an explanation of bore scoring
07-04-2018, 05:59 PM
#17
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Charles, will you see the tell tale signs of bore scoring with a historical set of UOA data?
07-04-2018, 06:48 PM
#18
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07-04-2018, 07:08 PM
#19
Rennlist Member
I know Toyota has been using all aluminum engines for eons and has the process down pat. They are the leaders in the MMC arena for all-aluminum engines:
http://210.101.116.115/fisita/pdf/A065.pdf
This research paper discussed in great technical details why OEMs have pushed away from iron liners for all aluminum engines. This is a great read if you're into this kind of stuff (like I am):
http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf
Although old, this article does cover the main processes for blocks used by auto makers:
http://www.wardsauto.com/news-analys...s-strong-ideas
An even older SAE paper from 1995. I have a copy of this one in my library of SAE papers. Basically an engineering preview of the move to all aluminum engines and the benefits, including NSC coatings (nikasil):
http://www.ncccoat.com/pdf/engine-performance.pdf
07-07-2018, 11:32 PM
#20
Race Car
No expertise in the area so read all of these except the last one which wouldn't download. Seems the best bet for durability is iron or Nikasil liner, sloppy tolerances and heavy oil?
07-08-2018, 06:05 AM
#21
Rennlist Member
Having witnessed far too many people jazzing cold engines I don't have any surprise that modern tight tolerance engines develop these issues. I used to work with a guy who drove a lexus and he would redline the thing leaving the parking lot at the end of the day regularly. It can't be all operator error but it would only take once...
07-08-2018, 06:36 AM
#22
Rennlist Member
04-28-2019, 11:48 PM
#24
I was planning on driving my 991.1 C4S year round including the cold Canadian winter, temps -20C or -4F sometimes colder but now reading about this issue is making me think twice.
Car is garaged overnight so will have better temps to start but will sit outside during the day and cold start in the evening when I leave work. Should I be leaving it for only "warm" winter days? Changing oil weight to 0-W40 for winter may make a difference (or not if the cylinder clearance is the big issue?).
Car is garaged overnight so will have better temps to start but will sit outside during the day and cold start in the evening when I leave work. Should I be leaving it for only "warm" winter days? Changing oil weight to 0-W40 for winter may make a difference (or not if the cylinder clearance is the big issue?).