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 04 Sportster refurb and build.
Last Post: ChinCactus
Posted On: 6 Minutes Ago
Replies: 118
Views: 9,000
0 Official XL Forum Random Image Thread (NO NUDITY!)
Last Post: cal43
Posted On: 20 Minutes Ago
Replies: 53,027
Views: 8,984,556
0 Hottie of the day, no nudity.
Last Post: cal43
Posted On: 44 Minutes Ago
Replies: 34,017
Views: 4,099,710
0 Keep & Kill
Last Post: Crusty
Posted On: 54 Minutes Ago
Replies: 26,885
Views: 1,561,578
0 This is gonna hurt.
Last Post: cal43
Posted On: 1 Hour Ago
Replies: 9,261
Views: 2,187,391
0 You asked for it! "The Tess' Coffee Thread"
Last Post: sportytrace
Posted On: 1 Hour Ago
Replies: 11,148
Views: 1,107,292
0 Rear Brake Squeal Fixed
Last Post: SonWon
Posted On: 1 Hour Ago
Replies: 3
Views: 567
0 What song do you have stuck in your head?
Last Post: iNSaNeSHaNe
Posted On: 1 Hour Ago
Replies: 2,494
Views: 279,044
0 Informed reviews!
Last Post: 2cam
Posted On: 2 Hours Ago
Replies: 5
Views: 183
0 Iree's late night cafe
Last Post: sportytrace
Posted On: 2 Hours Ago
Replies: 2,224
Views: 400,378
0 Primary thread
Last Post: Hippysmack
Posted On: 3 Hours Ago
Replies: 10
Views: 147
0 What did you do for your sporty Today?
Last Post: JimVonBaden
Posted On: 5 Hours Ago
Replies: 7,869
Views: 1,368,000
0 Show your favorite pic of your bike. just one
Last Post: JimVonBaden
Posted On: 5 Hours Ago
Replies: 4,859
Views: 1,975,273
0 VOES issues? Adjustments needed?
Last Post: Edster
Posted On: 7 Hours Ago
Replies: 0
Views: 42
0 Coulda' - Shoulda' - Woulda' - Solenoid/Bendix?
Last Post: ZTatZAU
Posted On: 8 Hours Ago
Replies: 52
Views: 1,095
0 Upside Down Monoshock IH - A Longterm Project
Last Post: sportsterpaul
Posted On: 8 Hours Ago
Replies: 334
Views: 73,826
0 Can't install kickstand spring
Last Post: IronMick
Posted On: 9 Hours Ago
Replies: 34
Views: 2,426
5 Late 50s XL to 60s XL Front End Compatibility
Last Post: Jhbox13
Posted On: 9 Hours Ago
Replies: 0
Views: 71
0 Another question re: Microsquirt
Last Post: Randy_rots
Posted On: 11 Hours Ago
Replies: 46
Views: 1,413
0 Oil system prime
Last Post: wedge
Posted On: 11 Hours Ago
Replies: 50
Views: 4,513
0 Snippets
Last Post: sportsterpaul
Posted On: 12 Hours Ago
Replies: 602
Views: 84,225
0 1971 with a Mag
Last Post: Whitewalls
Posted On: 12 Hours Ago
Replies: 4
Views: 228
0 1977 xlh
Last Post: Tim The Grim
Posted On: 13 Hours Ago
Replies: 4
Views: 171
0 Nicks custom cycle
Last Post: doodah man
Posted On: 13 Hours Ago
Replies: 3
Views: 129
0 old school prism oil filter/cooler
Last Post: 73HEAD
Posted On: 14 Hours Ago
Replies: 4
Views: 265
0 Regulator test 1974 xl
Last Post: Jaime1840
Posted On: 15 Hours Ago
Replies: 7
Views: 474
0 Allegheny National Park III
Last Post: rokytnji
Posted On: 17 Hours Ago
Replies: 97
Views: 6,375
0 WTB--shocks
Last Post: Doc308
Posted On: 17 Hours Ago
Replies: 0
Views: 49
0 Digital volt meter
Last Post: Tomcatt
Posted On: 20 Hours Ago
Replies: 7
Views: 297
0 Short in electrical system? Confused about points and ignition coil
Last Post: Iron Mike
Posted On: 20 Hours Ago
Replies: 17
Views: 436
More...
Members Birthdays
Reply
 
Share Thread Tools Display Modes
  #21  
Old 29th November 2021
brucstoudt's Avatar
brucstoudt brucstoudt is offline
XL FORUM TEAM MEMBER
 
Join Date: May 2010
Location: Pottstown PA.
Posts: 15,088
Sportster/Buell Model: xlch
Sportster/Buell Year: 1960
Sportster/Buell Model #2: 883 custom
Sportster/Buell Year #2: '03
Reputation: 1025691
brucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond repute
Default

