Engine Mechanical Topics Discussion for motor builds, cams, head work, stripped bolts and other engine related issues. The good and the bad. If it goes round and around or up and down, post it here.

Compression release installation angle

Thread Tools
 
Search this Thread
 
Old May 15, 2017 | 07:23 PM
  #1  
Road Star's Avatar
Road Star
Thread Starter
|
Seasoned HDF Member
Veteran: Marine Corps
10 Year Member
Liked
Top Answer: 1
Joined: Dec 2012
Posts: 6,674
Likes: 502
From: Orange County
Default Compression release installation angle

Does anyone know the angle and dimension at which the holes are drilled for compression releases on a Twin Cam?
 
Reply
Old May 15, 2017 | 08:17 PM
  #2  
Road Star's Avatar
Road Star
Thread Starter
|
Seasoned HDF Member
Veteran: Marine Corps
10 Year Member
Liked
Top Answer: 1
Joined: Dec 2012
Posts: 6,674
Likes: 502
From: Orange County
Default

I found this on another forum, I just don't understand the 2-5/16" measurement. Is it from the spark plug?

What I do is:
Measure in between the head bolt(short one on the intake side},and the spark plug hole 2 5/16" from the outer fin.
Center punch the spot.
Set the head up on an angle plate set at 15 degrees.
Use a wiggler or other method to keep the quill on the center punch mark.
Spot face with a 3/4" center cutting end mill.
Chuck up a 11/32" drill,and drill down 3/4".
Chuck up a .090" drill,and drill down through the chamber.
Set up a 10mm. tap,cut threads,and you're done.
 

Last edited by Road Star; May 15, 2017 at 08:26 PM.
Reply
Old May 15, 2017 | 10:52 PM
  #3  
Max Headflow's Avatar
Max Headflow
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,989
Likes: 8,062
From: poway
Default

Not sure how they compare to HDs specs, but you can pull this off the HD service portal..
 
Reply
Old May 16, 2017 | 12:24 AM
  #4  
Road Star's Avatar
Road Star
Thread Starter
|
Seasoned HDF Member
Veteran: Marine Corps
10 Year Member
Liked
Top Answer: 1
Joined: Dec 2012
Posts: 6,674
Likes: 502
From: Orange County
Default

Originally Posted by Max Headflow
Not sure how they compare to HDs specs, but you can pull this off the HD service portal..
Awesome!
thank you so much.
 
Reply
Old May 16, 2017 | 09:36 AM
  #5  
prodrag1320's Avatar
prodrag1320
Banned
Joined: Sep 2009
Posts: 3,569
Likes: 624
From: deland,florida
Default

when we install them,we put them right in front of the plug.alot easier to get too.i can get the specs to you if you want
 
Reply
Old May 16, 2017 | 10:01 AM
  #6  
Road Star's Avatar
Road Star
Thread Starter
|
Seasoned HDF Member
Veteran: Marine Corps
10 Year Member
Liked
Top Answer: 1
Joined: Dec 2012
Posts: 6,674
Likes: 502
From: Orange County
Default

Originally Posted by prodrag1320
when we install them,we put them right in front of the plug.alot easier to get too.i can get the specs to you if you want
That would be great.
Thanks!
 
Reply
Old May 16, 2017 | 02:10 PM
  #7  
prodrag1320's Avatar
prodrag1320
Banned
Joined: Sep 2009
Posts: 3,569
Likes: 624
From: deland,florida
Default

Originally Posted by Road Star
That would be great.
Thanks!

email me at veetwinracing@hotmail.com ,I can include pics & stuff.to hard to put pics on the forums
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
flhchaz
EVO
22
Oct 7, 2014 09:28 AM
zyban
Want To Buy Motorcycles/Parts/Accessories
0
Jul 2, 2011 08:21 PM
Electra1
Touring Models
5
Apr 12, 2010 11:09 PM
DPete
Sportster Models
8
Jan 10, 2009 09:33 PM
02Sporty1200C
Sportster Models
5
Mar 25, 2006 10:15 AM




All times are GMT -5. The time now is 03:05 PM.

story-0
10 Most Awkward-Looking Motorcycles Ever Built

Slideshow: Not every motorcycle can be a design icon, and these machines prove that bold styling doesn't always age gracefully.

By Verdad Gallardo | 2026-06-12 11:58:41


VIEW MORE
story-1
Jason Momoa Is Turning Classic Harleys Into PHEVs

Slideshow: Jason Momoa's latest restoration project blends 1920s Harley-Davidsons with modern electric technology, creating some of the most unusual hybrid motorcycles ever built.

By Verdad Gallardo | 2026-06-10 17:18:58


VIEW MORE
story-2
Harley-Davidson Fat Boy Becomes a Dark, Decepticon-Inspired Custom

Slideshow: Killer Custom's latest build relies on styling changes rather than performance upgrades, giving the cruiser an entirely different personality.

By Verdad Gallardo | 2026-06-03 18:28:05


VIEW MORE
story-3
6 Weirdest Harley-Davidsons Ever Sold to the Public

Slideshow: From military-inspired singles to scooters and three-wheel utility vehicles, these Harleys took the company far outside its comfort zone.

By Verdad Gallardo | 2026-06-02 18:34:10


VIEW MORE
story-4
7 Times Harley-Davidson Chucked Tradition Out the Window

Slideshow: Harley-Davidson built its reputation on nostalgia, but every so often, the company took a hard left turn into the future.

By Verdad Gallardo | 2026-05-20 11:18:19


VIEW MORE
story-5
7 Surprising Harley-Davidson Products that Are Not Motorcycles

Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.

By Verdad Gallardo | 2026-04-29 16:50:35


VIEW MORE
story-6
8 Best Harley-Davidson Motorcycles Ever

Slideshow: Not every Harley gets it right, but these are the ones that genuinely earned their reputation.

By Pouria Savadkouei | 2026-04-15 14:23:21


VIEW MORE
story-7
10 Worst Harley-Davidson Motorcycles Ever

Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.

By Pouria Savadkouei | 2026-04-01 20:01:09


VIEW MORE
story-8
Killer Custom's Jail Break Is The Breakout That Refused to Blend In

Slideshow: Killer Custom's "Jail Breaker" build focuses more on stance and visual aggression than mechanical overhaul.

By Verdad Gallardo | 2026-03-18 19:20:32


VIEW MORE
story-9
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.

By Verdad Gallardo | 2026-03-07 16:15:30


VIEW MORE