340 or 408?

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MOPARMAGA said:
My 470 would qualify as a tractor engine compared to even a 340 with x heads but that was my choice of building a street engine that changed directions.
Because of that I'll run 4.10 with a 31 inch tall tire.
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I'm gonna run 4.10s with either a 30 or 31" tire too. But I think I can keep mine under 2500, without me in it. (18x31 Hoosier QTP's for the moment.) And I definitely have a tractor motor at the moment.
 
mopowers said:
Another thread gone to ****. A little humility goes a long way.
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Lots of guys get butt hurt real easy. Some here worse than others.

However, the original question about stock stroke vs stroker: Like everything here, people have their preferences and opinions, which is cool. But 99% of the time, you take an engine combination---any engine combination, and change nothing but make the displacement larger, that combo will make more torque and power, pretty much everywhere.

Now, you would think guys would universally like a more powerful engine. But it turns out they don't. Again.... that's cool. Some guys prefer the knowledge of a stock stroke over having more power.

I know if it was me....if I went for a ride in a hotrod, and it was a nice fast 9-10s street strip deal. If you told me that was a strock stroke I'd be like "awesome!" The truth is, there's no way I'd know the difference if your car has a stock stroke, was a 422 stroker, or a 318. If it was running 9s that's all that matters because it's freaking fast.
 
Newbomb Turk said:
Yes. Lots of it. I won’t use a 4 inch stroke in anything.

And I’m sure I’ll have another one on the dyno soon.

I get it. Some guys haven’t learned (and probably never will) that rpm IS horsepower.

I will shift my 340 at probably 6800. That’s street/strip car stuff.

At 7800 you are what I consider a strip/street car.

There probably isn’t 20 people on the entire forum who would want 7800 rpm for anything.

They fear rpm.

They went full Rip Van Winkle and slept through the era where valve train caught up and 7800 for even a decent build.

Using parts like you have you might as well be turning it 6500. Guys don’t get that.

I suppose those who slept through the late 90’s spent their time and money on delay boxes, 9 hit cross over boxes and throttle stops.

That’s on them.
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Ok, so I and others (probably after too many beers) have toyed with the idea of building a high rpm, high HP small block to compete in FAST. The idea being it softens the launch and really comes alive down track, (and might allow for some high end converter magic) but the foundation for a build like that is having the maximum amount of head flow the LA architecture can support. Also with equally capable intake and exhaust components. Which I THINK isn’t possible starting with the stock castings and through x head. I just kept coming back to, I have to create the largest “depression” I can at the back of the intake valve. I can do that by longer stroke or more rpm, but at some point velocity gets too fast and things go sideways. It has always been interesting, but I think the box I’m forced into makes it not worth it. If I can create the same level of depression at the back of the valve with more stroke at a lower rpm, what’s the downside?
 
Didn't mean to create this 8 page battle of testosterone , Literally just seeing if 500 hp is realistic in my street car and my options compared to a 360/408. I am looking at the 340 and if it it looks good I'll probably scoop it up. Maybe it's my downfall but again , I'm an old school guy whos ways are out dated but still work and I have a ton of fun driving my car and ripping some gears. Thank you to all who helped me and put their .02 in. Much appreciated!!
 
furrystump said:
Ok, so I and others (probably after too many beers) have toyed with the idea of building a high rpm, high HP small block to compete in FAST. The idea being it softens the launch and really comes alive down track, (and might allow for some high end converter magic) but the foundation for a build like that is having the maximum amount of head flow the LA architecture can support. Also with equally capable intake and exhaust components. Which I THINK isn’t possible starting with the stock castings and through x head. I just kept coming back to, I have to create the largest “depression” I can at the back of the intake valve. I can do that by longer stroke or more rpm, but at some point velocity gets too fast and things go sideways. It has always been interesting, but I think the box I’m forced into makes it not worth it. If I can create the same level of depression at the back of the valve with more stroke at a lower rpm, what’s the downside?
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I’ve explained it already.

Comparing what the OP wants to a FAST car is a bad example.

The OP has already said he likes his 4.56 gears.

What many are doing is trying to convince the OP he doesn’t know what he wants and that what he wants in not doable.

It is doable and it’s not hard.

Maybe, just maybe he’s a guy that likes rpm. He must because he’s running a gear most wouldn’t even consider.

There are a number of reasons to not build a 4 inch stoke engine IF you are induction limited.

Let’s think it through.

Using a 4 inch stroke with ANY head with non offset rockers makes the engine induction limited.

You can use a tunnel ram but that’s worse than using 4.56 gears to most people. And that STILL doesn’t fix it. It helps a bit.

