Just wondering how much lift I can go with on a camshaft before valve to piston clearance becomes an issue. Stock pistons and stock compression ratio (10.4:1). Also is there any down side to higher lift on a camshaft (idle quality, power curve, emissions?) Thanks.

 

You can go well past .600" with the stock pistons/heads/cam, but why? Stock heads only flow so much.

 

It's not necessarily just lift you have to worry about, it also has to due with your valve events, where the open and when they open. I'd clay it if you're going .600 or over on a cam that nobody has had previous experience with. If you're going to run larger valves too you have to watch out, i think a 2.02 is to big to fit into the reliefs maybe somebody could confirm that. What are the specs on the cam you're planning on running? All the things you listed are not really effected by lift but by the duration of the cam.

 

No cam you would want to use on stock heads would cause a problem.

Rich

 

The cam I am looking at using is Crower Part#00562 - the specs on the cam are 221/230 duration @ .050, lift is .560/.582 with the 1.6 rockers I have and it is set on a 114lsa. The advertised duration is 274/284 which seems like pretty steep ramp speeds for those duration numbers at .050 - the big difference with this cam seems to be the big lift numbers that I would be getting. My current cam specs are 218/224 dur @ .050, lift is .528/.536 with 1.6 rockers and it is set on a 112lsa. Is it worth it to switch to the bigger cam or should I stick with what I already have?

 

If you have stock heads and go with the Comp 26918 beehive springs,
retainers, locks, shims, etc. you should be safe up to about .615" lift,
assuming you have no seal to retainer clearance issues. The coil bind
on this spring is 1.085" and allowing a .050" safety factor gets you to
.615", assuming a 1.75" installed height. With the.582" on the Crower
cam, and a 1.75" installed height, you'll have .083" to coil bind.

Here is a cut and paste of the Comp beehive info:

Parts needed to install Comp 26918 beehive springs on a stock
aluminum head LT1 (for iron heads just omit the spring seat).

7 degree hardware with 4705-16 spring seats (1.73" installed
height):

787-16 retainers
648-16 locks

10 degree hardware with 4705-16 spring seats:

795-16 steel retainers, or
794-16 titanium retainers
611-16 locks (standard), 1.70" installed height, or
614-16 locks (+.050), 1.75" installed height

For either installation you will need spring seats:

4705-16 spring seats, .062" thick

 

IF I change to the Crower cam am I going to see much of a power gain?