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Don't thank me, thank Bryan at BTR. I just repeated what he told me. Not sure where you are on lift, but a shim should do the trick. .030" makes a big difference on open pressure if you have the clearance, .045" even better.
Maybe take your rockers off and ship them to Carson and he can ship them back to you. They will be a lot lighter when you get them back.
EDIT: Possibly you can do me a favor and measure your installed height with that 660 kit. Not sure if you can get in there with a caliper or 6" scale but it would be good to know the compressed spring length when the valves are on the seat. Some rough checking looks like I'm in the low 300 lb. range for valve open with my lift but I just guess at the installed height...just enough for my stock rockers at 7000 IMO
Don't bother if it's a pain in the ***....thx man
Rum it is then!
Hahaha. I never thought about the idiot in NC customs! Good idea! I could just mark them up with little Xs that say "drill here"!
I would've never thought to look that up on the BTR website, if you hadn't pointed it out. I'm reinstalling my stock rockers today. I'll try to get a decent measurement and take a picture of it with my digital calipers.
for someone thats looking to make 1500, would you guys still recommend the gold rockers or oem ls7 with trunion?
Neither. At that power level, I would run a shaft-mounted adjustable setup, mainly because I would use a solid roller for an all out effort like that. Just my 2 cents, fwiw.
That's crazy that this rocker combo could be causing this weird issue for you Sammy. On one side I hope that's it because it's an easy fix.. but on the other side it's pretty bizarre, and not something I would have ever thought would actually happen.
Let us know how it goes when you swap back to stockers
From what I remember, the valve closed pressure is easy to figure out....just measure the installed height and see what pressure for that dimension. Then multiply lift * rocker ratio to get valve open height and find that pressure on the spring curve. Their might be easier or better ways to get rough calculations but this worked 20 years ago and got you close to selecting a spring...then shim as needed to dial it in. Quick chart below shows 650s vs 660s with interpolated mid points and from what I understand a good pressure to run stock rockers with my cam is 140 closed/350 open. Roller rockers should run over 400 open and I can't get near that without shimming. I barely hit 350 for the stock rockers with my cam.
EDIT: Please note I am in no way requesting and/or sanctioning and reader of this message to operate their motor vehicle at engine speeds that exceed the manufacturer's limits.
So you don't sue my *** in case something goes wrong.
Neither. At that power level, I would run a shaft-mounted adjustable setup, mainly because I would use a solid roller for an all out effort like that. Just my 2 cents, fwiw.
Exactly. For something like that, Jessel Mohawks, T&D, Crower with a big solid roller. Expect $1500-4500 for the rockers+machine work, but that is a small drop in the bucket for a 1500hp build.
Today, I ordered the OEM LS-3 rockers for my sock cube LS2 build. I also ordered the Holley Tall 241-112 valve-covers for the Superdeck 427 build. I should decide on rockers soon for that build. Seriously considering Jesel shafts at this point.
I'm beginning to suspect that I may be getting into valve float around 6600rpms, as I've been battling a problem with my car with boost dropping and then throttle flutter and then going into REP mode at the top of third (just past 6600rpm) and I'm pretty sure it only happened since I installed the Ultra Gold rockers on my car, and I'm running the .660" springs, without any shim. I can't be sure that this is the problem, but I'm going to throw the stock rockers back on and test it to see what happens.
How'd you make out with this? I wound up putting .045" shims in and set open pressure around 420 lbs. and waiting for my trunnion kit to be delivered.
How'd you make out with this? I wound up putting .045" shims in and set open pressure around 420 lbs. and waiting for my trunnion kit to be delivered.
I put the stock rockers with modded Comp trunnions back on, at least for now, but it didn't solve the issue I was having. I boxed up the Comp UG rockers until I get the right springs to match. I'll put them back in again though.
BTW: I swear my oil temps (which I always monitor) are now averaging ~10 degrees higher though. Can't say I have any impirical data on that, mind you. Maybe I have that same disorder I diagnosed for you...
LOL If you want, post or PM me a log showing that problem at high revs. I'm pretty used to seeing similar stuff in my logs running above 6500 caused by torque management, rpm limiting, etc.. I might spot something.
LOL If you want, post or PM me a log showing that problem at high revs. I'm pretty used to seeing similar stuff in my logs running above 6500 caused by torque management, rpm limiting, etc.. I might spot something.
You running cats?
Thanks man. I'm traveling right now though, and I'm a few thousand miles away from my tuning laptop, so I can't send you a log right now. Wait, I think I may have posted it on another thread. I'll take a look and see if I did and post up a link.
I think you may be right though, it was hitting the limiter on the 3-4 shift and I still had ETC activated in the TM tables. It was throwing the usual 2101 DTC and going into REP. I did some tweaks to the tune and I believe I may have fixed it, but didn't have the chance to test it properly before I left.
The cats are long gone. One collapsed last year, so I gutted them. Can't even tell they're gone, except that the boost dropped slightly and the car is louder now. No fuel rich exhaust smell at all. I've got a great tuner buddy though (Carson) so that makes a big difference.
Valve train noise is getting louder and hopefully these quiet it down a bit but might be changing lifters. Flanged bushings are a nice addition. 6 week delivery seemed to take forever.
Valve train noise is getting louder and hopefully these quiet it down a bit but might be changing lifters. Flanged bushings are a nice addition. 6 week delivery seemed to take forever.
che
Where did you order this bushing kit? Cost? I would be interested in these for the LS9 set-up. They look really nice.
Valve train noise is getting louder and hopefully these quiet it down a bit but might be changing lifters. Flanged bushings are a nice addition. 6 week delivery seemed to take forever.
07-09-2017, 11:31 AM
