to stroke or not to stroke?

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Will
You are, of course, stuck, in race mode. Thats ok, I was too, for years.
I said for a street brawler.
I was so stuck on hp, that the first iteration of my 366 was with a 292/509 cam. I set it up with a Scr of 11.0, net Dcr of 8/1 . That engine flew, from 5500 on. But it was sadly lacking down low. It needed 4.30s and a 3.09 low(13.29Starter gear) to get off the line, and I was forever shifting like a Mustang trying to find some power. Let me tell you that sucked on the street.The first guy that offered me cash for that cam, got it. And good riddance.
The next cam was a Hughes HE2430 . IIRC that was 270*advertised. Now you are talking.I set it up with a 10.7Scr and netted about 8.7 Dcr . With that wee little cam, I could run 3.91s and a 2.66low(10.4starter gear) and it pulled right off the line, like from idle! Well the 3.91s gave up in a hurry, so in went the 3.55s and a 3.09low(10.97starter).It still pulled like a champ. That was the funnest 2 summers ever. Right up until the day two lobes fell into the pan.
The next summer found me with a Hughes HE3037. IIRC this is a 276* intake.With no change in the Scr, this cam dropped the Dcr a bit, to 8.5ish. This cam makes quite a bit less on the bottom than the 270, and a bit less on the top than the 292. But its a good trade. Its got a big fat mid range,and more than the tires/chassis can handle on the bottom, and I dont care how many mph it pulls in the qtr, nor how quick it is.This car was built as a streeter. I sometimes miss the 270.But it was definitely shy on the top.
The 276cam is NOT shy. I dont think it makes a whole lot of power, But the power band is huge. It seems to start a hair under 5400, and goes forever(streeter,remember).I pull the stick between 7000 and 7200, not because I can feel it nose over. no-no.I shift cause I want an engine left for tomorrow.Cause this ear-to-ear grin is better than.........
I say seems to start at 5400, not because the hammer falls there, but it does seem to pull a bit harder after 5000 for sure. But the midrange is so fat. Its like a tractor. After 3500 or so Just stomp it. But really the torque curve starts down low, and just goes and goes and goes. It has such a sweet torque curve,that to get moving, I just blip the throttle and dump the clutch, we are gone. Short shift into second, and power up to 2400 rpm,cruising speed of 28mph. Sweeeet
So to recap, I've had 3 cams in the same engine; a292, a 270, and a 276. The 292 was a fail on the street. The 270 was an awesome stump puller. The 276 is my favorite.I think its been in there for 10 years now. If this one dies, Im ordering a custom grind.
 
madscientist said:
Read this entire thread and feel dumber for it. C'mon guys...how long will fairy tails with unicorns and crap like that go on? I have posted several examples of why stroke is not all that and then some. There are WAY more important parts of the equation than stroke. For me (and there are many of us out here who know the truth) torque is a by product of stroke length, port area, overlap, @.050 timing and rod ratio. I know some long haired type will post on here and try to tell us that HP is calculated from torque blah blah blah. Again, the reality is that torque is the by product of the above. To be realistic, we need some definitions to start with so we are all talking the same lingo.

I like simple best so here it goes:

Torque = twisting force.
Horsepower = time to do the twisting.
Really simple, isn't it?

So, here is an example I read probably 25 years ago that fits. Torque is the amount of WORK required to twist a doorknob (whatever the exact number is, we don't care, we just know work happened when we twisted the knob).

Horsepower is the amount of TIME it took to twist that knob. Again, we don't care what the time is we just know it took time to twist the doorknob and that time is HORSEPOWER.

If we make the knob harder to turn, it requires more TIME to turn so we used less HORSEPOWER. If the knob is still hard to turn and we turn it faster, we made more HORSEPOWER.

Simple really.

