Tue Jan 03, 2012 4:58 pm)
|
|
|
|
Don't know if this would work...........
A 2 piece splined camshaft where the 2 pieces and gear slide together............_________________ Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes
 |
|
| Back to top |
|
emsvitil
Supercharged
Joined: 12 May 2005
Posts: 4714
Location: So California
|
|
Post subject:
(Tue Jan 03, 2012 5:23 pm)
|
|
|
|
Or a splined shaft where you slide on all the bearing surfaces, lobes, gears and spacers between everything................
With a selection of lobes, you could mix and match to do anything you want._________________ Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes
|
|
| Back to top |
|
Rick Covalt
Board Sponsor
Joined: 23 Oct 2002
Posts: 2857
Location: Waynesboro, Pa.
|
|
Post subject:
?
(Tue Jan 03, 2012 6:05 pm)
|
|
|
|
| Quote: | | Tilley experimented with high-rate cams with higher lift and they were worse than his lower lift designs. Duration/LSA and centerline are most important, from my searches and experience. Lou |
Ran into this quote above from Lou in 2010. Cameron obviously knows how to make big horsepower, so there might not be as much to gain here as people think. Not trying to discourage anyone from trying something new, just thought his quote was worth repeating.
I am going to be lucky to get my car into the 13's, so I don't have horse in this race.
Rick_________________ 2 Mopars come with Spark plug tubes. One is a highly refined, record setting, world class, racing machine. The other is a 426 CI. boat anchor!
]  |
|
| Back to top |
|
CNC-Dude
Turbo Slant 6
Joined: 20 Feb 2010
Posts: 564
Location: N. Ga.
|
|
Post subject:
(Tue Jan 03, 2012 10:39 pm)
|
|
|
|
| Doc wrote: | | Quote: |
...I think I have the gear hobbing issue resolved, am waiting to hear back from 3 different sources now to see what kind of quantities they want to have to do it. I can tackle your castings once I get that sorted out. |
That is great news...
Careful if dealing with gear "hobbing" shops, I talked to 3 shops in my area and all of them said "sure, no problem, bring us the work".
The story changed when I showed-up at their door with parts in hand.
What I learned is that the center gear location on our long cam shaft, with 2 cam lobes right next to the gear, requires a special "worm hob", along with a special hobbing machine.
I did not look into the option of machining the gear profile on a CNC lathe, using special "live tooling".
DD |
I got a response back for the price quote of hobbing the gears and copper plating the blanks today and can say that it is very reasonable. They have experience in doing camshafts for close to 50 years, so I am comfortable with their skill level and abilities. I need to send them 4-5 cam blanks at a time to make it more beneficial to them for setup time, etc... but they aren't opposed to doing just one or two at a time without penalizing you price-wise. So I guess I need to get busy.
_________________
There's no such thing as too much cam....only not enough engine!
|
|
| Back to top |
|
Charrlie_S
SL6 Racer & Moderator
Joined: 19 Oct 2002
Posts: 6093
Location: Silver Springs, Fl.
|
|
Post subject:
(Wed Jan 04, 2012 4:47 am)
|
|
|
|
| What is the purpose of copper plating the blanks?
_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Cuda 170 nitrous
66 Valiant Signet 225 nitrous
64 Valiant Signet
64 Valiant 4dr 170
|
|
| Back to top |
|
CNC-Dude
Turbo Slant 6
Joined: 20 Feb 2010
Posts: 564
Location: N. Ga.
|
|
Post subject:
(Wed Jan 04, 2012 10:21 am)
|
|
|
|
| The copper foil is placed on the cam barrel portions of the camshaft to shield those areas of the cam from being heat treated as deeply as the exposed bearing journal and lobe areas of the cam. Heat treating the cam barrel areas as deep as the bearing journal or lobe sections makes the cam very difficult to straighten after heat treating and can make it too brittle as well and can break when they are straightening it. The typical heat treat depth on the lobes and bearing journals is around .100-.150 while the cam barrel sections are only around .030-.050 deep. Chet Herbert figured this out over 50 years ago when he made the first roller cam, and its been the standard everyone else has followed for the most part since then.
