Blower Cams
#1
Blower Cams
Things I've learned:
They mostly seem to have at least -10deg overlap (-10 to -18 being average)
Also the more Neg overlap there is, typically = a smoother idle or is associated with Cams of smoother idle (usually on a 114-115 LSA)
Are these observations correct?
They mostly seem to have at least -10deg overlap (-10 to -18 being average)
Also the more Neg overlap there is, typically = a smoother idle or is associated with Cams of smoother idle (usually on a 114-115 LSA)
Are these observations correct?
#6
TECH Senior Member
iTrader: (1)
Join Date: Jan 2003
Location: Armpit of East TX
Posts: 9,342
Likes: 0
Received 0 Likes
on
0 Posts
I say second one ... I low end isn't gonna matter much with that blower sitting on top of the engine. Trust me. As small as these cams are too ... you won't have to worry about any drivability issues.
Trending Topics
#8
TECH Veteran
iTrader: (6)
Join Date: Nov 2003
Location: Tallahassee, FL
Posts: 4,397
Likes: 0
Received 0 Likes
on
0 Posts
Also the more Neg overlap there is, typically = a smoother idle or is associated with Cams of smoother idle (usually on a 114-115 LSA)
210/210 @ .05, Comp Lobe. With a lobe seperation angle of 115*, it has -20* of valve overlap @ .05 valve lift. Tightening the lobe distance to 110* creates more overlap... -10*. Take a look at that chart. It helps. Move the seperation closer, and you see how the lobes overlap. Move the seperation apart and you have less overlap.
So for example, a 220/220 on a 115lsa, may have the exact same idle characteristics of a 210/210 on a 110lsa.
Overlap causes misfires at idle and that makes the lope or choppy idle. It causes a lot of intake reversion which causes the engine to basically choke on it's own exhaust during idle. The more the overlap the more the lope will be.
#10
TECH Senior Member
iTrader: (1)
Join Date: Jan 2003
Location: Armpit of East TX
Posts: 9,342
Likes: 0
Received 0 Likes
on
0 Posts
Personally ... I still don't like the huge split going on there knowing your gonna be putting headers on there. I would go with the 218/224 without a question or second thought. The only 2nd thought I might have would be going to something a little bigger.
There will be plenty of power under the curve with the blower on top.
There will be plenty of power under the curve with the blower on top.