Has anyone had any issues with their LSx AFR heads? The shop that is doing the work on my car suggested that we have the heads checked out. Here is what the machinist found:

• Heads were not flat, off by .005
• not all valves were seating perfectly

In addition one of the valve cover retaining bosses was not tapped deep enough for the bolt to go in all of the way. The same problem was encountered with two of the threaded holes on the front of the head that are used to attach the alternator/ps bracket. In all cases the holes were drilled plenty deep but not tapped deep enough. This problem was encountered using stock hardware and bracketry.

 

Did you contact AFR about this before posting?
Be nice to let the vendor know

 

No I have not. I will be doing that but I think that Tomy Mamo is at the PRI show right now. I plan on calling him early next week.

I am not trying to bash nor am I upset. I am just asking a question.

 

I didnt see it as a bash, it is just asking a question to see if anyone else has ran into this

 

I would definately call AFR, and would have before having work done on the heads IMO.

If indeed those things were incorrect, I think AFR would of sent you brand new heads and I'm sure they would want to know and see the exact problems to assure that it doesn't happen in the future. I would of also asked the machinest to call AFR as well, maybe he is not familiar with the AFR valve job? At minimum, They may refund the extra $$ you spent to take care of the issues. Did you purchase thes from a sponcer? my .02

Dan

 

Given that AFR didn't let him know his heads weren't QC, I'd say it's fair to post here. He's not bashing, just posting facts and asking for others' experiences.

My SBC AFR heads had the valveguides too tight as delivered, but I wrote it off to having bought them unasssembled (no valvetrain hardware) so I didn't feel like that was AFR's fault...not possible to set clearance when you don't have the valve in hand.

 

This is the same problem I had. I Just ground the nipples on the end of the bolt's and they worked fine. I didn't check any thing else though. I just slapped the heads on there.

 

How tight were they???

From the AFR installation sheet...

"VALVE CLEARANCE GUIDE:
INTAKE AND EXHAUST GUIDE CLEARANCE ARE .00125. ON SOME SEVERE APPLICATIONS WITH HEAVY NITROUS, MARINE OR BLOWER USAGE, LOOSER GUIDES MIGHT BE REQUIRED."

Just wondering what your shop opened them up to??

Ed

 

I wouldn't have had another shop touch the valve job IMO. The AFR valve job is partly what you paid for when you bought the heads. Hopefully they are't ruined.

 

I had the same issue with PS bolts and valve cover bolts. Nothing on this car has ever been without some issue, so it seemed "normal."

 

How did you fix it? Re-tap the holes? Thanks...

 

That is correct. They just tapped the 3 problem hols slightly deeper.

 

That is a good question and one that I will be asking. I put my faith in them that they knew what they were doing...

 

I thought I did read something about the bolt hole depths...But I would have not let somebody/anybody touch them until I talked to AFR, unless it was really obvious/or they were an "LSx expert" which I expect AFR to be to begin with. Those things are expensive and they better come PERFECT.

 

It's a good idea to see what they felt was "correct"...

Like everything else in this world, there are a lot of "opinions"...

Ed

 

 

FWIW, I'd always check and double check aftermarket heads. Just because you paid an arm and a leg doesn't mean they're gonna be perfect. I had several things I had to correct on the AFRs on my car (LT1). Spring pocket was too small, heads had to be decked flat, burrs on the threads for the valve cover bolts, etc.

 

Just some info for what it is worth. After 24 years of running a machine shop, I can say without question that new, "green" castings (that have never been "heat cycled") will warp due to many factors. This occurs during shipping when things are stacked on them or when they are subjected to lying flat on a cold surface, etc. I have milled well over a thousand new OE heads (aluminum and cast iron) that were warped .005-.006 out of the box. In addition, I would never install a new flywheel(except for dual mass types) or brake rotors or drums (without taking light clean up cut to true them up after shipping). This is true even when it says on the box not to take a clean up cut. I have put a dial indicator on rotors and seen them with up to .003 runout. That will cause a pulsating pedal. I can't address the tapped holes, but don't blame AFR for the deck surface being warped. That is very common with new, green castings. You should see how much they will move around after they have been heat cycled a few times!!!!

 

You are absolutely correct about raw castings warping. I always rough out the new LS6 blocks then vibratory stress relieve the casting on our Stress Relief Engineering Formula 62 stress relief machine prior to doing the finish machining for Darton MID sleeves. The blocks will warp all to hell after a heat cycle if this is not done. I had a Formula 62 working away in our Block Pro booth at PRI.

The valve guide issue is debateable. Valve to guide clearance depends on the guide material and use the engine will be put to. You do not want the guides loose on a street engine to get long life from the valve job. On the other hand if the guides are run at street clearances on a racing engine, the valve is sure to get stuck in the guide.

AFR uses a pair of hundred thousand dollar Newen Contour guide and seat machines to do their valve jobs by the way.

In any case, give Tony a call and discuss your issues with him.

Steve Demirjian

 

Hello Guys...

As most of you know, I was away all last week attending the PRI tradeshow.

First and foremost....if ANYONE feels they have issues with any of our heads, (especially a new set out of the box), PLEASE contact AFR first before you take them to a third party shop. Once you do, any type of warranty becomes null and void and we will NOT reimburse you any monies you laid out of pocket (We address this policy in our pricelist, website, and the instructions enclosed with the cylinder heads). It is in your best interest in every aspect to let us, the manufacturer, decide whether you do or do not have any legitimate issues that need addressing not to mention we will foot the entire bill if we find that to be the case. Also, very few smaller shops have the type of equipment that could produce the type of results that would mimic a perfect head that leaves our door....especially concerning honing guides and valve job profiles (which are proprietary and would be difficult to "copy"). I'm curious how the guide clearance as well as the head deck figures were actually measured. I know our guides will seem a bit on the tight side when using the "wiggle" method because the diamond hone we use on our CNC equipment is extremely accurate and when we spec a .0012-.0014 guide clearance, that’s exactly what is found up the entire length of the guide boss...the tool is extremely accurate and provides much closer tolerances than would typically be produced by manual honing methods. Just an FYI here....obviously we will never have the opportunity to check this particular set but we certainly would have liked to. As far as the bolt hole thread goes, some of our very early heads were not quite drilled and tapped as deep as they are now, but at the time it wasn't a problem until using aftermarket brackets and hardware (such as ones from a blower install). My car has one of the very first 205's with the slightly shallower bolt holes and I had no problems bolting on my factory accessory brackets, etc. Once the situation with aftermarket bolts and brackets was brought to our attention, engineering changed the drilling and tapping depth to better accommodate all situations. Again, I'm not saying your heads didn't have a problem, but I am certainly puzzled why they did.

Guys...PLEASE let us address any situations you might encounter. Its not worth the time you save if the heads are possibly "repaired" incorrectly....especially if a "repair" might not have actually needed to be performed. We are a stand up company and will bend over backwards to take care of you....its almost silly not to take advantage of that fact and let us look over the cylinder heads...not to mention you might be helping your fellow piers if in fact there are issues that need to be addressed. A few days or possibly weeks just isn't worth it when you look at the big picture and your ultimately concerned with getting the most performance possible from the purchase of your new cylinder heads.


Regards,
Tony Mamo