^^ because they're not good at getting rid of the forementioned crankcase pressure?
__________________
72 1000cc barrels and heads, s&s 41/2'' flywheels, sifton cams, s&s super B w/ zippers thunderjet w/yost powertube, andrews gears,and shafts, competition engineering kevlar wet or dry clutch, 72 oil pump, morris magneto w/auto advance and single fire module, cycle electric generator w/electronic regulator,73 cu.in.
Reply With Quote
  #22  
Old 29th November 2021
Ferrous Head's Avatar
Ferrous Head Ferrous Head is offline
XL FORUM TEAM MEMBER
 
Join Date: Jun 2009
Location: Sunshine Coast
Posts: 7,578
Sportster/Buell Model: XLB, XLCH, Sporton
Sportster/Buell Year: 1962
Sportster/Buell Model #2: XLCH
Sportster/Buell Year #2: 1966
Other Motorcycle Model: XLCH (Another one)
Other Motorcycle Year: 1966
Reputation: 3148938
Ferrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond repute
Default

Mostly mods done by owners who think they are mechanics.
__________________
"I know only too well the evil that I propose. But my inclinations get the better of me."
Reply With Quote
  #23  
Old 4th December 2021
DR DICK's Avatar
DR DICK DR DICK is offline
Senior Master Custom Bike Builder
 
Join Date: Jan 2010
Posts: 6,482
Reputation: 455163
DR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond repute
Default

So the sportster oil pump is 2 pumps in one. We all know the scavenge pump has a greater capacity then the feed pump. This means that more oil is trying to be pumped out of the motor then is actually pumped in.

So how do we get the oil out of the crankcase? We need to supply a medium that moves this oil out of the crankcase so the oversized scavenger pump can pick it up . That that medium is air.

It's just like the top side of the piston, we can't Scavenge the combustion chamber without air flow. Valve timing or port sizes don't mean **** if no air is flowing. Put your hand over to throat the carb or the exhaust pipe and sooner or later your engine will die. No airflow.

In order to scavenge the sump same thing has to happen. It's not gonna happen because of oil flow, that is a set quantity. It's gotta happen with air flow which is not a set quantity.

Now here's the question?
how does this extra scavenge air get into the sump, and what happens to this airflow as RPMS change.
These are same questions you ask yourself when selecting cams, valve sizes, carburetors, and exhaust systems.

So understanding air flow under your Pistons is just as important is understanding what happens over your Pistons.
__________________
D.D._____________________________-o&o____________________________
Reply With Quote
  #24  
Old 4th December 2021
Ferrous Head's Avatar
Ferrous Head Ferrous Head is offline
XL FORUM TEAM MEMBER
 
Join Date: Jun 2009
Location: Sunshine Coast
Posts: 7,578
Sportster/Buell Model: XLB, XLCH, Sporton
Sportster/Buell Year: 1962
Sportster/Buell Model #2: XLCH
Sportster/Buell Year #2: 1966
Other Motorcycle Model: XLCH (Another one)
Other Motorcycle Year: 1966
Reputation: 3148938
Ferrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond repute
Default

I've always thought the area of concern for us with this system was the gallery at the back of the cases. My understanding was that the "positive" flow of air as the pistons descend help to push the oil down this gallery and into the can chest area.
I've also always assumed the engine will wet sump if any of this first part of the process isn't sufficient.
ie if the gallery were to fill up no more oil could be scraped off the wheels into the gallery.

This may not be correct, just my assumptions.

My thoughts were it was always a race between the first part of this oil return system and the amount of oil being delivered to the crankcase.

And that the timed breather was timed to produce the highest differential in air pressure to induce the highest velocity of air at this point.
Reply With Quote
  #25  
Old 4th December 2021
brucstoudt's Avatar
brucstoudt brucstoudt is offline
XL FORUM TEAM MEMBER
 
Join Date: May 2010
Location: Pottstown PA.
Posts: 15,088
Sportster/Buell Model: xlch
Sportster/Buell Year: 1960
Sportster/Buell Model #2: 883 custom
Sportster/Buell Year #2: '03
Reputation: 1025691
brucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond reputebrucstoudt has a reputation beyond repute
Default

the timed breather was my first thought,but it became obsolete in 1976 replaced by a one way valve in'77.
Reply With Quote
  #26  
Old 4th December 2021
DR DICK's Avatar
DR DICK DR DICK is offline
Senior Master Custom Bike Builder
 
Join Date: Jan 2010
Posts: 6,482
Reputation: 455163
DR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond reputeDR DICK has a reputation beyond repute
Default

Quote:
Originally Posted by Ferrous Head View Post
. My understanding was that the "positive" flow of air as the pistons descend help to push the oil down this gallery and into the can chest area.
your a racer and tuner so, please explain to me---where does the cyclical
replenishment of "positive flow of air flow" come from?
Reply With Quote
  #27  
Old 4th December 2021
Ferrous Head's Avatar
Ferrous Head Ferrous Head is offline
XL FORUM TEAM MEMBER
 
Join Date: Jun 2009
Location: Sunshine Coast
Posts: 7,578
Sportster/Buell Model: XLB, XLCH, Sporton
Sportster/Buell Year: 1962
Sportster/Buell Model #2: XLCH
Sportster/Buell Year #2: 1966
Other Motorcycle Model: XLCH (Another one)
Other Motorcycle Year: 1966
Reputation: 3148938
Ferrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond repute
Default

I don't play much with the later stuff. But the oiling system was changed for 77 with the new pump as well. I don't know what other improvements may have been made.

