Driving feel differences between 390, 427, 428, and strokers

[EricDS]

I'm still new to FE's so my 390 is all I've driven.  I'm curious what is the "seat of the pants" feel of the others usual FE engines.

Obviously every build is different but I'm basically looking to understand which is the most fun to drive on the street, assuming a mild-moderate street build.  Also how does a 427 feel compared to a 428?  Wondering how the different bore and stroke combos affect the "fun factor"

[Drew Pojedinec]

Kinda a tough one to answer.....
I mean, the car, gearing, camshaft, intake, heads, etc are going to play a huge difference.

Mind you they are drastically different engines, but my 390 is a great driver, works great everywhere I'd need it.
The stroker has just mountains of torque off idle to 6000rpms.... just twisting hard the whole way up, get all 8 venturi to open up and Woooooaaaaahhhh. 

My view is, build the biggest engine you can afford and cam/gear/head/intake it to what the intended purpose is.
But I'm a street car guy, I'd prefer a super tame 500ci engine than I would a high strung 400ci engine.
Maybe the racer's will have a different point of view.

[chris401]

I'm still new to FE's so my 390 is all I've driven.  I'm curious what is the "seat of the pants" feel of the others usual FE engines.

Obviously every build is different but I'm basically looking to understand which is the most fun to drive on the street, assuming a mild-moderate street build.  Also how does a 427 feel compared to a 428?  Wondering how the different bore and stroke combos affect the "fun factor"

Big bore short stroke will tend to wind up faster. Longer stroke, smaller bore engines of the same size will have torque earlier. I had a stock 410 that had a noticable difference in low end power over any 390 I have owned. Daily drivers tend to be better on gas and reliability with lower torque and rpm range. If your going to twist a street 390 to 6500 for fun spend the money on your rotating assembly. It's fun till the oily bang crashes the party.

[Tommy-T]

Here's my experience.

Myself and 2 pals all had 390 Mustangs. Mine was running high 12's, and the 2 others were running very low 13's.

I built a 454 inch Hi Riser and running the same 11 inch converter, gears, and slicks, dropped to the mid 11's running a very streetable .590 lift cam and a single 850 Holley.

My other 2 pals ran a stock stroke 427 with Low Riser heads, a bunch bigger cams and more converter, and dual quads dropped into the high 11's.

It's a HUGE leap in a regular street driver car going from a 390 to a 427.

[blykins]

I'm still new to FE's so my 390 is all I've driven.  I'm curious what is the "seat of the pants" feel of the others usual FE engines.

Obviously every build is different but I'm basically looking to understand which is the most fun to drive on the street, assuming a mild-moderate street build.  Also how does a 427 feel compared to a 428?  Wondering how the different bore and stroke combos affect the "fun factor"

Big bore short stroke will wind up faster. Longer stroke, smaller bore engines of the same size will have torque earlier. I had a stock 410 that had a noticable difference in low end power over any 390 I have owned. Daily drivers tend to be better on gas and reliability with lower torque and rpm range. If your going to twist a street 390 to 6500 for fun spend the money on your rotating assembly. It's fun till the oily bang crashes the party.

I would be careful about making generalizations about the stroke making an engine quick to rev or slow to rev.  I can show you several examples that are to the contrary.  Also, torque is not based on the stroke, but on the displacement (among a ton of other things). 

To the OP, the larger the engine, the easier it is to make more horsepower without having to go to extremes...big cams, big compression, etc is not as necessary.

[plovett]

I agree.  Torque is primarily the result of displacement, compression, and volumetric efficiency.   Bore and stroke are not directly related to torque.  Indirectly there's all sorts of stuff going on.  Piston speeds and friction and valve shrouding, etc.  But still it's mostly just displacement, compression and volumetric efficiency.

How fast an engine revs depends on how much power it is making and how much mass it is accelerating, and the gearing it has. 

A bigger engine makes things easier.  It allows you to get the same job done with less rpm and less gearing.

JMO,

paulie

[plovett]

Oh yeah, to your original question.  For 90% of people, more displacement equals more fun.  The power comes on at earlier rpms and it "feels"  stronger.   Don't get hung up on the exact bore and stroke too much.  It's mostly the displacement that gives that "right now, kick in the pants feel".

