It’s Winter. Let’s discuss strokers. How much faster
- Thread starter pittsburghracer
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The stroker had more CR, enough to make up hp differences.
But turns less rpm, so not necessary more power.
B3422w5
Well-Known Member
I asked Ken Hensley( Hensley performance) this very question many, many moons ago when they built me one of the first 4 inch stroker shortblocks anybody had. This was just after the advent of these cranks coming into being.
He told me all else being the same, about 3 or 4 tenths at the track.
To this day, i think that was pretty darn accurate.
I just recently swapped a stock stroke 360 for a stroker
Used same heads, eddies,( made a bit better) same cam, same headers, same gear, same convertor( adjusted) big changes were more compression on the stroker and going from an airgap to a small single plane( Weiand Excellerator)…actually probably not much of a change, this intake i am convinced now, is too small for this size motor.
Car went from a one time best of 11.26, to an off the trailer first pass 10.77 with the stroker. About 5 tenths. I figure the extra squeeze and little bit better head after minor work likely account for the bit more than 3-4 tenths typical gain.
That’s pretty real world comparison….
He told me all else being the same, about 3 or 4 tenths at the track.
To this day, i think that was pretty darn accurate.
I just recently swapped a stock stroke 360 for a stroker
Used same heads, eddies,( made a bit better) same cam, same headers, same gear, same convertor( adjusted) big changes were more compression on the stroker and going from an airgap to a small single plane( Weiand Excellerator)…actually probably not much of a change, this intake i am convinced now, is too small for this size motor.
Car went from a one time best of 11.26, to an off the trailer first pass 10.77 with the stroker. About 5 tenths. I figure the extra squeeze and little bit better head after minor work likely account for the bit more than 3-4 tenths typical gain.
That’s pretty real world comparison….
My wife and I are together for 40 years. I have come to believe a long stroke is what works best. As far as fast I suggest keep it slow .
Super-Cuda
MOPAR .. Move Over, Plymouth Approaching Rapidly!
I can't comment on how much faster a car will be but a member on here OLDIRON posted this last week.
Addresses your question directly I believe.
Cheers!!
Stroke a stock 360
Addresses your question directly I believe.
Cheers!!
Stroke a stock 360
I have 2 engines, 'big' engine is a .070 over 383 stroker with a 3.685 offset ground crank, stock 360 main journal, 2" rod journal with 6" small block chevy rods. The 'small' engine is a .030 over 360 with stock stroke. Both have W2 econo heads that have had some porting work done on them, nothing extensive. The 'big' engine has a comp cams roller .654 intake, .655 exhaust. 'Small' engine has a MP 590 cam. My best 1/4 ET with the 'big' engine is a 10.05. I haven't run the 'small' engine in my Dart yet, but in a similarly built, but all steel Duster (except for the hood, and a Holley 750DP vice the 1050 Dominator on the 'big' engine) it would run 10.20s all day. Big difference between the two, not really, at least in my set up. I still have the feeling that the car should be running better with the 'big' engine, that something is holding it back, but I haven't been able to determine what it may be.
I'm interested to see the results of this, it is my suspicion that unless each package was specifically set up for its displacement, (cam, convertor, header size, cylinder head port volume, carb, manifold, and gear selection) results might not be as drastically different as one might think. 60 ft times will be interesting as the rate of rpm increase between the two different strokes should be considerably different using same combination. Either way you slice it, this combo was tailored to either the 360 or the 408 initially, therefore the other combo is making due with what it has.
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Cuda416
Well-Known Member
Volumetric Efficiency? No replacement for displacement on NA engines?
Without boost, there are only so many ways to get more A/F through the engine. Increasing volume is easy. Making it pass through (head porting, cam choice etc) is harder. Like others have said, most people are ripping it up on the street so high rpm's aren't that important as long as you feel it in the seat light to light and smoke'm nicely.
Without boost, there are only so many ways to get more A/F through the engine. Increasing volume is easy. Making it pass through (head porting, cam choice etc) is harder. Like others have said, most people are ripping it up on the street so high rpm's aren't that important as long as you feel it in the seat light to light and smoke'm nicely.
Rat Bastid
Dunamis Metron
If HP=TQ*RPM (and it does) you can’t ignore the RPM apart of the equation. If you add stroke and drop 500-700 RPM, you lost peak power and moved peak TQ down.
