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quatrini
10-24-2013, 10:20 AM
Hello all.
if you do not know i am building a 93 SC engine to swap into a mustang. i have one question, what is neccesary to accomodate 1.7 or 1.73 roller rockers?
i am using the comp cams stage 2 camshaft found on super coupes unlimited website. it is .500 lift and duration at .050 is 210 for intake and 226 for exhaust.
i am also running comp cams recomended hardened push rods and beehive spring suited for .625 maximum lift and steel retainers.
my only concern is if i use 1.7 or 1.73 roller rockers, will i need to change anything else? such as push rod length, or any other valvetrain geometry?
other concern is will i have valve to piston clearance? ive heard of people using cams with up to .540 lift on these engines but i am not too familiar with all the clearances.
one last thing to mention is i will be using wiseco drop in pistons bored .030 oversize. main question, what brand, ratio is recommended and will it work with my springs and setup?

BKB
10-24-2013, 11:50 AM
You are asking a question only you can answer. To many variables for anyone to give you an answer. Block deck height, head deck thickness, hg thickness, and piston brand all change push rod length and piston to valve clearances. You need to assemble the motor and check push rod length and geometry.

rzimmerl
10-24-2013, 12:12 PM
I run a .610 lift cam with 1.73's with no issues. Be prepared to measure for pushrod length and shimming of the rocker arms for proper valve tip location.

davec73
10-24-2013, 01:30 PM
most guys use 1.73s but I use 1.8s. It doest really matter what cam you use the push rod lengths will have to be checked with an udjustable rod from comp and they may still have to be shimmed. I used the 1.8s to get mine near 600 lift

HwyStar
10-24-2013, 02:32 PM
http://www.sccoa.com/forums/showthread.php?t=128996

Pretty much everything you need to know in the above post. I did the same combo you did except stock pistons. I was thorough.

BlkBirds
10-24-2013, 10:45 PM
Somebody I tend to believe told me 1.72 is the stock ratio. Is that not correct? I bought 1.73 rollers as an upgrade, and I figure I'm at least getting the benefit of the rollers. But when I bought em, I thought I was getting more ratio also.

HwyStar
10-24-2013, 11:01 PM
1.7 is stock. The difference in ratios is insignificant. The rollers and more rigid arm body was what I was after. More precise to ratio. Right word? May also be lighter which a big deal with a heavy valve train.

David Neibert
10-29-2013, 08:27 AM
Stock rocker ratio is 1: 1.73

David

Mike Bolduc
10-29-2013, 06:49 PM
Go with 1.73!! between .500" and .650" lift you have 5cfm maximum gain!! So dont mess with the lift over .500" lift!! The only thing you do when you raised your lift is to play with danger because you reduce you pistons clearance!!