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914World.com _ 914World Garage _ Ghetto engineering - Master cylinder style
Posted by: Mikey914 Aug 31 2017, 11:43 PM
As may of you know we are in the process of producing master cylinders. Unlike some vendors with impeccably clean "Laboratory " complete with Periodic table. This is how we get things done.
Phase 1
We have a test bed that simulates braking, and are looking to see where our weak points are. We will put no less than 25,000 cycles on this part. This will take awhile as we can only get about 200 at a time without the motor heating up, but believe this to be a very rigorous test.
Phase 2
If we make it to 25,000 we will start measuring output from the pressure lines. This will be thoroughly broken in system we will be testing, not just testing with air pressure.
After the final round of testing we will tear it down to determine wear on critical components and examine the seals to see how well they have held up. If they show excessive wear we will look at improvements that may need to be made. Especially so if we don't make 25,000.
My only serious concern is that the metal on the test stand may fatigue making us repair it before we hit 25,000 cycles. We are currently a little less than 5000 cycles.
I thought I'd share this as many of you don't realize what we do behind the scenes t o actually make the parts we all need.
https://youtu.be/UskyAeVAF9Y
https://www.youtube.com/watch?v=UskyAeVAF9Y
Posted by: Andyrew Sep 1 2017, 06:18 AM
How about you put some aluminum fins on the motor and put a fan flowing on it? Also maybe one of those home timers that can cycle something every 15 minutes so its not pumping for hours at a time? Your going to create heat that the MC was never designed for.
Posted by: mb911 Sep 1 2017, 06:50 AM
How about you put some aluminum fins on the motor and put a fan flowing on it? Also maybe one of those home timers that can cycle something every 15 minutes so its not pumping for hours at a time? Your going to create heat that the MC was never designed for.
Posted by: saigon71 Sep 1 2017, 06:50 AM
Love it! 
Posted by: GeorgeRud Sep 1 2017, 07:51 AM
Well, at least the flexing of the stand helps replicate the flexing of the body over these 40 something years of use. 
Thanks for sharing the testing video.
Posted by: tygaboy Sep 1 2017, 08:39 AM
I have a few spare wiper motors... 
Can you say "Electronic Power Brakes"?
Posted by: Elliot Cannon Sep 1 2017, 09:41 AM
Your test devise sounds like my heart when I wake up in the morning. 
Posted by: KELTY360 Sep 1 2017, 09:53 AM
That's a really boring video. Maybe if you had a girl in a bikini fanning the motor it would liven things up. 
Posted by: Mikey914 Sep 1 2017, 10:07 AM
Your test devise sounds like my heart when I wake up in the morning.
Elliot "Jarvack"
We actually thought about the additional heat, knowing that this would exceed normal use is actually a plus for us. Also one of the reasons we wanted to do an analysis of the unit after the test.
We may also go to a larger motor and let it run til it fails. The kill switch is the brake warning switch. Although I'm pretty sure the stand would fail 1st.
Posted by: 914Sixer Sep 1 2017, 12:25 PM
Probably a more vigorous testing setup than the industry standard and thousands of dollars less in costs. 
Posted by: PanelBilly Sep 1 2017, 01:04 PM
Move this thread to the sandbox and I'll post some photos of machine that will work the brake back and forth much faster. 
Posted by: bigkensteele Sep 1 2017, 04:17 PM
I love it. Good engineering is the exercise of creatively solving a problem, not necessarily spending a ton of money to solve a problem. Or at least I think I remember hearing that in an episode of McGyver.
Posted by: Dr Evil Sep 2 2017, 09:45 AM
Awesome, but needs over dub with porno music and sound effects.
Posted by: Mikey914 Sep 2 2017, 09:48 AM
Yes Brown chicken brown cow
Posted by: bdstone914 Sep 2 2017, 09:49 AM
I think you are going to metal fatigue the pedal set housing based on the amount of flex that is happening. Support at the master cylinder will reduce that.
Posted by: Mikey914 Sep 2 2017, 10:23 AM
Figured I'd see what broke 1st.
Posted by: ConeDodger Sep 2 2017, 02:31 PM
My experience with not just our 914 Master cylinder but in general is they don't fail because of use, they fail because of disuse. The sit with the piston in one place for long periods and it results in corrosion, particularly if the system isn't bled in a timely manner.
As for posting this in the Sandbox, someone's been watching too much porn...
Posted by: timothy_nd28 Sep 23 2017, 09:25 PM
Is this thing still chugging away or did something break?
Posted by: porschetub Sep 23 2017, 09:31 PM
My experience with not just our 914 Master cylinder but in general is they don't fail because of use, they fail because of disuse. The sit with the piston in one place for long periods and it results in corrosion, particularly if the system isn't bled in a timely manner.
As for posting this in the Sandbox, someone's been watching too much porn...
Not sure appears some (URO) last a shorter time,nothing wrong with this test IMO and nice to see someone doing it...appears some don't bother...did I mention that before
Posted by: Mikey914 Sep 23 2017, 10:08 PM
Broke somewhere around 10k. The weld broke. Kept cycling but not a full pressure as the plate flexed at the weld.
The EURO one I put on my car lasted 5 cycles.
Posted by: AZBanks Sep 23 2017, 11:04 PM
Your testing is 100% unrealistic and not related to any 914 known to man...
I don't a single speck of rust anywhere.
Posted by: euro911 Sep 23 2017, 11:11 PM
Posted by: r_towle Sep 24 2017, 09:28 AM
Awesome to see, and great backyard engineering!
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