just like the title states, What would i gain by going to 1.7 Roller rockers? P&P heads, stock cam, stock intake (other mods in sig). is it worth it right now or is money spent better elsewhere? i think i know a fair bit about the 5.0 basics, but a lot of the top end stuff is new to me. is there much benefit to go from stock to 1.7 RR's with a stock cam?
I would run 1.6's. If you can get the 1.7's cheap enough then get them. If it comes down to it you could always re-sell them. By putting the 1.7's on your stock setup it would be similar to having the smallest Motorsports cam. It will net about .500 lift which will help your combo breath. It's also cheap and gains a few HP from friction loss if you go roller.
Good post Samick, the only thing I have ever noticed about 1.7 is they give you a little more RPM up top, but they take that good bottom end grunt away. So if your geared steep do it if not you will problably be upset. They are a cheap way to help out the restrictive stock exhaust ports but you have that covered already. For the money you would have in a set you could buy a cheap motorsport cam and get a real performance improvement you could feel.
If you can pick them up cheap, I would get them. And when you do get a Motorsport cam for the car, you will be that much better off. I was thinking of going to a bigger cam for my car and the tech guys at Mustangs Unlimited told me to save my money and just go to 1.7 RR's. Although this was also the time when I was going to aluminum heads.
1.7 rockers arent going to net you much at all in the SOTP performance dept. You will hardly notice a difference. Your exhaust note may change just slightly and the engine may run slightly smoother. with that being said they are an excellent modification and i consider them a must on a performance car. If you can get a good deal go for it. The install be very straight forward. Make sure you order the 10 dollar shim kit with them! good luck
good info so far, i agree with ninety15.0's post completely. also, they wont net you .500 lift. it will bring it up from .444 to .471 though, which is pretty close to the same LIFT as the B cam, but duration, lobe seperation and so forth is still different/lower so it won't really sound or act like a B cam. i have them on my car, and i like them....but they are noisy and it drives me crazy! and definitely make sure you get a shim kit if you get them.
IIRC, the stock rockers are 1.5:1. The 1.7:1 will yield .503 lift. A 1.6:1 will yield .474. Now if the stockers were 1.6:1 with a .444 (lift @ valve w/1.6) cam and you switched to 1.7:1 you would have .472 lift.
everything you just said is correct, but i always thought/been told stockers were 1.6's, just non roller. i know cheby's have 1.5's from the factory...
Stock rockers are 1.58...so basically they are a 1.6. So if you do the proportion you would be looking at (.444 x 1.7) / 1.6 = .47175
stock is 1.6.... You will get some gains from the 1.7's extra lift and such because your cam is stock, but most of the gain will come from the fact that they are roller rockers. I've got 1.7's on mine and I like them, but you have to be careful that they will not cause the pushrods to rub on your head castings, because the 1.7 brings the pushrod closer to the valve.
What would happen if you didn't have the shim kit? Mine are noisy and I have never popped the valve cover to take a look why....can the VC's be removed w/o taking the upper intake off?
if you bought the rocker arms new, they should have come with a shim kit. not all rocker arms will need a shim, but if one does and you don't have any, you won't have the proper preload for that lifter. and no, you have to take the upper off to remove the valve covers.
Yup the upper has to come off....only takes about 10 minutes. Its better to just leave the TB/EGR spacer all attached to the upper and pull it off together. Then you just need to take off the vac lines, undo the 6 upper intake bolts and snap off the throttle cable. real quick
Thanks guys...I'll have to tear it open and take a look. Are the 1.7 rockers known to kill the stock valvesprings overtime (Like since the early 90's)?
