The Sportster and Buell Motorcycle Forum - The XLFORUM®
 

Go Back   The Sportster and Buell Motorcycle Forum - The XLFORUM® > SPORTSTER MOTORCYCLE FORUM > Sportster Motorcycle Era Specific and Model Specific > Ironhead Sportster Motorcycle Talk (1957-1985)
XLF Blogs XLF Arcade XLF Disclaimer/Privacy Statement/Terms Of Use

Notices

Ironhead Sportster Motorcycle Talk (1957-1985) For all those that wanna talk about Ironhead Sportster Motorcycles

Active Threads
0 new from socal
Last Post: juzyHD
Posted On: 4 Minutes Ago
Replies: 12
Views: 74
0 Grenade Plate
Last Post: harley506d
Posted On: 9 Minutes Ago
Replies: 25
Views: 3,662
0 Hot Chicks on Hot Bikes
Last Post: cal43
Posted On: 30 Minutes Ago
Replies: 11,564
Views: 2,368,007
0 Official XL Forum Random Image Thread (NO NUDITY!)
Last Post: cal43
Posted On: 31 Minutes Ago
Replies: 49,454
Views: 8,045,623
0 Hottie of the day, no nudity.
Last Post: cal43
Posted On: 35 Minutes Ago
Replies: 26,017
Views: 2,671,391
0 Arlen Ness Big Sucker question
Last Post: Nailz
Posted On: 1 Hour Ago
Replies: 0
Views: 16
0 Keep & Kill
Last Post: wongjohnson
Posted On: 2 Hours Ago
Replies: 19,541
Views: 1,166,925
0 Clutch diaphragm spring question
Last Post: IXL2Relax
Posted On: 2 Hours Ago
Replies: 9
Views: 2,916
0 This week on Craig's list
Last Post: Steve9
Posted On: 3 Hours Ago
Replies: 5,029
Views: 731,958
0 Mid West Meet & Greet
Last Post: Crusty
Posted On: 4 Hours Ago
Replies: 797
Views: 79,319
0 Transformer XR1200
Last Post: jkinkade
Posted On: 4 Hours Ago
Replies: 515
Views: 61,849
4 2021 - only 3 Sportster models left
Last Post: kitabel
Posted On: 4 Hours Ago
Replies: 5
Views: 164
0 did .you ever kick a good man when he,, was down
Last Post: Iron Mike
Posted On: 5 Hours Ago
Replies: 1
Views: 87
0 Boardtracker Project
Last Post: JonesL
Posted On: 6 Hours Ago
Replies: 636
Views: 131,120
0 That Stupid F@#$&in' Speedometer
Last Post: Steve9
Posted On: 6 Hours Ago
Replies: 34
Views: 3,260
0 Sweetwater Motorcycle Rally & Cook-Off
Last Post: rokytnji
Posted On: 7 Hours Ago
Replies: 0
Views: 38
0 never mind
Last Post: IXL2Relax
Posted On: 7 Hours Ago
Replies: 228
Views: 35,802
0 1986-90 Evo Sportsters: What every owner should know but were afraid to ask
Last Post: Gary E
Posted On: 7 Hours Ago
Replies: 437
Views: 67,807
0 Flat Tracker Pics
Last Post: Gary E
Posted On: 9 Hours Ago
Replies: 1,163
Views: 652,956
0 Celebrating Sportsterpedia's 5th Anniversary
Last Post: DéDé
Posted On: 9 Hours Ago
Replies: 7
Views: 280
0 valve seals?
Last Post: Bob F
Posted On: 10 Hours Ago
Replies: 29
Views: 1,632
0 History of Harley; One Man's Perspective
Last Post: Bob F
Posted On: 10 Hours Ago
Replies: 13
Views: 701
0 This is gonna hurt.
Last Post: rokytnji
Posted On: 11 Hours Ago
Replies: 8,225
Views: 1,784,440
0 Removing Rear Shock
Last Post: 45Brit
Posted On: 11 Hours Ago
Replies: 27
Views: 863
0 Tires & Shocks Needed: '90XLH 883
Last Post: Rollbar
Posted On: 11 Hours Ago
Replies: 19
Views: 734
0 Garage space - Leeds WY UK
Last Post: denguy
Posted On: 12 Hours Ago
Replies: 2
Views: 98
0 Identity crisis
Last Post: Steve9
Posted On: 12 Hours Ago
Replies: 46
Views: 3,113
0 Smoke and top end job
Last Post: Kingrabbit
Posted On: 12 Hours Ago
Replies: 24
Views: 1,559
0 front end conversion
Last Post: sungod
Posted On: 12 Hours Ago
Replies: 15
Views: 512
0 Food porn
Last Post: Stairman
Posted On: 13 Hours Ago
Replies: 2,209
Views: 458,164
More...
Members Birthdays
Tags
exhaust, heads, ironhead exhaust, ironhead heads, modify

