Why do interference engines exist?

>>13984896
Because reasons

>>13984896
More valve lift. If you're not a retard you shouldn't have a problem with your timing belt breaking anyway.

>>13984896
because it means you can get more valve lift, more compression and thus more power from the same physical size and even same head/block castings just new camshafts and valve springs.

them darn libruls gonna keep messin round and we aint gonna have no more 350s to haul up back the el camino because obama sucks and ted nugent guns. fuck yea

>>13984934
a lot of faith in a flimsy rubber band

>>13985012
>Gates belts
>flimsy
nigga
pls

I'd rather have a belt I can replace only twice as often, than a chain that I can't without tearing everything apart.

>>13984951
this desu also because pedestrian safety

>>13985012
If it's so flimsy you'll be fine if I hang you with it?

>>13984951
hwut?

>>13984896
The real question is, why do interference engines come with timing belts? Sure timing chains can break, but they are far less likely to.

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>2 valve per cylinder

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>>13984934
>owning a car with a timing belt
nigga.

>>13984896
Muh compression ratio
Muh valve lift
Pretty much any high performance engine is interference design.

Because they are better.

More lift, tighter timing, more compression = more efficient engine.

Basically every car made in the last 10 years is interference. Probably even longer than that.

>>13987500
Subaru boxers are non interference

>>13987471
Timing belts are easier to design and service.

>>13987520
ha. Okay. Ask someone who does timing Belts on Audis.

>>13987523
I won't ask someone who does service about why the timing belt approach is used.

>>13987502
They are absolutely interference. One look at the combustion chamber of an EJ would tell you that.

The squish zone are like 5mm from the seated valves.

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>>13987523
>he thinks this is easier to service than a timing belt

>>13987529
well apparently according to you, they're easier to service. So...you can feel free to ignore the fact they're not. Doesn't change reality. Timing belts are fucking pleb tier design. All it is is making sure you get work for your service centers.

>tfw dodge 360 has timing gears

>>13987537
There is nothing simple about Audi V8s. Btw, that is the REAR of the engine too.

>>13985187

Kek

>>13987500
>Basically every car made in the last 10 years is interference

Objectively wrong across so many planes of reality.

Vast majority of Toyota and Mazda engines are NI.

>>13987531
well I ran an EJ without setting the timing just to make sure it had oil pressure. Didn't smash any valves.

>>13987562
>you're wrong!
Except I'm not.

>>13987491
12v Cummins would like a word with you

>>13987537
>>13987555

Shitty engineering requires timing CHAIN services. The main benefit of a timing chain is that it's designed to last the lifetime of the engine. Failing that, it should last significantly longer than a belt, and is usually paired with a heavier water pump to compensate.

Audis are poorly designed and prone to failure, which is why their chains require frequent service. They are designed for performance alone, not longevity. There is really no good reason they couldn't use a belt, considering they manage to negate the inherent benefits of a chain.

>>13987568
sohc?

>>13987583
yeah

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>>13987571

>I'm right
>no you're wrong, I'm right
>no actually I am correct
>no you're wrong, I'm still right
>you are not right, I am
>you are incorrect, I am correct here
>you aren't right here, I am
>no I am correct, you are wrong

>>13987580
>designed to last the lifetime of the engine.

Hey anon, whats "the lifetime of the engine" a thousand miles? a hundred thousand miles? a million miles?

whats "a lifetime" when you can replace seals and bearings?
whats "a lifetime" when you can replace cams, pistons, valves, cranks, blocks.

>>13987595
well I've seen Ford Triton motors without chain service go past 800k so...a million is a good number?

>>13987587
thats why

>>13984896
isnt that why pistons are dimpled?

>>13987621
in some cases thats done to maximize how much they can close the gap in engine operation. But if the timing is off, they'll still smash together. This is perfect mechanic timing shit. The valves move as the piston is moving away and the cuts are there to make that as tight as possible.

>>13987578
>truck engines

i guess its a truck so the simpler the better

>>13987636
2 valves generally make for more low end torque. Not every world calls for 5 valves per cylinder and 12:1 compression ratios.

>>13987621
yes and no.

they have valve reliefs so you can maintain the proper timing and/or lift after you've decked the head, or added a new camshaft, or high comp pistons, or any other reason the piston would be close to the valve.

but that isn't going to stop a valve from dropping if your timing belt snaps with a valve wide open.
an interference engine will only interfere if the timing gets radically messed up. a non-interference will never interfere no matter what unless you modified your engine.

basically all modified engines are interference it's unavoidable. if you want the most power out of your engine it has to be interference. which is a none issue for people who maintain their timing systems.

>>13987595

A lifetime is what a manufacturer reasonably expects an engine to last (in terms of mileage) before a major rebuild is required. This would mean taking apart pistons and replacing rings, replacing seals, head gaskets, possibly new sleeves, etc.

It would be significantly longer for a Japanese vehicle than it would for a North American or European vehicle, with the exception of some older Volvos.

>>13987605

Tritons were objectively some of the worst engines ever produced by FoMoCo. There is literally no argument you could ever present at any time in human history that would ever refute this. It is the most absolute fact that has ever been. Seriously nigger, you'll implode the universe if you even try.

>>13987646
I own 3 of them. Endlessly reliable engines.

https://www.youtube.com/watch?v=3zd-hMXeMoA

>>13985025
Some belts aren't that easy to get to either.

>>13987643
>2 valves generally make for more low end torque.

no they dont

>>13984935
How much more?

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>>13987643
>2 valves generally make for more low end torque
ok

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>>13987662

Literally some of the worst engines Ford has ever made. The 4.6 and 5.4 modular are fucking TERRIBLE designs.

Enjoy your seized spark plugs, or having them blow themselves out of the engine for no fucking reason.

But hey, specialized tools to change spark plugs on a work vehicle are normal, right? And being forced to pay a dealership $1000 for something so routine is just the norm, right?

Super great engines my ass. You're a fucking idiot if you don't realize that you've just been extremely lucky not to encounter these massively common problems, which are endemic to the Tritons. They are shitty engines, period.

>>13987676
its the same as how with all other things being equal an i4 will make more torque than a v8, but the v8 would make more power

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>>13987683
i bet this dumb ass is not trolling

>>13987662


As per an actual ford tech:

A Ford Motor Co. warranty inspector says the Ford Triton V-8 engines are "dropping like flies" because of blown spark plugs and a Ford Dealer technician wants his customers to know it's not his fault.
"I am a Ford dealer technician. I would like to address the Ford spark plug blowout issue," the technician wrote as he was working on a Ford vehicle that had blown a spark plug out of its aluminum head.
"I would like the customers to know that it is Ford's defective engine design and not the fault of the technicians or dealerships," said the technician, who asked that his name and hometown not be used for fear that he would be fired if his identity was made public.
He had this warning for Ford truck owners: "The warranty inspector from Ford told me the 5.4-liter engines are dropping like flies referring to spark plug blowouts."
Despite spark plug problems in the Ford Triton engines, our Ford technician said his "hands are tied by Ford and Ford decides what it will and won't pay for even when people have warranties."
The Ford technician told ConsumerAffairs.Com that the Triton engines are very difficult and time-consuming to repair. He accused Ford of squeezing mechanics in the repair process with "insufficient flat rate times," and said, "the techs end up working free hours."
"It is not on our shoulders to repair these problems at our expense," he wrote, "even to keep a customer. I can tell you that we are seeing spark plug blowouts more and more often. At times 3 or 4 vehicles a week."
The Ford policy, he complained, unfairly paints the technician as the person refusing to stand behind the Ford product.
"The customers need to understand that these poorly designed engines are a huge burden on the people that fix them and I am tired of subsidizing Ford like some kind of welfare," the technician wrote. "The people that are fixing these engines are not at fault but we get beat up by the customers."

>>13987545
>well apparently according to you, they're easier to service
Not just me, every engineer who ever chose to use one.

>>13987678
broken spark plugs are isolated to the 5.4 3V, which have been recalled and you get your plugs replaced for free with a improved one piece design. Spark plugs blowing out are caused by moron mechanics that don't know how to use a torque wrench and destroy the threads in the aluminum heads.

The only major issue they all have is the intake manifold coolant crossover was made of plastic on the earlier motors and is prone to cracking. All newer motors and replacement manifolds use a cast aluminum crossover.
Other than that, I have three, 2 with over 200k, 1 with over 300k. All have had the intake manifolds upgraded and thats all the issues there ever were.

>>13987580
>The main benefit of a timing chain is that it's designed to last the lifetime of the engine
Nearly impossible to do.

>>13987669
>>13987676
>valve design can't change an engines powerband!

Are you retarded? It's common knowledge that all things being equal less valve area will give you more low rpm torque.

>>13987683
>i4 making more torque

that doesn't happen very often.

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>>13987615
soch ej25
bearing locked up snapped bolt bent 2 exhaust valves.
Subaru... never again

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>>13987699

All this damage control. You still haven't refuted that the engines are a shit design, you've just stated a half-assed remedy that took Ford years to formulate.

They are not "endlessly reliable" engines by any means; they're throwaway trucks designed to last 5-7 years at best. After that it's a gamble as to what will break next, or if it hasn't broken already. They are almost guaranteed to kill their torque converter past 200,000km, destroy joints, wear out breaks prematurely, kill fuel pumps...and not to mention the overall CHEAPNESS of the materials used. The plastics are all so flimsy and junky, they snap and scratch from normal use.

There's a reason Ford sells so many F-150s. They sell in volume because they make them so cheaply. They make them cheaply because they're poorly made and use low-grade components.

Your trucks are shit, deal with it faggot. Not gonna convince anyone here that Ford makes a quality product.