You also have to run less gear. It’s easier to move the car with gear than it is with stroke.
You also have to run less gear. It’s easier to move the car with gear than it is with stroke.
Now we are thinking. But what if weight, gearing, shift rpm, and head flow stays the same. I think we can all agree if you have a 170cc runner on a 360 and a 170 runner on a 408 the gap is going to close up some unless chassis, gearing is changed.
I hear it 10 times a day. Should I build a 360 or a 408. Zero questions asked and the 80% crowd jumps in “stroke it”.
If I was to stroke a 318, I'd buy the kit and go 390. You get the crank rotating assembly. I wouldn't put a 360 crank in a 318 either, I'd just get a 360 and get the .090 bigger bore... means 360's are so easy to get.
Cuda416
Well-Known Member
Fair point, and this is coming from the slow guy in the room, but even of everything else stays the same, you're going to make more low end power (and high) regardless so naturally your shift point is going to change, no? Again, slow guy here so bear with me.
I get what you're saying but I think you're over simplifying it a little.
I agree, questions should be asked before throwing out that same answer, 408.
To me especially on a street, street strip deal I would want to know what the investment is going to get me because it’s not a cheap upgrade. My son took me for a warm up drive in his 360 (3200 pound) (3450 with me tagging along) duster. The only thing keeping his car from passing PA state inspection was the wiper motor was removed. Caltracks, rancho shocks, cheap 90/10 front shocks, street legal radial, 4:10 gears and with zero tire heating I couldn’t believe how that car booked it.
Pistons for the 318 - 349 are hard to find. A 360 crank into a 340 block is easier. 318 - 390 is easier and a better path.
Cuda416
Well-Known Member
I think one way to "justify" it is this....
A head change is easy, cam change not too bad, rotating assembly, ugh...
So, with that in mind, one might look at this as a long term project. Stroking the motor shouldn't have any adverse effects, so doing that first and bringing everything else in line over time might be a good way to spread the pain out out over time and see an immediate return on investment.
Just thinking out loud.
A head change is easy, cam change not too bad, rotating assembly, ugh...
So, with that in mind, one might look at this as a long term project. Stroking the motor shouldn't have any adverse effects, so doing that first and bringing everything else in line over time might be a good way to spread the pain out out over time and see an immediate return on investment.
Just thinking out loud.
But what if it’s not needed. The .20-.30 max that most guys would see could create traction issues and go slower. Chassis work is a lost science to many.
Cuda416
Well-Known Member
Not needed?!!!! WHAT! lol, yeah now I'm tracking... Like I said, bigger is "easier"....
I for one have a LOT to learn and I know that, so any tutorial on Chassis tuning, gear selection, torque converter choice, shocks, weight transfer etc are more then welcome.
Cuda416
Well-Known Member
Annnnnd, your discounting bragging rights when people can say "I stroked it"... wait... you know what I mean.
I think larger bragging rights to the guy who cleans house, then says it is stock stroke.
Cuda416
Well-Known Member
Well yeah but you're making sense. Stop it
Bobzilla
Well-Known Member
It seams like the early 80s cars had lots of chrome added. More chrome parts the better. In the 90s it was all the ugliest colors and patterns of paint. Now it seams like strokers are the new old man chrome. Like others said, any response gets the answer to go ahead and stroke it. Even some of the responses here strayed off topic. I doubt many have the done he cubic inch stroker crank route without changing anything else. The few posts with experience always had something else different. I wonder how the torque converter will act with an increase in displacement and torque, and then what that does to the rest of the chassis impact on the tires.
In fairness, many responses to just build a stroker are based on the current cost of parts. Starting from scratch, and if I needed a new crankshaft, an increase in cubes with a stroker kit is a good suggestion, nothing wrong with it. But when you see the questions of "what is the biggest/longest stroke that will fit in the block?" that is old man chrome with no real consideration to combination.
Either way, great winter conversation.
In fairness, many responses to just build a stroker are based on the current cost of parts. Starting from scratch, and if I needed a new crankshaft, an increase in cubes with a stroker kit is a good suggestion, nothing wrong with it. But when you see the questions of "what is the biggest/longest stroke that will fit in the block?" that is old man chrome with no real consideration to combination.
Either way, great winter conversation.
So, if you were to add 1/4" stroke to the crank, and all else remains the same in the engine, would adding some length to the camshaft duration be worthwhile in order to take full advantage of the longer stroke?
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