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VL valves in UL?

Moderators: Curt!, Pa

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flatheadrider

Posts: 74

Joined: Thu Aug 11, 2005 11:14 am

Location: Wichita, KS

Post Sun Nov 19, 2006 9:26 pm

VL valves in UL?

I have a set of VL (#165 - 30) valves in hand. I am building a ground up UL motor. I do not have a set of UL valves to measure or mic. Anyone know actuall demensional differences ( I assume overall length) as to why I cannot use VLs. New motor will be running lightened valve train so stems will be turned. Thanks. Would also ask if anyone knows where to get stronger valve springs.
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panic

Post Mon Nov 20, 2006 11:21 am

Too short.
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don

Posts: 551

Joined: Fri Oct 01, 1999 12:01 am

Location: Spokane WA USA

Post Mon Nov 20, 2006 7:58 pm

I get about .315" longer on UL vs VL Stock H-D valves.
Have You read this?
http://www.flatheadpower.com/BB/viewtop ... ock+valves
don
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steph

User avatar

Posts: 630

Joined: Fri Feb 21, 2003 1:01 am

Location: belgium

Post Mon Nov 20, 2006 11:36 pm

Iff you use the longer K tappet adjusting screw, they do the job just fine.
Have a U that has done already 15000m like this , no problems!
Stéph
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flatheadrider

Posts: 74

Joined: Thu Aug 11, 2005 11:14 am

Location: Wichita, KS

Post Mon Nov 27, 2006 3:40 pm

Thanks Panic, you were right on. Just picked up a pair of UL's and set them beside the VL's.
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panic

Post Mon Nov 27, 2006 6:23 pm

Happy now?
Last edited by panic on Wed Dec 06, 2006 3:22 pm, edited 1 time in total.
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flatheadrider

Posts: 74

Joined: Thu Aug 11, 2005 11:14 am

Location: Wichita, KS

Post Tue Nov 28, 2006 8:58 am

Reducing stem diameter and tapering the guides (reducing transfer area) are suggestons in the 80 Power book, why would you now offer that they are not good ideas because of heat transfer. You also raise the next question I have which is Can the exhaust port be welded and downsized? I understand that optimum flow needs an exhaust valve 75% of the intake size. Victory's info says you can o/s the intake but do not o/s the exhaust, they're already to big.
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steve@vlheaven.com

Posts: 132

Joined: Sun Mar 28, 2004 1:01 am

Post Wed Dec 06, 2006 12:13 pm

The VL valves are about 1/4" shorter than the UL ones and you should be able to take that up with the adjusters. I've made VL/UL valve springs for racing with one less turn of wire which are about 15% stiffer than stock.

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