Roller Rockers Geometry

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I fired the motor today and didn't have any problems. The Hughes hold down kit was very nice. It uses studs instead of bolts and the hold downs are made of billet steel. It also comes with shims in order to locate the rockers perfectly center of the valve stem. I had to use some shims to get them perfect but not a whole lot. These rockers are much healthier than the ones I had initially. Thanks to everyone.
 
I would like to ask you guys a question. I have drove my car with the 360 for sometime now and never had any detonation problems until today! I wouldn't think changing rockers would have anything to do with that would it? The motor runs smoother it seems than it used to.

I'm running 10:7 compression on 93 octane fuel. Maybe I got a bad batch or something but I would hate to have loose compression or have to run race gas. Any thoughts?
 
Ck where you got gas some places in NJ are going to 91 not 93.Also ck your timing you may have hit the dizzy.
 
Mullinax95 What length of push rods are you using? I have the same set of rockers for my Eddy heads but when I tried to install them the pushrods seem to be to short.
 
jefflock said:
Mullinax95 What length of push rods are you using? I have the same set of rockers for my Eddy heads but when I tried to install them the pushrods seem to be to short.
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Jeff

It has been awhile since I bought those push rods.... I believe they was 7.5 long... I wish I could remember for sure. My heads had been milled down so it brought everything a little closer to the block. If it was me I would find a old push rod that will work with your rockers (some require ball/ball and others ball/cup) and cut it in half , thread and make you a adjusting push rod to determine the correct length. Talk to fishy68 ... he told me he had a old push rod if I needed it... so he has one. Or buy the adjusting push rod from Summit. I was going to drop my machinist and see if he would let me borrow one but I didn't need it. Maybe you know someone that has one.

The push rods I have allowed one thread showing on the rocker adjusters.
 
Mully 1 thread showing may or may not be enough. When I first put my rockers on that are like yours I had pushrods that were a little too long and when I put them on and adjusted them to load the lifter properly only about 1 thread was showing and it let the cup of the pushrod hit the rocker body at full lift. Pull your valve covers and turn the engine over to where one is at full lift and look at where the top of the pushrod cup is. If it hits the rocker body that may be your problem. On mine it made a clattering similiar to spark knock.

As Mully said I do have some extra pushrods if anybody wants one to make an adjustable pushrod out of. It's real easy. I just cut it in half taking about an extra 1/4" out of the middle and threaded it with a 5/16" fine thread die about 1" on both pieces then screwed on nuts all the way down then used a long coupler nut I found at ACE that serves as the coupler/adjuster. When you put it in you adjust it to the desired length and lock the nuts down against the long coupler nut and take it out and measure. Took me about 10 minutes to make it. If anybody wants one I have about 10 left so pm me and you can have one.
 
fishy68 said:
Mully 1 thread showing may or may not be enough. When I first put my rockers on that are like yours I had pushrods that were a little too long and when I put them on and adjusted them to load the lifter properly only about 1 thread was showing and it let the cup of the pushrod hit the rocker body at full lift. Pull your valve covers and turn the engine over to where one is at full lift and look at where the top of the pushrod cup is. If it hits the rocker body that may be your problem. On mine it made a clattering similiar to spark knock.
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Oh no don't say that!

I'll check out.

Wouldn't it make that noise all of the time? I only notice the spark knock noise under heavy load going through the gears. Not WOT but a good pedal pressed down.
 
Those are the same rockers that I had so much trouble with in the early 90's. The roller tip pin is held in place by pressing a tool in the end of the roller pin causing it to expand and stay in place.
Over time they loosten up and, if not caught and changed, they break!
If you are going to use them make sure you take a close look at the clearance around the spring reatainers and pushrod cup during the full sweep. Those rockers are real tight on clearance and the pushrods (Crane??) have a fairly wide top edge to them. The spring retainers and Crane pushrods have no clearance issues with the Crane Gold Race Rockers. I know, that's what I changed to!

P.S. You should probably have 2.5 threads showing, if you can't, the pushrods are too long. Shim the shafts up for the correct geometry and then check for the required pushrod length.
 
mopar340dave said:
Those are the same rockers that I had so much trouble with in the early 90's. The roller tip pin is held in place by pressing a tool in the end of the roller pin causing it to expand and stay in place.
Over time they loosten up and, if not caught and changed, they break!
If you are going to use them make sure you take a close look at the clearance around the spring reatainers and pushrod cup during the full sweep. Those rockers are real tight on clearance and the pushrods (Crane??) have a fairly wide top edge to them. The spring retainers and Crane pushrods have no clearance issues with the Crane Gold Race Rockers. I know, that's what I changed to!

P.S. You should probably have 2.5 threads showing, if you can't, the pushrods are too long. Shim the shafts up for the correct geometry and then check for the required pushrod length.
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Oh great!

That's real nice to hear!

I bought the rockers to get rid of the roller bearing type rockers and now I find out these might break?

At the time of purchase I thought I was getting the "Pro magnum" and not the "Magnum" type! But I really didn't like the Pro magnum adjusters so I just stuck with these.

Screw it!

I'm going to run the bastards!
 
mopar340dave said:
P.S. You should probably have 2.5 threads showing, if you can't, the pushrods are too long. Shim the shafts up for the correct geometry and then check for the required pushrod length.
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I was told by a engine builder never no more than 2 threads always!

The geometry is fine I already checked that. What length pushrods did you use with these rockers?
 
