e-cam with 1.7 RR's on a 331???

[Blaster]

My buddy has some 1.7 roller rockers he wants to sell me but I'm not sure if they will work with my stock valve covers or if they will work well with my current cam. I have 91 GT w/ported edelbrock 6037 heads and a e-303 cam, the engine has been stroked to a 331 and the 1.7 rockers would give me some nice lift with my current cam if it works????

[mustangII460]

Personally I wouldn't put on 1.7's with that cam. 1.6's sure.

[83GTMUSTANG]

Whats Wrong With This Cam With The 1.7's, I ALREADY GOT THE E CAM IN THE CAR IM GOING TO INSTALL THE 1.7'S TO GET MORE LIFT AN DURATION ..... INSTEAD OF BUYING AN F OR X CAM THIS SET UP SHOULD GIVE ME ABOUT .528 IN. OF LIFT AN 222,223,OR 224 DURATIONS RIGHT...........

[mustangII460]

Hope You Have Great Springs.

B303 = 224/224 @.050 .480/.480 lift w/1.6's .510/.510 w/1.7's
E303 = 220/220 @.050 .498/.498 lift w/1.6's .529/.529 w/1.7's

[Blaster]

So is it a good idea??? I thought the stroker engine might love the extra lift of the 1.7's with my e-cam but if my valve springs will wear out rapidly I'm not so sure. Any other opinions???

[mustangII460]

Blaster,

The 1.7's on the E cam provides the maximun amount of lift. In short, the springs will weakin rapidly. It creates alot more stress on everything, espcially pushrods. Depnding on what heads you run, the valve comes very close to the piston, especially critical in a stroker motor.

When the roller motors first came out we all bought 1.7's. When we finally had to tear apart the motors to modify them we stayed with 1.7's. After a short while we broke springs due to the cam lift causing stress. Good springs were installed and we bent pushrods. Finally we went back to a 1.6. On the dyno there was no change in power other than moving the power band around in the RPM's.

But,,,,,as always "Don't believe what I say, search google."

[83GTMUSTANG]

Wanted To No The Difference, It Seems An X Cam Has .542 In. Lift Vs. An E Cam With 1.72 Rr's = .529 In. Of Lift,..........so How Is It The E Cam An 1.72 Will Break Springs An Bend Push Rods..............but I No Plenty Of People Running A X Cam Or Similar Cam And Never Had A Problem...........explain This Agian To Me ..........thanks

[mustangII460]

Maximum lift on any cam wears parts and breaks parts faster.

Whats so hard to understand about that?

[HotRoddin]

Originally Posted by 83GTMUSTANG

Wanted To No The Difference, It Seems An X Cam Has .542 In. Lift Vs. An E Cam With 1.72 Rr's = .529 In. Of Lift,..........so How Is It The E Cam An 1.72 Will Break Springs An Bend Push Rods..............but I No Plenty Of People Running A X Cam Or Similar Cam And Never Had A Problem...........explain This Agian To Me ..........thanks

Look at it this way 83GTmustang... you get more lift from 1.7 ratio rockers because you are moving the pivot point of the rocker arm closer to the pushrod ... the change in leverage gives you more movement on the far end of the rocker from the same movement on the pushrod end ... but that same change in leverage (in this case negative leverage) means you have to push harder to get that valve spring to compress, so you're putting more pressure on the pushrod and the lifter and the cam lobe with the higher ratio rockers. That being said, unless you're running very high spring pressures, very high lift, and very high RPM's it usually isn't that big an issue, just be aware it will tend to bend pushrods and flatten cam lobes quicker, the higher the rocker ratio goes.

If you're going to do it, make sure the extra lift doesn't cause your valve springs to bottom out, and make sure your valve to piston clearance is adequate to handle the extra lift.

I hope that didn't confuse you even more

Rod

[83GTMUSTANG]

Would An X Or Z Cam With 1.6 Rr's Do The Same To Your Valve As A E Or F Cam With 1.72 Roller Rockers?????

[HotRoddin]

Originally Posted by 83GTMUSTANG

Would An X Or Z Cam With 1.6 Rr's Do The Same To Your Valve As A E Or F Cam With 1.72 Roller Rockers?????

If I understand your question correctly, yes ... There are just a couple of different ways to get extra lift. One is buy a more agressive cam, and install it, which gives you more lift by having physically bigger lobes ... that would be your X or Z cam ... the other way is to keep the cam you have and just change the pivot point on the rocker arms (higher rocker ratio), the drawback to the more agressive cam idea is, you have to buy a new cam and install it ... the drawback to the higher rocker ratio method is it puts more stress on your valve train componets.

Rod

[~The Jester~]

Originally Posted by 83GTMUSTANG

Would An X Or Z Cam With 1.6 Rr's Do The Same To Your Valve As A E Or F Cam With 1.72 Roller Rockers?????

No. That's what they're trying to tell you guys. A "bigger" cam is actually less strain on the components than a "smaller" cam with bigger ratio rockers. It's all physics, and leverage more specifically.

Think of the grade school teeter-totter. 300# kid on one end, and my 100# azz on the other. Put the fulcrum in the middle, and not such a big deal. But the closer to the fat kid that the fulcrum gets, the more effort is needed to get the fat kid off the ground. Same 100# azz on the other end, but the pivot has moved.

Take the 1.6 rockers, and do nothing else but replace them with 1.7's and you add a BUNCH of stress, forces, wear & tear on the valve train. You moved the pivot point closer to the fat kid. Plain and simple. Yes, you get more lift/duration for an inexpensive easy fix. But in this game the inexpensive/easy way will ALWAYS bite you in the azz. Name one other time that the cheap/easy way was the way to go.

[83GTMUSTANG]

Your Right I Got It, Now Would It Be Ok If I Didnt Race My Car Just Normal Street Driving And Not High Reving

[83GTMUSTANG]

What Size Springs Do You Reccomend

[Dark_5.0]

You would see about 20HP at the wheels with a custom cam. 300 bux from www.cammotion.com.

Do it and be done with it.

[fiveOguy20]

Originally Posted by ~The Jester~

No. That's what they're trying to tell you guys. A "bigger" cam is actually less strain on the components than a "smaller" cam with bigger ratio rockers. It's all physics, and leverage more specifically.

Think of the grade school teeter-totter. 300# kid on one end, and my 100# azz on the other. Put the fulcrum in the middle, and not such a big deal. But the closer to the fat kid that the fulcrum gets, the more effort is needed to get the fat kid off the ground. Same 100# azz on the other end, but the pivot has moved.

Take the 1.6 rockers, and do nothing else but replace them with 1.7's and you add a BUNCH of stress, forces, wear & tear on the valve train. You moved the pivot point closer to the fat kid. Plain and simple. Yes, you get more lift/duration for an inexpensive easy fix. But in this game the inexpensive/easy way will ALWAYS bite you in the azz. Name one other time that the cheap/easy way was the way to go.

since when did 1.7s increase duration?? lol. they only increase the lift. am i the only one who caught this?