Reply
 
Share Thread Tools Display Modes
  #1  
Old 22nd May 2011
DCMC_Scooter DCMC_Scooter is offline
Biker
 
Join Date: May 2011
Posts: 1
Sportster/Buell Model: XLH
Sportster/Buell Year: 1985
Reputation: 10
DCMC_Scooter is an unknown quantity at this point
Lightbulb Is there any benefit to putting 85 XR heads on an 85 XLH?

I ride an 85 XLH and have been toying with the idea of putting XR heads on it from the same gen of ironhead. I'm wondering if there is any benefit to this or would it be too much hassle for too little of any positive result. I thought it might be like putting buell heads on another type of harley motor. Any thoughts on this?

Also, I've researched shorter exhausts on ironheads. Seems like the consensus for those owning ironheads that it runs fine, but depending on how short and how big the id is on your exhaust determines where your gain and loss is, whether you gain or lose top and bottom. I know on an ironhead you want very little back pressure ( how ever you want to define the generic term). Most arguments for back pressure are from people who don't own an ironhead and may not realize the heads are designed different than say an evo. I have a standard length drag pipe. I want to cut about 12 inches off the end on both pipes, then drill billets down the rest of the length up to the first bend. My theory Is this make allow the motor to breathe more while still maintaining some slight back pressure (due to the billets). And yes of course make it louder. Not a problem for me, loud pipes save lives right?

Any feedback would be appreciated!
-SCOOTER-
Reply With Quote
  #2  
Old 22nd May 2011
thefrenchowl's Avatar
thefrenchowl thefrenchowl is offline
Senior Custom Bike Builder
 
Join Date: Nov 2006
Posts: 2,990
Sportster/Buell Model: KHK
Sportster/Buell Year: 1954
Sportster/Buell Model #2: IronHead XLH
Sportster/Buell Year #2: 1978
Other Motorcycle Model: XLRTT
Other Motorcycle Year: 1966
Reputation: 233459
thefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant future
Default

Hi and welcome here...

If you mean 83/84 XR 1000 alloy heads, you'll need heads, barrels and rods as an absolute minimum.

Don't know about late evo Sportster, but early evo Sportster rods will do...

Patrick
__________________
Flat Head Forever
Reply With Quote
  #3  
Old 22nd May 2011
Gone Gone is offline
Land Speed Record
 
Join Date: Nov 2004
Posts: 745
Reputation: 37552
Gone is an unknown quantity at this pointGone is an unknown quantity at this pointGone is an unknown quantity at this pointGone is an unknown quantity at this pointGone is an unknown quantity at this pointGone is an unknown quantity at this pointGone is an unknown quantity at this pointGone is an unknown quantity at this pointGone is an unknown quantity at this pointGone is an unknown quantity at this pointGone is an unknown quantity at this point
Default

