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1.7 yella terra non adjustables. What's the lash supposed to
Posted: September 27th, 2014, 8:36 pm
by Defcon92
Gonna pull the valve cover tomorrow to fix a small leak (bent cover). And I wanna recheck the lash. Builder set it up before so I never knew the specs.
Re: 1.7 yella terra non adjustables. What's the lash suppose
Posted: September 28th, 2014, 5:39 am
by the grey ghost
I try to shoot for around .030 or thirty thousandths, mine are all + or -2 or 3 thousandths, the rocker ratio doesn't matter unless your changining to a 1.7 ratio from a 1.6 or vice versa, then you reset preaload, you pretty much reset preload whenever changing anything in the valvetrain that puts preload out of spec, how to know ahead of time takes experience with building the same engine
Re: 1.7 yella terra non adjustables. What's the lash suppose
Posted: September 28th, 2014, 6:28 am
by SilverXJ
Defcon92 wrote: And I wanna recheck the lash.
FYI, Mechanical cams with solid lifters have lash, which is clearance in the valve train. Hydraulic cams have preload, no clearance.
Re: 1.7 yella terra non adjustables. What's the lash suppose
Posted: September 28th, 2014, 11:10 pm
by Defcon92
SilverXJ wrote:Defcon92 wrote: And I wanna recheck the lash.
FYI, Mechanical cams with solid lifters have lash, which is clearance in the valve train. Hydraulic cams have preload, no clearance.
So what would the clearance between the roller & valve tip be called? I always thought it was valve lash lol.
Re: 1.7 yella terra non adjustables. What's the lash suppose
Posted: September 29th, 2014, 4:52 am
by SilverXJ
You have a hydraulic cam. There is no clearance.
.030"-.060" preload is what you want on a hydraulic.
Re: 1.7 yella terra non adjustables. What's the lash suppose
Posted: October 19th, 2014, 10:27 am
by RenoF250
Defcon92 wrote:SilverXJ wrote:Defcon92 wrote: And I wanna recheck the lash.
FYI, Mechanical cams with solid lifters have lash, which is clearance in the valve train. Hydraulic cams have preload, no clearance.
So what would the clearance between the roller & valve tip be called? I always thought it was valve lash lol.
Lash is straight clearance with no tension. With a hydraulic lifter you should always have the tension of the spring in the lifter, that is the preload. The springs are not very strong so you can push on them and make clearance at the rocker tip.