Annealed aluminum line + miata engine - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 07-26-2012, 09:41 AM   #1
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: May 2005
Location: Mass.
Posts: 816
Total Cats: 41
Default Annealed aluminum line + miata engine

On a scale of 1 to 10, how f--king stupid am I for trying to do this:



on a balance shaftless vibrating turd that is the Mazda 1.6?

I see annealed aluminum used all the time on local cars for EFI, however, with people on here claiming their hard coolant lines have failed, I'm concerned I maybe building the car up only to have it burn to the ground.

I convinced myself it would be fine since the line is very short and rigidly mounted at both ends - flex isn't an issue.

-Zach
Attached Thumbnails
Annealed aluminum line + miata engine-46605_514270147962_162101051_30620039_978906_n.jpg  
thasac is offline   Reply With Quote
Old 07-26-2012, 06:02 PM   #2
Junior Member
iTrader: (4)
 
Join Date: Sep 2007
Location: Detroit, MI
Posts: 124
Total Cats: 0
Default

Quote:
Originally Posted by thasac View Post
On a scale of 1 to 10, how f--king stupid am I for trying to do this:



on a balance shaftless vibrating turd that is the Mazda 1.6?

I see annealed aluminum used all the time on local cars for EFI, however, with people on here claiming their hard coolant lines have failed, I'm concerned I maybe building the car up only to have it burn to the ground.

I convinced myself it would be fine since the line is very short and rigidly mounted at both ends - flex isn't an issue.

-Zach
Coolant lines usually see relative motion, so you don't have that working against you. How thick is your tubing? What fuel pressures are you going to run? What kind of aluminum are you using?

Or, instead of trying to engineer it, just go buy some SS braided hose along with some peace of mind.
zzyx7 is offline   Reply With Quote
Old 07-26-2012, 06:10 PM   #3
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,894
Total Cats: 109
Default

I have aluminum line running the full length of the car from fuel pump to regulator.

If you engineer it properly, protect it from damage, and inspect it regularly, I would say you will be fine.

There is nothing wrong with taking calculated risks when engineering a lighter, faster car. If it becomes a failure point, move up to stainless.

I know it is legal for the track use I am doing. Check to make sure it is legal for any track use you may do with the sanctioning body you participate in.
miata2fast is offline   Reply With Quote
Old 07-27-2012, 03:27 AM   #4
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,355
Total Cats: 1,322
Default

I wouldn't run it like that. Aluminum hardlines make me nervous as hell. Just buy a little piece of -6AN with a pair of 90s on it - you should be able to buy it pre-made even.
Savington is online now   Reply With Quote
Old 07-27-2012, 10:52 AM   #5
Elite Member
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,009
Total Cats: 583
Default

Aluminum is weak and subject to fatigue cracking. Hard lines that carry combustibles (gasoline or oil) and are subject to vibration should be steel.

Flexible lines are always a safe option too. If a line is subject to movement, it must be flexible. Keep in mind that AN fittings are made in both anodized aluminum and steel. Engine-mounted fuel lines should use steel AN fittings.

A hard aluminum fuel line mounted to the chassis is OK as long as it's reasonably protected.

All of the above is approved aircraft practice. FAA AC43.13-1B can be downloaded here and has a wealth of readable, useful information:

http://www1.airweb.faa.gov/Regulator...E?OpenDocument

Last edited by hornetball; 07-27-2012 at 11:02 AM.
hornetball is online now   Reply With Quote
Old 07-27-2012, 11:11 AM   #6
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,824
Total Cats: 1,781
Default

oh wait, we aren't talking about the dual feed itself
Braineack is online now   Reply With Quote
Old 07-27-2012, 11:37 AM   #7
Junior Member
 
Join Date: Jan 2005
Location: Fort Worth, Texas
Posts: 242
Total Cats: -1
Default

Quote:
Originally Posted by Savington View Post
I wouldn't run it like that. Aluminum hardlines make me nervous as hell. Just buy a little piece of -6AN with a pair of 90s on it - you should be able to buy it pre-made even.
I take it you don't fly?
fwMiata is offline   Reply With Quote
Old 07-27-2012, 12:23 PM   #8
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,894
Total Cats: 109
Default

Quote:
Originally Posted by hornetball View Post
Aluminum is weak and subject to fatigue cracking. Hard lines that carry combustibles (gasoline or oil) and are subject to vibration should be steel.

