"Big" Cam + Comp R's = Adj Rockers/Shims/????? Need Help From Sponsors/Experts!!
03-03-2004, 08:30 PM
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"Big" Cam + Comp R's = Adj Rockers/Shims/????? Need Help From Sponsors/Experts!! Just picked up a G5x3/112 LSA and will be receiving a set of Absolute Speed Stg2 5.3L's with Comp 977's in the next few weeks. Because of the spring pressure created by the Comp 977's, I've also got a set of Comp R lifters.
I currently have stock rockers, and as I'm now painfully aware, the Comp R's require significantly less preload (.002-.004) than do our stock lifters.
I've done a lot of research (ok, I've read everything I can get my hands on
), and I've seen people going all the way from one end of the spectrum to the other to address this situation. I've also seen that there are A LOT of people out there right now in pretty much the same position. From what I've read, there seem to be 3 setups being run most often to address this issue.
(1) Adjustable Rockers
With all of the "big" cams out there now, I know there are a lot of people out there with the same questions, and there's probably going to be a lot more once these cams become the norm, rather than the exception.
Help from any of the experts (sponsors, others, you know who you are ) for us little people would be greatly appreciated 
Paul...
I currently have stock rockers, and as I'm now painfully aware, the Comp R's require significantly less preload (.002-.004) than do our stock lifters.
I've done a lot of research (ok, I've read everything I can get my hands on
), and I've seen people going all the way from one end of the spectrum to the other to address this situation. I've also seen that there are A LOT of people out there right now in pretty much the same position. From what I've read, there seem to be 3 setups being run most often to address this issue.(1) Adjustable Rockers
This would appear to be the simplest solution. However, the only "affordable" adjustable rockers I can find are the Comp Pro Mags, and they only come in a 1.75 ratio, not our stock 1.70. Given the lift of the G5x3, I'm somewhat concerned about the impact of going from a 1.70 to 1.75 rocker, although I do have 2cc valve reliefs. Would I be safe doing this? Would picking up a set of Pro Mags be all I'd need, or is there something else I'm missing?
(2) YT's/HS's w/ShimsSeems like a lot of people are going this route; not sure if this is to avoid the additional lift of the Pro Mag's, or simply the fact that they *may* cost less. Here you gain the benefit of full roller rockers, but you still have the somewhat inexact science of trying to shim as appropriate, particulary for someone like myself, who will be trying to set and adjust preload for the first time.
(3) Stock Rockers w/ShimsThis is definitely the least expensive way to go; however, the same issue exists as described in (2) above, and you also don't get the advantage of full roller rockers.
My question is this; of the methods described above, which offers the best solution for the relatively mechanical, average joe out there who wants to do this right the first time, but doesn't want to spend $500+ in the process?With all of the "big" cams out there now, I know there are a lot of people out there with the same questions, and there's probably going to be a lot more once these cams become the norm, rather than the exception.
Help from any of the experts (sponsors, others, you know who you are
) for us little people would be greatly appreciated Paul...
03-03-2004, 08:34 PM
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I ended up keeping the YT rockers, using 7.35 pushrods on the exhaust and 7.4 pushrods on the intake to to even out the difference between my intake/exhaust preload on the Comp R's. I then shimmed as I deemed appropriate.
03-03-2004, 08:52 PM
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Originally Posted by verbs
I ended up keeping the YT rockers, using 7.35 pushrods on the exhaust and 7.4 pushrods on the intake to to even out the difference between my intake/exhaust preload on the Comp R's. I then shimmed as I deemed appropriate.
03-03-2004, 08:58 PM
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Well I know Crane and several others sell adjustable pushrods. I dont know about LS1 applications but it might be worth a call. Do a Google search on adjustable pushrods and I think that Crane comes up first.
03-03-2004, 09:02 PM
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Originally Posted by 02bluess
If you don't mind me asking, what was your primary reason for going this route? Were you influenced more by the extra lift of the 1.75 Pro Mags, was it a cost issue, a little of both?
Cost was an indirect factor. I would have had to change out my brand new springs/retainers and take a $400 hit there, plus labor, etc.
