cam selection
Thread Starter
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
cam selection
there are a lot of threads here on cam choice. i want to throw in my lot with that.
i think its time to change out the cam and just looking for advice on a good choice.
it is a 72 454. it as an edelbrock torker II intake with a holley 750.(i wont get a different hood so changing intakes is out of the question)
it has heads from a L36 427.
it also as 1 7/8 primary headers into a 2.5 inch dual exhaust.
from my reading a lot of people like the xe268h and the xe262h.
supposedly the 262 gives a little more low end torque
it has a stock th400 trans. the compcams site says that 268 is the largest i can go with the stock converter so i will if anyone has any advice on a good upgrade for that as well i am listening.
the rear end are 3:55s
i think its time to change out the cam and just looking for advice on a good choice.
it is a 72 454. it as an edelbrock torker II intake with a holley 750.(i wont get a different hood so changing intakes is out of the question)
it has heads from a L36 427.
it also as 1 7/8 primary headers into a 2.5 inch dual exhaust.
from my reading a lot of people like the xe268h and the xe262h.
supposedly the 262 gives a little more low end torque
it has a stock th400 trans. the compcams site says that 268 is the largest i can go with the stock converter so i will if anyone has any advice on a good upgrade for that as well i am listening.
the rear end are 3:55s
Instructor
Joined: Nov 2008
Posts: 106
Likes: 1
I put the 268 compcam in our 350 and it seems to be the perfect set up for the 350.My brother in law helped me take the engine out and he wanted to go with the 272 but in the 350 the 268 in exactly what it needed. We bored it over 40, new pistons, roller rockers, 1400 series edelbrock carb. I took a lot of time researching everything to get the perfect set up for our needs and this engine. I do suggest doing the same thing to whatever you need or want out of your car. Check everything out, ask questions, instead of regretting something afterwards.
Ray/aka/Pa
Ray/aka/Pa
Thread Starter
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
yeah thats what i am trying to get into.
i know that up to the 268 i can keep the stock converter and pushrods but thats all i know so far
id like to hear from anyone that has the same basic setup regarding engine, intake and exhaust to see what they have
i know that up to the 268 i can keep the stock converter and pushrods but thats all i know so far
id like to hear from anyone that has the same basic setup regarding engine, intake and exhaust to see what they have
Instructor
Joined: Jan 2009
Posts: 144
Likes: 0
From: Go'n 2 Surf City.. it's 2 to 1
There aren't going to be any Big Blocks hurting for off the line
torque.. where they are going to falter is top end airflow... cam
so that your Big Block doesn't run out of air at 4700-5000r's.
Most Cams have a 4000rpm "sweet spot".. this does not mean
they will be dead or soggy outside of that spot.. in fact I usually
allow for 500 rpm's outside of the sweet spot.
The sweet spot can be widened by using intake and exahuast lobes
with different durations... usually a lower duration intake and higher
duration exhaust.
The ZZ4 cam is a good example of a dual pattern cam that widens
the effective sweet spot and has good torque off the line and
power up to 6000rpms... it has a lower duration intake and higher
duration exhaust.
ZZ4 Cam Specs:
duration: 208 intake/221 exhaust @ .050
lift: .474in/.510ex
lsa: 112
Big Inch Small Blocks and Big Blocks like longer duration cams...
I would say start out looking at cams in the 218-228 int range @ .050
at a minimum.
Sub 1500 rpm power will not be much of a issue on a
motor swinging a 3.75 inch stroke or bigger.
torque.. where they are going to falter is top end airflow... cam
so that your Big Block doesn't run out of air at 4700-5000r's.
Most Cams have a 4000rpm "sweet spot".. this does not mean
they will be dead or soggy outside of that spot.. in fact I usually
allow for 500 rpm's outside of the sweet spot.
The sweet spot can be widened by using intake and exahuast lobes
with different durations... usually a lower duration intake and higher
duration exhaust.
The ZZ4 cam is a good example of a dual pattern cam that widens
the effective sweet spot and has good torque off the line and
power up to 6000rpms... it has a lower duration intake and higher
duration exhaust.
ZZ4 Cam Specs:
duration: 208 intake/221 exhaust @ .050
lift: .474in/.510ex
lsa: 112
Big Inch Small Blocks and Big Blocks like longer duration cams...
I would say start out looking at cams in the 218-228 int range @ .050
at a minimum.
Sub 1500 rpm power will not be much of a issue on a
motor swinging a 3.75 inch stroke or bigger.
Thread Starter
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
i honestly do not know the Compression ratio. it is a 72 so i know the CR is low on those years but it has the different L36 427 heads on it that have different size combustion chambers that is supposed to bump it up some.
Last edited by baxsom; Feb 22, 2009 at 06:24 PM.