Let’s see what engines use a 4 inch crank with PRODUCTION HEADS.

400 Chevy 3.75
396 Chevy 3.76
427 Chevy 3.76
454 Chevy 4.00
470 Chrysler 3.91

What do we see? One 4 inch crank. The OE’s aren’t stupid. They are FAR more concerned about drivability than power.

And, a 375 horse 396 had square port heads on it. It’s only 375 horsepower and it needed all that port area.

I forget the 427 numbers but I know a 450 horse 454 had square port heads too.

And none of the above was an rpm screamer.

Look at the G3 Hemi. How much stroke does it have?
 
67_Slimer said:
Didn't mean to create this 8 page battle of testosterone , Literally just seeing if 500 hp is realistic in my street car and my options compared to a 360/408. I am looking at the 340 and if it it looks good I'll probably scoop it up. Maybe it's my downfall but again , I'm an old school guy whos ways are out dated but still work and I have a ton of fun driving my car and ripping some gears. Thank you to all who helped me and put their .02 in. Much appreciated!!
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This is exactly what happens when bad orthodoxy is exposed.

Testosterone has nothing to do with it. It’s common sense engine building and most of the guys in here popping off aren’t engine builders.

Like I said to YOU in my first post. Do not lie to yourself about who YOU are. You can do 500 hp with a single 4 barrel and solid lifters.

It’s even easier with a small solid roller cam.

And at most it should be about 6800 rpm to do it.

If you want more stroke and less rpm find a 3.79 stroke crank. Turn it down to 2.100 rod throws, use a 6.125 Chevy rod and a 4 inch stroke piston.

You can use off the shelf parts for that. You will still be out of cylinder head sooner.

I’m going to use a 3.79 stroke deal but I’m going to use W2 heads. Otherwise I wouldn’t even do that.

And no matter what you decide, make sure you get the intake manifold ported. Putting an unported intake on a 3.313 stroke is a power killer. It’s even worse when the stroke gets longer.

Be honest with yourself and don’t let other people superimpose what they can’t or won’t do on you.

Just like my first post said.
 
67_Slimer said:
Didn't mean to create this 8 page battle of testosterone , Literally just seeing if 500 hp is realistic in my street car and my options compared to a 360/408. I am looking at the 340 and if it it looks good I'll probably scoop it up. Maybe it's my downfall but again , I'm an old school guy whos ways are out dated but still work and I have a ton of fun driving my car and ripping some gears. Thank you to all who helped me and put their .02 in. Much appreciated!!
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Leaning and doing things your way is how we learn. Some guys are happy plopping their money on the counter and picking up an engine and some aren’t. I learned somewhere around 46 years ago I wasn’t and my first 340 ran better than the one by the “mopar specialist”. I gave up on being a so called good driver years ago as my joy is building something then making it faster next time. It doesn’t matter in a street car whether it’s 400 horsepower or 450 if it doesn’t hook on the street. Enjoy your build and go have fun.
 
Newbomb Turk said:
This is exactly what happens when bad orthodoxy is exposed.

Testosterone has nothing to do with it. It’s common sense engine building and most of the guys in here popping off aren’t engine builders.

Like I said to YOU in my first post. Do not lie to yourself about who YOU are. You can do 500 hp with a single 4 barrel and solid lifters.

It’s even easier with a small solid roller cam.

And at most it should be about 6800 rpm to do it.

If you want more stroke and less rpm find a 3.79 stroke crank. Turn it down to 2.100 rod throws, use a 6.125 Chevy rod and a 4 inch stroke piston.

You can use off the shelf parts for that. You will still be out of cylinder head sooner.

I’m going to use a 3.79 stroke deal but I’m going to use W2 heads. Otherwise I wouldn’t even do that.

And no matter what you decide, make sure you get the intake manifold ported. Putting an unported intake on a 3.313 stroke is a power killer. It’s even worse when the stroke gets longer.

Be honest with yourself and don’t let other people superimpose what they can’t or won’t do on you.

Just like my first post said.
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Thanks man , much appreciated. You're right , I love gear , sticks and revs , very old school. My current 340 is so much fun and plan on keeping it a few more years if all goes well but just looking to have a good replacement ready to go when the time comes. I want that replacement to work with the current drivetrain setup I currently have. Bingo!!
 
67_Slimer said:
Thanks man , much appreciated. You're right , I love gear , sticks and revs , very old school. My current 340 is so much fun and plan on keeping it a few more years if all goes well but just looking to have a good replacement ready to go when the time comes. I want that replacement to work with the current drivetrain setup I currently have. Bingo!!
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We are from the same era I suppose. I grew up following Modifed Eliminator which were ALL stick cars and what would be considered micro sized engines that spun to the moon.