I can't remember the length, that was a while back. The rockers you have (I just remembered) have a newer version adjuster than mine came with.
When mine were falling apart, the ones they replaced them with had the same adjusters you have.
The original adjusters were longer and allowed more adjustment.
They sent my set back to me with one extra rocker so if another one failed, I would have an extra to replace it. Very nice of them. Too bad they missed one of the loose tipped rockers!

Sorry I didn't read all the threads before posting, I have now.
I'm glad to here someone has used the cheapo ebay "full roller rockers". I figured they were junk. Too bad it had to cost you money to find out.

I'll take a pic of the rockers I have and post it.
 
I just got back in the house. I pulled the valve covers and looked at the pushrod on max lift and the cups aren't coming anywhere close to touching the rocker. I then counted the threads and I guess I really should say they are 1.5 threads showing. My shop isn't brightest place in the world so I used a flash light this time.
 
Looks like you have clearance between the rocker and retainer too, at least from what I can see in the earlier pictures you posted. If there is valve train noise it would be there all the time. Take it from someone who has experienced that first hand.
 
mullinax95 said:
Oh no don't say that!

I'll check out.

Wouldn't it make that noise all of the time? I only notice the spark knock noise under heavy load going through the gears. Not WOT but a good pedal pressed down.
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I know it sounds strange but mine only made noise on accelleration too. After I installed shorter pushrods the noise went away. I just read your post below where yours are clearing the pushrods. Do they have excessive side clearance that is allowing them to slap back and forth against the hold downs? Mine seemed to have alot of side clearance I noticed.

If you don't find an obvious problem at the rockers to make sure it isn't spark knocking maybe you should check the timing to make sure something didn't slip there. Maybe try backing it off 3~4 degrees degrees just to see what happens. That'll rule out if it is actually spark knocking or not.
 
fishy68 said:
I know it sounds strange but mine only made noise on accelleration too. After I installed shorter pushrods the noise went away. I just read your post below where yours are clearing the pushrods. Do they have excessive side clearance that is allowing them to slap back and forth against the hold downs? Mine seemed to have alot of side clearance I noticed.

If you don't find an obvious problem at the rockers to make sure it isn't spark knocking maybe you should check the timing to make sure something didn't slip there. Maybe try backing it off 3~4 degrees degrees just to see what happens. That'll rule out if it is actually spark knocking or not.
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No I don't have excessive side clearance ... everything is very healthy in that area. I have checked everything.

I just cranked the motor up, waited for it to get warm and checked the timing. It was off. I usually run it with 34* all in past 2500rpm. It was in the 40* area. I backed it off back to 34* ... I would test drive it but the roads are wet. The cam has the lick it used to have now. I wouldn't think changing rockers would have a effect on timing but I guess it does. I didn't touch the distributor the whole time while installing the rockers.
 
OK, upon further inspection it appears that the old adjuster screw and the newer one are only different in the height of the screw above the threads. The nuts, thread length and the ball end are identical. They just got rid of extra weight on the screw that is not needed. Here is a crappy picture of them side by side:
02-14-09_1252.jpg


These two pics below are of the same rocker. I pushed the roller pin all the way left in one pic and all the way right in the other. Notice that the pin that the roller rides on is sticking out to the left in one pic and centered in the other. It is loose.
02-14-09_1246.jpg
02-14-09_1247.jpg


I spoke to Bob Mazzollini last year about all of this and he uses the Pro Magnums on some lower level high performance engines with the cup end adjuster screws. He said he prefers them. I did not ask why. He was surprised to hear what I had been through with them but he had not used the Magnums, just the Pro Magnums. I believe that all of the new Pro Magnums have a different way to retain the pin, but I have not gotten a look at them, so I'm just guessing.
He uses T&D on high end motors.
I honestly believe you can't beat the Crane Gold Race Rockers for the price. Mercruiser uses them exclusively because they just don't fail.

Since you are happy with the geometry, check your pushrod length:
Roll the engine over so the both valves are closed on the #1 cylinder.
If you have an adjustable pushrod, pull the left rocker shaft off and remove the pushrods.
Put the adjustable pushrod in the #1 exhaust lifter (and one in the #1 intake lifter if you have another) and install you rocker shaft.
You should have your rockers adjusted at the recommended thread protrusion.
Tighten the adjustable pushrod(s) until they make contact with the rocker.
Remove your rocker shafts and pushrod(s) and measure them. Add the preload amount to that measurement. That is the correct length for your motor.

As far as Comp Cams goes, I don't like them and I no longer deal with them. They are the self-proclaimed leader in valvetrain technology....what a crock!
For years they told us how aluminum rockers suck and now, all-of-a-sudden, they have discovered a way to make them so that they are good????? They just got sick of losing too much business to Crane and others who make aluminum rockers...that's my opinion.
I don't like these giant conglomerations that buy up every company they can find just so they can make more money. Hooker Headers used to be great. I had a set of Super Comps on my Dart for years and they were rusty and dented so I bought new ones....same part number...only now they are made elswhere and they would not fit worth a crap and they clocked the collectors different so I would have had to cut my exhaust and re-weld the collectors. I sent them back and bought TTI's.


I hope this is helpful....maybe Comp would be willing to swap them for Pro Magnums???
 
Your rocker arms can not effect ignition timing.



P.S. The pushrod tip is spray oiled from the rocker, so it should not make any difference lube-wise as to whether the cup is up or down.
 
Glad you found the timing off. That should solve the issue. Dave's right that the rockers can't affect timing. Something else must have happened to cause it to be off.
 
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