tkoral 6 Posted October 4, 2016 Report Share Posted October 4, 2016 I can't seem to decide which of the two I should go with. Schimmel main bearings have oil grooves on both halves where oem only has it on one bearing half. I'm just worried of what the schimmel bearings are made out of compared to the oem material. Any advice or info will be greatly appreciated. VR6Pete 1 Link to post Share on other sites
VR6Pete 1,455 Posted October 4, 2016 Report Share Posted October 4, 2016 5 hours ago, tkoral said: I can't seem to decide which of the two I should go with. Schimmel main bearings have oil grooves on both halves where oem only has it on one bearing half. I'm just worried of what the schimmel bearings are made out of compared to the oem material. Any advice or info will be greatly appreciated. What type of application are you putting these into ? Usually Scimmel are highly regarded so wouldn't have any doubts over the quality, if you are not going with a high performance application then stick with OEM Link to post Share on other sites
tkoral 6 Posted October 5, 2016 Author Report Share Posted October 5, 2016 Application is a aaa 93 slc with 140k miles. NA I just had my whole head freshly rebuilt with new drc268s and super tech valves. I wanted to rering the block as well along with new bearings and arp hardware. I am on the fence with boost due to financials but when the time comes I would want my motor to be ready for it. Thanks Link to post Share on other sites
VR6Pete 1,455 Posted October 5, 2016 Report Share Posted October 5, 2016 I have a boosted application - 294BHP and running standard OEM bearings. I dont see any advantage with going with schimmel in this instance. Link to post Share on other sites
RBPE 198 Posted October 5, 2016 Report Share Posted October 5, 2016 A bit of extra lube is always good! I can't see why a decent aftermarket tuner like Schimmel wouldn't do their homework in part development, probably a lot better than oem! Not sure why oem has such a high regard either, when I researched the material specifications VAG used for engine parts in manufacturing, it was your typical cheap ass factory vehicles way! Engineer's might want to use top spec material but the money men get involved, spec the preferred material down for cost to the point it just about does the job it is intended for and then use that material/forgings etc across the board on other cars to save further costs! Really was poor compared with what you can spec up in aftermarket and the custom materials you can get nowadays! tkoral 1 Link to post Share on other sites
tkoral 6 Posted October 7, 2016 Author Report Share Posted October 7, 2016 Thanks for the input VR6Pete that makes sense RBPE I always thought oem was had better material than most other manufacturers. I am currently looking into Calico bearings... Anyone ever have any experience with those? From what I've read they seem reassuring. Link to post Share on other sites
RBPE 198 Posted October 8, 2016 Report Share Posted October 8, 2016 (edited) Material spec and manufacturing processes can vary massively and a lot of the time you have to do a lot of deep research into the oem suppliers manufacturing processes to get the in's and out's - everything else is hear say really! In researching some aftermarket companies they had a lot of info about their various "new tempering techniques" and slight alloy changes that offer greater resilience for x, y or z in application with test results. Prime example was one company offering their new hybrid alloy for pistons - they had test data for 4032 and 2618 alloys against their's and it was interesting to see, re:2618, that although harder and generally considered more durable at the expense of the rattling you get as the material expands, the 4032's fared slightly better at the sustained temperatures that are often encountered/were tested to replicate an engines operating cycle. In short the 2618's fared up slightly better apart from long term at full temp in an engine cycle where the 4032 took over slightly. So although 2618 might be harder and more resilient in most circumstances - with the downside being they rattle more due to expansion differences over 4032 - at prolonged temps 4032 was better. You then balance that with your intended use! Of course their custom material outperformed both, not only due to the material but also the manufacturing used, but it certainly wasn't cheap! Take rods as well for example; I think (was 5+ years ago) that I read that the rods on the Audi's were made using AISI 4130 whereas you see the modern aftermarket ones are usually 4340. They also all seemed to use the same material from 1.4 to 3.2 if I remember right. Now if you look at the hardness variances (HRc below) and imagine that it takes, say an additional 2 hours to machine whatever cast or forged part made in such a harder material, then times that by 20,000 cranks/pistons/rods etc there's a lot of labour hours stacking up there! So if they test the engines cycles over many miles and a lesser material holds up, which is often cheaper due to the alloying/manufacturing before you even get to parts moulding and machining variances mentioned, then the money men at a major manufacturer will go with that - simply to save all these millions of pounds in costs! http://www.westyorkssteel.com/alloy-steel/oil-and-gas/aisi-4130/ http://www.westyorkssteel.com/alloy-steel/oil-and-gas/aisi-4340/ So - to answer your questions - yes, stock bearings can and will hold up, depends on how much you are pushing your set up within or outside of factory specifications - additional heat and stresses and strains under forced induction I would think about upgrading or adding a coating for better protections against loads, be that thermal resilience or stresses and shearing forces! OEM can be fine as Pete said, it's more tolerances being out and old engines that would destroy your engine anyway due to the magnitude of additional stress placed on it! That's why I recommend you never just stick in forged parts without refreshing all others and re-building the engine properly - something may have a better HRc but a 1mm variation can add huge amounts of stress comparatively! Aftermarket ones that are coated are usually done as people have researched basically what I have said, make sure it's a proper coating and not just paint or something but it should usually tell you on the websites of sellers. Co's like 034/USP etc have very much likely done what I mentioned above in research! Apart from that and "I've used them and they have held up right" which most of the ones you are looking at will be fine for if said co. has done it's homework, it can be a long winded answer to tell you the facts as I just gave you an overview on - you're engine builder or how it is put together could destroy your engine and spin a bearing which has nothing to do with material spec then! Do all your research on these things though and you'll be fine! Edited October 31, 2016 by RBPE Link to post Share on other sites
RBPE 198 Posted October 8, 2016 Report Share Posted October 8, 2016 (edited) P.S. I can't wait till carbon nanotube technology comes into play in the aftermarket scene! Edited October 8, 2016 by RBPE Link to post Share on other sites
tkoral 6 Posted October 14, 2016 Author Report Share Posted October 14, 2016 That was quite a bit of info RBPE really appreciate all of that info! RBPE 1 Link to post Share on other sites
Recommended Posts