Edelbrock Head/Guideplate Adjustment Question: PLEASE HELP

Discussion in 'Street/strip 400/430/455' started by Dan Gerber, Feb 1, 2017.

  1. christy staunto

    christy staunto Well-Known Member

    I thought last year it was the lifters so i replaced them with new ones as at the time i was unaware of the offset problem with the heads,The cam has less than 2000 miles on it,but anything is possible i guess
     
  2. No Lift

    No Lift Platinum Level Contributor

    Maybe I missed it but has anybody ever tried the self guided rockers that later SBC/Vortec/LT1 used? They have little flanges that ride on either side of the valve tip and keep it aligned.
     
  3. Jim Weise

    Jim Weise EFI/DIS 482

    You would have to take the guideplates out completely Mike, I don't know if I would trust that..
     
  4. No Lift

    No Lift Platinum Level Contributor

    Yes, you can't run both type guides. The pushrod holes in the later heads are larger like they are in the Buicks while the earlier SBC heads seem to have pushrod "slots" that keep them aligned and don't need steel guides for general use. The 90's LT1 engines seem to be working fine with no guide plates and self-aligning rockers. You need to talk to a real Chevy expert although you would have thought E-Brock would have thought about it too. The offset might be enough to throw the self-aligning rockers off. Just something to consider.
     
  5. Jim Weise

    Jim Weise EFI/DIS 482

    All Edelbrock Buick heads have 11/32 stem valves.
     
  6. 455'ed80Regal

    455'ed80Regal Well-Known Member

    Well, Edelbrocks BBB head isn't the only one that suffers from these rocker arm alignment issues. I have a set of SBC AFR heads on a 383 that are pretty bad in there own right. Isky adjustable guide plates didn't completely fix the issue. Not there fault, they did what they could, but when the pushrod is rubbing against the head before it's centered that means something is way off. Even after adjusting everything the best it could be, the valve train was not quiet. Never had these issues with the cast iron heads, but they didn't make the power either. I guess that's the trade off. These are just some of the issues you run into with mass produced heads as not every head is checked after it leaves the final operation.
     
  7. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Some sbc heads actually call for offset rockers because they made the intake port larger to flow more air and had to move the pushrod hole over.

    Which pushrods are rubbing? I would guess that the intake pushrods are the ones giving you the problems you're having with your AFR heads on your sbc 383? PM me when you figure out what offset you're suppose to run with your heads and I can PM you some decent shaft rockers that will fix your problems and won't kill your wallet.
     
  8. 1969RIVI

    1969RIVI Well-Known Member

    This thread is great! After reading it a couple times I can actually visualize what JW is saying these guide plates do. If I understand it correctly you use the plates to push/pull the pushrods side to side which inturn pulls the roller rockers more center on the valve tips which then makes the valve train less noisy as it's running straighter-ish.
     
  9. Jim Weise

    Jim Weise EFI/DIS 482

    That's correct.. it eliminates the rocker unloading as it goes over the nose of the cam, and the resulting noise from the pushrods slapping the guide plate. because the design of the Buick valvetrain side loads the rocker, "pointing" the loads correctly solves this issue. It's not a perfect solution, but it has proven to work over the long term here.

    The first motors that I did this to, have been in the field now for about 5-6 years, and no wear issues have been reported to me.

    The difference in valvetrain noise is dramatic.

    Of course, with Edelbrock heads at nearly $1500 each now, they are considerably more expensive than the TA heads, and the vast majority of street applications, with either flat tappet or small hyd roller cams, don't require the thousand dollar roller rockers. I have used the stamped steel on mild combos for years with success, more aggressive flat tappets or hyd rollers require the 67-9 rocker setup, and the correct hybrid pushrods. I have 6 motors out there now with this setup, all hyd rollers, and have to date only had one customer that broke the steel insert valve pad on the alum rocker.. Which is an easy fix.. We originally tried using the nylon button located 70-71 Aluminum rockers but the two motors that were used with that setup, both snapped off a nylon button in a very short time.. They made it thru the dyno, but not long after that.. too much side load on the nylon button. I have an idea to produce and test a metallic button in place of the nylon, but have not followed up on that yet. Still enough 67-9 rocker sets out there, to meet the needs.

    With this viable alternative to the expensive aftermarket roller rockers, the use of the TA head over the Edelbrock parts becomes more clearly an advantage. The only leg to stand on with the E heads was less expensive roller rockers, but you have to go thru the rigamarole above, to have a decently quiet engine.

    JW
     
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  10. 1969RIVI

    1969RIVI Well-Known Member

    Hey Jim two Questions for you, 1. What is the lifter stud torque spec on these Eddy heads? 2. When I'm setting lifter lash on these it is my understanding that while spinning the pushrod with my fingers I snug up the Polylock (I'm using pro magnum roller rockers) to the rocker just so there's a bit of drag/resistance and so I can't lift/wiggle the pushrod up and down, then turn the Polylock another half turn to set lifter preload then I can tighten the set screw on the top of the Polylock?
     
  11. Jim Weise

    Jim Weise EFI/DIS 482

    It's a 7/16 fastener in alumium, I would go 45 ft/lbs

    Your correct on your rocker adjustment.
     
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  12. 1969RIVI

    1969RIVI Well-Known Member

    Excellent, thanks Jim!
     
  13. 1969RIVI

    1969RIVI Well-Known Member

    I Just thought I'd post on this topic again since I've now finished the guide plate fiasco. All in all it wasn't really that difficult, more just intimidating for a first timer to dive into it but once I got going it became repitious and easier. My confidence level was already quite high as I have read over this a gazillion times before tackling it. So my feed back is follow Jim's instructions and it will work out. I guess I'll know how I really did :rolleyes:once the engine goes to the dyno hopefully in the next couple weeks, fingers crossed and another big thanks to JW for his helping hand:).
     
    DaWildcat and Super Bald Menace like this.
  14. Mark Demko

    Mark Demko Well-Known Member

    I agree, the Edelbrock heads seem to be a more generic head for the BBB, lower cost yes, but for the guy that wants a set of better than iron heads, spend the extra and buy TA's heads that are designed for the BBB:D
     

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