So what we are talking about is that really, horsepower is how long it took to do work. In drag racing (and horse racing and golf cart racing and about any other kind of racing) if you did the work in less TIME you had to have more HORSEPOWER. Period. That is why every power speed calculator I know of uses HORSEPOWER to calculate ET and not torque. Torque is a by product.
Real world example: Had a customer come in the shop and tell us he wanted 850 lb/ft of torque. I said what the ruck for? He said, because I want to go 10's. I said well what does the car weigh? He says 3600 with me in it. I calculated about 600 HP and that would get him about 600 lb/ft of torque (because his combo was already screwed up I couldn't dump any more torque of I would have). After hours of discussion we gave in and built him what he wanted, all the time me telling him his disappointment would be great.

Put the pig together and it made 425 HP and 880 lb/ft of torque. I told him to plan on 11.40's or so. He was pissed because he should go 10.60's by his torque numbers (I should have bet him but I don't like taking money from an already pissed customer.

So, down to the track. It starts off in the 11.65 range and it was tuned to the 11.50's that night. He fought traction issues. So he spent ANOTHER grand on upgraded suspension and it went into the 11.30's and that was where it lived. He was pissed and sold the car.

If he would have LISTENED, for the SAME money I could have made way more HP with way less torque. The car would have been faster and easier to drive. Torque is a by product and has little overall impact on ET in the real world application (yes I can prove that too).

The problem is that the real hot rodder is dead. Those of us who don't mind a 3.90-4.56 gear on the street (I use 4.56's in my car) don't lose sleep over 50 lb/ft of torque or even 100. But I get berserk over 10 HP for damn sure. And I'll give up 50 lb/ft of torque at 2500 to gain 15 HP at 6800 ALL DAY LONG.

I'm also confused by this current idle speed issue. Seems like if you idle is faster than 1200 RPM some guys wet the bed. Idle is just a number. Unplug your tach and see if you can tell
the difference between a correctly set 1200rPM idle and a correctly set 1600 RPM idle. Bet you can't. So we give up midrange torque by using a wide LSA so we can lower the idle speed? That's what GM did with the old 30/30 Duntov and the first LT-1 cams. The 30/30 was on a 114 LSA and the mighty LT-1was on a ridiculous 116 LSA!!! Sure was fun using my 292 DC cam to take money from fools, suckers and chumps.

My point is this: Horsepower is KING. To dispute this is stupid.

A man much smarter than me said this words probably 30 years or more ago. It hasn't changed. I would take a 4.125 bore 3.58 stroke engine over a 4.03 4.00 engine every day of the week and ten times on Sunday when they are signing the checks. And I would use a 6.25 rod in the 3.58 stroke. Then set my cam numbers to my RPM range, and gear and tire size would follow.

Simple really.

HORSEPOWER is KING for sure.

Rant over.
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Just curious- what do you do for a living?
 
Thats a loaded question. Are you baiting me? Reread the post and my next post, #76

No I wasn't baiting you. I wil re-read what you wrote. I think my question was what got your car moving when you stuck your foot in it in 3rd gear? Was it the torque of the motor or the leverage of the gears? I may have misread what you wrote. I'll look.
 
Mad Sci just didn't address one thing, one very small thing

The added torque of the long arm helps get the car moving faster off the line.
This is why strokers are well liked.

2 engines, displacement the same, HP at the big end the same.
The long arm gets off the line easier and quicker. More torque also equals more HP.

You all are getting carried away. Have a nice day fellas and don't forget to breath deeply before typing. ;)

Some say I'm going fishing, I say I'm going wrenching. ;)
 
ebigga
It comes to the same thing, when you think about it.
It doesnt matter if the engine sees a 3.09 low and a 3.55 rear, or a 3.55low and a 3.09rear. The rear axles are seeing a 10.97 torque multiplication. So if the engine is putting out 100 ftlbs. the axles are seeing 1097ftlbs, a b o u t.
The only time(stick-car) that theres no multiplication going on is in Direct.And thats why, AT THE TRACK, guys can say hp is king, cause in direct,Its all motor, no help from the box. And to hit a certain mph, at a certain rpm, the diff is a default ratio.
But ON THE STREET, its all about torque and gears, cuz you're never at any optimum speed or rpm, unless you're idea of 28mph at 4400rpm is cruising(1st gear/4.1s).That would be ready to pull the trigger, but there would be no takers.Your screaming pipes gave you away 2 blocks back.
For me the perfect gears are 4.3rear and 1.92-2nd. That puts me at 28mph/2975rpm. If I stick it in OD, thats2300. Sleepy 2300.When its go-time, I just flick the button, and stomp on it.Kapow! Redline gets me 70 mph. With the GearVendor pulling the 4.3s down to 3.35, all is good!
 
What if my horse is stronger then your horse?
does horsepower matter?
It would be like comparing a clysdale to a shetland pony

Horsepower is a general calculated number from torque ...

But this argument can go on for years and has been for decades ... nobody will solve the argument in this thread
 
Whenever I'm faced with such a decision, the girlfriend always has the right answer.:tongue8:
 
rumblefish360 said:
Mad Sci just didn't address one thing, one very small thing

The added torque of the long arm helps get the car moving faster off the line.
This is why strokers are well liked.

2 engines, displacement the same, HP at the big end the same.
The long arm gets off the line easier and quicker. More torque also equals more HP.

You all are getting carried away. Have a nice day fellas and don't forget to breath deeply before typing. ;)

Some say I'm going fishing, I say I'm going wrenching. ;)
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Really? Because your point is proven incorrect by none other than HAROLD BETTES of Super Flow fame. Would you agree he's a pretty smart guy? I've met him at least 5 times I remember and talked on the phone with him probably in excess of 40 hours over the years. I know, for a FACT, he is way smarter than I am. And you are posing the opposite of what Bettes teaches. You can buy his book and read it for your self . what he says is this: if you want to see how your torque works, put you car in high gear (must have a full manual valve body or a real trans...a stick) and from a DEAD STOP mash on it. How will that torque work for you then, It will be a pig. Very few combos can run one gear and that is usually fueled by nitro,

If we are going to have this discussion, we at least to be intellectually honest. If you can't do that, I won't respond to this thread again.
 
mopowers said:
Just curious- what do you do for a living?
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I bake cookies for little kids birthday and barmitzvah parties. We have clowns and ponies and unicorns.






























































Actually I am a semi-retired machinist and engine builder and I love to play with guns on the side. That is my grown up life. Buy mostly I am best friends to my dogs, husband to my wife and father to my son. And damn good looking. Can't forget that. I am sizzling hot to look at. Sweet eye candy to look at. Other than that...not much.
 
^^^^honestly if you respond to this thread again I seriously would love to see some kind of parts list or motor size or something showing that 850 pounds of torque and 425 horsepower build. It really stirs my thinking process, it's not something you hear often or in my case ever! and it's a drag race motor? I hope you don't take offense to me calling
" bull crap"!!
 
rmchrgr said:
I meant to say build two engines, one stroked, the other not and see which makes more overall power.

Please tell me how my assertion that larger displacement will make more power if all else is equal is bogus. Again, this is physics, not opinion. Maybe I am wrong. Enlighten me.

Consistency at the drags will put any combo on the trailer. Cut a perfect light and run right on your dial you win. What does it matter what the guy next to you does? People run mimivans and win races because they are consistent, has little to do with what engine is in the car.
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You are wrong in two ways. Stroke length usually on affects torque output. You can add an inch of arm and the torque will go up but you wont see much power gain. The induction, rod length, LSA, duration @ .050, port cross section and a couple of other things make the power (horsepower).


Lets take a classic example...a 360 verses a 408. Same induction, same cam profile, same heads all that crap. The 408 will make the same power, but at a lower RPM. The 360 will make equal power but up the range a little.

Now, let's fix what's wrong. Since the 408 is SUBSTANTIALLY underinducted, we need a butt load @ .050 timing to get it to rev. It's now 2015.5 and with the parts and pieces out there if you can't make power at 7000 you deserve to get smoked. So now you have a big cam with lots of overlap and a bunch of .050 timing and probably a 106 LSA because , well I will keep that to myself for now. In a 3300 pound car, I say you need a 28 inch tall tire and about a 3.7 gear (even your big torque monster won't pull 3.55's that good).

Now, the lowly 360. I would order custom pistons that would let me run 6.25 long chevy rods. I could use about 12 less @ .050 on the intake and about 8 less on the exhaust so my cam is smaller (smaller is better right?). I now have the ability to run the engine to 7800 RPM with good parts and little trouble. That gives me 800 MORE RPM top work with. Now, I can run a 4.30 gear and use my mechanical leverage to leave you far behind because I have that leverage all the time.

If you think about it, it will make sense. It's way easier to get a less torque engine down a marginal track.
 
Back to the basics of this thread: Post an E.T. and tell us if it's a stroker or stock stroke. Tell us more about your build if ya want. So far, I'd call the stock strokers being up in the E.T.'s that has been posted...
 
j par said:
^^^^honestly if you respond to this thread again I seriously would love to see some kind of parts list or motor size or something showing that 850 pounds of torque and 425 horsepower build. It really stirs my thinking process, it's not something you hear often or in my case ever! and it's a drag race motor? I hope you don't take offense to me calling
" bull crap"!!
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First off I don't care what you think. Second, neither you or I paid for the engine or the testing so why should I post any facts about something you may not understand. Evidently, you are having comprehension issues right now.

I will say this: we did make that torque. It was validated. It did make that HP and was validated. Some of the biggest pudwhacking heros came to the track saying the cars not hooked or the tune up is off and they left wrong. The didn't learn anything, they just left the track wrong.

With that said, it was NOT a MoPar this was done with. It was a GM brand. The original port work was done by a well known GM super hero (I hear he has his own cape too) and he wanted in on the "loop" while I corrected the heads for "big torque". When he read the final print out he said I was nuts...that I had killed every bit of torque and it would wind up like a sewing machine (among other things). For the record...I spent hours killing flow below .250 lift. Just murdered it. But by .500 lift they were killing the super hero ports. Then, to really piss him off, I killed the exhaust the same. The GM super hero now wants me to never pick up a grinder again. But my mid and high lift numbers were ball busters (because the customer wanted TORQUE and NOT horsepower and the customer is ALWAYS RIGHT).


We then added compression until we had 11.85:1 and this was a pump gas engine. Now GM super hero guy wants to strangle me. He tells me 550 HP and 520 TQ. So then I tell him I put as much cross section in the intake as I could without welding. Now the GM super hero wants to call a 5150 on me and have me fed jello 3 times a day.

In the end, the customer got EXACTLY what he paid for. And it ran exactly what I told him it would.

You can't fool mother nature.

FWIW this was a corporate GM build well over 500 CID. We didn't do anything without long, comprehensive phone calls with my cam guys. I spent more than billable hours on those heads just in testing. If we had used an HP cam, took 100 inches out of it, it would have made 650-675 HP and about 600TQ and it would have ran in the 9's. Instead, he had an 11 second car to match his 11 second mouth.

Anything else?





