292 cam questions

[1972fritz]

getting a 292 cam what else should i do? do i need to check piston to valve clearance if i get the 9.5:1 pistons from ireland? and as far as the cam timing is it crutal to time the cam with an adjustable gear? what works for every one? i am new but i have alot about cars and not so much about 1970s bmws

[wagnerf15]

The Ireland pistons are cut for the specific head you're using. I have the 292 cam with Ireland 9.5 pistons and the e12 head and they fit fine. Of course, timing should be correct, or no piston is gonna fit.

[1972fritz]

well i am planning on having the deck resurfaced and the head so i dont know if i need to degree the cam because the height diffrence? and i have heard that getting a cam and not degreing it is a waste is that true?

[Guest Anonymous]

well i am planning on having the deck resurfaced and the head so i dont know if i need to degree the cam because the height diffrence? and i have heard that getting a cam and not degreing it is a waste is that true?

Who made the cam? If it's a Dr Schrick 292 they are made accurate enough to install "straight up" without an adjustable cam sprocket. If it is a regrind then it would be better to use the degree wheel and verify what you have from the grinder, there is a much greater chance timing is off.

Copied from an old archive post (what I wrote about stock cam below would apply to a mild cam like a 292 as well):

Milling the head, or decking the block will slightly retard the cam.

You can do the math & figure how much:

The 36 teeth on the cam sprocket cover 720 degrees of crank timing, so each tooth = 20 degrees.

The timing chain uses 3/8" links, so 0.375" = 20 deg

Divide 0.375" by 20, and find that each 0.01875" = one degree (that's roughly one-half mm per degree)

Retarding the cam slightly often helps to make more power at the higher RPM, as the slight delay in valve closing can work well to move more charge thru the chamber (like the later valve closing that a greater duration cam offers).

Bottom line is, the normal amount of milling done to clean up a head is not likely to require adding an adjustable cam sprocket. In fact, the resultant retard of cam timing might help a stock cam make power.

Before adding the adjustable cam sprocket, you should degree your cam & know where things sit beforehand.

The added complexity of the sprocket adjusters might not gain you anything -- unless you can use a dyno to experiment it might not be worthwhile.

[1972fritz]

thank you that is whaat i was looking forthe cam will be a IE regrind