I know that at slower speeds the scavenge pump works OK. You can see the oil being returned as "spurts", not a steady stream. To my mind this means the amount of oil going into the scavenge pump is not sufficient to flood the pump.

I think the "timed" breather system can be timed to get maximum benefit whereas the OCV id going to be more arbitrary.

And the garroter pump with PCV may work perfectly for stock or longer stroke engine but what would happen if you de-stroked it and ran it to much higher rpm's ?
Reply With Quote
  #28  
Old 4th December 2021
Ferrous Head's Avatar
Ferrous Head Ferrous Head is offline
XL FORUM TEAM MEMBER
 
Join Date: Jun 2009
Location: Sunshine Coast
Posts: 7,578
Sportster/Buell Model: XLB, XLCH, Sporton
Sportster/Buell Year: 1962
Sportster/Buell Model #2: XLCH
Sportster/Buell Year #2: 1966
Other Motorcycle Model: XLCH (Another one)
Other Motorcycle Year: 1966
Reputation: 3148938
Ferrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond repute
Default

Quote:
Originally Posted by DR DICK View Post
your a racer and tuner so, please explain to me---where does the cyclical
replenishment of "positive flow of air flow" come from?
Sorry, not meaning that the air flow is only one way.

Just "positive" in terms of moving the air from the cases into the gear case.

Your always going to have some blow-by into the cases.

Between the maelstrom that must be going on inside the cases and effects like inertia (the bike isn't often just standing still) it amazes me the system works at all.
Reply With Quote
  #29  
Old 4th December 2021
Ferrous Head's Avatar
Ferrous Head Ferrous Head is offline
XL FORUM TEAM MEMBER
 
Join Date: Jun 2009
Location: Sunshine Coast
Posts: 7,578
Sportster/Buell Model: XLB, XLCH, Sporton
Sportster/Buell Year: 1962
Sportster/Buell Model #2: XLCH
Sportster/Buell Year #2: 1966
Other Motorcycle Model: XLCH (Another one)
Other Motorcycle Year: 1966
Reputation: 3148938
Ferrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond repute
Default

I took my info from the FSM.
8. Oil accumulated in the crankcase base is scavenged by the flywheels to the breather oil trap.
9. The rotary breather valve is timed to open on the downward stroke of pistons allowing crankcase exhaust pressure to expel scavenge oil from crankcase oil breather trap into the timing gearcase.. Breather closes on upward stroke of the pistons creating vacuum in the crankcase.

Now we know this system works up to a point.

We also know that the HD racers running 750's way back when at Daytona had problems with oil buildup in the cases. This only became apparent at sustained high rpm.

Has this ever been a problem on stock engines or stroker engines ?

My best guess is probably not.

The HD race department got around it by reducing the output of the oil pump on the feed side.
Later on the went to a "mini sump" engine that allowed oil to collect in a small sump where it was scavenged from.

S&S have their pinion shafts Drilled and tapped to take a restrictor (several sizes were available). this prevented too much oil from going into the bearings and cases to begin with.
Reply With Quote
  #30  
Old 4th December 2021
Ferrous Head's Avatar
Ferrous Head Ferrous Head is offline
XL FORUM TEAM MEMBER
 
Join Date: Jun 2009
Location: Sunshine Coast
Posts: 7,578
Sportster/Buell Model: XLB, XLCH, Sporton
Sportster/Buell Year: 1962
Sportster/Buell Model #2: XLCH
Sportster/Buell Year #2: 1966
Other Motorcycle Model: XLCH (Another one)
Other Motorcycle Year: 1966
Reputation: 3148938
Ferrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond reputeFerrous Head has a reputation beyond repute
Default

I'll be honest and say I'm not that impressed with the IH oil system.

But is has worked reasonably well for many years in stock engines.

Had this been a tractor or stationary engine it would have been fine from the start.

I know they worked out timing points and widths of windows to get the maximum bang for the buck and used a 1/4 speed oil pump to help. But this just tells me the system was marginal to begin with.

And in fairness it was designed for a 30 hp 750 engine to start with. We stretched that envelope somewhat.
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 11:29.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
XL Forum® - Linson Media LLC