_________________
There's no such thing as too much cam....only not enough engine!
|
|
| Back to top |
|
Doc
Guru
Joined: 14 Oct 2002
Posts: 4968
Location: Working in Silicon Valley, USA
|
|
Post subject:
(Wed Jan 04, 2012 10:59 am)
|
|
|
|
With heat treated steel cams I was working on, the shop would rough-out the blank, copper plate the whole thing, rough grind the cu plating off the lobes & journals, then send it to be heat treated. The plated-on copper "covering" acts like a "mask" to limit the amount of hardness depth, in the shaft and on the OP gear teeth.
As noted we want the lobes & journals to have a deep hardness but we don't want the shaft or gear to be as hard or "brittle", those areas need to be more flexable.
DD
|
|
| Back to top |
|
Charrlie_S
SL6 Racer & Moderator
Joined: 19 Oct 2002
Posts: 6093
Location: Silver Springs, Fl.
|
|
Post subject:
(Wed Jan 04, 2012 1:06 pm)
|
|
|
|
They say "if you learn something new, the day is not wasted". Thanks for making this a not wasted day. 
_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Cuda 170 nitrous
66 Valiant Signet 225 nitrous
64 Valiant Signet
64 Valiant 4dr 170
|
|
| Back to top |
|
CNC-Dude
Turbo Slant 6
Joined: 20 Feb 2010
Posts: 564
Location: N. Ga.
|
|
Post subject:
(Sun Jan 08, 2012 11:36 pm)
|
|
|
|
Here's my 3D Solidworks drawing of the Billet Chevy 6 roller cam blank, I am doing the Slant 6 and Ford 300 6 cylinders now.
[img]<a target='_blank' title='ImageShack - Image And Video Hosting' href='http://imageshack.us/photo/my-images/38/292camblank.jpg/'> </a>
Uploaded with <a target='_blank' href='http://imageshack.us'>ImageShack.us</a>[/img]
_________________
There's no such thing as too much cam....only not enough engine!
|
|
| Back to top |
|
slantzilla
Board Sponsor & Moderator
Joined: 17 Oct 2002
Posts: 9348
Location: Park Forest, Illinoisy
|
|
| Back to top |
|
CNC-Dude
Turbo Slant 6
Joined: 20 Feb 2010
Posts: 564
Location: N. Ga.
|
|
Post subject:
(Wed Jan 25, 2012 12:22 am)
|
|
|
|
| $550 is awful expensive for just a round lobe blank.
_________________
There's no such thing as too much cam....only not enough engine!
|
|
| Back to top |
|
Ceej
SSRN National Champion
Joined: 31 Mar 2003
Posts: 6327
Location: Oregon
|
|
Post subject:
(Wed Jan 25, 2012 7:01 am)
|
|
|
|
I thought so too.
OCG may be able to provide a finish ground part for Just a bit more than that.
CJ_________________ 
Tyrde-Browne Racing
I'm off to find myself. If I should return before I get back, keep me here. |
|
| Back to top |
|
Doc
Guru
Joined: 14 Oct 2002
Posts: 4968
Location: Working in Silicon Valley, USA
|
|
Post subject:
(Wed Jan 25, 2012 9:42 am)
|
|
|
|
What Howard has is one of the semi-finished" roller cam blanks made by the Coxs boys, years ago, the lobe shape is already there, it's heat treated and ready for finish grinding. ( I also have one of these blanks")
The bad news, the lobes were designed for a race cam with .600+ lift so it would have to be rough ground and re-heat treated if you want to go with a smaller profile.
DD
|
|
| Back to top |
|
CNC-Dude
Turbo Slant 6
Joined: 20 Feb 2010
Posts: 564
Location: N. Ga.
|
|
Post subject:
(Wed Jan 25, 2012 10:54 am)
|
|
|
|
| Ceej wrote: | I thought so too.
OCG may be able to provide a finish ground part for Just a bit more than that.
CJ |
Ceej, could you contact OCG and see what they charge to finish grind a round lobe roller blank and heat treat one for a Slant 6. I have gotten several quotes from other companies and the average is $400 for just one cam. So couple that to the cost of my cam blank and you are at $650 for a finished cam with your custom specs on it. Not bad I don't think, it places the finished cost right in line with the roller cams of the inline Chevy's and Ford's. Maybe OCG would do a group price on several cams at the same time if members sent them their blanks together, might get a better per cam price.....Thanks!
_________________
There's no such thing as too much cam....only not enough engine!
|
|
| Back to top |
|
|