It was great watching those cars. Most were well under 300 inches (I know why that was but most on here won’t accept that truth because it fits right into what we are talking about here) with 50 pound flywheels and gearboxes you had to shift.

That’s why I build what I build. RPM is horsepower. Valve train is so much better than the junk they had in 1973 that it’s just crazy what those guys did with what they had.
 
Newbomb Turk said:
We are from the same era I suppose. I grew up following Modifed Eliminator which were ALL stick cars and what would be considered micro sized engines that spun to the moon.

It was great watching those cars. Most were well under 300 inches (I know why that was but most on here won’t accept that truth because it fits right into what we are talking about here) with 50 pound flywheels and gearboxes you had to shift.

That’s why I build what I build. RPM is horsepower. Valve train is so much better than the junk they had in 1973 that it’s just crazy what those guys did with what they had.
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And I have seen a few telltale needles purposely left at 10,000 after a missed shift. Just to prove that it could.
 
Newbomb Turk said:
I’ve explained it already.

Comparing what the OP wants to a FAST car is a bad example.

The OP has already said he likes his 4.56 gears.

What many are doing is trying to convince the OP he doesn’t know what he wants and that what he wants in not doable.

It is doable and it’s not hard.

Maybe, just maybe he’s a guy that likes rpm. He must because he’s running a gear most wouldn’t even consider.

There are a number of reasons to not build a 4 inch stoke engine IF you are induction limited.

Let’s think it through.

Using a 4 inch stroke with ANY head with non offset rockers makes the engine induction limited.

You can use a tunnel ram but that’s worse than using 4.56 gears to most people. And that STILL doesn’t fix it. It helps a bit.

Let’s see what engines use a 4 inch crank with PRODUCTION HEADS.

400 Chevy 3.75
396 Chevy 3.76
427 Chevy 3.76
454 Chevy 4.00
470 Chrysler 3.91

What do we see? One 4 inch crank. The OE’s aren’t stupid. They are FAR more concerned about drivability than power.

And, a 375 horse 396 had square port heads on it. It’s only 375 horsepower and it needed all that port area.

I forget the 427 numbers but I know a 450 horse 454 had square port heads too.

And none of the above was an rpm screamer.

Look at the G3 Hemi. How much stroke does it have?
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Uh, you forgot 455 Pontiac (4.21) 455 Olds (4.25) and Cadillac 500 (4.304) I guess cause they are all tractor motors with barrels full of torque, and great street engines.
 
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Mean416 said:
Lots of guys get butt hurt real easy. Some here worse than others.

However, the original question about stock stroke vs stroker: Like everything here, people have their preferences and opinions, which is cool. But 99% of the time, you take an engine combination---any engine combination, and change nothing but make the displacement larger, that combo will make more torque and power, pretty much everywhere.

Now, you would think guys would universally like a more powerful engine. But it turns out they don't. Again.... that's cool. Some guys prefer the knowledge of a stock stroke over having more power.

I know if it was me....if I went for a ride in a hotrod, and it was a nice fast 9-10s street strip deal. If you told me that was a strock stroke I'd be like "awesome!" The truth is, there's no way I'd know the difference if your car has a stock stroke, was a 422 stroker, or a 318. If it was running 9s that's all that matters because it's freaking fast.
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Depends how you look at it, from a drag racing point of view your only concerned about stall to shift points there's no reason a 340 can't make as much and or more between those two points just gonna happen generally at higher rpms.

Yes the larger the engine is almost always gonna make more low end power, but smaller engines are generally gonna/should run more gear so at any given mph they are gonna be running at a higher rpm possibly making the similar hp.

Here's a 302 vs 327 vs 350 the 302 and 327 built identical the 350 has a different cam.

Now down low the power band are fairly spread out but with the right gearing eg.. The 327 makes the same power as the 350 but only around 200 rpms more at lower rpms so just with a little bit more gear the 327 match bottom end power plus got all those extra top end rpms. Which is more streetable ? probably the 350 and the main advantage for most it needs less gearing. Now the 302 needs 500-700 rpms down low which you ain't gonna get without crazy gearing but with more gearing it's going be closer in reality then on this graph.

Yes if you just run the standard 3.55 gears the 350 probably be best all around which to me is the main benefit of displacement not needing as much gears.