On the other hand a smaller displacement engine running more rpm, with more gearing,  is a screaming good time.   But more rpm means more attention to detail on the build, better quality parts, more maintenance, and probably shorter engine life.   I know, I know, big displacement engines can be made to rpm, too.  But at some point that has it's issues, also. 

For most people in most situations, in street cars, bigger equals more fun.  I swing both ways.   I have a 428 that I zing up to 7000+ rpm with 4.11 gears and a 3600 stall speed and run 11.40's on street tires, but I'm planning to build a 470+ inch engine that can do the same thing with less cam, less gear, less rpm, and less stall speed.  I guess I'm getting old. 

JMO,


paulie

[chris401]

I'm still new to FE's so my 390 is all I've driven.  I'm curious what is the "seat of the pants" feel of the others usual FE engines.

Obviously every build is different but I'm basically looking to understand which is the most fun to drive on the street, assuming a mild-moderate street build.  Also how does a 427 feel compared to a 428?  Wondering how the different bore and stroke combos affect the "fun factor"

Big bore short stroke will tend to wind up faster. Longer stroke, smaller bore engines of the same size will have torque earlier. I had a stock 410 that had a noticable difference in low end power over any 390 I have owned. Daily drivers tend to be better on gas and reliability with lower torque and rpm range. If your going to twist a street 390 to 6500 for fun spend the money on your rotating assembly. It's fun till the oily bang crashes the party.

I didn't intend to make an absolute statement. I see where my wording made it look that way but I changed it.

[blykins]

Wasn’t trying to harp on you, Chris, but it’s just a pet peeve of mine to see the whole “stroke vs rpm” argument.  The whole "long stroke engines won't rev" topic is a wives tale that's perpetually passed on around the forums. 

There are plenty of anemic big bore/short stroke engines out there and there are plenty of small bore/long stroke engines that will turn 9000-10000 rpm in the bat of an eye.  I'm doing some modular Ford stuff right now and there's an MMR 10.5 Outlaw engine that's 351 cubic inches (3.750" bore x 4.165" stroke) and makes peak horsepower at 10000 rpm. 

Take a 400 SBC in a 70's pickup truck:  4.125" bore with a 3.750" stroke.   Grab the throttle and give it a wing and it would do good to make it to 4800 rpm in a couple of seconds.  Now, build that 4.125" x 3.750" combo with good cylinder heads and a big cam and watch it zip to 8000 rpm in a heartbeat in a dirt track car.

As Paulie stated, it’s more of a function of component weight and the power that’s being made. 

[chris401]

Wasn’t trying to harp on you, Chris, but it’s just a pet peeve of mine to see the whole “stroke vs rpm” argument.  The whole "long stroke engines won't rev" topic is a wives tale that's perpetually passed on around the forums. 

There are plenty of anemic big bore/short stroke engines out there and there are plenty of small bore/long stroke engines that will turn 9000-10000 rpm in the bat of an eye.  I'm doing some modular Ford stuff right now and there's an MMR 10.5 Outlaw engine that's 351 cubic inches (3.750" bore x 4.165" stroke) and makes peak horsepower at 10000 rpm. 

Take a 400 SBC in a 70's pickup truck:  4.125" bore with a 3.750" stroke.   Grab the throttle and give it a wing and it would do good to make it to 4800 rpm in a couple of seconds.  Now, build that 4.125" x 3.750" combo with good cylinder heads and a big cam and watch it zip to 8000 rpm in a heartbeat in a dirt track car.

As Paulie stated, it’s more of a function of component weight and the power that’s being made.

No problem, I didn't think anyone was. My line of thinking was concerning the same basic set up with only the bore-stroke being the change. Back in the late 90's I knew of a 428 Mustang from Mansfield that could twist 7500 all day. Never could keep my own 390's together very long after 6000. My current 352 has more low end towing power than the stock 69 2v Galaxie 390 I ran in my F-100. Lots of variables between those vehicles, just depends on how they are built. There are a few local's with stroked 460's that run but I have never been interested enough to know the particulars. However a local builder has a 4.4" stroke MEL that has gotten me a little interested in aftermarket cubes.

