What rocker arm studs do you guys use??
02-20-2009, 02:08 PM
#1
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What rocker arm studs do you guys use?? I'm going to upgrade my stock studs, i'll need 3/8, i purchased a set when i bought my rockers, but i don't think they will work, there just a straight through stud with no shoulder to tighten them with a socket, does anyone know if they will work?
02-20-2009, 04:48 PM
#7
Since we're discussing "studs".....
Several years ago, I decided to throw a set of roller rockers on my LT1. I don't know why, since I don't race the car, but I guess I figured they'd free up a few horsepower through reduced friction. Anyway, while I was in there, I also figured to install a set of ARP studs. Naturally, I ran into the "Heli-Coil tang" situation, since the ARPs have a little more length on the cylnder head side. (I tried, but just couldn't knock the tangs off)
Since I was still working at the time, I bought 16 grade 8 flat washers, and took them into work, and passed them through the surface grinder, to A) get them FLAT, and B) get them all the same thickness. I put them in, under the studs, and then dinked around with the supplied PolyLocks to get the correct lifter preload.
I wasn't too hapy with the "standard" PolyLock nuts, however, as they're somewhat awkward to adjust. And later I was discussing the preload setting for the lifters with a CompCams tech, and found I had to go in and reset the lifters. So, I bought a set of the "trick" ARP PolyLock nuts, and went with their longer, "roller rocker" studs. Unfortunately, they wouldn't fit under the OE valve covers.
I then bought a set of the black crinkle finished Proform aluminum covers, and "notched" the RH cover to clear the alternator. The only problem, is the Proform covers do not have any internal bracing, and they warn you of this in the instructions, telling you to only "snug" the bolts. Well, no matter how carefully I "snugged" the bolts, they A) never would stay tight, and B) the covers themselves eventually warped from the heat and bolt tension. Consequently, I always was fighting oil leakage...unacceptable!
Two days ago, I got ambitious, and decided to go back to the OE studs, and the original PolyLocks, so I could go back to the OE valve covers (repainted black crinkle), and I could sufficiently tighten the cover bolts, therefore stopping the oil leakage. However, I have a situation, and I'm a little concerned.
Generally accepted mechaincal practice says that for sufficient fastener clamping strength, you should have thread engagement that equals the diameter of the fastener. If this applies to the amount thread that the PolyLock nut engages on the rocker stud, it should be 3/8", or .375". I don't have that, I have only about .160", or 5.75 turns of the adjusting nut, from when the threads first engage. Just for reference, with the "long" studs, and the ARP PolyLocks, I had about 11 turns from first thread engagement to the preload setting.
Is 5 turns enough? Has anybody else ever checked this?
Several years ago, I decided to throw a set of roller rockers on my LT1. I don't know why, since I don't race the car, but I guess I figured they'd free up a few horsepower through reduced friction. Anyway, while I was in there, I also figured to install a set of ARP studs. Naturally, I ran into the "Heli-Coil tang" situation, since the ARPs have a little more length on the cylnder head side. (I tried, but just couldn't knock the tangs off)
Since I was still working at the time, I bought 16 grade 8 flat washers, and took them into work, and passed them through the surface grinder, to A) get them FLAT, and B) get them all the same thickness. I put them in, under the studs, and then dinked around with the supplied PolyLocks to get the correct lifter preload.
I wasn't too hapy with the "standard" PolyLock nuts, however, as they're somewhat awkward to adjust. And later I was discussing the preload setting for the lifters with a CompCams tech, and found I had to go in and reset the lifters. So, I bought a set of the "trick" ARP PolyLock nuts, and went with their longer, "roller rocker" studs. Unfortunately, they wouldn't fit under the OE valve covers.
I then bought a set of the black crinkle finished Proform aluminum covers, and "notched" the RH cover to clear the alternator. The only problem, is the Proform covers do not have any internal bracing, and they warn you of this in the instructions, telling you to only "snug" the bolts. Well, no matter how carefully I "snugged" the bolts, they A) never would stay tight, and B) the covers themselves eventually warped from the heat and bolt tension. Consequently, I always was fighting oil leakage...unacceptable!
Two days ago, I got ambitious, and decided to go back to the OE studs, and the original PolyLocks, so I could go back to the OE valve covers (repainted black crinkle), and I could sufficiently tighten the cover bolts, therefore stopping the oil leakage. However, I have a situation, and I'm a little concerned.
Generally accepted mechaincal practice says that for sufficient fastener clamping strength, you should have thread engagement that equals the diameter of the fastener. If this applies to the amount thread that the PolyLock nut engages on the rocker stud, it should be 3/8", or .375". I don't have that, I have only about .160", or 5.75 turns of the adjusting nut, from when the threads first engage. Just for reference, with the "long" studs, and the ARP PolyLocks, I had about 11 turns from first thread engagement to the preload setting.
Is 5 turns enough? Has anybody else ever checked this?
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02-20-2009, 05:00 PM
#8
Since we're discussing "studs".....
Several years ago, I decided to throw a set of roller rockers on my LT1. I don't know why, since I don't race the car, but I guess I figured they'd free up a few horsepower through reduced friction. Anyway, while I was in there, I also figured to install a set of ARP studs. Naturally, I ran into the "Heli-Coil tang" situation, since the ARPs have a little more length on the cylnder head side. (I tried, but just couldn't knock the tangs off)
Since I was still working at the time, I bought 16 grade 8 flat washers, and took them into work, and passed them through the surface grinder, to A) get them FLAT, and B) get them all the same thickness. I put them in, under the studs, and then dinked around with the supplied PolyLocks to get the correct lifter preload.
I wasn't too hapy with the "standard" PolyLock nuts, however, as they're somewhat awkward to adjust. And later I was discussing the preload setting for the lifters with a CompCams tech, and found I had to go in and reset the lifters. So, I bought a set of the "trick" ARP PolyLock nuts, and went with their longer, "roller rocker" studs. Unfortunately, they wouldn't fit under the OE valve covers.
I then bought a set of the black crinkle finished Proform aluminum covers, and "notched" the RH cover to clear the alternator. The only problem, is the Proform covers do not have any internal bracing, and they warn you of this in the instructions, telling you to only "snug" the bolts. Well, no matter how carefully I "snugged" the bolts, they A) never would stay tight, and B) the covers themselves eventually warped from the heat and bolt tension. Consequently, I always was fighting oil leakage...unacceptable!
Two days ago, I got ambitious, and decided to go back to the OE studs, and the original PolyLocks, so I could go back to the OE valve covers (repainted black crinkle), and I could sufficiently tighten the cover bolts, therefore stopping the oil leakage. However, I have a situation, and I'm a little concerned.
Generally accepted mechaincal practice says that for sufficient fastener clamping strength, you should have thread engagement that equals the diameter of the fastener. If this applies to the amount thread that the PolyLock nut engages on the rocker stud, it should be 3/8", or .375". I don't have that, I have only about .160", or 5.75 turns of the adjusting nut, from when the threads first engage. Just for reference, with the "long" studs, and the ARP PolyLocks, I had about 11 turns from first thread engagement to the preload setting.
Is 5 turns enough? Has anybody else ever checked this?
Several years ago, I decided to throw a set of roller rockers on my LT1. I don't know why, since I don't race the car, but I guess I figured they'd free up a few horsepower through reduced friction. Anyway, while I was in there, I also figured to install a set of ARP studs. Naturally, I ran into the "Heli-Coil tang" situation, since the ARPs have a little more length on the cylnder head side. (I tried, but just couldn't knock the tangs off)
Since I was still working at the time, I bought 16 grade 8 flat washers, and took them into work, and passed them through the surface grinder, to A) get them FLAT, and B) get them all the same thickness. I put them in, under the studs, and then dinked around with the supplied PolyLocks to get the correct lifter preload.
I wasn't too hapy with the "standard" PolyLock nuts, however, as they're somewhat awkward to adjust. And later I was discussing the preload setting for the lifters with a CompCams tech, and found I had to go in and reset the lifters. So, I bought a set of the "trick" ARP PolyLock nuts, and went with their longer, "roller rocker" studs. Unfortunately, they wouldn't fit under the OE valve covers.
I then bought a set of the black crinkle finished Proform aluminum covers, and "notched" the RH cover to clear the alternator. The only problem, is the Proform covers do not have any internal bracing, and they warn you of this in the instructions, telling you to only "snug" the bolts. Well, no matter how carefully I "snugged" the bolts, they A) never would stay tight, and B) the covers themselves eventually warped from the heat and bolt tension. Consequently, I always was fighting oil leakage...unacceptable!
Two days ago, I got ambitious, and decided to go back to the OE studs, and the original PolyLocks, so I could go back to the OE valve covers (repainted black crinkle), and I could sufficiently tighten the cover bolts, therefore stopping the oil leakage. However, I have a situation, and I'm a little concerned.
Generally accepted mechaincal practice says that for sufficient fastener clamping strength, you should have thread engagement that equals the diameter of the fastener. If this applies to the amount thread that the PolyLock nut engages on the rocker stud, it should be 3/8", or .375". I don't have that, I have only about .160", or 5.75 turns of the adjusting nut, from when the threads first engage. Just for reference, with the "long" studs, and the ARP PolyLocks, I had about 11 turns from first thread engagement to the preload setting.
Is 5 turns enough? Has anybody else ever checked this?
02-22-2009, 08:31 AM
#9
It's good to know that others are running like this and hopefully not having any problems. I just don't like having a set-up that's marginal.
Having said that, maybe I'll hook up with one of my buddies that has a lathe, and trim off some of the threads on the "short" ARP studs I have, and put them in. They have about 1/8" more height on the top side, compared to the stockers.
(I knew I was going to miss having access to the machine shop at work, after I retired....but I don't miss it enough that I want to go back to work!)
02-22-2009, 11:40 AM
#10
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It's good to know that others are running like this and hopefully not having any problems. I just don't like having a set-up that's marginal.
Having said that, maybe I'll hook up with one of my buddies that has a lathe, and trim off some of the threads on the "short" ARP studs I have, and put them in. They have about 1/8" more height on the top side, compared to the stockers.
(I knew I was going to miss having access to the machine shop at work, after I retired....but I don't miss it enough that I want to go back to work!)
Having said that, maybe I'll hook up with one of my buddies that has a lathe, and trim off some of the threads on the "short" ARP studs I have, and put them in. They have about 1/8" more height on the top side, compared to the stockers.
(I knew I was going to miss having access to the machine shop at work, after I retired....but I don't miss it enough that I want to go back to work!)
02-26-2009, 07:08 AM
#12
Getting back to this, I got together with my buddy, and used his lathe to cut about .060" off the cylinder head side of the studs, so they'll clear the heli-coil "tang" that remains in the head.
I was mentioning that I was doing this so I could use the ARP studs, which have close to 1/8" more thread height on the "top side". He then asked why I was doing this, as it involved a bit of work, changing out all the studs, lashing the valves, etc. I explained that I only had maybe .150" or so, of thread engagement in the ploy-lock nuts. He whole heartedly agreed that it would be a good idea, as he felt that little amount of thread engagement was asking for trouble.
I should add that this friend, although recently retired from behind the wheel, was a fairly successful oval tracker, in the NASCAR modofied series. I value his comments, even though I'm talking about a street driven engine, compared to the 8000 RPM, 750 HP, solid roller cammed engines he used.
Update...I started putting the "modified" APR studs in the car. I'm getting 4 more turns of thread engagement...I'm happy!
Last edited by leadfoot4; 02-28-2009 at 07:42 AM.