1727367979847.png
 
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67_Slimer said:
Didn't mean to create this 8 page battle of testosterone , Literally just seeing if 500 hp is realistic in my street car and my options compared to a 360/408. I am looking at the 340 and if it it looks good I'll probably scoop it up. Maybe it's my downfall but again , I'm an old school guy whos ways are out dated but still work and I have a ton of fun driving my car and ripping some gears. Thank you to all who helped me and put their .02 in. Much appreciated!!
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My daughter's 340 stock stroke, with Edelbrock heads not ported, Bullet cam, pump gas 10.7-1 KB pistons that are 15 years old, lightweight i beam rod, M1 intake, with 4.56 gears. runs 10.60s in the quarter mile. got to be 485 hp +or-, and its just a street car that is not driven on the street anymore. still has the factory radio. have fun with your build and driving it.
 
ValiantRacing said:
My daughter's 340 stock stroke, with Edelbrock heads not ported, Bullet cam, pump gas 10.7-1 KB pistons that are 15 years old, lightweight i beam rod, M1 intake, with 4.56 gears. runs 10.60s in the quarter mile. got to be 485 hp +or-, and its just a street car that is not driven on the street anymore. still has the factory radio. have fun with your build and driving it.
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awesome , what are the cam specs? Stick car?
 
Ummm...not sure if it matters but the GM LS7 (7.0L/427) engine was a 4" stroke and fuel cut-off was set at 7200 rpm. 505hp and had to meet all the modern emission standards and durability too. "More than 1 way to get the job done."

Remember I have both a 340 and a 408 and love'em both!! :thumbsup:
 
Demonx2 said:
Ummm...not sure if it matters but the GM LS7 (7.0L/427) engine was a 4" stroke and fuel cut-off was set at 7200 rpm. 505hp and had to meet all the modern emission standards and durability too. "More than 1 way to get the job done."

Remember I have both a 340 and a 408 and love'em both!! :thumbsup:
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How was it 427 inches with a 4 inch stroke?

The 396 and 427 have the same stroke and different bore sizes.

The 427 and 454 have the same bore size and different strokes.

If it’s a 427 it has a 3.76 stroke.
 
67_Slimer said:
Driving it to work daily and to cruise nights every night I assume?
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No, I didn’t expect a 10.00 car to be a daily driver. It’s not cantankerous, don’t foul plugs and doesn’t get hot.

I built it just like I’ve built all of my engines. Yes, I did pay someone to port the heads and do the machine work. I guess that makes me a check writer, LOL.
 
Newbomb Turk said:
How was it 427 inches with a 4 inch stroke?

The 396 and 427 have the same stroke and different bore sizes.

The 427 and 454 have the same bore size and different strokes.

If it’s a 427 it has a 3.76 stroke.
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I think he's talking about LS 427 it has a 4" stroke.
Not BBC 427 with a 3.76 stroke.
 
273 said:
Depends how you look at it, from a drag racing point of view your only concerned about stall to shift points there's no reason a 340 can't make as much and or more between those two points just gonna happen generally at higher rpms.

Yes the larger the engine is almost always gonna make more low end power, but smaller engines are generally gonna/should run more gear so at any given mph they are gonna be running at a higher rpm possibly making the similar hp.

Here's a 302 vs 327 vs 350 the 302 and 327 built identical the 350 has a different cam.

Now down low the power band are fairly spread out but with the right gearing eg.. The 327 makes the same power as the 350 but only around 200 rpms more at lower rpms so just with a little bit more gear the 327 match bottom end power plus got all those extra top end rpms. Which is more streetable ? probably the 350 and the main advantage for most it needs less gearing. Now the 302 needs 500-700 rpms down low which you ain't gonna get without crazy gearing but with more gearing it's going be closer in reality then on this graph.

Yes if you just run the standard 3.55 gears the 350 probably be best all around which to me is the main benefit of displacement not needing as much gears.

View attachment 1716308258
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Trust me I definitely understand the general sentiment. But if you're looking at what you would actually feel by the butt dyno, The larger displacement area under the curve difference is huge.

In fact I would go so far as to say that even properly geared stalled etc the bigger engine is going to win by virtue of that increased area under the curve. It's making more power across a broader RPM range you can work with that.
 
Mean416 said:
Trust me I definitely understand the general sentiment. But if you're looking at what you would actually feel by the butt dyno, The larger displacement area under the curve difference is huge.

In fact I would go so far as to say that even properly geared stalled etc the bigger engine is going to win by virtue of that increased area under the curve. It's making more power across a broader RPM range you can work with that.
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No, it won’t. Think it through. Area under the curve is meaningless in ANY form of racing.

What matters is area under the curve between minimum and maximum rpm.

What happens at 2 or even 3k means nothing in a race.

On my drag stuff any thing under 5500 didn’t mean a thing. It never saw rpm below that.

If you are taking about street driving then you can use ANY testing at WOT because no one that has a clue is at WOT at that rpm.

And if they are it’s only in one gear.
 
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