[scott foxwell]

Long stroke engines eat up induction with piston acceleration speed, so typically, a longer stroke engine is going to end up making power in a lower rpm range with most typical induction choices. If you can feed it, the stroke becomes meaningless other than what mechanical limitations it puts on the engine. It took a long time for the big "mountain motor" drag engine builders to figure out how to keep them from coming apart because of those limitations. Brent's example of a grossly over-square engine is definitely the exception...it has a four valve cylinder head that could feed a locomotive. This is the big advantage of these smaller engines...having the valve area to feed that long stroke but again, it's the displacement that makes the power, not the configuration. You couldn't get away with that and use an older two valve cylinder head.

[My427stang]

This is an interesting discussion.  I think everyone will agree that all the engines he asked about can run great.

However, I wonder what the curves would look like if a 390/427/428/445/489 were all built for the same car and same end use with the same quality parts and assembly.   Typically, the bigger you go, other than class racing the "better" the builds get.  (I know general rule sorry)

The various desktop dynos could certainly give a hatchet-level look at the curves for trending although I place little stock in the numbers it can show curve trends, and we could certainly use math on the peaks, 1.2 per CID = 468 hp for a 390 and 534 for a 445, same idea with torque.  Even just that number right there says something, 60+ HP, even for a WAG is a strong indicator

My experience is, cram as much atmosphere into the engine as you can afford, and do it right, and for the intended use, and that is the most fun.  In a given RPM range I haven't found where the smaller motor would be more fun, unless you have traction issues you do not want to fix (resto car etc).

[scott foxwell]

sorry...meant to edit my last post, not quote it.

[EricDS]

Thanks for the info.  I love the history of Fords performance efforts in the 60's.  So it would be great if I could open my hood and see a true 427 under there.  But I also really want a good cost / fun ratio.  So these conversations just confirm that the stroker is probally going to be there winner there. 

Not really a surprise at all.  I was just looking to see if there was something about a 427 that really can't be duplicated with other engine builds.  Fun conversation   

[My427stang]

So, day off, and sore from shoveling snow, so a little math fun to show why the strokers pull harder on a port.

Before the engineers and detailed math guys shoot holes, this is a SIMPLE evaluation of the change in cylinder volume over full stroke.

1 - The top section gives me bore/stroke of each engine divided by a simple common step, 20 data points across the entire stroke, as well as the volume of a chamber converted to cubic inches. 

2 - The second section (STEP) shows quench distance at TDC, then the 20 steps for each engine converted to stroke.  The 20 steps were just what easily fits on the screen, and the last bit of stroke because wonky with rounding.  The goal was to account for rate of change over a single intake stroke (NOTE: this is comparison only and does not account for rod length for the 445, just total vertical movement divided by 20)

3 - The third section converts the bore and the step size into displacement so I could evaluate the difference between movement of a big bore/short stroke and a small bore/long stroke.  This allows us to see how much "room" is being evacuated by the step size

4 - The 4th section (Delta vs 427) compares the change of displacement for each engine and each step against the 427.  FYI as Excel rounded the upper steps are less precise, so ignore that final displacement per cylinder doesn't add up for those checking my math

If you look at the 428, at 1 inch of stroke, noted in RED, the 428 starts to overtake the 427 in rate of change in displacement, and will then "pull" harder on the port.  It's really atmosphere pushing in, but pulling on a port seems to sound better.  Also note that the 427 and 428 never get too far apart.  In this case, likely less shrouding, bigger valves, etc all contribute a 427 actually making more power than a 428, but it does show if you feed the beast many say a 428 runs with a comparable 427.

The big numbers are for the 445, despite the small bore, the piston moves so much more in the same time frame it creates a significant change in displacement early, in this case, about a 1/4 of an inch of stroke, in green, the 445 is pulling harder on the port and continues to for a significant amount

Don't take this as gospel because rod length matters, cam timing matters, overlap and exhaust design, cylinder head flow and interference with the cylinder wall all matter, but it shows clearly that a stroker quickly pulls harder on a port as Scott mentioned