Slant Six Forum
https://www.slantsix.org/forum/

Valve Geometry
https://www.slantsix.org/forum/viewtopic.php?t=34290
Page 1 of 1

Author:  66aCUDA [ Sat Mar 14, 2009 6:42 am ]
Post subject:  Valve Geometry

Just wondering if taking .100 off the top of the valve stem will help the push rod geometry? As I am putting in valves that have to be cut down anyway??
Any body try this.
Frank

Author:  Joshie225 [ Sat Mar 14, 2009 10:51 am ]
Post subject: 

Longer valves increase the effective rocker ratio on a slant. If you're putting in longer, larger headed valves and the seats end up higher in the chamber it will offset some of the extra stem length. I'd put two of the the valves in with light checking springs and bolt on the rocker assembly and see where the rocker contacts the valve stem. You want the rocker to contact the center of the stem and scrub across the stem as little as possible. Our long rockers tend to be fairly forgiving of errors is valve length.

Author:  Dart270 [ Sat Mar 14, 2009 12:38 pm ]
Post subject: 

You don't want shorter valves than stock. A bit longer is probably better for the reasons Josh states. More than 0.100" over the stock installed valve tip position will start to get you into trouble, I think.

Lou

Author:  Doctor Dodge [ Sun Mar 15, 2009 12:33 am ]
Post subject: 

I have use a lot of .100 longer valves in the SL6 with great results. (big block mopar valves)

As noted, get the valve up into the chamber as much as possible to off-set some of the added lenght.

I use rocker shaft shims to fine-tune the contact pattern at the tip to stem interface.

I do not "face down" the tip to make the valve stem shorter.
Check spring pressures / installed spring height.
DD

Author:  66aCUDA [ Sun Mar 15, 2009 5:39 am ]
Post subject: 

Thanks Guys
I wondered about the scrub angle. As Doc says I told the machinist to keep the valves down in the chamber. I have the stand shims.
Anyone know where to get some light springs??
Thanks,
Frank

Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/