THENASCAR

iTrader: (19)

well i have knowledge to a certain extent. still learning and i know bigger is not always better. and since these are stock parts with smaller valves i beleive duration to be a big determining factor in power due the the valve size. now i dont know if duration will make up for lack of valve size/lift but i guestimated off of what ive read. So what is yalls opinion? with the 112+2 overlap on the exhaust side it will allow for increased exhaust flow which is good for performance on the bottle. look if im completely off tell me. just trying to learn. but also i understand that with more duration and lift i can lose low to midrange power as well. will the lower lsa such as a 109 im almost making this a top end only cam. now with a 112+2 its still keeping a bit of mid range power correct?

KMS.1320

iTrader: (1)

Well, I was remembering your 109+4 spec, and a 105 ICL is too soon, you'd run into PTV contact there. duration isn't making up for valve size or lift really.. cylinder fill is different at different lift values as well as different valve sizes. The fluid dynamics that explain all that are beyond me at this point, but I am also learning. I wanted to hear why you chose your IVO and IVC.

THENASCAR

iTrader: (19)

right on my first lsa configuration i hadnt taken into account the massive overlap which would infact like u said put my ICL to soon at 105. so yes i wuld have piston to valve clearance problem. now at a 112+2 it would put it at 110 which with a lowered duration should be ok. but since the lsa is still fairly low am i going to be giving up some midrange power?

PREDATOR-Z

If you are going 112+2 then you'll be very close to a MS3 cam, no custom here.

I see you changed the specs to 232/238 112+2 LSA

I prefer that one on a 111+3 LSA
These are your VEs at .050 for that LSA/ICL

0.050
232/238,
111 LSA
108 ICL


8>IVO
44>IVC
53>EVO
5>EVC
114>ECL
13* Overlap

That is how I would run that cam for your purpose.

JPH

iTrader: (2)

Dang it Mark, you beat me to it. I was going to recommend the same events also.

THENASCAR

iTrader: (19)

now i understand most... of that... haha. these valve events listed above im trying to inerpret. the 8 of the IVO(intake valve opening would be at 8 degress? is that correct?) 44 degress intake valve close 53 degress exahust valve opens and 5 degress exhaust valves closing. 114 exhaust centline and 13 degress of overlap. slap me if im wrong but thats how im interpreting that. i see the specs you posted and that would be a 111+3 would give me a 108 centerline?woudl that not have piston to valve clearance problems? o and i see u said u prefer a 111+3 and what makes these valve events better at that particular lsa?

PREDATOR-Z

Yes, you are correct in * (degrees)

On a cam only setup, no, no PTV issues, it will clear. However, PTV should be measured. I would say about .06x on intake, plenty on exhaust.

THENASCAR

iTrader: (19)

ok good to know. now on these valve events is there a formula u used to figure out the degree on the ICL end ECL? or how is that determined ?

so for this cam were looking at a 232/238 598/610 on a 111+3

nowthose specs to me would be a booger to tune and have a bit of mid to high range power.

also if i wanted a purely top end cam with mountains of top end power....i would have to retard the cam correct?so instead of a +4 or +2 i would have the advance set for 0 degrees, or even more -2. ive never seen an off the shelf cam with retard of -2 or more. is this becase they are hard to tune? or not as drivable?