It should hold just long enough to break while torqueing again!!!  Hang in there Bob. 

That's a hard no on the JB weld.  I'll trade you a set of stock 289 heads for your AFRs anytime, just let me know.  May even be willing to toss in a few $ on top to sweeten the deal. 

RV6 wrote:

I have 4 one piece guide plates

And I'll throw in 4 more out of the 7 I have.
As John said, hang in there bro.

Last edited by Bearing Bob (2/16/2021 6:10 PM)

Bullet Bob wrote:

Gary, the problem with fixed plates is that I have no idea if they will put the pushrods where they need to be to put the rollers over the valve stem.  I've been thinking of trying some but the heads came with the adjustable type.  BB2 said he had to scrap the fixed ones that came with his AFR's  and go to adjustable.  I've actually considered making a custom set of fixed ones but hardening them might be a problem.  If you want to drop one in an envelope I will sure see if it will work.   Thanks.

TKO, yeah I was reasonably sure JB...or even super glue wouldn't work LOL.  As for swapping the heads, thanks for the offer but I'm not quite at that point.....yet.  If I got real serious I'd just bolt on the old set of ported E7TE's I have setting on the shelf.  I just hate having to mess with stuff that really should not need messing with.  As I've said before, the AFR guide plates do not inspire confidence.  I just hope the Comps are better but I won't be surprised if they are the same.  I think the main problem is due to the size of the elongated hole in the plates and the relative size of the flange on the studs.  I'm planning to use some grade 8 washers under the stud to provide a better clamping surface between the studs and the clamps.  I tested this idea earlier today and it seems to be a better solution.  I'll let you know what's what when Summit gets the new plates to me.

If everything is machined properly fixed plates will work. They work for me. those single adjustable plates are a fix to a problem, not a solution.

Were all the threaded bosses at same height?

I used Comp Cams single piece on the 69 heads.

In the old magazine articles, they would tack the two pieces together.

Doesn’t look like much surface area for the studs to clamp down.

Plates are also made with a step as well. Overkill for the street in my opinion, they are “guides”for the pushrods.  If there are side loads, that means geometry issues.

Last edited by Nos681 (2/16/2021 6:45 PM)

Bearing Bob wrote:

RV6 wrote:

I have 4 one piece guide plates

And I'll throw in 4 more out of the 7 I have.
As John said, hang in there bro.

Thanks Brother Bob.  If the ones Gary has will work I'll let you know...or just order a set from EB.  I still think it's the elongated holes that cause the trouble...One size fits nothing crap.

Lt. Dan:  No problem with the machining.  The plates are held down by the studs but as I have stated, I think the trouble is the oversized "adjustable" holes which prevent the flange on the studs from evenly clamping the plates to the head.  I considered tacking them together....might.  I agree with your assessment of side load requirements.  In fact, I've even considered making a set of fixed plates from mild steel and see how much they wear with the hardened pushrods.  I'm betting not much.
 

Nos681 wrote:

Have you considered the material used for conveyor belts/wear plates.

I only know the term UHMW. Hard plastic in layman’s terms.
They work really well in logging and iron ore mining where I have worked in the past.

Thinner material might be more prone to cracking.

Perhaps a “pushrod liner” for your homemade plates?

That's something to consider however I'm really hoping I can make something "off the shelf" work.  I love re-inventing but I'm at the point right now where I just want the Heap back on the road.

MS wrote:

One concern of adding washers is that the rocker arm might contact the hex on the stud.
Be sure to check clearance.

I did some prelim checks but will run it through good.  Washers are Grd 8 at around .050 so I don't expect a problem butt (TS&T)......

TKOPerformance wrote:

I'm wondering if the issue is with the studs.  You definitely don't want a hex tightening down directly on the guideplate.  That's a bad situation that just begs for it to come loose, let alone break.  The studs I've seen for guideplates usually have in essence a washer machined under the hex so you get proper bearing and therefore clamping.

My AFRs use the same system and I had zero issues with any of it.  I had the studs in and out several times as I was checking pushrod length and rocker geometry.  It seems you got something that was machined wrong, or the wrong studs for the application, etc.

Did you buy these heads new?

Heads were new and at this point have around 16K on them with no problems.  The studs do have a very shallow round flat mating surface on the bottom of the hex.  Problem is that the hole in the plates is elongated for side/side adjustment and that makes it too wide for the clamping area of the hex to clamp evenly.  There is also a rounded chamfer or "entry" into the hole on the top side of the plates apparently due to the stamping process.  You can see this in the photo I posted at the beginning of this thread.  That's why I have decided to use a hardened washer between the plates and the studs that will provide a larger clamping surface.  The fixed plates, as shown in the photo Gary posted, are much better IMO.  The holes are small enough that the clamping surface under the hex will pull down evenly.  Now that I've studied this setup I can't imagine why AFR didn't provide a washer under the stud.  As far as reliability goes it seems to be fine once it's properly set up and I saw no evidence of movement after 16K.  If that plate hadn't broken I would have had it back together as before and it probably would have been fine, but now that it got my attention I think there is a better way.
 

I would reach out to AFR.  I don't think you have anything to lose.  My concern was you may not have been the original purchaser and they could claim someone changed something, but if that's not the case I'd see what they are willing to do for you.  Good companies take care of their customers.  I had Mahle send me a set of new rings once when I screwed mine up on installation.  Told them it was my fault, they didn't care.  Said they wanted to take care of their customers.  AFR seems like that kid of company.  I'd at least give them the chance to make it right. 

BUT, does it flatten out when torqued into place?  I'd torque one down and recheck. 

Why couldn't you use the one-piece ones, Bob?