I'd be sending that back to ARP! On the next to last picture, it looks like the rocker base has worn a half moon witness mark just below the threads on the stud...............is that what that is? Just lucky you didn't do more damage. How old are the studs?
so.....I'm getting these: [ame="http://www.amazon.com/ARP-1347104-Performance-Series-Rocker/dp/B000CFO0PY/ref=sr_1_1?s=automotive&ie=UTF8&qid=1339470901&sr=1-1&keywords=ARP+1347104"]Amazon.com: ARP 1347104 High Performance Series Rocker Arm Stud Kit: Automotive[/ame]
What would that indicate. The studs are the ones that AFR sends their heads out with. They are not ARP bolts.
When you see witness marks that high on the shank of the stud it usually means the rocker geometry is off. Usually the witness mark is mid way on the shank or a little lower. If the rocker was actually riding that high I could see why the top of the stud broke off, and there was too much stress on top 1/4 of the threads........................I have seen this happen before but not on motors that never see past 5500rpm................................I am just pointing this out because my eye caught it.................not to say it is actually that way because I have not been involved with the motor, but I am sure Bryant will take care of it and make it right. I've been using stud girdles since the early 70's on anything that spins over 6000rpm.
this was the second set of afr heads that i have had this happen to. the first set was on a car that was just a cruiser and was never above 4000 rpm. it broke in about a month. the engine machinist i use said he sees this allot. he said the studs afr use are cheap. im confident that the girdle will end all of mo's valve train woes. they will definitely help with the silver state run.
Should I keep my metal hood and just add pins or is there an advantage to getting a fiberglass hood? As for the air dam, if anyone has any suggestions I'm curious.
Personally I wouldn't drill holes in a perfectly good steel hood...........I'd just get a glass hood or better yet maybe a Carbonfiber hook. The amount of weight saved would be whatever the difference in the stock hood vs a Carbonfiber which should be at least 65lbs..............and since the Maverick is probably nose heavy it would help braking and cornering. I would pin it in three places in the front, one at each corner and one in the center (I have shown pictures of my Maverick.................3 places along each side and two in the back, but if you do use a fiberglass or Carbonfiber hood make sure you pin or attached in the center of the front of the hood............because if not it will try and come loose and either break/fracture/spider crack the hood as it tries to lift ( I know from experience that over 130mph it happens). It's easy to use Dzus fasteners and a rail setup that can easily be taken off to put your stock hood back on............just a thought. As for an "air dam", you should talk to "Streamliner" for some suggestions.
The markets on the stud is normal according to the engine builder. The stud on the right is the stock one and the ones on the left a little taller and ARP. I installed the taller poly locks. The ones in the corners accept snap rings.
The girdle installs pretty easily. I have to still make sure the lifters don't hit the girdle on rotation.
I agree that the witness marks on the studs are normal, but in the picture you show both the new ARP Studs and the original ones.....notice the difference in length....it's not a lot, but noticeable. The wear on the original stud is mostly centered on the bottom of the threads, which is the weakest point in the stud for lateral movement........looking at the side by side picture you will notice that the witness mark should be lower on the shank of the new ARP stud....it's almost like the original stud was too short, which would have caused fatigue and eventual failure..........just like yours, but it looks like you are on your way now.
I snapped the top off a stud like that on my old engine. Turns out the stud bosses where machined off to much.
you sure do know your stuff and I would have to agree with all of that 100%. It's also likely that since the threads are slightly smaller in diameter than the shank where the rocker was riding a bit higher than normal.. that it allowed more movement of the fulcrum and only added to the witness marks/wear and likely gave the bearings a bit tougher time as well. Those witness marks certainly aren't anything severe enough that I would be seriously questioning the rockers bearing wear.. especially with milder rpm/spring pressures.. but you would definately want to inspect the fulcrum holes and check the bearing slop out with a quick visual. I've run dozens and dozens of cheaper studs on basic or mild builds.. but making sure that the rockers sit primarily(about 2/3) on the studs shank is the key to avoiding slop, wear, and potentially over stressing/side loading the threaded section(which as I said before are smaller in diameter and allows irregular torsional loads due to the added slop which is typically were these types of failures come from). I've run moderate HP motors for over 2 years pretty hard and never had that much of the oxide coatings wear off.. so proper fitment is the key. What air cleaner do you run on top of that HP? PS. if you run a resistance test on those stock replacement style wires?.. you'll likely see the benefit to moving to an MSD wire or other low resistance setup. Might even see an extra few horsies out of the deal too. I typically only use the Moroso Ultra 40's($$$).. or the MSD's on all of my personal stuff(if they don't make a kit for something?.. I buy a spool and make my own). And even after many years of running them.. they still test out lower than fresh new factory style stuff and eventually pay you back over the long run.
