Sbc shaft rocker arms, how much side to side play is normal?

[Bill Chase]

Purchased these circa 2020. Scorpion racing products 1.6/1.6 shaft rocker arms. #scp-3902. Ran with mikes ehr 71360-72360 lobes. 276/280 adv 228/232 @ .050 .360/.360 lobe lift. Steel core with everwear cast gear. Good cloyes timing set. OEM spider and dog bones, OEM thrust plate. Afr 195 street heads with 8017 springs, car has never seen over 6000 rpm. Runs good, just have a quiet street exhaust and at idle it sounds pretty aggressive. Like a sewing machine on steroids.

I have authentic gm 12499225 lifters purchased pre COVID from local Tyler Chevrolet. Good Manley 5/16 .100 wall 7.100" pushrods, made sure nothing was rubbing the heads on mockup. Probably pulled each rocker pair 3 times since break in looking for pushrod galling, and any other abnormal wear.

I have tried adjusting the preload from 1/4 to 1 full turn and everything in between. Measured pushrod length, have good centered sweep pattern, zero abnormal wear after a few thousand miles. I've tried running penn grade sae 30, rotella 15w40, Valvoline 10w30 vr1 (seen Straub recommend this specific blend, centistroke count or something like that figured I'd try it, made no difference)
I'm not trying to be a Pansy, realize aggressive cam lobes are a little noisy. It doesn't bother me, just constantly wonder if I'm hurting it is it normal to have .010-.015 side to side end play on each rocker?

Anyway, it sounds like a sewing machine no matter what I do. Doing my spring maintenance, and noticed some side to side play on the rockers, not sure if it is normal. It has not gotten worse since break in. There is no axial play, just side to side almost like it could be shimmed tighter. Play averages about .010-.015 ". They sent a huge assortment of shim washers, I just verified each roller was centered over the valve tip, did not change the side to side end play at all. Is this normal? I took a video of it, but forum settings will not let me upload it.

[Dave B]

I'm pre maching a engine for assembly now. My T&D stuff is .005- .007 total. So pretty limited per side.Some of cheaper stuff I have saw bind if you try and run them this tight. There are numbers of reasons that cause this. Oil types etc lead to what clearances you can get by with.if geometry is not correct or your setup doesn't have good control. Tight will bind, burn up or break. You could try snugging one rocker with shims and monitor it closely. There is no exact answer to allot of this. Most engines I work on are so loud through ex ,most guys wouldn't ever hear valve trane until it was missing. That being said, imo your way on too much clearance side of things.

[Bill Chase]

Thanks, it gives me something to try at least. The side to side was at 165-170 ° fahrenheit after a long drive.

Maybe take half of the end play out on the intakes, and a quarter of it on the exhausts?? What's a good starting point Dave B?

[bill jones]

---in the 1975 era I started chasing using a timing light to watch the valve springs and rockers thru clear plastic valve covers
---I had a “dial back” timing light that could change the timing around about 30 degrees or so
---we were running typically running roller rockers and two bar girdles and 7/16” studs

---one of the first things I could see was the trunnions were oscillating front to rear
---I didn't like that at all---could even see it happening at idle

---I took the valve cover off and reached my fingers down in there and got a hold of the sides of the trunnion to see if I could actually control any of the errant motion

---well---that didn't work---to do that I had to get one finger down in between the pair of trunnions
---and that about beat the end of my finger off real quickly
---so I learned that I could NOT affect the trunnions or the rocker bodys in any manner at all with my fingers

---so the lead to me building some thinwall stainless steel tubing sleeves to install onto the rocker stud before installing the rockers---and these sleeves were slightly longer by maybe .080” than the zero lash point---so the valve lash would require snugging down the stainless steel and the trunnons would push the sleeves down and the bottom of the sleeves would flare outwards on the rocker studs shank radius

---the trunnion would also leave two curved dents in the top of the stainless steel sleeves
---BUT---this positively fixed the loose trunnions with no other unforseen issues
---the two dents in the tops of each of the sleeves needed to be rotated each time the valves were loosened up

---the stainless steel tube pieces were cut using a tubing cutter
---the tubing was 1/2” OD x .062” wall thickness
---the tubing lengths varied between every engine

---7/16" rocker studs I like are Crower #88401 which are 1.250" long from the guide plate to the first thread
---I strive to have all the trunnion on the shank---to the point that if I have to I will machine away several threads from inside the adjustment nuts so the shank can protrude .060" or so above the trunnion

---later on I started making the stainless steel sleeves a little longer---and I'd take all the rockers and clamp the trunnions upside down and machine the curved bottom surface flat for a full circle
---this means there now was no dents into the preload sleeves

---using these preload sleeves locks the trunions firmly in place sort of like pedestal mount rockers are

6-2-2022---checked the lengths of the sleeves I happen to still have in stock
---.359”---.417”---.420”---.425”---.427”---.429”---.435”---.500”---.566” ---.581

[Dave B]

Bill Chase
I did quick inet look and Scorpion has a tech line. It might be worth giving them a shout and get their opinion. I would think they should be close to the .0025 -.0035 each way I'm seeing with T&D stuff I have here.

[Bill Chase]

Bill Chase
I did quick inet look and Scorpion has a tech line. It might be worth giving them a shout and get their opinion. I would think they should be close to the .0025 -.0035 each way I'm seeing with T&D stuff I have here.

Tried that, all they could tell me is make sure each roller is not hanging off the side of the valve stems. Pretty crude setup instructions for the cost. They have a video on YouTube, it doesn't mention it either. Sounds like if I cut current clearance in half and it gets quieter I'll be on the right track.

[Dave B]

I think that's all you can do or maybe do 1 int and 1 ex and monitor those for a few miles, inspect for rubbing ,coloring etc. I'm not sure if you can just replace 2 if prob occurs.if good to go, do all and then see what that does for noise?

[ProPower engines]

My crower stuffis .005"