Also, kek at this:

>Spark plugs blowing out are caused by moron mechanics that don't know how to use a torque wrench

They are absolutely NOT caused by the techs. They are caused by a shitty aluminum head used by FORD.

>>13987705
only because it flows worse, which means gasses have a higher velocity

its like saying "premature ejaculation is good because you reach your orgasm faster"

if an engine is modifed in its optimum range given it design a 4 valve wil flow better at low end and at higher rpm

>>13987725
The Ford shop manual calls for 12 ft/lbs on the spark plugs. One click only. I've must have been doing it all wrong because out of the dozens of Triton motors I've worked on, none have ever blew out their plugs. Ford wouldn't sell as many trucks as they do if they weren't dependable. Btw, that picture isn't of "ejected" spark plugs, those are the ones that snap in the 5.4 3V if they have not been replaced before the recommended change interval, carbon builds up around them and seizes them in. So far we've isolated the issue to..incompetent technicians and people who don't service their vehicles.
>km
oh now I understand.

>>13987732
no one said 4 valve wasn't better.
but 2 valve will make more torque.

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>>13987491
8v B230FT would like to have a chat with you too...

>>13987747
only if its tuned to sacrifice all top end power

>>13987754
that's basically how truck engines are designed. Both gas and diesel. You want lots of low end torque. Nobody is revving them out.

>>13987743
>Ford wouldn't sell as many trucks as they do if they weren't dependable.
Yes they would. It's called marketing.

>>13987766
For a new product sure, but they've been the best selling pickup brand for decades. If they sucked, people wouldn't keep buying them. They obviously still do in massive quantities.

>>13987747
>no one said 4 valve wasn't better.
>but 2 valve will make more torque.
No it won't. All things equal, the 4 valve will have a wider toque curve, as the smaller valves allow a higher velocity over a wider range for a given area..
>>13987732
>>13987754
This.

>>13987758
Then how come truck engines have been 4 valve for a long time now?

>>13987779
there's more to designing an engine than just power. You gotta consider running costs and reliability. In a vehicle that is meant to work, those are important factors. With 2V designs you have a less complicated engine with less parts. And it also gives you the torque characteristics you desire. It is right for its application.

>>13987689
>>13987711
its the same as with all things being equal a 2v will make more torque than a 4v and the 4v will make more power. its like you've never resarched on how surface area effects power production inside an engine.
but as we all know the best engine is always a 4.0L inline six with gear driven dohc

>>13987787
fuel economy and emissions have become a greater concern for diesel and large displacement engines. Engine designers have had to balance all sorts of things. Yes its hard to find a 2 valve now, but it was very common 10 years ago. Now we got all sorts of smart engine management so you can still get the type of engine performance you want.

>>13987798
but all things equal is retarded, you dont tune a 4v as you would tune a 2v

the advantage of a 4v is that intake port volume stays low, but you have two of them

as this guy said >>13987792 the advantage is cost and simplicity

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>>13987792
>With 2V designs you have a less complicated engine with less parts.
I don't disagree, but even semi trailer prime movers have been fitted with 4 valve cylinder heads for the last thirty years, without any inherent issues with valve train failure due to configuration.
>And it also gives you the torque characteristics you desire. It is right for its application.
Disagree with this one, given you can achieve just as great a peak at a similar RPM with a multi valve setup, with the advantage of more torque either side of the peak.

>>13984896

Interference engines are fine...

Interference engines with timing belts is the stupidest fucking thing on the planet

>>13987836
Every engine has its characteristics for a reason.
Many of the smaller diesels from the 90s have 2 valves, like the 7.3 Ford/International. Cost is another factor. 4 valves means doubling (more or less) the moving parts in your valve train.

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>>13987806
>Yes its hard to find a 2 valve now, but it was very common 10 years ago.
I can't think of too many commercial highway engines in the last 30 years with less than 4 valves, and hell, even severe duty stationary and mobile plant engines have been 4 valve for just as long.

>>13987848
well when I said "truck" I meant more like...light to medium duty pick-ups and full size SUVs. I'm not very well versed on commercial diesels.

>>13987842
And that's starting to move away from the point I'm refuting here >>13987747
A multivalve engine can maintain the same air speed velocity as a 2 valve, but with greater valve area. So where the 2 valve may peak at a particular point, the multivalve has the capacity to not only match that peak at the same place, but also develop more torque prior to, and after said peak.

>>13984896
because valve lift + compression = more power

>>13987848
cummins 12-valve was put into pickups until the late 90s I believe

>>13987496
sorry, I cant hear you over that chain whine

>>13990294
sorry I can't hear you over your valves getting smashed

>>13988001
the 24 valve seemed like it was not worth the upgrade
it was louder, and seemed to have a more fragile pump

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>>13985012
>a lot of faith in a flimsy rubber band

>>13990300
horry shit burn.

>just replaced my subajew's timing belt.

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>Almost 2016
>Cams
>Timing Chains/Belts

I know its expensive, but why cant one Automaker test the waters with a Performance Car?