Home 
Home Search search Menu menu Not logged in - Login | Register
> Jensen Healey & Jensen GT Tech > Engine & Transmission > Valve clearances and Camshafts

 Moderated by: Greg Fletcher Page:  First Page Previous Page  1  2  3  4   
New Topic Reply Printer Friendly
Valve clearances and Camshafts  Rating:  Rating
AuthorPost
 Posted: 01-27-2010 02:06 am
  PM Quote Reply
61st Post
roverman
Member
 

Joined: 11-07-2008
Location:  
Posts: 84
Status: 
Offline
Hi, Maybe under the, dumb question category, has anyone considered use of, or plagerizing the design of," Vega "buckets? No shims, just a "tapered" adjusment screw. Yes, they make some noise because adjustment is only to .002",(half turn of adjustment screw).I won't even mention hyd. buckets-oops!  roverman.

Back To Top PM Quote Reply  

 Posted: 06-16-2019 03:10 pm
  PM Quote Reply
62nd Post
Dakota123
Member
 

Joined: 03-20-2009
Location: Colorado USA
Posts: 180
Status: 
Offline
Greg Fletcher wrote:
. Snip...

BTW, the JHPS 104 cams are 0.432" lift and 268 degrees duration but with 235 degrees duration at 0.040" lash. These will give slightly better torque than most of the profiles out there.


That’s interesting, Greg— It’s been a long while since I started on my 2.2L build, and I was sorting through the cams I have on hand. One of them has three grooves (which may or may not mean anything, I know), a wide nose rather than the sharper nose of the two 104s I have on hand, and ~0.430” lift. Does this sound like the club store 107, maybe?

Back To Top PM Quote Reply

 Posted: 06-19-2019 02:22 pm
  PM Quote Reply
63rd Post
Dakota123
Member
 

Joined: 03-20-2009
Location: Colorado USA
Posts: 180
Status: 
Offline
Or, if not Greg, anyone? The relatively high lift has me confused as to what cam that might be.

Back To Top PM Quote Reply  

 Posted: 06-20-2019 04:31 pm
  PM Quote Reply
64th Post
Greg Fletcher
Administrator


Joined: 03-11-2005
Location: Lake Nacimiento, California USA
Posts: 425
Status: 
Offline
I don't know what 3 grooves could mean on a camshaft. 2 grooves would be a "E" camshaft from Lotus. On the 104 cams from the club store, those have .428 lift, no markings. The 107 would have a .387 lift. I believe a 104 cam originally from Lotus would be marked on the nose with a "444".

Back To Top PM Quote Reply

 Posted: 06-21-2019 01:34 am
  PM Quote Reply
65th Post
Esprit2
Member
 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 503
Status: 
Offline
LOTUS Cam ID . . . C . . . . . . D . . . . . . E . . . . . . . . 107 . . . . . 104
Marking . . . . . . . . None . . . 1 Groove . 2 Grooves . . 7777 . . . . 4444
Lotus Lift (inch). . . 0.340" . . 0.350". . . 0.344". . . . . 0.378" . . . 0.420"
JHPS Lift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.387" . . . 0.428" (what else is different ?)
Delta Motorsports'. . . . . . . . . . . . . . . . . . . . . . . . . . 0.361" . . . 0.416" (what else is different ?)
Int. Opens, BTDC . 26°. . . . . 25° . . . . . 27.5° . . . . . 22° . . . . . 32°
Int. Closes, ABDC . 66°. . . . . 65° . . . . . 52.5° . . . . . 50° . . . . . 60°
Exh Opens BBDC. . 66°. . . . . 65° . . . . . 52.5° . . . . . 50° . . . . . 60°
Exh Closes ATDC. . 26°. . . . . 25° . . . . . 27.5° . . . . . 22° . . . . . 32°
Overlap . . . . . . . . 52°. . . . . 50° . . . . . 55°. . . . . . . 44° . . . . . 64°
Duration. . . . . . . . 272°. . . . 270° . . . . 260°. . . . . . 252°. . . . . 272°

Besides lift, what else about the JHPS & Delta versions of the 104 & 107 cams is different from the Lotus versions? Lotus coined all the original cam names. For JHPS, Delta, or any other cam grinder to use the same names without clearly noting any differences only adds confusion. That's not a 'service'.

Regards,
Tim Engel

Last edited on 02-01-2020 10:05 pm by Esprit2

Back To Top PM Quote Reply  

 Posted: 06-21-2019 02:56 pm
  PM Quote Reply
66th Post
Dakota123
Member
 

Joined: 03-20-2009
Location: Colorado USA
Posts: 180
Status: 
Offline
Weird... well, one groove looks a bit different than the other two now that I look more closely, so I’m betting it started life as an E. Think I’ll get a degree wheel and try and figure out what it is.

