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It requires detailed training to build/rebuild an engine from scratch as well. Making sure the clearance tolerance for the bearings, valves, and a bunch of oth

by Washuu 5y ago

It requires detailed training to build/rebuild an engine from scratch as well. Making sure the clearance tolerance for the bearings, valves, and a bunch of other critical stuff are correct. Accounting for how much the piston rod expands and contracts under load.(The rod will lengthen slightly at the top of the stroke.) Bolts for the bearing caps and cylinder head must tightened in a specific pattern and in iterative amounts of torque. Get some of this wrong and the engine self destructs. In the worst case hot internal parts of the engine exit the engine and cause a fire. Porsche had an issue where they used some bad bolts causing catastrophic engine failure and several vehicles to burn on their GT3 line. https://www.motorauthority.com/news/1090959_porsche-fires-every-911-gt3-engine-will-be-replaced https://www.motorauthority.com/news/1090959_porsche-fires-ev... Basically, there are many components on cars that require specialist skills to get right every time.

MikeBVaughn 5y ago
Woah, that's wild. Is a screw-up that universally catastrophic across engines? My very, very naive understanding of cars is pushing me towards thinking that a homologation version of a GT3 car is sort of an extreme outlier, but I know very little about engines, and my intuition is almost certainly way off.
- analog31 5y ago
  How often do cars get an engine rebuild by a local mechanic these days? When the timing chain failed in my Saturn, a new engine was more than the car was worth.
  - MikeBVaughn 5y ago
    That's a good point; my VW GTI got one at a local shop under insurance a few years back. The turbocharger wasn't hooked up quite right the first time. It wasn't a severe issue - the engine was just noticeably less powerful. Luckily it was a quick fix and they were very good about rectifying the issue, but yeah, what you're saying checks out, even in the outlier cases where a fix is covered. (Humorously, in a chain of weird luck, I also had a full rebuild of a regular Golf engine in the same five year span, but that one was done at the dealer.)
  - mgarfias 5y ago
    I’ve got an LS6 build in process right now. Lots of us do it on the regular. It’s not that common with shitboxes, but even then it happens. We swapped my kids Honda Civic’s head about a year ago after a blown head gasket.
  - King-Aaron 5y ago
    I've just finished rebuilding my BP4W race engine for my mazda. It seems like an annual event for me considering the amount of power I'm pushing through the poor thing.
- coryrc 5y ago
  Rare. More common in high-performance because they're pushing the limits.
- 14 5y ago
  No it is not universal think of all those beater cars you see on the road they don’t need the precision as a 300+ hp car. Just keep adding oil. Also people do things like valve adjustments because they can be out by a certain factor and still run just with decreased performance. Obviously you can have certain aspects of an engine that will later prove to be fatal but there are lots of engines that run like crap and get people from A to B just fine. I am not saying some precision isn’t needed but for a lot of applications it is somewhat forgiving.
aetherspawn 5y ago
Right, and in my experience they get it wrong more often than not on ICE cars, but the result is an engine with poor fuel economy that smells, knocks, throws a rod or runs roughly, not the whole car spontaneously catching fire and melting into a puddle.

by Washuu 5y ago

MikeBVaughn 5y ago

Woah, that's wild. Is a screw-up that universally catastrophic across engines? My very, very naive understanding of cars is pushing me towards thinking that a homologation version of a GT3 car is sort of an extreme outlier, but I know very little about engines, and my intuition is almost certainly way off.

analog31 5y ago
How often do cars get an engine rebuild by a local mechanic these days? When the timing chain failed in my Saturn, a new engine was more than the car was worth.
- MikeBVaughn 5y ago
  That's a good point; my VW GTI got one at a local shop under insurance a few years back. The turbocharger wasn't hooked up quite right the first time. It wasn't a severe issue - the engine was just noticeably less powerful. Luckily it was a quick fix and they were very good about rectifying the issue, but yeah, what you're saying checks out, even in the outlier cases where a fix is covered. (Humorously, in a chain of weird luck, I also had a full rebuild of a regular Golf engine in the same five year span, but that one was done at the dealer.)
- mgarfias 5y ago
  I’ve got an LS6 build in process right now. Lots of us do it on the regular. It’s not that common with shitboxes, but even then it happens. We swapped my kids Honda Civic’s head about a year ago after a blown head gasket.
- King-Aaron 5y ago
  I've just finished rebuilding my BP4W race engine for my mazda. It seems like an annual event for me considering the amount of power I'm pushing through the poor thing.
coryrc 5y ago
Rare. More common in high-performance because they're pushing the limits.
14 5y ago
No it is not universal think of all those beater cars you see on the road they don’t need the precision as a 300+ hp car. Just keep adding oil. Also people do things like valve adjustments because they can be out by a certain factor and still run just with decreased performance. Obviously you can have certain aspects of an engine that will later prove to be fatal but there are lots of engines that run like crap and get people from A to B just fine. I am not saying some precision isn’t needed but for a lot of applications it is somewhat forgiving.

aetherspawn 5y ago

Right, and in my experience they get it wrong more often than not on ICE cars, but the result is an engine with poor fuel economy that smells, knocks, throws a rod or runs roughly, not the whole car spontaneously catching fire and melting into a puddle.