CLASS..............................................DISMISSED
 
Love your Post MadScientist, i've never laughed so hard while learning quite a bit, Keep swinging, I'd love for 1 of these engine builders to chime in on this thread, Very Interesting Topic, myself i'm running a stock stroked 360 and love the hell out of it, no tracks close to me anyways!!!!!
 
j par said:
^^^^honestly if you respond to this thread again I seriously would love to see some kind of parts list or motor size or something showing that 850 pounds of torque and 425 horsepower build. It really stirs my thinking process, it's not something you hear often or in my case ever! and it's a drag race motor? I hope you don't take offense to me calling
" bull crap"!!
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I was going to say, must of been a negative pressure supercharger :wack:
 
^^^^honestly if you respond to this thread again I seriously would love to see some kind of parts list or motor size or something showing that 850 pounds of torque and 425 horsepower build. It really stirs my thinking process, it's not something you hear often or in my case ever! and it's a drag race motor? I hope you don't take offense to me calling
" bull crap"!!

Just curious j par, what do you do for a living to call bull crap?
 
So we have a best E.T. of 10.3's from a stock stroke motor after 4 pages in. Kind of funny, more bickering than posting of E.T.'s :D
 
Kind of funny, more bickering than posting of E.T.'s

I agree. I was just looking to make the scrutiny fair. Mad seems to be the only one having his credentials in question here. Madscientist presented a difference of popular opinion and backed his ideas up with simple facts and logic that no one has been able to really make a good argument against other than to question him and his abilities or knowledge.
I too am interested to read about builds and results so I can compare what I want to do with what has been done or is being done. Maybe I can learn from other peoples mistakes? So, this is the last I will comment on this issue. The OP's thread has been hijacked enough and in fairness to him, and my interest in the builds as well, I'm going to sit back and look for results.

If someone has a 3.79 stroke build I'd be especially interested in that.
 
I agree. I was just looking to make the scrutiny fair. Mad seems to be the only one having his credentials in question here. Madscientist presented a difference of popular opinion and backed his ideas up with simple facts and logic that no one has been able to really make a good argument against other than to question him and his abilities or knowledge.
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Logic is often something no one will question just because it makes sense, but simple facts still sometimes require validation through empirical data. Now, I'm not questioning mad's skills, but I've seen quite a few builds too, and I don't think I've seen any 500ci big blocks that made less than 500hp when the torque rating was over 800lb/ft (UNLESS...you're talking about where the hp sat AT the torque peak, which says nothing about the hp peak). Typically, It's the other way around, just not to that extreme...like if you build up a 360 to make over 500hp, the torque won't be quite as high unless you find ways to fortify the oxygen content unless you're talking about a nitrous engine in which case, I've witnessed those dyno runs where a LS1 on a 180 shot made 520hp, but 680lb/ft of torque. (EDIT: this one was on a chassis dyno, FWIW)

All that being said, I'm not questioning it on here because it turns into a pissing match...and this thread is already full of it.

If someone has a 3.79 stroke build I'd be especially interested in that
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...look at MRL...use the search function...he might've made one in the past.
 
ebigga67 said:
^^^^honestly if you respond to this thread again I seriously would love to see some kind of parts list or motor size or something showing that 850 pounds of torque and 425 horsepower build. It really stirs my thinking process, it's not something you hear often or in my case ever! and it's a drag race motor? I hope you don't take offense to me calling
" bull crap"!!

Just curious j par, what do you do for a living to call bull crap?
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I clean out houses for a living, my job sucks crap! so I know bullcrap when I smell it! you read his half assed explanation of how to make 850 foot pounds of torque and only 425hp? because someone gets on the internet and has a bunch of laid out writing and it sounds all good doesn't make it true or werth crap. He questioned our thinking, could I question his??. Bonjour, l'm a supermodel!! so back to it my best time is at 11.88 @ 117mph. moving forward.......?

20 post newbee what do you do for a living? Wait a minute ..... that's none of my business and I don't care!
 
Personally I love my stroker. Wide flat torque curve with good street manners. Mine has around 15" hg vacuum too. See the dyno sheet.
 

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20 post newbee what do you do for a living?
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Easy J...we all entered this forum with zero posts...some with over 20 years worth of car/engine building under their belt. I tend to agree it's bad form to show up and start flinging poo, but hey, it's a forum...the trolls abound ;)
 
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