Edelbrock Head/Guideplate Adjustment Question: PLEASE HELP

I pulled this comment by Jim Weise out of the ...street motor 455 500hp then 600hp? thread:

Edelbrock heads require isky adjustable guideplates, and careful setup to get the valve train to be decently quiet. Or you get to listen to your new engine rattle like a sewing machine. Especially with the stock valve covers. Adjustable guideplates and careful rocker setup, along with cast alum valve covers offer a very tolerant noise level with these heads. Don't forget that out of the box, those heads need to have the guides sized correctly, and the valve job redone, or your playing Russian Roulette with your engine. Broken valves do bad things to pistons and alum heads."

Im kind of curious how an amateur engine builder would adjust the Isky adjustable guideplates properly. I assume that the valve train would have to be mocked up, if not completely installed, and cycled enough times to determine the optimum location for each and every guideplate.

I mean, if the engine has just been assembled but not yet run in, wont the assembly lube be scraped off the bearings, cam lobes, etc. when the is being turned over enough times to check clearances, adjust the guide plates, recheck clearances, etc.?

Or should all this checking and adjusting be performed after the cam has been broken in on the dyno or in the driveway (if the cam is broken in upon first start-up of an engine in the car)?

Please explain.

Thanks.

 

Subscribing.

 

I spoke with Jim Weise about this via pm not long ago and he said he'd be doing a full write up on how to do this soon. Perhaps since it's coming up more he'll go ahead and fill us in if he gets a chance.

 

That would be good. Thank you.

Best case/Worst case: Jim has figured out a way to accurately locate the guideplates prior to installing the heads/ It would cost me a good-sized chunk of change to ship my heads and associated parts to him to do the work and return them.

 

I believe that is the case. In our conversation it appeared it was something I could do with the heads on the engine. There was another member who built a very precise fixture for setting them up, but unfortunately the fixture is no longer available.

 

If one new the proper spacing between the pushrods. It would be easy enuf to make a jig for welding.

This is going to be on my list of to do's this spring. Just wish the car wasn't buried for winter storage now.

 

I explained this problem to Jim years ago of the noise, at that time he had not dealt with it yet. The stud / shaft mount rocker makes a fair bit of noise because it is constantly trying to straighten the rocker alignment which is on an angle once installed on the head. The guide plate is what keeps it where it is. Every time the valve opens the pushrod, rocker and components get slammed in one direction as they try to find alignment. The roller tip is not sitting flat on the tip of the valve even though it may appear to be, it's not. The rocker would have to be straight for that to occur. When rocker starts it's travel the roller tip is trying to square it's self on the valve tip causing all components to load in one direction, that is the noise you hear.
An easier solution for most.
For most street engines and performance builds, a few alternative rocker choices are at hand. Simply installing a set of stock Chevy stamp steel rockers, these will work very nice as well as a stock type roller rocker. These rockers are designed with a ball fulcrum. They allow the end of the rocker to square up with the valve tip. The pivot ball allows the rocker to smoothly and quietly adjust through the valve motion not forcing it into a corner so to speak. This will be a much easier choice for most of you instead the expense of adjustable guide plates and the set up. The Edelbrock heads come with guide plates that can be used with these other rockers. These rockers are also less expensive than the stud/shaft rockers. TA1309C-1.60B $125.00 Roller tip self aligning rocker for 3/8 stud. For example.
Jim did take the time trying to straightening out the rockers with the adjustable guide plate the best he could, there are limitation. The results showed to quite things up a bit.

 

Problem is with that is that the Edelbrock heads would need the studs moved.

 

I couldn't find any details, photos, etc. regarding the TA1309C-1.60B in the TA Performance on-line catalog. So, I sent a PM requesting more information.
Thanks Mike.

 

It's really pretty simple.

First, prepare the guideplates.. you have to deepen the slot on them for the pushrod, by about 1/4 inch.. they are hardened, so you have to use a die grinder and carbide burr. You also need to modify the outside two plates, so the valve cover will fit on. As Mike said, making a rocker that is correct would be difficult, but making the correct adjustable guide plates would be a snap, and a set should be sold to everyone with a pair of E heads. Most folks buy those heads because of the lower cost roller rockers, and I think a set of rockers in a package with the correct adjustable guide plates would be a good seller. I know I would buy them, grinding the guide plates is the worst part of this job.

The adjustable guide plates are held in place by the rocker studs. When setting up the valvetrain you leave the rocker studs just a touch loose, so you can tap the plates around as needed. For each cylinder, (in the firing order sequence) simply set the pushrods in place, then loosely install the roller rocker.

The guideplates have bit of slop in them, which will allow the rocker to sweep back and forth across the valve tip. Trick here is to center that sweep.. move the guide plate as required so the "center" of the rocker side to side movement will be centered on the valve stem.

Now that you have the guide plate position, comes the tricky part.. you have to tighten up the rocker stud, without moving the plate.

Best way I found to do that is to 1. have the plate tight enough in the first place so you have to tap on the guide plates to move them, and then 2. use a electric or 3/8 air impact to just give it a quick shot of torque, and once you have that, you can then torque the studs properly with your torque wrench.