Flexible lines are always a safe option too. If a line is subject to movement, it must be flexible. Keep in mind that AN fittings are made in both anodized aluminum and steel. Engine-mounted fuel lines should use steel AN fittings.

A hard aluminum fuel line mounted to the chassis is OK as long as it's reasonably protected.

All of the above is approved aircraft practice. FAA AC43.13-1B can be downloaded here and has a wealth of readable, useful information:

AC 43.13-1B CHG 1 [Large AC. This includes Change 1.] Acceptable Methods, Techniques, and Practices - Aircraft Inspection and Repair
Don't get me wrong. I understand being safety conscious, but isn't that just a bit over kill?
miata2fast is offline   Reply With Quote
Old 07-27-2012, 12:51 PM   #9
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,091
Total Cats: 90
Default

Steel fittings are over kill, they dont see much bending loads so they wont see much fatigue loading except from the cycling of the fuel pressure. That line might have an issue but my gut doesnt say so, if it worries you, support it in the middle with a little bracket and a proper tube clamp support for that size. Yes aluminum fatigues, but if you limit the the fatigue stress you can achieve essentially infinite life, do you know how long it takes to reach 10^8 cycles for most cyclic loading scenarios?

And its annealed so its fatigue properties should be better than normal aluminum though to be honest, I'm not sure if you can even get non-annealed Al tubing.

Last edited by Leafy; 07-27-2012 at 01:48 PM.
Leafy is offline   Reply With Quote
Old 07-27-2012, 04:14 PM   #10
Junior Member
 
Join Date: Jan 2005
Location: Fort Worth, Texas
Posts: 242
Total Cats: -1
Default

Quote:
Originally Posted by miata2fast View Post
Don't get me wrong. I understand being safety conscious, but isn't that just a bit over kill?

No, and yes I would always use stainless for fuel on the engine. Braided would be a much easier choice though.

you are not fighting bending loads, you are fighting vibration.
fwMiata is offline   Reply With Quote
Old 07-27-2012, 04:17 PM   #11
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,091
Total Cats: 90
Default

That vibration is making the tube move in a direction consistent with a bending load, hence why I called it a bending load.
Leafy is offline   Reply With Quote
Old 07-27-2012, 05:33 PM   #12
Elite Member
 
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,476
Total Cats: 114
Default

Flex isnít an issue but vibration is very bad and aluminum not very fatigue resistant to high frequency vibration. I have cracked seemed steel hard lines used for turbo oil with similar length to that. Also interesting that one of my current work projects is measuring strain on fuel hard lines on a diesel engine and trying to come up with a mass damper system to keep them from cracking due to vibration.

FWIW my setup below.

Attached Thumbnails
Annealed aluminum line + miata engine-7379240122_large.jpg  
bbundy is offline   Reply With Quote
Old 07-27-2012, 08:55 PM   #13
Senior Member
 
Join Date: Aug 2010
Location: Maumelle, AR
Posts: 618
Total Cats: 2
Default

I bet that rail has a big enough Id for way more power than you'll ever make, likely bigger than your fuel line. Put a plug in it and don't worry about fuel distribution problems.. dual feed is always overkill for overkill sake, read the thread.
ianferrell is offline   Reply With Quote
Old 07-28-2012, 01:40 AM   #14
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: May 2005
Location: Mass.
Posts: 816
Total Cats: 41
Default

Thanks for the input guys. Its one of those situations where I think I could get away with it - for a while. This being said, I've gone out of my way to throw reliable parts at the car (minus the manifold, derk) so with that mindset, I should probably just switch it over to braided line and worry about other things.

It does look purty though

-Zach
thasac is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
elesjuan's mediocre 95 Miata adventure (google fiber edition) elesjuan Build Threads 8 02-16-2016 09:36 PM
NEW-Wiseco Piston, K1 Rods, Supertech Valves & Spring/Retainer, TB&C pedals Rudes333 Miata parts for sale/trade 17 11-05-2015 02:16 PM
FS/FT: 03.5 Mazdaspeed Protege leatherface24 Cars for sale/trade 15 10-16-2015 12:35 PM
1997 Miata Misty_Miata pineda92 Meet and Greet 4 09-20-2015 10:22 PM
New here, saying hi, here's what I'm workin with. SuperSneakySecretSquirrel Meet and Greet 5 09-06-2015 09:30 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 03:30 PM.