I'd also have to flycut my pistons again, and the flycut would have been so much that I wouldn't feel safe spraying should I decide to go that route later on.
03-03-2004, 10:23 PM
#7
If your heads aren't decked, you could do the 1.75 pro mags and not worry about P/V clearence. Your lift would be bigger, but not enough to fill up the .150" deep valve reliefs. On the other hand, I believe someone does offer a 1.7 ratio adjustable rocker. I'd have to look it up, but I know Patriot is coming out with some very soon.
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03-03-2004, 11:00 PM
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T&D and Jesel Make Adjustable Rocker Arms for LS1 in 1.7 ratio ... anywhere from 800-1000 dollars... plus u will need spacers and thats another 200$~ ... ask me how i know 
my T&Ds with needle bearing roller tips were almost 1200 bucks
my T&Ds with needle bearing roller tips were almost 1200 bucks
03-03-2004, 11:24 PM
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Ive heard from countless people.. I'd say experts in the field.. that the compRs are fine w/ stock rockers and stock tq specs.. Not ideal, but not going to hurt anything.. seems like everyone has a different story on the boards..
03-03-2004, 11:26 PM
#11
Originally Posted by PK 01somWS6
Ive heard from countless people.. I'd say experts in the field.. that the compRs are fine w/ stock rockers and stock tq specs.. Not ideal, but not going to hurt anything.. seems like everyone has a different story on the boards..
Run what you want, but Comp has a spec for a reason.... Would you torque your head bolts to 150 Lbs because someone told you too reguardless of what GM says?
The only Jesel adjustables they have are $1200+. The SS series arent adjustable ($700)
03-04-2004, 12:16 AM
#13
I believe sometimes that manufactuers of parts are a little lost, case in point, when I worked at Holley in the mid 90's developing the SysteMax crap, I saw first hand how lost a bunch of engineers can be.
Now that I have said that, approach this thing with an open, unbiased, common sense attitude. Don't just say, well, they told me to jump off the cliff, so thats what I am going to do. As on of the top Comp dealers in the country I see alot of their products. When they gave me the specs on the lash, my first question was WHY, after a long discussion with one of the top techs there he said, it doesn't really matter how much it is lashed, because it is designed just like an OEM lifter, except with tighter tolerence. So they were saying .010-.015, like 2 months ago, now someone else has decided it needs to be .002-.004. When I ask this Comp employee why,(and he is a young, new employee) he said because if you lash it any deeper then this then you might pop the clip at the top of the rocker off. NOW, think about that for a minute, I know that most of you on here have never even adjusted a set of lifters and I know that I have been doing it for about 25 years. THE CLOSER THE CUP IN THE LIFTER IS TO THE CLIP, IT SEEMS THE GREATER THE CHANCE THE CUP WOULD CONTACT THE CLIP DURING ANY VALVE FLOAT, AND THE GREATER THE CHANCE THAT IT WOULD THEN KNOCK THE CLIP OUT.
With that being said, I challenge any one, any where, including the guys at Comp, to give me a good reason why these lifters can not be preloaded just like a stock lifter. And don't give me the reason, "because they said so", not good enough. We have run these lifters, they are what I made 700 RWHP with my little 5.7, not shimed or anything. Just bolted em down with a Harland Sharp rocker. It is my opinion that the #1 reason this is being told is so that they can sell their adjustable rockers. I hope I will stand corrected on this issue, but I don't believe I will be.
Now that I have said that, approach this thing with an open, unbiased, common sense attitude. Don't just say, well, they told me to jump off the cliff, so thats what I am going to do. As on of the top Comp dealers in the country I see alot of their products. When they gave me the specs on the lash, my first question was WHY, after a long discussion with one of the top techs there he said, it doesn't really matter how much it is lashed, because it is designed just like an OEM lifter, except with tighter tolerence. So they were saying .010-.015, like 2 months ago, now someone else has decided it needs to be .002-.004. When I ask this Comp employee why,(and he is a young, new employee) he said because if you lash it any deeper then this then you might pop the clip at the top of the rocker off. NOW, think about that for a minute, I know that most of you on here have never even adjusted a set of lifters and I know that I have been doing it for about 25 years. THE CLOSER THE CUP IN THE LIFTER IS TO THE CLIP, IT SEEMS THE GREATER THE CHANCE THE CUP WOULD CONTACT THE CLIP DURING ANY VALVE FLOAT, AND THE GREATER THE CHANCE THAT IT WOULD THEN KNOCK THE CLIP OUT.