Then re-install your rocker arm, and adjust preload as normal.

It takes about twice as long to set up a E head motor like this than to do the typical TA roller rocker adjustment, and you will have to go back and make tweeks, but it does really quiet down these heads.

Use a pair of cast alum valve covers and it's very acceptable.

Well worth the cost of the guide plates and the hassle.

I have a board members set of e heads here for some porting, with his permission I might do a video on this... it's harder to explain in words that it really is to do.

JW

 

I'm using plain old stamped steel rockers, not even a roller tip. People have said my eddy heads are quieter than others. This might be why.

Would adding adjustable guide plates to stamped steel rockers help reduce noise further?

 

Something just dawned on me:

We seem to be seriously concerned about the noise aspect of what I interpret as binding, pre-load, misalignment, etc. issues.
What about the abnormal wear, etc. problems related to these issues? Isn't that a greater concern?

 

All the more reason to buy TA heads...

 

The threaded stud hole should be inline with the valve. This would keep the rocker straight and the roller tip flat on the valve. You ma find that the pushrod hole might need to be moved slightly once the pushrod cup is off set. The best way would be to build a shaft/bar mounted rocker set up. But I don't think it's worth that type of investment on Edelbrock heads. Just can't get the air out of them to make it worth that type of investment.

Yes, the parts are kinda being pushed into a bind, kinda. Over time you may see wear but these engines are not being driven near that much. It would be more beneficial if we could get everything out of the bind that Edelbrock created, then look to see how much more power or how much quicker would the engine accelerate. Buick did just those things when they redisigned the 3.8 and built the 3800, and it was a seat of the pants improvement.

 

Derek,

Actually, the adjustable guide plate is "the" fix. I looked at doing offset rockers and decided against it, due to the issues of side loading the studs. Attempting to bend them every time the valve open. Without some serious rockers 7/16 studs, and a stud girdle, it's my opinion that offset rockers would further weaken a less than optimum situation.

As to the ball fulcrum stock type rockers, that's an ok solution with small flat tappet hyd cams. Cams like a TA 212... I actually did a mock setup with that type of rocker on a .580 lift cam... wow.. you want to talk about the rocker dancing a hula across the tip of the valve.. it looked bad in setup, but WTH.. I tried it on the dyno.. NOT.. at high RPM I actually had number 6 intake rocker jump out of the pushrod.

It was at that time, Ron, my dyno guy, suggested the adjustable guide plates... "HUH? never heard of them" (I am a Buick engine builder)-

So I went to school on SBC valve-train setup with a couple of my buddies who run machine shops, and build chevys and pontiacs by the boatload,... and the multitude of variables can be intimidating... stud shank lengths, centering, long slots, girdles, stud diameter, ratios, nut types and diameters, lock types ...... AAAAAHHHHHH....... it was then I realized the beautiful simplicity of the Buick shaft rocker system...

So let's tackle this deal..

First off the basics.... In an ideal situation, the valve-pushrod-rocker-lifter run in a straight line. This is exactly how the SBC is designed.

Our Buicks are not. The lifter is not centered on the valve, it's about .080 offset. The valve centerline is outside of the lifter centerline. To visualize that, take a piece of paper, and make two dots, then below it make two more dots, with more space between the second set. That's exactly what we have. The upper dots are the lifters, the lower the valves.

It's why the Buick rocker arms have pushrods seats offset toward the rocker tower. With a shaft rocker system, the engineers deemed this as an acceptable loading situation, especially with the tiny stock cams and light stock valve springs.. Now us long haired freaks come along, and put a big rowdy bump-stick in and a set of serious valve springs, and we have really asked for trouble... But by in large, we got away with it, and when it became an issue, we had first KB, and then TA roller rockers to solve the issue.

Now we eliminate the Buick Shaft rocker system, and adopt the SBC/Pontiac setup. BTW.. did you know that the stud rocker system was first used by Pontiac, and Chevrolet actually copied them?... little trivia for your next dinner party...

Now, we have rocker studs, valves, and lifters positioned in a position that I can only term as "operators choice"...Edelbrock's solution was to use a guide plate that split the difference so this is what you end up with..







So you have a rocker not centered on either the valve or the lifter.. about the worst of both worlds.. production tolerances with the heads, rockers, and block vary how far everything is off. Some line up ok, others are half way off the valve.

So how do you set it up?

First, we must establish pushrod length.

To do this use an adjustable pushrod, a light checking spring, and a felt tip pen: set the valve train up with the checking spring, color the tip of the valve and then adjust the pushrod so the roller of the rocker touches near the center of the valve. Now rotate the cam by hand one revolution.. take the rocker off and examine where the coloring is gone on the valve tip. You want the valve tip to roll from just above center, to just below center on the valve. It's a procedure known as "checking the valve sweep" or rocker sweep. The correct length pushrod is determined thru this process.. And no cheating.. the SBC "pushrod length checker" does not work with the Buick..

