For all the 2.0s: ....2007, 2017, 2054, etc...

[FreeBug]

Came across this, thought y'all might find it interesting:

https://www.eng-tips.com/viewthread.cfm?qid=452804

500ccs is the magic number.............?

[bugguy1967]

He didn't explain how much stroke is a short stroke though. We ould have been nice to know...
_________________
"A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine"

[jeffrey8164]

I suppose, if you believe Marquis.

He could be right. I have no idea what BSFG is.
If he is right, why wouldn’t all engines have 500cc cylinders?

I do like what he said about shorter rods promoting more flow.
Not sure how much .048 in my scenario would matter though.
_________________
Volkswagen!
Turning owners into mechanics since 1938.

“Let he that is without oil throw the first rod”
(Compression 8.7:1)

[jpaull]

Are you bored again? That article means nothing and has no bearing in our ACVW world lol.

Remember when you were asking if 86 was the magic number and thinking square engines might be the ticket? https://www.thesamba.com/vw/forum/viewtopic.php?t=698741&highlight=

There is no free lunch, build the largest engine possible and reap the rewards of more torque/power.

[oprn]

Large single cylinder displacement comes with a balance/vibration issue. Mitsubishi found it necessary to add countershafts to thier large displacement 4 cylinder engines and I believe Porsche was licenced under thier patent to do the same for the 2.5 to 3.0 liter 4 banger water pumpers.

I personally believe the secret to an outstanding engine is the relationship between bore, stroke and rod angle more than overall displacement.


The Chevy 302 small block was an amazing performance engine that had little off the line torque but made a lot of power in the higher rpms. The 307 was a dog all around while the 305 made pretty good mileage but not a lot of power. All different outcomes in the same displacement with different bore/stroke combinations.

[FreeBug]

[bugguy1967]

Shorter rod/stroke ratios can promote more flow that a longer rod because they don’t dwell as long at TDC and BDC and because they accelerate faster everywhere else. That’s probably the reason why the majority of the ACVW world thinks strokers make more torque. They usually have better rod ratios to improve cylinder fill.
_________________
"A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine"

[jpaull]

[modok]

Bore size determines power, because it limits valve size, and the stroke is adjusted to make the engine CC fit the rules.
so.....given the 2000cc limit, the 74 stroke will make more power without a doubt.

OPRN didn't mention the 327! That's the one.
In 2000cc that would scale to 92x75 with a 40 horse length rod. Certainly a classic size

The new subaru engine is 86 stroke, but they are continuing to use the older EJ for the Souped up models....because, bigger bore, shorter stroke, it makes MORE power.
tho personally I like the 2.2 better, the 2.5 subaru FEELs kinda rough, just subjectively.

[oprn]

Yes the 327 was on the tip of my fingers but I could not remember the bore and stroke combination and whether it fit the bill. Same bore as the 350 and same stroke as the 283 not? Or was that the 302?

Then there was a 267 in the early '70s? '71 Monza Spider? You had to lift the engine part way out to change the left rear spark plug?

I used to know all that at one time... then I got old!

[modok]

chevy 327, 4 bore, 3.25 stroke, 5.7 rod

I'm not sure what the type-4 would be..hmm, Maybe a emissions big block ford, lot of torque, poor MPG, exhaust manifolds nearly glow red

[FreeBug]

Bore is a limiting factor for valve sizes (one of the reasons they went hemi in the past), and often, valve size is the limiting factor. Sometimes, it's detonation which is the limiter, and here, smaller bores can help. Sure enough, a 1.5 litre formula 1 engine is never 3 cylinders of 500cc each. There're reasons they are (were?) 12 small cylinders ...or 10, or 8, unless boosted, then there are 4-cylinder F1 engines.

Why aren't all engines with 500 cc cylinders? Because different things have different priorities for different manufacturers. Sometimes overall engine size is more important, sometimes mileage, sometimes noise, economy, etc...

And then there's noise and marketing: who would buy a 4-banger Ferrari? Or Corvette? (i know the 'vette started with a straight six, but it was the v-8 that made that car).

[modok]

Sure great idea. All cylinders are 400 to 600cc, so just choose how many you want. Your about 20-40 years late tho, with this realization

tiny car you get a three cylinder,
small sedan gets four,
station wagon gets five
minivans, small trucks, vee six

Just fine BUT......straight fives and vee sixes just don't FEEL good.
bad vibes man. Bad vibes

[FreeBug]

[Wreck]