With that being said, I challenge any one, any where, including the guys at Comp, to give me a good reason why these lifters can not be preloaded just like a stock lifter. And don't give me the reason, "because they said so", not good enough. We have run these lifters, they are what I made 700 RWHP with my little 5.7, not shimed or anything. Just bolted em down with a Harland Sharp rocker. It is my opinion that the #1 reason this is being told is so that they can sell their adjustable rockers. I hope I will stand corrected on this issue, but I don't believe I will be.
03-04-2004, 12:49 AM
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In agreement with Brian.....
Back when the Comp R's first came out I ran them like normal lifters also in the 35-45 thousanths preload range. Now I shim them to around 10 thousanths, sometimes though you can't get exact using shims and some have been around 20 thousanths with stock rockers. I've never seen any problems with that at all.
Back when the Comp R's first came out I ran them like normal lifters also in the 35-45 thousanths preload range. Now I shim them to around 10 thousanths, sometimes though you can't get exact using shims and some have been around 20 thousanths with stock rockers. I've never seen any problems with that at all.
03-04-2004, 01:44 AM
#15
on some parts I agree Brian..and on some parts I don't..In the real world it will probably be ok to run the standard preload. I don't think that comp would say that mainly to just sell rockers..more than anything I would think that in doing their research(knowing that comp does more spintron research than chevy,ford,or mopar)
I would think that they might have seen an issue to where they had some lifter failures due to excessive preload, because of the lifters design..that being said comp's instructions for the preload will keep them in the good if someone uses excessive preload which in turn may damage the lifter and could possibly result in other internal engine failures
I would think that they might have seen an issue to where they had some lifter failures due to excessive preload, because of the lifters design..that being said comp's instructions for the preload will keep them in the good if someone uses excessive preload which in turn may damage the lifter and could possibly result in other internal engine failures
03-04-2004, 01:52 AM
#16
Originally Posted by spectacle solutions
on some parts I agree Brian..and on some parts I don't..In the real world it will probably be ok to run the standard preload. I don't think that comp would say that mainly to just sell rockers..more than anything I would think that in doing their research(knowing that comp does more spintron research than chevy,ford,or mopar)
I would think that they might have seen an issue to where they had some lifter failures due to excessive preload, because of the lifters design..that being said comp's instructions for the preload will keep them in the good if someone uses excessive preload which in turn may damage the lifter and could possibly result in other internal engine failures
I would think that they might have seen an issue to where they had some lifter failures due to excessive preload, because of the lifters design..that being said comp's instructions for the preload will keep them in the good if someone uses excessive preload which in turn may damage the lifter and could possibly result in other internal engine failures
I still say that if I have almost always set preload towards the top of the plunger travel and LPE does it almost all the way to the bottom and I have done it everywhere in between, then I would like some hard data that disputes what I have seen work in the real world. Thanks
03-04-2004, 02:03 AM
#17
all I'm saying is that if any preload works fine...great!...But I'f the guy that ports my heads(those incredible TEA heads which I love sooo much ) says that my springs need to be insatlled at 1.900" or to torque them to a certain spec..I would do just as he asks so that there wont be any questions later on
on another note..when things like this(patriot heads...918's..etc.) get made into a big deal people start freaking out and worrying about if their motor is gonna blow up...lol
) says that my springs need to be insatlled at 1.900" or to torque them to a certain spec..I would do just as he asks so that there wont be any questions later onon another note..when things like this(patriot heads...918's..etc.) get made into a big deal people start freaking out and worrying about if their motor is gonna blow up...lol
...work comes early