quick question about rockers
01-17-2013, 01:27 PM
#1
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quick question about rockers
Hey all,
I'm building a mild performance 383--- aluminum heads, 190cc runners, 64cc chambers, springs good for .600 lift, guides, screw in studs.
running 10.5:1 compression.
Comp XE256H, flat tappet cam, new lifters, probably new pushrods too, 110* lobe sep, 256/268 duration, .447/.454 lift--- (I know this is a small cam but I wanted more torque than upper RPM range).
is it advisable to re-use the original stamped rockers?
if not, and I need to get new ones, is there any benifet to getting roller tip or full roller rockers? I mean, any value there considering the flat tappet cam?
also, if I get new rockers, should I go with the 1.5's or up to the 1.6's?
thanks,
I'm building a mild performance 383--- aluminum heads, 190cc runners, 64cc chambers, springs good for .600 lift, guides, screw in studs.
running 10.5:1 compression.
Comp XE256H, flat tappet cam, new lifters, probably new pushrods too, 110* lobe sep, 256/268 duration, .447/.454 lift--- (I know this is a small cam but I wanted more torque than upper RPM range).
is it advisable to re-use the original stamped rockers?
if not, and I need to get new ones, is there any benifet to getting roller tip or full roller rockers? I mean, any value there considering the flat tappet cam?
also, if I get new rockers, should I go with the 1.5's or up to the 1.6's?
thanks,
Last edited by Jig A Low; 01-17-2013 at 01:30 PM.
01-17-2013, 01:47 PM
#2
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St. Jude Donor '05
You can use the stock ones dont see why not.
for small cams I never use a full roller just not worth it. Some Summit roller tips arent a bad bang for thebuck.
for small cams I never use a full roller just not worth it. Some Summit roller tips arent a bad bang for thebuck.
01-17-2013, 03:10 PM
#4
the stock ones do not give a true 1.5 ratio closer to 1.37. The Competition Cams roller tip give a true 1.52. For the 1.6 you have to check clearances in the head since the push rod is moved.
Read this link concerning the true ratio
http://www.camaros.org/302valves.shtml
Read this link concerning the true ratio
http://www.camaros.org/302valves.shtml
Last edited by MelWff; 01-17-2013 at 03:17 PM.
01-17-2013, 07:11 PM
#5
Burning Brakes
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you need long slot rockers.check out comp cams cam quest 6,the ex268h should make more tq/hp .aluminum heads allow you to 1/2 more point of compression .what intake are you using ?if it has provisions for rear coolant lines ,use them.
01-17-2013, 11:45 PM
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Since the rocker arm swings through an arc, the ratio does not remain constant. The article referenced by MelWff mentions the 1.37 ratio as the actual ratio at the lash points for stock rockers. The ratio at the max lift is what we are discussing here, which would be the 1.44 number provided by the stock rocker arms discussed by the article.
I just want to point out the correct math so someone doesn't think they will go from 1.37 to a greater ratio with new rocker arms. Based on the measurements by the author of the article, you should improve from the 1.44 ratio provided by the stock rockers at max lift.
So, I believe MelWff is correct in theory, just needed to fine tune the actual number.
I just want to point out the correct math so someone doesn't think they will go from 1.37 to a greater ratio with new rocker arms. Based on the measurements by the author of the article, you should improve from the 1.44 ratio provided by the stock rockers at max lift.
So, I believe MelWff is correct in theory, just needed to fine tune the actual number.