PR Preload Noise Recommendations
Thread Starter
Teching In
Joined: Nov 2015
Posts: 34
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From: Philadelphia
PR Preload Noise Recommendations Hey guys , I'm just looking for peoples opinions on their experiences with valve train noise do to preload. I have Comp Cam 218/224 .528/.535 , Harland Sharp RR, and tooley springs. I have factory Lifters and originally had 7.4 Rods . Ran good but developed an unusual tap. Checked preload with my adjustable PR checker and I didn't have enough preload. At 7.45" length I get 5 (1/4 turns) and at 7.5" I get 6 (1/4 turns) from zero lash. So I was planning on going with 7.475". Now with the factory preload recommendation being .05-.08 , have you found less valve train noise on the low side or the heavy side???
2001 T/A WS6 M6 60K - comp cam 218/224, Brian tooley springs, Powerbond 25%UD, Pacesetter LT & Y, SLP Lid/MAF/LM1 exhaust, and BBK 80mm TB.
Tuned @CompleteStreetPerfomance by Andrew
HP 396/ TQ 396
2001 T/A WS6 M6 60K - comp cam 218/224, Brian tooley springs, Powerbond 25%UD, Pacesetter LT & Y, SLP Lid/MAF/LM1 exhaust, and BBK 80mm TB.
Tuned @CompleteStreetPerfomance by Andrew
HP 396/ TQ 396
Id spend the $25 for a Harbor Freight 8" caliper and measure your adjustable pushrod. It'll be more accurate than the turn method, so you can really dial in the preload better. What preload are you coming up with for each measurement?
From what I've read, a little more preload (still within the range) quiets down the valvetrain. My noise went away with proper length pushrods, but I can't tell you if that was more or less preload since I didn't measure the first time.
I'd also recommend measuring all 16, documenting each, then measuring your news ones and assigning them based on your measurements. I believe that really helped my car spit out some good dyno numbers, which make it even more fun to drive. Read up on Darth_v8r's write up if you haven't yet, it's a good one.
From what I've read, a little more preload (still within the range) quiets down the valvetrain. My noise went away with proper length pushrods, but I can't tell you if that was more or less preload since I didn't measure the first time.
I'd also recommend measuring all 16, documenting each, then measuring your news ones and assigning them based on your measurements. I believe that really helped my car spit out some good dyno numbers, which make it even more fun to drive. Read up on Darth_v8r's write up if you haven't yet, it's a good one.
Thread Starter
Teching In
Joined: Nov 2015
Posts: 34
Likes: 0
From: Philadelphia
Id spend the $25 for a Harbor Freight 8" caliper and measure your adjustable pushrod. It'll be more accurate than the turn method, so you can really dial in the preload better. What preload are you coming up with for each measurement?
From what I've read, a little more preload (still within the range) quiets down the valvetrain. My noise went away with proper length pushrods, but I can't tell you if that was more or less preload since I didn't measure the first time.
I'd also recommend measuring all 16, documenting each, then measuring your news ones and assigning them based on your measurements. I believe that really helped my car spit out some good dyno numbers, which make it even more fun to drive. Read up on Darth_v8r's write up if you haven't yet, it's a good one.
From what I've read, a little more preload (still within the range) quiets down the valvetrain. My noise went away with proper length pushrods, but I can't tell you if that was more or less preload since I didn't measure the first time.
I'd also recommend measuring all 16, documenting each, then measuring your news ones and assigning them based on your measurements. I believe that really helped my car spit out some good dyno numbers, which make it even more fun to drive. Read up on Darth_v8r's write up if you haven't yet, it's a good one.
Extended my checker while tapping my rocker. It' starts Mateing with the rocker at 7.375 and at 7.4 the tapping completely gone. Then I'll add preload first doing .05 and then .075 and then .1 of preload just for the sake of it. All the valves I did were consistent i would get 1 1/4 turns for .05 , little over 1 1/4 turns for .075, and 1 1/2 turns for .1 of preload. But the main reason I wrote this is because I read mixed reviews with valve train noise from preload. Some people claiming .05 was quiet and others saying it was noisy.
