Another valve setting question........curious

[Rusty Davenport]

If you read enough, there is one common descrepancy in all the different valve setting techniques from Comp Cams to Friendly Freddies Speed Depot.... everybody agrees that (SB Chev) when using the EO-IC method, set the INTAKE when the exhaust BEGINS to open......now the EXHAUST, the descrepancy---set the Exhaust when the intake just begins to close or when it is almost closed ??? Anyone ever noticed that or have a comment ???

[Alan Roehrich]

You set the exhaust lash as the intake valve just closes, as in when the intake valve is almost on the seat.

[Run to Rund]

With firing order 18436572, I checked the Mopar chart vs. base circle and it works very well:
TDC #1 firing, 2i, 8e
rotate 90 deg. 1i, 4e
90 deg. more, 8i 3e
90 deg. 4i, 6e
90 deg (#6 firing), 3i, 5e
90 deg. 6i, 7e
90 deg. 5i, 2e
90 deg, 7i, 1e

[Mike Taylor 3601]

90 degree method does'nt work well with unsymetrical lobes or inv.radius lobes
ex opens set in/ in almost close set ex will work with anything as long as you rotate engine direction it runs.
Mike Taylor 3601

[Jim B]

Originally Posted by Mike Taylor 3601

90 degree method does'nt work well with unsymetrical lobes or inv.radius lobes
ex opens set in/ in almost close set ex will work with anything as long as you rotate engine direction it runs.
Mike Taylor 3601

Definitely x2 with some of today's race cams. You can always set one cylinder int & exh with this accurate method and check the lash the old Mopar sequence way to see if you really need to do it this way or your particular grind doesn't require it.

[1320racer]

EO/IC is the method every professional engine builder and race team uses to set/check valve lash regardless of lobe or lifter type.

Go the the Pro Stock pits immmediately after a round of qualifying, walk over to your favorite Team's trailer/pit and watch them check their valve lash, one cylinder at a time, using the EO/IC method.

[Ed Wright]

My intakes are loosest when my exhausts are almost fully open. My exhausts are loosest when my intakes just start to close. Lobe separation angles have some influence there too.

[buzzinhalfdozen]

Originally Posted by 1320racer

EO/IC is the method every professional engine builder and race team uses to set/check valve lash regardless of lobe or lifter type.

Go the the Pro Stock pits immmediately after a round of qualifying, walk over to your favorite Team's trailer/pit and watch them check their valve lash, one cylinder at a time, using the EO/IC method.

How do you know this to be fact? Do you know every professional engine builder? I know several and each one seems to have their own quirk on how they lash valves. I lash my V6 stuff differently from my old V8 stuff,saying EO/IC is a very vauge explanation....how far open?....How far closed? Heck me and my brother who raced together for years, lashed valves differently. As with many things everyone seems to develope their own "style" of doing things. I believe the procedure I wrote, to be the most accurate way of setting lash...some may disagree that's OK it has worked for me thus far. Joe

[Run to Rund]

On my cam, the Mopar sequence seems to adjust a valve when the lifter is at the center of the base circle--how could that be on a ramp? Maybe my cam is too small, lol.

[Mike Pearson]

The most important thing is to make sure you are doing the exact same thing each time you check and adjust the lash. With the Jesel rockers there should not be any change in lash when you check your rockers once all of the parts have been "run in". If something is loose then you have a problem. This is for super stock style engines. I adjust mine using the degree markings on the balancer to make sure I am checking the vales at the exact same point in the engine rotation. Its not so much the process of how they are set. They need to be set consistently the same. That also goes for trying different lash settings. You just need to find a method that you are comfortable with and stick to it.