Spec's for a stock grey motor CAM?

CHO576 · Post by **CHO576** » Mon Jun 15, 2009 4:00 pm

Does anyone know what are the exact specs for a stock grey motor cam?

Has anyone had one ground recently / could advise where to start / or what your experiences where with this? Any ideas on cost?

Cheers,
Jamie.

Craig · Post by **Craig** » Mon Jun 15, 2009 6:50 pm

Hope this helps sorry havent had a cam done for a long time

CHO576 · Post by **CHO576** » Tue Jun 16, 2009 11:45 am

Thanks Craig ...
Maybe I could take this to a cam shop - and hopefully this is all the information that they need?
Cheers
Jamie

Cal · Post by **Cal** » Tue Jun 16, 2009 11:56 am

Jamie, I have one of those workshop manuals that covers from FX to HR Holdens.

It has one page with camshaft profiles and stuff I can't understand.

I'll try and scan it if I can

CHO576 · Post by **CHO576** » Tue Jun 16, 2009 1:05 pm

Cheers Cal - any help I can get on this is appreciated.

oldnek · Post by **oldnek** » Tue Jun 16, 2009 1:50 pm

Going by those specs in the manual.

Intake opens at 6 degrees (B.T.D.C) Before Top Dead centre
Intake closes at 48 degrees (A.B.D.C) After Bottom Dead Centre
Exhaust opens at 52 degrees (B.B.D.C) Before Bottom Dead Centre
Exhaust closes at 12 degrees and 13 minutes (A.T.D.C) After Top Dead Centre
Advertised Total Duration for Inlet is 234 degrees and
244 degrees and 30 minutes for exhaust.

What does this mean?........................Its a non performer cam

To all you grey purists thats why she idles oohh so smoothly and quitely.

You may have heard the terms 30/70.....35/70.........40/80 so on.
These are performance cams and they are measured in degrees B.T.D.C as the Inlet opens and closes. with the Exhaust figures very similar to inlet other there stated in reverse.

So take the 30/70 cam as example:
Intake opens at 30 degrees B.T.D.C and closes at 70 degrees A.B.D.C.
With the Exhaust opens at 70 degrees B.B.D.C and closes at 30 degrees A.T.D.C
Duration for this cam is Total 280 degrees,
*Using the Picture from the Manual as reference, Change the 6 to a 30 and the 48 to 70
So all you do to work out the duration, you just add the 30 Before Top + 180 (for half the circle) + 70 After Bottom.

So the Stocker grey job is a Whopping 6/48 or has an average 10/50..So WARNING DO NOT OVER CARB YOUR ENGINE, its just not worth it.

I hope I haven't confused anybody.

Regards John

CHO576 · Post by **CHO576** » Tue Jun 16, 2009 2:12 pm

Thanks John ...

Its all starting to make a little bit more sense now

I'm after a really smooth, quiet ride - with smooth acceleration.

My current cam is a little lumpy - which means Ive gotta give it heaps just to get her going. (But on the upside, she goes great on the highway).

Trev · Post by **Trev** » Tue Jun 16, 2009 4:14 pm

Excellent info John, especially for the uneducated (me) , thanks, Trev

.

Cal · Post by **Cal** » Tue Jun 16, 2009 10:02 pm

Jamie, my manual has basically the same info that oldnek posted

CHO576 · Post by **CHO576** » Thu Jun 18, 2009 9:42 am

thanks John / to all those who replied...

I called Waggott cams today with those specs - and thats the sizes that they quoted as well. So it all looks sorted ...

BTW ... Waggott are quoting $165 to regrind an existing cam (including postage back to Sydney).

Cheers,
Jamie