Raising compression, Changing Lifters & Cam
09-29-2010, 02:03 PM
#11
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Thanks for the great response so far guys. What about lifters? I read the LS7's were good. Is the LS7 the highest revving of the LS family? I had aftermarket but I think the GM guys did their homework on the LS stuff.
09-29-2010, 02:27 PM
#12
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the ls7's will cover your 7200 RPM range there is a set of cadillac racing lifters that are a step above the LS7's and they arent cheap. i'd say go with ls7's and youll be fine.
09-29-2010, 08:21 PM
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What about the pushrods and springs? I'm not sure the Patriot Dual Gold springs are up to the task.
What are my options for springs?
Should I look more at opening and closing pressures than the amount of lift they will handle?
I have the stock length hardened pushrods, If I shave the head .05 and the cups on the LS7 lifters are .05 taller then I should use a 7.3" pushrod?
What are my options for springs?
Should I look more at opening and closing pressures than the amount of lift they will handle?
I have the stock length hardened pushrods, If I shave the head .05 and the cups on the LS7 lifters are .05 taller then I should use a 7.3" pushrod?
09-29-2010, 09:12 PM
#14
you can get to 11 to 1, but you need edelbrock 4.8/5.3 heads, and a .040 head gasket. I would not shave more than .050 off the heads, nor run lower than a .040 gasket. I run a ported 5.3 862 heads, and a .040 for a 10.6 to 1 and they are 55cc chamber. I think the cam you picked out will run into PTV issues. The springs you have are prefect. push rods will need to be measured.
09-29-2010, 10:13 PM
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you can get to 11 to 1, but you need edelbrock 4.8/5.3 heads, and a .040 head gasket. I would not shave more than .050 off the heads, nor run lower than a .040 gasket. I run a ported 5.3 862 heads, and a .040 for a 10.6 to 1 and they are 55cc chamber. I think the cam you picked out will run into PTV issues. The springs you have are prefect. push rods will need to be measured.
I had valvetrain problems already with Comp Pro magnum roller tip rockers (1.75:1 ratio) and the Comp type R pro Magnum lifters. I took the rockerarms off and the problem went away. I'm not sure what exactly caused the problem, it could be the springs couldn't handle the extra lift. It's Patriots heads, springs and Cam. Comps lifters pushrods and rockerarms.
09-29-2010, 11:27 PM
#17
what springs do you have ? rated for what lift .600 or 650
whats the lift on the 226 cam .581? with the rockers it could be to much lift and coil binding the spring if your spring cant handle the lift of cam and rockers combined
could be why the problem went away when removing the rockers...took away lift spring wasnt in a bind any more
whats the lift on the 226 cam .581? with the rockers it could be to much lift and coil binding the spring if your spring cant handle the lift of cam and rockers combined
could be why the problem went away when removing the rockers...took away lift spring wasnt in a bind any more
09-29-2010, 11:59 PM
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Springs are Patriot Gold duals rated for .650, Cam lift is .585, with 1.75 ratio I figured it was .614 lift. Stock ratio is 1.7, Pro Magnum rockers were 1.75 means .05 more lift. .585 x .05=.029 .585+.029= .614, Correct formula?
