When I installed cam in my block a few years ago a couple things checked wrong. 1.LSA was 112.5 instead of 114
2.begin of exhaust opening was 2 to 3 degress earlier.

I run a SC and was wondering if these things hurt anything. I have always heard that SC cars like 114 or more lsa. Would the 112.5 make car more prone to knock or anything?

 

Did you make sure the cam lobe was clean, and all the slack in the valve train
was taken up?

If you haven't already, try dialing the cam again. See if you get the same numbers.

It's possible the pointer moved, or some assembly lube on the lifter/lobe
skewed the results.

 

MOtor is in car now been running couple years I just ran acrooss the specs and was wanting peoples thoughts. WE did it numerous times made sure everything was clean. And always got same numbers.

 

Would all the numbers fall into place if you had a new timing set perhaps?

Wear on the chain, or cam lobes themselves are going to throw the results off.

EDIT: Read your post incorrectly.

What specs did you have (or use) when you first dailed in the camshaft a couple of years ago?

 

Not sure where the cam card is. I thought about the chain but if it was you would think that everthing would be off. Cam card had what the events were supposed to be.

 

Looks like you still run decent times judging by the limited info in the sig. And as long as the motor still builds boost then there really is no need to worry. The reason people go with a wider LSA(114) is so there is less valve overlap because too much overlap bleeds off boost.

You didnt mention ICL but if you measured that and it was also a few degrees advanced over what the cam card specs say then you COULD be more prone to detonation since the DCR will increase slightly... my guess is you wouldnt notice any difference.

 

Whats ICL?

 

You must have a lot of confidence in your ability to "degree" the cam. I always get numbers a degree or two off on repeated measurements. I think it's difficult to get exactly right.

Rich

 

Intake Centerline. It is where the lobe reaches max lift. Generally(loosely) speaking in the realm of off the shelf LT1 cams like you are running.. if you advance the ICL a few degrees it will help boost cylinder pressures by closing the intake valve earlier and opening the exhaust valve later, thus producing more torque. Downside to all of this however is that overlap, event of the intake valve closing in conjunction with the exhaust valve opening, is increased somewhat. And like I state previously overlap works against building boost.

 

Intake CenterLine

See page 5:

http://compcams.com/Technical/Instru.../Files/145.pdf

 

Doesn't the cc305 have 4 degrees advance ground in?

Originally Posted by rskrause
You must have a lot of confidence in your ability to "degree" the cam. I always get numbers a degree or two off on repeated measurements. I think it's difficult to get exactly right.

Rich

At the time it was my first but the guy showing me had done many.

 

???

 

Referring to the cam card it should say LSA of 114 + 4 if there is 4 degrees advance ground into the intake.