anyone ever installed roller rockers and guide plates only to find that the rocker just touches the nut on the stud when it rocks. the guide plates i have are the comp cam ones that are shaped like a step. hard to expalin but they come up bend and then bend again to get the guide plate at the maximum possible height. i have heard of ppl machining the bottom of the roller rocker for clearance . wouldnt it be better to put the stud on a lathe and have the very edge of the stud nut taken away or even machine the guide plate where the stud bolts it downto maybe 1.5 mm thinck since it is 3 mm thick to begin with.... whats your tips?

 

Hi Ginger,

I'm not sure but it sounds to me like your pushrods has a wrong lenght.

If you get a set of 0.1" longer or shorter pushrods they will change the hight of your rockerarms so they no longer touches the nuts.

If you uses a tool like this you can finde the best lenght for your parts.

http://store.summitracing.com/partde...1&autoview=sku

I guess if your rod has the right lenght then you wouldn't hurt your nuts.

Best regards, DK.

 

i have a push rod measurer and used bearing blue to get the roll of my rocker perfectly centre on the top of the valve so i definatly have the right length push rod..if i went to one size push rod longer or shorter for that matter it would not be the perfect size. the geometry would be slightly wrong. i just put new heads and cam etc on the motor and it was all running fine but i did notice after its first run that a few of the rockers ( even though i bought crane self aligning )had slightly twisted cause it is a faily decent cam ( 107 lift on the intake)and has alot of spring pressure. ..so once i noticed they had twisted a little bit i put the guide plates on > this is the extra thickness that causes me the problem for the clearance between the stud and the roller. so what you think...any more ideas?

 

Never use self aligning rockers with guide-plates!

A severe risk of binding will be present.

But, for shure you changed you roller-rockers before to install the guide-plates.... I hope!

Anyway I know the stepped guide you mentioned, and I guess the thikness is the same of the others.

The correct solution to your issue should be the machining of the bosses where the studs are bolted, with the consequent new and shorter pushrods.

Of course if the heads are allready bolted on...... you should take a different way..... and, for my opinion, the right one is to lathe the studs.

The most important thing in the studs is the big radius they have at the base.... and you have to keep it.

If the clearance issue is on the very edge of the hexagone.... you have two options:

1) to modify the edge of the hexagone,
2) to make thinner the head of the stud, machining the BACK of the hexagone.

Finally, for my opinion; NEVER to machine the underside of a rocker.... this is the most stressed part.... and any machining will result as a crack point in a very short time...... specially with aggressive cams and springs!

Have a nice job !

 

thanks for both your replies !.
*of course i took my rollers off before i installed guide plates . there is no way you cant .is that what you meant?
*i have never heard that before that you cant use guide plates and self alligning rockers. what binds?
*yes i also think the stepped guides and flat guides are the same thickness, maybe some brands vary though.
* couldnt agree more about not machining rocker arms,i have heard of people doing it but on my engine - no thanks .
*yes the point of interference is the corner of the hex on the stud. it is only very very slight but enough to leave a mark on the rocker underside. it is so slight that when i am adjusting the posi loc pressure with the finger turning method + half a turn i feel resistence at the same time so it is only a very very small interferance but ENOUGH.
* so yes sounds like time to machine the edge of the hex : ) hopefully it will be enough . i have fast burns so maybe even different studs are an option .

 

You cannot use self aligning rockers with guide plates. This will constrain the pushrods at 2 points and it will bind.

There was a thread about this several months ago and the motor ended up breaking pushrods.

 

[QUOTE=bashcraft;1562212766 You cannot use self aligning rockers with guide plates. This will constrain the pushrods at 2 points and it will bind.

There was a thread about this several months ago and the motor ended up breaking pushrods.[/QUOTE]

Can I ask a silly question here? Are the stock rocker arms self aligning? If so what type of rocker arms should be used is someone installed 041/186 heads that had guide plates installed?

Thanks!

 

Stock rockers for 041/186 heads are not self aligning. These heads will either have slots which act as guide plates, or round holes which dictates that guide plates be used.

 

Thanks Bashcraft, I installed 041/186 heads that included guide plates on my '80. They used the stock rocker arms. I had a problem with a push rod and I'm trying to figure out if I can use my stock rocker arms on the setup listed below?

 

Thanks Bashcraft, I installed 041/186 heads that included guide plates on my '80. They used the stock rocker arms. I had a problem with a push rod and I'm trying to figure out if I can use my stock rocker arms on the setup listed above?

 

Here's some info from Crane's website, this is for the 10758 full roller gold rocker, not sure what you have.

"INCREASED RATIO AND STANDARD STUD DIAMETER (CANNOT BE USED WITH A MECHANICAL LIFTER CAM) FOR USE IN SELF-ALIGNING APPLICATIONS. DO NOT USE WITH PUSHROD GUIDEPLATES OR WITH CYLINDER HEAD CASTINGS THAT GUIDE THE PUSHRODS, AS SEVERE PUSHROD WEAR WILL OCCUR."

Sounds like you need to remove the guideplate, then you have the clearance needed to keep the bottom of the rocker off the stud.

 

I've got a stock '80 that I had a head gasket leaking. I got some 186/041 heads off of the forum for a really good price (cheaper than having the '80 heads reworked) they had about 1200 miles on them. I did not do anything else to the stock motor except install the new heads. The car ran flawless all summer long. I ended up with some loose rocker arms and a bent push rod, I also have a lifter that came apart. I'm trying to make sure I correct any problem when I put it back together, I don't want a repeat!

 

Could you post a picture?

The rockers should be way up on the stud if your push rod is the right length.

Nobody i have ever heard of had to machine the stud for clearance. What length pr's do you have

 

I used the original stock pushrods.

I can't access photobucket here from work but I think these are the links to the pictures.





I bought all new hardened push rods to re-install. I also found the number one intake lifter had came apart.

I'm thinking at the very least I need to replace that lifter, my buddy wants to replace all of them.

I also checked and the springs that were installed are the 981 comp cams, they're a little stronger than stock but I've been told by comp and my local speed shop they will be alright.

 

Actually my reply was for Ginger, but let's see what I can do for you. Are the pushrod holes in your heads slots or larger holes? I don't remember if your heads came with guideplates or not. If they didn't & the heads are just slotted then you don't need the guideplates with factory style rockers. On the lifter question, it's probably just the one lifter that was bad, but heck if you have to open it up & have the funds, then replace all the lifters with a quality brand.

 

here are some pics but its kinda hard to get a camera in under there to show much detail.you can see the tiny little marks that the points on the stud nut are leaving on my roller rocker underside. in one of the pics you can even see the roll marks on the top of my valves and it is perfectly central so the pushrod geometry must be correct.

 

Ginger,
The first pic shows the underside of the rocker arm. Do the ears on the rocker sit either side of the valve stem? If they do, then this would be a self aligning rocker (to me with my limited knowledge) and should not require guide plates.

 

Your rocker arms are self aligning remove the guide plates, if you have
a hydraulic cam you can use those rockers.

 

little mouse and rhd ...try reading all the thread...your a bit behind to what my actual problem is.i wrote in my second post the reason i put the guide plates on is because after my first drive after building the motor i noticed a few or the rockers had twisted slightly even with the self aligning rockers. i have a decent size roller cam and fairly big spring pressure. its all above .