Back To Top PM Quote Reply

 Posted: 06-21-2019 04:29 pm
  PM Quote Reply
67th Post
Esprit2
Member
 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 503
Status: 
Offline
Dakota123 wrote:
Weird... well, one groove looks a bit different than the other two now that I look more closely, so I’m betting it started life as an E. Think I’ll get a degree wheel and try and figure out what it is.Years ago, I bought a 907 cam carrier on eBay. It came with a cam installed that had none of the usual Lotus ID marks, but it did have "Delta" stamped on the back end. I called Delta Motorsports and they said it wasn't one of theirs. So I called Delta Cams, and they also said it wasn't one of theirs. :-/

I used a degree wheel to map it's lift profile, and it's a wild, long-duration cam, clearly not for street use. It's not a Lotus cam, and I've never found any cam spec that matches it.

It's unfortunate that aftermarket cam grinders weren't more diligent about marking their products, and/or obliterating any original marks that might be confusing down the road. And it's unfortunate that, as a group, they weren't more respectful of existing Lotus cam names.

If you don't know the source (ie, from Lotus), "104" and "107" have become as meaningless as "3/4 Race". 'Back in the day', every cam grinder made a "3/4 Race" cam for your small block V8, and they were all different. I would have preferred to have the true meaning of "104" and "107" preserved, but what you get now depends upon where you buy them. Besides frustrating my 'OCD', it makes email-helping someone de-bug their cam timing problems very difficult, since you really don't know what they have.

FYI...
Other LOTUS cams. Competition only, not used for street applications, and no longer available from Lotus.

Cam . . Part Number . . ID Mark . . Lift (inch) . . Duration . . . MOP . . . . Comments
105 . . . A908E0105 . . . 105 . . . . . 0.433 . . . . . 296 . . . . Per event . . Sunbeam-Talbot Rally Engine
106 . . . A908E0106 . . . 106 . . . . . 0.450 . . . . . 320 . . . . Per event . . Motorsport Cam
108 . . . A908E0108 . . . 108 . . . . . 0.460 . . . . . 304 . . . . Per event . . Motorsport Cam

Regards,
Tim Engel

Last edited on 06-21-2019 04:31 pm by Esprit2

Back To Top PM Quote Reply  

 Posted: 06-21-2019 05:15 pm
  PM Quote Reply
68th Post
Esprit2
Member
 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 503
Status: 
Offline
Greg Fletcher wrote:
I believe a 104 cam originally from Lotus would be marked on the nose with a "444".Correct.

Lotus Markings are on the exposed bit of cam that's visible between the pulley and the cam carrier:

In Lotus' early part numbering system, all cams had the same part number, but with a letter prefix to identify each cam. The C, D & E cams were from that era. The A & B cams were 'developmental' cams from before the 907 went into production, and were never sold.

At some time between the E-Cam and 104-Cam, Lotus changed their part numbering format. Each cam got it's own part number, and the cam's ID referred to the last three digits of it's part number. The early C, D & E cams were also issued new part numbers, but the old 'alpha' names stuck as 'street' names.

Lotus Cam Names and Part Numbers. . . . . . . . . . . . . ID Mark on the Cam's exposed shank.
C-Cam = C907E0351Z = 101-Cam = F907E0101G . . . None... a smooth shank.
D-Cam = D907E0351Z = 102-Cam = G907E0102G. . . One groove cut all around the shank
E-Cam = E907E0351Z = 103-Cam = J907E0103G. . . . Two grooves
. . . . . . . . . . . . . . . . . . 104-Cam = A912E0104F. . . . 44444444... stamped all the way around the shank.
Competition Only. . . . . . 105-Cam = A908E0105 . . . . 105 stamped in one place on the shank, not 'all around'.
Competition Only. . . . . . 106-Cam = A908E0106 . . . . 106 in one place
. . . . . . . . . . . . . . . . . . 107-Cam = A912E0107F . . . 77777777... all around.
Competition Only. . . . . . 108-Cam = A908E0106 . . . . 108 in one place

Regards,
Tim Engel

Last edited on 06-21-2019 05:22 pm by Esprit2

Back To Top PM Quote Reply

Current time is 09:44 pm Page:  First Page Previous Page  1  2  3  4     
> Jensen Healey & Jensen GT Tech > Engine & Transmission > Valve clearances and Camshafts Top




UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems