What is the difference in hp and tqr curves between a split pattern and a single pattern? Reason I am asking is I'm looking at the xe 230/236 or get a custom 230ish single pattern xe cam and was wanting to know if there was a differnce in power between the cams on the same motor. My heads flow very close to 80% so thats why I was wondering.

Thanks,
Jeremy

 

There's a reason almost all LT1 cams are split: it works better! The relatively efficient intake relative to the exhaust on a 4th gen F-body needs a split to work efficiently. IF you had a set of heads with great exhaust ports and were running something like an open exhaust, you might consider a cam without a split. Otherwise, you should get cam like the 230/236. It will make more power.

Rich Krause

 

So given a 224/238. 115lsa.
What should the Installed centerline be with only a 68% ratio?

 

If you are talking about an LT1, the cam must (for all practical purposes) be installed straight up. Advance can be "ground in" however. Most cams are either installed with 4 dergrees of advance or have 4 degrees ground in. I selected my current cam to give the desired valve timing ground (and installed) straight up and it seems to work well.

You can tell the amount of advance ground into a cam by comparing the LSA and the intake center line (ICL). When they are the same, there is no ground in advance. My cam, for example, has a 114ICL and a 114LSA. If the cam had 4 degrees of advance ground in the ICL would be 110 degrees.

Rich Krause

 

Here is a link to an intersting article on the subject:
http://www.iskycams.com/techtips.html#2003