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#1
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Butler set me up with a roller package that includes limited travel roller lifters.
The manufacture's lifter specs are .035" -/+ .010 preload. .035" would be about a 3/4 turn. Cam lift is .598" with 1.5 roller rockers. Butler's site recommends starting at 1/8 turn for these lifters, which would be .006" preload. That is a wide range. What am I looking for here...best vacuum, quietest operation.? Currently I have set up at .025" preload (1/2 turn)..a bit noisy but performs well. |
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#2
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I dunno nothin, but i would have went for 1/4 turn to account for thermals in Summer and Winter.
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#3
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What lifters are being run and do you know what lobes are used on the cam?
The intensity of the lobes will have an effect on noise. I currently run a .398 Q series comp lobe with Johnson short travel hydraulic rollers. I had the engine professionally assembled so I don't know the preload exactly on these, but this setup is fairly quiet. There's a slight sewing machine sound, that I mostly attribute to the Harland Sharp roller rockers. If it's really loud, you may have aggressive lobes, collapsing lifters etc.
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-Jason 1969 Pontiac Firebird |
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#4
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Quote:
Comp Custom Billet cam - 13546B/13551B HR 113 .594/.597 Harland Sharp 1.5 roller rockers The intensity of the lobes will have an effect on noise. A not so good video recording.... https://drive.google.com/file/d/1A6p...ew?usp=sharing Already went through the collapsed lifter experience. One of the new lifters would not pump up. I contacted Johnson support before installing, but they said it would be OK once installed. It wasn't OK...ticked like a SOB. I had to RMA it and that took almost 3 weeks before the new one arrived. I just do not understand what Butler wants by starting at 1/8th of a turn when it takes a 1/2 turn to reach the manufacturer's minimum spec. One would expect that the manufacturers specs would overrule.
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1981 Trans Am - Dark Maple Metallic 1976 Pontiac 455(462), Kauffman Northwind Intake, Performer RPM Eheads, 11.5:1 compression, Comp Billet Custom cam, Venolia domed pistions, Dougs Headers, Pypes 2.5" Dual Exhaust/X-Over, Solid Body Mounts, GenIV SFCs, FiTech EFI, Walbro 400lph pump, TanksInc. EFI tank. MSD 6AL2, MSD ProBillet. |
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#5
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You use the same QNI lobes as I am currently using, just a couple degrees smaller and you've got more exhaust to intake spread than I do. These lobes are designed to be a bit softer on and off the ramps to help with noise.
I use the ST21120PR lifter. While you're using a reduced travel lifter, I'm using a short travel. I don't have a video of just the engine, but here's my car idling with the hood down. https://www.youtube.com/shorts/1O3aU7SHp88 There's not a ton of valvetrain noise and I do think that yours is a bit excessive. When I built this engine Kauffman spec'd the cam and I'm using his heads. He specifically wanted the short travel lifter with the .397 lobe lift cam. I would try the manufacturer setting on these and see if that helps.
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-Jason 1969 Pontiac Firebird |
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#6
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What are the specs of the Short Travel lifter? The Reduced Travel is .093" travel, preload .035" +/- .010". It is a rain day so I think I will bump up the preload from the current .025" to .035".
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1981 Trans Am - Dark Maple Metallic 1976 Pontiac 455(462), Kauffman Northwind Intake, Performer RPM Eheads, 11.5:1 compression, Comp Billet Custom cam, Venolia domed pistions, Dougs Headers, Pypes 2.5" Dual Exhaust/X-Over, Solid Body Mounts, GenIV SFCs, FiTech EFI, Walbro 400lph pump, TanksInc. EFI tank. MSD 6AL2, MSD ProBillet. |
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#7
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What valve springs does it have and how are they set up?
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#8
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Springs are Comp 914-16
Setup as follows... installed Height - 1.820" Seat Pressure - 162.5 lbs. Open Pressure - 385 lbs. @ .570" CoilBind - .700" Comp spring locators - 4785-16 Cut for Springs - 1.580" .570"
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1981 Trans Am - Dark Maple Metallic 1976 Pontiac 455(462), Kauffman Northwind Intake, Performer RPM Eheads, 11.5:1 compression, Comp Billet Custom cam, Venolia domed pistions, Dougs Headers, Pypes 2.5" Dual Exhaust/X-Over, Solid Body Mounts, GenIV SFCs, FiTech EFI, Walbro 400lph pump, TanksInc. EFI tank. MSD 6AL2, MSD ProBillet. |
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#9
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Quote:
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-Jason 1969 Pontiac Firebird |
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#10
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I bought a set of Johnson #2112OPR lifters from Butler. Standard travel. I didn't quite understand the preload instructions on Butler' webste : Preload= .035" +/-.010 + 1/8-3/8 Turn**. I emailed Johnson. The response was .035 +/- .005. On a 20 tpi stud that .030to .040 variance equates to .6 to .8 of a turn. So roughly 3/4 of a turn should do. Since the pushrod cup is a short length away from the stud, one turn at .050 on the stud will not equal .050 because of rocker arm ratio. However I believe the minuscule difference will not matter. Perhaps I am being anal, but just for s***s & giggles I plan on doing a measurement eventually.
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Frank M. 75 Firebird 68 Firebird 400 RAIII 66 Chevy II 461 Pontiac in AZ |
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#11
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Sounds like center of the plunger travel is a good place to start
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Will Rivera '69 Firebird, 400/461, 290 Eddy D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears '69 LeMans Vert, XS 350, #47 heads, TH400, 10 Bolt 3.23 gears, work in progress ‘66 Lemans, 455, 310 KRE D-Ports, HR 236/245, TH400, GV OD, 12 bolt 3.73 gears - see it here: https://youtu.be/RP_s1wJKm_Y?si=K0NZxoTyaGcj8Dcb |
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#12
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The springs look ok. With those springs and that cam running 160 seat pressure the engine is never going to be overly quiet with those lifters. It will always have the sowing machine whirl. But it will likely be a little quieter and clatter less hot with the preload set deeper. Keep in mind the recommended .035” is a moving target once the engine is hot. Setting it for .025” cold plus the engine expansion of the AL heads and your running about 1/2 of the recommended preload. Which could be fine, don’t set them deeper than necessary. You won’t know what it likes until you try setting them deeper.
Last edited by Jay S; 06-19-2025 at 09:41 PM. |
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