Crank Bearing material |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Crank Bearing material |
malcolm2 |
Dec 13 2019, 08:29 AM
Post
#1
|
Advanced Member Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
WHat is the difference, or benefit of using Bronze (edit below) main bearings vs "steel backed".
I am building a daily driver, not a race car, so I am after long lasting, good quality. EDIT... oops. I asked the vendor, they really don't know what the difference in material is. and it turns out BRZ in their description means Brazillian. So they question may or not be about material, but it is still: "Is there a difference or benefit to BRZ bearings?" THanks |
Superhawk996 |
Dec 13 2019, 12:27 PM
Post
#2
|
914 Guru Group: Members Posts: 6,469 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
In theory steel backed bearings are supposed to help distribute the bearing load better and prevent some of the "pounding" that will elongage the main bearing bore on the case.
No so much a concern at stock HP levels. With a big bore there are a lot of other incremental forces at work (increased RPM's, increased rod & piston inertias from big bore pistons, etc.) and I'm not sure that steel backed would really help under those conditions. |
Mark Henry |
Dec 13 2019, 02:27 PM
Post
#3
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
Only steel backed babbitt coated are available as far as I know for our engines . The bearing center main are steel, copper alloy and then lead alloy babbitt coatings.
For a while early 2010- during the bearing shortage, there was aluminum backed center mains, don't use them. Bearings are soft babbitt for a reason, it's considered a sacrificial surface. FOD will to a point sink into the surface and if metal to metal happens hopefully the crank journal won't be damaged. Cranks have to run on dissimilar metals, one hard (crank or cam) and the other a softer metal. This prevents galling if low oil pressure happens. Cams run at only half the speed of the crank, The T4 has bearings, but engines like the 996 the cams run right on the alunimum casting. |
Lo-Fi Version | Time is now: 27th September 2024 - 05:49 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |