How much horsepower would I get from Crane 1.7 roller rockers? and dont tell me its a waste of money because I already bought them long time ago for $200, and also would I need different pushrods?

 

wow nobody knows this ?? or dont care

 

Are those the accelerated lift ones? Either way, I think with regular roller rockers people usually say 5hp due to less friction and such. 1.7 is the stock ratio anyway, so you're not going to see much change off the bat.

 

Is it the same procedure as the old small block when installing the springs and roller rockers.

 

remove sparkplug, pump compressed air in the cylinder, use a good valve spring tool, switch springs, install new rockers, move to the next cylinder...pretty darn easy

btw - you shouldn't need new pushrods.

 

Go to the Vinci High Performance website...they have the exact procedures written down on their website, free for your perusal.

 

Copied from their site:

We have had several questions from individuals installing our Crane Gold Race LS1 Rocker Arms about why we wrote the instructions the way we did. Our premise was that most of the time, these rockers would be installed on the engine with the engine in the vehicle. The most important of these considerations is that the stock LS1 valve springs have relatively low seat pressures (70# new and frequently 55-60# after 20-30,000 miles of use). Our instructions call out a procedure of turning the crankshaft one revolution and adjusting any loose rockers to zero lash. Here is where the confusion occurs.

Zero lash should be determined by carefully lifting up on the front of the rocker arm.. at the roller tip and letting the rocker fall against the valve stem. The loose motion, or lash, causes the rocker to click against the valve stem. The adjusting nut should then be adjusted clockwise, by finger, a little at a time, until the click or loose motion is just removed. Do not turn the nut any tighter for this will depress the pushrod into the lifter. When in doubt, back off the nut and repeat the procedure. When all 16 nuts have been zeroed, The engine must be rotated, from the crank pulley bolt, or with a strap wrench. I recommend rotating about 1/4 to 1/2 turn at a time. When you check for zero lash again, you will see that some of the rockers are loose because the cam has rotated and those lifters have moved toward the base circle. Simply repeat the rocker arm lash checking and adjusting procedure again. Remember! Only tighten the nuts "by finger" on the obvious loose rockers, and only enough to cause the tip of the rocker to lightly rest on the valve stem. Next rotate the engine another 1/4 to 1/2 turn. Check lash and adjust again. Repeat the lash checking and engine rotating until you no longer have any loose "clicking rockers", you are finished with step one. Please note that sometimes the engine must be rotated several times before all the loose rockers are at zero lash. Now, you will not rotate the engine again. Step two requires you to tighten the adjusting nuts on all 16 rockers 1/4 turn. Wait about 10 minutes and repeat. That is, rotate the rocker nuts another 1/4 turn. Wait 10 minutes and rotate the nuts 1/4 turn again. You must rotate the rocker nuts, in this manner a full 1 and 1/2 to 1 and 3/4 turns, so keep an accurate count of the number of times you make 1/4 turn adjustments. You must wait 10 minutes between each 1/4 turn rotation to prevent the depressed valves from contacting the pistons. When you have finished the adjustment procedure, tighten the jamb nuts by holding the adjusting nut with your wrench and tightening the jamb nut with an Allen tool, and then rotating the tools simultaneously clockwise about 1/4 turn to complete the adjusting procedure. At this time it is a good idea to take a compression test to insure that all cylinders have equal pressure. A low compression cylinder probably has a rocker that is too tight. It is real easy, now, to readjust the rocker before installing the valve covers etc. All of this is necessary to allow the “relatively weak” stock valve springs to “bleed down” the hydraulic plunger in the lifter to allow proper lifter preload adjustment. If this procedure is not followed, valves could be “hanging open” when the engine is cranked over. This could result in bent valves. We realize that this procedure seems unnecessary or “overly-complicated” at first glance; but it works and, in the long run, minimizes installation aggravation. The use of higher seat pressure springs can reduce the waiting periods from 10 minutes slightly, during rocker arm installation. If the rockers are being installed as part of a complete rebuild, we recommend adjusting lifter preload to .060 -.100.” Extensive testing has shown this preload to provide the best power and performance, as well as minimizing valve train noise. When the engine is started for the first few times an audible clicking valve train noise may be heard. Run the engine for about fifteen minutes. Vary the rpms up and down during the procedure. After this run in time, the lifters, pushrods, and rockers should fill with oil and the noise will subside. The tech department at VHP will gladly help you through this procedure if issues occur. 407-478-8388

 

With these rockers, I think you DO need new pushrods...they use shorter ones since the rockers are changing the geometry.

 

ok thanks guys, I guess I'll do all this when a get a cam

 

i thought these lifters were still 1.7:1 ratio - i'm not too familiar with this rocker setup but most times when someone changes rockers only and keeps the same ratio, they don't need new pushrods, right?

 

EXACTLY

why would you need new springs or PRs if nothing changes with the ratio???

granted if you have alot of miles...new springs wouldn't be a bad idea...but not just for the rockers.

on the LS1:

pull the old rockers off, install new ones and torque down to 22lbs (double check that).

it was a half hour project when i did my harland sharp rockers.

as for power....maybe 5hp...only difference is the roller tip.

 

lol @ two guys with a total of TEN posts giving advice and arguing with someone that has over 4,000 posts i'm not admitting that i'm wrong or insinuating that teke184 doesn't know his stuff, i just find a little humor in it

 

They are no longer a non-adjustable valvetrain when you buy this kit from Crane. That is why there are specific directions above on how to PROPERLY adjust the rocker arms. To due otherwise will result in failure and more money spent fixing your mistake.

 

They are indeed a 1.7 ratio (can be a 1.8 as well), but you are missing the point of the design of these particular rocker arms. They change the geometry of the valvetrain completely on the pushrod side. Do me a favor...go to the Vinci High Performance website, and look around for these Crane rockers. I don't want to misquote specs on parts I don't own, but Vinci did nearly all (if not all) of the testing on these rocker arms.

 

The Crane 1.7 (1.79 variable ratio) and 1.8 (1.89 variable ratio) do require a shorter pushrod. The correct length for stock heads is 7.250. This is the pushrod that comes with the rocker arm kit.

If this is still questionable, call Crane tech support or Roger Vinci. Vinci High Performance did the R&D for Crane on most all of their LSx products.

 

+1 for that answer.

 

It also sounds like you only have rockers, the kit includes the pushrods, rockers, adjusting nuts, jam nuts, guide plates and studs. If you don't have all these parts, you can't install them anyhow. Also, these are fully adjustable rockers so anyone saying just bolt them in is not familiar with them.

 

Are u talking about the nuts that are in top of the rockers if u are then I do got those. My biggest concerned is that the rockers wont match a particular cam that I might want because of pushrods.

 

If your changing cams than you should check pushrod length anyway. To use these rockers make sure you have the correct studs, guide plates, and lock nuts.

 

didn't realize the cranes were different form the other styles.

guess i'm glad i got the Harland Sharp rockers. they were a direct bolt in.