Run some 1.75 primaries into a 2" collector with a unbaffled reversecone megaphone. Make the primaries 33-35" long, but no more then a half inch different in length from eachother. It will be loud enough and give real gains in tork.
Here is some good info http://www.drchaos.org/files/ExhaustTechnology.htm
Reply With Quote
  #4  
Old 22nd May 2011
Bob F's Avatar
Bob F Bob F is offline
XLF LIFEMEMBER Im retired
 
Join Date: Feb 2007
Location: Pittsburgh, PA
Posts: 14,414
Sportster/Buell Model: XL50 0596 Black
Sportster/Buell Year: 2007
Other Motorcycle Model: E-Glide
Other Motorcycle Year: 2003
Reputation: 886328
Bob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond reputeBob F has a reputation beyond repute
Default

Welcome to the XLForum.
__________________
Bob, a glutton and a winebibber, a friend of bartenders and sinners!
Reply With Quote
  #5  
Old 22nd May 2011
jharback's Avatar
jharback jharback is offline
Senior Master Custom Bike Builder
 
Join Date: Dec 2006
Location: Sunny Italy
Posts: 21,951
Sportster/Buell Model: XLH 1200
Sportster/Buell Year: 1993
Other Motorcycle Model: Moto Guzzi California EV
Other Motorcycle Year: 1998
Reputation: 6791041
jharback has a reputation beyond reputejharback has a reputation beyond reputejharback has a reputation beyond reputejharback has a reputation beyond reputejharback has a reputation beyond reputejharback has a reputation beyond reputejharback has a reputation beyond reputejharback has a reputation beyond reputejharback has a reputation beyond reputejharback has a reputation beyond reputejharback has a reputation beyond repute
Default

Welcome to the forum!
__________________
Jim in Italy
'93 1200
4"Extended Jaybrake Forward Controls
Wide Wishbone Girder Front End
Super E Carb w/Forcewinder Air Cleaner
WetDreamz Pipes
Holographic Metal Flake Paint Job
Four Piston Jaybrake Calipers front & back
16" Carlini Apes
Reply With Quote
  #6  
Old 22nd May 2011
IronMick's Avatar
IronMick IronMick is offline
Rider Of The Iron Steed
 
Join Date: Dec 2003
Location: London, ON Canada
Posts: 32,521
Sportster/Buell Model: XLH
Sportster/Buell Year: 1978
Reputation: 1280341
IronMick has a reputation beyond reputeIronMick has a reputation beyond reputeIronMick has a reputation beyond reputeIronMick has a reputation beyond reputeIronMick has a reputation beyond reputeIronMick has a reputation beyond reputeIronMick has a reputation beyond reputeIronMick has a reputation beyond reputeIronMick has a reputation beyond reputeIronMick has a reputation beyond reputeIronMick has a reputation beyond repute
Default

Welcome! to the IronHead forum. Cool to have another member willing to experiment and risk.
__________________
Mick
IronHead Forever!

Visit Mick's WebSite
[And Check Out My Autobiog]
Reply With Quote
  #7  
Old 22nd May 2011
thefrenchowl's Avatar
thefrenchowl thefrenchowl is offline
Senior Custom Bike Builder
 
Join Date: Nov 2006
Posts: 2,990
Sportster/Buell Model: KHK
Sportster/Buell Year: 1954
Sportster/Buell Model #2: IronHead XLH
Sportster/Buell Year #2: 1978
Other Motorcycle Model: XLRTT
Other Motorcycle Year: 1966
Reputation: 233459
thefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant futurethefrenchowl has a brilliant future
Default

Hi again, DCMC_Scooter

Basic formulae to calculate lenght and ID of exhaust pipes:

1) Pipe length in inches = 850 x ED / rpm

Where ED is 180 degrees + the arc in degrees between exhaust valve opening and BDC.

2) Pipe ID area = rpm x cylinder size in ci / 88200

Patrick
Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT +1. The time now is 09:06.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
XL Forum® - Linson Media LLC