My ex truck CABX 28 camshaft is now like new cam. It is done by that GT-motor machine shop in Helsinki and it is very very close to Iskys rpm-300 grind. Lift from lobe is .291" and that makes .417 lift with 1.43 rockers. Duration is 270 degrees. I was just an hour ago at my garage with LordMrFord and we did some "ultra accurate" measurements out of that cam. These are the results that are taken with .050" lifter rise:

Intake opens at 3 deg before TDC and closes at 44 deg after BDC.
Exhaust opens at 50 deg before BDC and closes at 2 deg before TDC.

So exhaust duration is 228 degrees and we got 226 degrees for intake but I quess that is measuring error with 2 degrees. So 228 to both sides.
Overlap with .050 lifter rise is then only 1 deg. I have to go back to garage and do that all again with .020 lift. But not today anymore. Last night I was assembling the block until 0.15 am!
The cost for that grind was 140 euros this time and that includes that center groove at the middle bearing surface and phosphate coating for the lobes.

Time will tell us how that works with Twin Turbo setup

I hope that Jim will add some pics to this message about that cam

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

HH,

       Machine shop or automotive machine shop is correct. Just that most US machine shops don't have cam grinders. Most of our aftermarket cams are done by 4 or 5 specialty companies that only do cams. Well, cams and valve train parts like lifters, springs, and pushrods. Most likely they purchase most of that stuff, rebox it and sell it to us as their own.

                                 Frank

Frank/Rebop

Bristol, In ( by Elkhart) 

Jim, what is bad to be awake at the lessons? You just learn more and you just get more attention by being foolish yourself . ( or maybe not Snoring makes other people happy!)

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

Haha, should have been awake eh? Seppo, you are a funny guy!

Jim (site owner)
'56 Club Sedan - Ted Eaton built 429 hp '292/318, '54 Sunliner - stock '302

I was just calculating the possibilities of that CABX-28 cam and I have no real meaning to get that grind to that .611 inch lift. And for that turbo engine I'll keep it stock otherwise than grinding that groove to that center journal. But, it would be nice to have one cam grind to, for example, Iskys 505-t specifications and to try it with some other engine.

Anyhow, I'm still interested about Stock cams and their degrees and lifts. Opening and closing points and all that stuff. 

What is the correct word for the place where the cams get grind and engines bored etc? Sorry about my bad english. Should have been awake at the lessons.... 

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

H.H.: Correction- Sorry, I said Jim, I should have said "Frank" 

Paul

H. H.: The Cab -X is a very mild 246 degree (advertised) replacement for the original cams. I have a bit of trouble believing your grinder can achieve what you're telling us. By the way according to J. Mummert, you will have to shorten the valve guides to achieve that lift. I think you should go with Jim's suggestion and contact Mummert for professional advice. As I understand it, to achieve that lift from your cam, will require reducing the base circle of it & that may not be a good idea... ??

  

Paul

Hollow.

         That's some machine shop. I've never seen one in the US with a cam grinder.

The theory on Turbo cams is to not allow to much overlap, nowadays they spec it with the "lobe centers". Keeps the boost from allowing the mixture to blow right out the exhaust valve. That's an awful lot of lift for a Y. Best run real good springs and check the piston to vale clearance, could get close.

                                                         Frank   

Frank/Rebop

Bristol, In ( by Elkhart) 

And the answer is... .568 inch with 1.43 ratio and .611 inch with 1.54 ratio. Quite awesome .

Lunati has great sites...

http://www.holley.com/data/TechService/Technical/Understanding%20Camshafts.pdf

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

Ok. I was at my garage a moment ago and took some measurements out of that CABX-28 camshaft. These are taken from the lobes, so we are talking about cam lift, not valve lift. Stock cam lobe is about 1.6 inch high when the basic circle is about 1.3 inch wide. At the bottom of the lobe there is extra material for about .161 inch that can be grind away to get more lift. Stock lobe in that camshaft has about .236 inch cam lift. When we calculate these two together we end up to .397 cam lift . How much is then the valve lift with 1.43 rocker arm ratio? Or with 1.54 ratio? Just wondering....

BTW The cost for that grind in Finland was 150 euros. I had to check that from the owner of that Edsel. Sorry about false information. Also he stated that that camshaft has about .433 inches of lift measured from the valve. 

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)