I have a feeling GM is going to keep making pushrod v8's until the eventual death of the internal combustion engine.

This comment made me question the specifics of my mental model pushrod vs overhead cam engine. I found this site that has three nice gif’s which was exactly what my visual brain wanted to see for comparing the differences - https://www.samarins.com/glossary/dohc.html

Thanks for the comment as it was the impetus for me to expand my engine knowledge today!

	▲	sedawkgrep 2 hours ago \| parent [-]
		Thanks for the link. Like you, it really helped me understand what's going on with all three of the designs shown.

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Zak 4 hours ago | parent | prev | next [-]

I used to view them with disdain - a clearly obsolete design GM kept using because they're cheap or lazy or some such.

I no longer hold that view. GM's pushrod V8s are considerably smaller than their competition, and lightweight relative to their displacement, for which there is famously no replacement.

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olyjohn 2 hours ago | parent [-]

Turbos are the replacement for displacement.

	▲	throwawaylaptop an hour ago \| parent [-]
		Ok, stick a huge turbo on a 100cc engine and power my 1 ton pickup please. Id like it to feel quick in traffic but also tow a few thousand lbs uphill without really noticing it.

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potato3732842 5 hours ago | parent | prev [-]

Someone will, because it's a useful form factor. And that someone is gonna be the people who are the experts in it, which is pretty strongly arguably GM.

There have been sooooo many SBCs shat out into the world in industrial applications that even if GM stops making them someone will keep making them. You can't make a compatible single replacement because you'll break a ton of applications. You can't make a ton of different replacements because that's not economical. Only makes sense to keep making them.

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officeplant 5 hours ago | parent | next [-]

>Someone will, because it's a useful form factor.

Definitely, and the old carborated beasts just work and can be fixed with minimal tools and ran off of just a few wires.

I've been enjoying watching a coworker resurrect his M715 Military Truck (basically a government J-Series truck from Kaiser/Jeep) with a fresh blueprint SBC and a mix mash of GM and aftermarket drive train parts.

It may be the least efficient truck I've ever ridden in, but it can reliably pull tree stumps out of the ground.

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bluedino 5 hours ago | parent | prev [-]

> And that someone is gonna be the people who are the experts in it, which is pretty strongly arguably GM.

They were, at least.

Massive recall on the 6.2L versions of their V8 engines right now.

https://www.lemonfirm.com/blog/gm-6-2l-engine-recall-what-tr...

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potato3732842 5 hours ago | parent [-]

A lot of bigger engines are running right on the edge of oiling problems these days. With fuel economy rules being what they are it's just how it is. GM isn't special in this regard. Ford is killing a lot of cams and lifters (a problem GM fought through some years ago).

Meanwhile Toyota[1] is recalling blown up turbo v6s left and right (for problems that you can't just dump different oil in to solve) because they didn't invest in keeping a big v8 on the cutting like GM did and they didn't invest in making small turbo stuff last long like Ford did.

[1]Mentioned not because they have unique problems but because who if not a Toyota fanboy makes a comment like yours

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officeplant 5 hours ago | parent | next [-]

To be fair Ford's small turbos are also notorious for shitting the bed, but mostly due to cooling system failures or the terrible choice of still running a timing belt. (1.0L Ecoboost engines)

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6SixTy 4 hours ago | parent | next [-]

Ford's big mistake with the 1.0L Ecoboost wasn't exclusively using a timing belt, it was using a timing belt submerged in oil. They did state that they engineered the rubber to withstand being submerged in oil, but ultimately it didn't really work out like they had hoped.

	▲	olyjohn 2 hours ago \| parent [-]
		Lol. The most insane thing about the 1.0 is that they switched back to a timing chain due to the belt issues. But guess what? The fuxking oil pump is still driven by a rubber belt submerged in oil... And guess what happens to the oil pump belt? Just mind blowing that they would half ass this fix so badly.

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potato3732842 4 hours ago | parent | prev [-]

>terrible choice of still running a timing belt. (1.0L Ecoboost engines)

3.0 Duramax says hold my beer (for the readers not familiar, it has a wet belt driving the oil pump and it's mounted in the back making proactive replacement prohibitively expensive).

My jaded take is that they're sticking with the wet belt on what's generally a europoor economy car engine in order to force planned obsolecense.

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paddy_m 4 hours ago | parent | prev [-]

I’d love to read about how emissions / fuel economy is causing the oiling problems. Any articles?

Would putting an aftermarket oil pump in these modern engines protect them or is it a deeper design issue?

	▲	potato3732842 4 hours ago \| parent [-]
		https://www.youtube.com/watch?v=pbEdr6Q6cKw They spec the thinnest stuff they can get away with to add .0001mpg. Multiply that by all the Chevy 1500s GM makes or F150s Ford makes and you see the draw. Sometimes it turns out that the thinnest stuff they can get away with just not quite thick enough at the margins or in transient conditions. And of course they stretch out the oil change interval to reduce on-paper TCO as well which doesn't help. You can mitigate this with thicker oil (what GM did for the recall) by can go too far and create other oiling issues because thick oil drains back slower and going to some super high spec 0-W-<whatever> Euro oil may cause other problems related to soot and sludge so there's no silver bullet. The "safe" advice most people give out is to use whatever the <nation with no emissions or fuel economy rules> version of your owners manual says to use for oil. And if you have a high strung turbo engine you ought to take your oil change intervals seriously.