Now that you have the correct length pushrod.. set your rocker back on and examine where the fulcrum is sitting in relation to the shank of the rocker stud. It's very important that the rocker fulcrum is on the shank, not on the threaded part. Where that ends up is determined by pushrod length, valve tip height, and rocker arm design, and must be checked every time. If your on the threads, ARP sells different studs with varying length shanks.

Now is a good time to talk about stud diameter.

Two options, 3/8 and 7/16.

The E heads come out of the box with 3/8 studs, and as such, use 3/8 rockers and nuts. That's fine for up to .525 lift flat tappet cams, with open spring pressures of 300 or less. All roller cams and big hydraulic and solid flat tappet cams should have the stronger 7/16 studs in my opinion.

But in your setup.. the heads already have 3/8 studs, so if you want to change to the bigger studs, how do you know what shank length to buy?... without buying a full set?.. ARP gives an out here, they offer rocker studs in a two pack, that will allow you to determine what shank length you actually need. ARP 135-7121 is a pair of 7/16 studs, and good place to start.

For those of you wondering, the head side of the stud is 7/16-14, for both 3/8 and 7/16 diameter studs, so no machine work is required to change.

Now our goal here is to align the lifter and valve in a straight line.. That straight line does not have to run from 12 o'clock to 6.,.. it can run from 11 to 5... (won't be that far, but you get the point). The straight line is the key, this loads the cam, the rocker and the valve evenly.

Enter the adjustable guideplates.

We switch motors now... this motor is a 650 HP solid roller cam pump gas bracket engine, with Comp Cams Ultra Pro Magnum rocker arms, a .680 lift solid roller, and 750 lbs of open spring pressure. A much more serious deal here.

The first pictured engine with the pep rockers was actually the second E head motor that I ran on the dyno.. it ran with the stock type ball fulcrum rockers (unsuccessfully), as pictured (worked but noisy) and then we went with the adjustable guideplates, and lined everything up, and were very satisfied by the operation and sound. It was pretty quiet. No pictures of that motor with the guideplates, hence the switch to the bracket motor..



I went thru the procedure to adjust everything above, the pictures should help fill in any holes in understanding that may exist.









Line it all up, and get the pushrod length and stud shanks right, and you will have success.

But for sure, there is more work, and more parts required here. We have been spoiled by TA and taking stuff out of the box and bolting it on, and having it work... you have to work with the E heads a bit more.

When the E head first came out, and you could get them for $700 each or less, complete, they were a smoking deal. But with current prices in the 1K range now, plus having to go thru them and size the guides and re-do the valve job, along with everything related to the rockers, I can tell you that TA heads and roller rockers, vs E Heads and comp cams rockers as pictured, is about the same price when I build them here.

Performance wise- Out of the box the TA heads have a small edge, but they respond very well to a $350 bowl/chamber job, flowing 315ish at .500 on the intake... The E head requires a full $700 street/strip port to get there. That same money in the TA head will get you well into the 320's in airflow.

315cfm is a nice number, a good balance between money/power.. and is the basis for nearly every alum head street build you have seen from me over the years. Sure, port the heads more, and the motor makes more power, but in reality, on the street, it's money wasted. Not much difference between 600 HP and 650 in the real world. I mean, how hard can you spin the tires at 60mph and stay alive?

Of course if your drag racing, that's a different deal, for above 700 HP your going to run the tall port Stage 2 stuff from TA. Makes the Edelbrock vs TA conversion irrelevant.

On that note..

I should have the first Super Wildcat billet heads on the dyno in the late spring/early summer.. 500 cfm is going to make things interesting. :eek2:

 

Thanks Jim for the info that is very informative!

We have the same funky setup on the SBC roller rocker conversion on the SBB and the pushrod guild plate is built into the conversion plate itself. No noise on this setup, runs well and been reliable:

 

Derek

Are you saying that for low quantity, American made pieces specifically designed to fit the Buick Edelbrock heads would be the same price as any one of the three Chevy rocker assembly examples shown in your post?

Paul

 

That's all I wanted to know. Maybe I should have worded my question differently.
Thanks Derek

 

It might feasible to purchase some bulk rockers and run off the stands on a bar fed live tooling lathe.
You'll have to be concerned with roller tip concentricity and bearing quality.
The aluminum ones are often 6061, so street duty only ("PC" pn's), the others are a bit better.
For that matter, you might be better off running the rockers from a bar feeder too.

Otherwise, one of the issues you deal with when contracting parts from across the globe is the 3 month boat ride before it's stalled up in customs here, then trucked to wherever you are at.
Also, they want their $$ guaranteed somehow, inspection and reject problems aside from that.
To get good pricing you have to either contract long running steady shipments or huge quantity, meaning widely dispersed product lines.
Well, that's large castings anyways...I suppose small parts are easier to deal with.

 

Why not weld up stud hole and actually correct the problem, not bandaid it. Adjustable push rod guide plates work if you actually weld them once you correct it corrected to your heads. Many 800+ HP SBC's have it done on the AFR 235's and 245 cc heads.