Rocker arms?

[Tyler J]

I have looked and looked and cant seem to find a rocker arm for my application. I'm in search of a self aligning arm for a 7/16 stud mount and 1.6 ratio preferably. Has anyone come across such a thing? Or should I find a set of 3/8 studs to screw in for a set of comp cams 1417-16?

 

[el camino ss 84]

Harland sharp makes the best 3/8 and 7/16 rocker arms, also scorpion , crane cams are good too. go to summit racing or jegs website and you will find all different brands and for 7/16 and 3/8.

 

[-83MONTESS-]

I can't answer your question as I didn't find any while looking on Summit but why not just use guide plates and forget the self aligning part of it?

 

[Tyler J]

That's what I am using right now but I'm not 100% sure they are set up correctly and they aren't the split plates. I just can't seem to get the roller tip centered on the valve stem on both rockers on a cylinder. And of course I would need new pushrods because I forgot they have to be hardened haha!

 

[el camino ss 84]

looking over the summit again looks like it only comes in 3/8s since most people using 7/16 are using guide plates.

 

[64nailhead]

That's what I am using right now but I'm not 100% sure they are set up correctly and they aren't the split plates. I just can't seem to get the roller tip centered on the valve stem on both rockers on a cylinder. And of course I would need new pushrods because I forgot they have to be hardened haha!

The rockers do not have to be parallel to each other and the roller does not need to be centered on the stem - IT IS UNIMPORTANT! Putting another set of rocker arms on is not going to resolve the issue. If you really feel the need to get them centered, then it will require offset rocker arms. Depending on the heads, a set of adjustable guide plates can help, but still not resolve all of it. Also, you can cut and weld your current guide plates to move the push rod side to side to get the roller where you want it. But depending on the heads, with straight rockers, you won't be able to move it far enough without having the push rod rubbing against the head.

How about some part numbers of the rockers and heads. And a couple of pics.

 

[Tyler J]

The rockers do not have to be parallel to each other and the roller does not need to be centered on the stem - IT IS UNIMPORTANT! Putting another set of rocker arms on is not going to resolve the issue. If you really feel the need to get them centered, then it will require offset rocker arms. Depending on the heads, a set of adjustable guide plates can help, but still not resolve all of it. Also, you can cut and weld your current guide plates to move the push rod side to side to get the roller where you want it. But depending on the heads, with straight rockers, you won't be able to move it far enough without having the push rod rubbing against the head.

How about some part numbers of the rockers and heads. And a couple of pics.

The heads are vortec with comp rockers 17002-16 and an XE274H cam I believe. Just a street car, no trips to the drag strip.

A few questions then. If they dont have to be centered on the valve stem, then what is important in terms of a correct setup? Also I am wondering what kind of clearance should I have between my guideplate groove and the pushrod? And since I'm using 1.6 rockers, am I going to run into problems down the road since the passage for the pushrod in the head hasn't been enlarged (Didn't have any problems yet during break in)? Note, I am not running hardened pushrods, and I know I should be. If I do keep the guideplate setup, I will purchase a set.

I figured if I found a set of 1.5 self-aligning rockers, it would be the simplest solution to any issues with minimal setup? I was thinking a set of Comp 1417-16. At this point, I'm just wanting a relativity easy setup that will require little maintenance with little chance of part failure.

 

[64nailhead]

'Proper setup' refers to correct rocker geometry which results in the narrowest possible footprint on the valve stem - usually around .060" This video explains how to determine pushrod length for correct rocker geometry - this is the 'mid-lift method' :

Clearance between pushrod and guide plate slot should be less .030-.035". The hole in the head for the pushrod should be fine with a Vortec head when using 1.6 rockers, but you need to check it to make sure. Regarding using hardened push rods, if you aren't, then expect metal to be getting pushed through your motor. The guideplates will eat up the soft pushrods in a hurry.

 

[Tyler J]

'Proper setup' refers to correct rocker geometry which results in the narrowest possible footprint on the valve stem - usually around .060" This video explains how to determine pushrod length for correct rocker geometry - this is the 'mid-lift method' :

Clearance between pushrod and guide plate slot should be less .030-.035". The hole in the head for the pushrod should be fine with a Vortec head when using 1.6 rockers, but you need to check it to make sure. Regarding using hardened push rods, if you aren't, then expect metal to be getting pushed through your motor. The guideplates will eat up the soft pushrods in a hurry.

Thats the video I used to select pushrod lenght during the engine build. I obviously overlooked using hardened pushrods but can easily install them. And the 0.060" footprint, is that the measurement of the 'travel' of the roller tip? Or the width if that makes any sense?

This is my current wear pattern on cyl #2 after break in. All the cylinders look very similar. What do you think?

 

[64nailhead]

Looks acceptable. If you used that method, then you are close enough from looking at that pattern. When looking for hardened push rods, Competition Products is probably going to be the cheapest you'll find.

Without attempting to cause too much concern, hopefully that pattern is only after a VERY short run period, because it looks like those valves are not rotating. Regarding swapping to 1.6 rockers, there is a good chance that you'll need a different set of pushrods. How a out some engine specs, i.e. cam, piston, deck height so we can see if the 1.6's will be worth the time. Personally I'd leave the 1.5 full rollers and leave those roller tips on the shelf. They are overrated - if you want roller rockers, then get roller rockers, not roller tip. The advantage of full roller rockers is the trunion bearing that the roller tips do not have. You might as well run standard stamp steel rockers - same hp and cheaper.

Edit, forgot to add, if you're looking for a new rocker, then Scorpions are a great quality, budget minded rocker with a lifetime warranty. I used a set of the Comp's that you have and they made it season's before the trunion bearings were destroyed. I'll never buy another set. The Scorpions are another $100 with a lifetime warranty. And try to find someone that has had to use the Scorpion warranty - the best warranty is one that you never need to use.