Noisey valvetrain (sewing machine)
02-15-2010, 09:02 PM
#45
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Oil pump pickup Oring swap to a LARGER UNIT WITH A PORTED PUMP worked on my buddy's H/C swap... and I REALLY wish they would sticky the solution thread... Granted it's NOT always the problem, but it IS an often OVERLOOKED part. THEN you get the flood of threads asking "Why is my caM insTaLl TickinG!?!?" 
Most cams are quiet, but the aggressive lift cams get noisy because of the valves being closed so quickly.
But this is my list to a quiet valvetrain:
-PICK UP TUBE O RING!! ( )
-Use a pushrod Length checker and compensate properly for lifter preload.
-Check the rocker swipe -if you REALLY want to find the EXACT length PR's needed.
-When in doubt, replace lifters while the heads are off.
-If you have the money, go with a set of stock ratio RR's.
Most cams are quiet, but the aggressive lift cams get noisy because of the valves being closed so quickly.
But this is my list to a quiet valvetrain:
-PICK UP TUBE O RING!! (
)-Use a pushrod Length checker and compensate properly for lifter preload.
-Check the rocker swipe -if you REALLY want to find the EXACT length PR's needed.
-When in doubt, replace lifters while the heads are off.
-If you have the money, go with a set of stock ratio RR's.
Last edited by bayer-z28; 02-15-2010 at 09:13 PM.
06-09-2014, 10:07 PM
#48
Staging Lane
To clear up some of this math confusion, how about looking at it from a engineers perspective instead of an egg heads perspective? It's effectively a reversed fulcrum lever. 
When you move the bolt or "Load" down with a fixed end fulcrum then the pushrod or "Effort" moves at a higher ratio to the rocker bolt ie "Load": it's ratio varies and if you think on it you can see how the farther away the valve or ""Fulcrum" gets (ie, higher the lift ratio) the lesser the ratio will be on the pushrod. In our case, just shooting from the hip since I refuse to do math at home I would guess a ratio of 1.25: considering what we are doing, that translates to probably 15 to 18 thousandths difference between your two ways of measuring it. Well within any listed or tribal knowledge range we are talking about.
When you move the bolt or "Load" down with a fixed end fulcrum then the pushrod or "Effort" moves at a higher ratio to the rocker bolt ie "Load": it's ratio varies and if you think on it you can see how the farther away the valve or ""Fulcrum" gets (ie, higher the lift ratio) the lesser the ratio will be on the pushrod. In our case, just shooting from the hip since I refuse to do math at home I would guess a ratio of 1.25: considering what we are doing, that translates to probably 15 to 18 thousandths difference between your two ways of measuring it. Well within any listed or tribal knowledge range we are talking about.
