It’s Winter. Let’s discuss strokers. How much faster

[pittsburghracer]

Don’t be bashful about posting up car weight (I never am) as that tells a story too. I think the thing I’ve tried to get across on this site more than anything is these engines LOVE lots of converter stall. Mats at 5600 and I’m at 5760. And please don’t say you can’t run high stall on the street. That has been proven wrong.

 

[B3422w5]

What was your N/A ET for your small block ?

11.26 with 360
10.77 with stroker

 

[318willrun]

11.26 with 360
10.77 with stroker

Then I'm not wrong as of your ET, you weren't nowhere near the fastest et posted. There were low 10 and 9 second et's posted by stock stroke N/A cars. Again, I think the fastest et's posted were by stock stroke motors. I'm not saying that proves anything, but it is a testimony.

 

[B3422w5]

Then I'm not wrong, you weren't nowhere near the fastest et posted. There were low 10 and 9 second et's posted by stock stroke N/A cars.

my bad then. I was talking the difference between running a combo as a non stroker, then moving all your parts onto a stroker short block then comparing the ET’s.
That is what i actually did….
Yes, i am certainly not the fastest, never claimed to be.
Fastest stock stroke i know of runs mid 9’s with a 20 over 340 with 1.88 valve production heads. It isn't mine..lol

 

[318willrun]

my bad then. I was talking the difference between running a combo as a non stroker, then moving all your parts onto a stroker short block then comparing the ET’s.
That is what i actually did….
Yes, i am certainly not the fastest, never claimed to be.
Fastest stock stroke i know of runs mid 9’s with a 20 over 340 with 1.88 valve production heads. It isn't mine..lol

But your car is a nice comparison of a before and after. That is a testimony to the topic for sure. Thanks for sharing.

 

[9secRR]

Don’t be bashful about posting up car weight (I never am) as that tells a story too. I think the thing I’ve tried to get across on this site more than anything is these engines LOVE lots of converter stall. Mats at 5600 and I’m at 5760. And please don’t say you can’t run high stall on the street. That has been proven wrong.

2860 lbs, 5600 stall, 4.86 gear.
Years ago I ran 5400 stall on the street with no issues.

 

[moparstud440]

With everything being equal and just changing the short block from 360 to a 408 I'd say it's prob worth 4-5 tenths in the 1/4. My dad went from 11.70s (360 with .533 hydraulic cam, 10:1) to 10.70s (408 with .570s cam and 12:1). Car weighs 3250ish with him, 727, 8" convertor, Dana 60 with 4.56 gears. Shifts at 6,000, crosses strip around 6400.

Unless your starting with a decent short block that doesn't need the crank turned it really doesn't cost much more to go the stroker route. Some guys start with a bare block and have to buy an entire rotating assembly and in most cases a 360 vs 408 cost the same. I built a 360 about 5 years ago and wish I did things differently. I had Scat rods and didn't realize a 360 and 408 uses the same rod length. I had to have my crank turned $200. At that time a forged stroker crank was maybe $4-500. Pistons pretty much cost the same, so for another $2-300 I could've had a stroker that would've made more HP. If car is strictly a street car, just use whatever you have, it's not like most are utilizing all the HP the car has on the streets anyways.

 

[273]

Top end makes power eg. Heads cam bore intake carb cr etc. displacement dictates where that powerband will be eg. idle -5000 or 3000 - 7500 etc.

Which we all know for the street lower is better but for the track bore size with a stroke that allows good stroke to bore and rod ratio and minimal friction. I read a long time ago Chrysler recommended a max of 92% bore to stroke ratio for power to friction.

A lot keep on saying displacement makes torque and hp, never say how that can be accomplished, we all know displacement is the main way to make torque but more displacement trades rpm for torque with a given top end.

How does displacement make hp ??

 

[fishmens67]

Another short story. My first car was a 1970 six cylinder (300) that I learned how to tune on. I raced almost anything back then but it was a time period where almost everything made had a doggie 350 Chevy in them. Most of the guys were older but knew me so after I beat them and we stopped to BS they always said “what’s in that thing”. I would always tell them a 302 and they would be happy they weren’t beat by a 6 cylinder. My buddy’s would crack up laughing.

What was your ET/ MPH difference between the 360 and 408.

 

[pittsburghracer]

I met and talked to the guy that was one of the engineers that planned, designed, and made the Ritter block with Ken. While sipping on a few adult beverages he was trying to talk me into building a small block instead of my 572 for my heads up car. I forget if he ran Stock or Super Stock class but he couldn’t get over the fact that everyone was moving to and promoting stroker engines for every build.

 

[pittsburghracer]

What was your ET/ MPH difference between the 360 and 408.

Not as much as you guys are seeing. I like to sit back and read and listen before I chime in. I’m checking out the girls at Walmart right now but I’ll post up numbers when I get home.

 

[B3422w5]

Top end makes power eg. Heads cam bore intake carb cr etc. displacement dictates where that powerband will be eg. idle -5000 or 3000 - 7500 etc.

Which we all know for the street lower is better but for the track bore size with a stroke that allows good stroke to bore and rod ratio and minimal friction. I read a long time ago Chrysler recommended a max of 92% bore to stroke ratio for power to friction.

A lot keep on saying displacement makes torque and hp, never say how that can be accomplished, we all know displacement is the main way to make torque but more displacement trades rpm for torque with a given top end.

How does displacement make hp ??

The old IHRA “ mountain motor” pro stocks were quicker and faster than the NHRA pro stock cars. Correct me if i am wrong, but i think basically the only difference was the cubes

 

[B3422w5]

What was your ET/ MPH difference between the 360 and 408.

my just completed swap( last season) the difference was about 4.5 mph from 360 to 418

 

[fishmens67]

I met and talked to the guy that was one of the engineers that planned, designed, and made the Ritter block with Ken. While sipping on a few adult beverages he was trying to talk me into building a small block instead of my 572 for my heads up car. I forget if he ran Stock or Super Stock class but he couldn’t get over the fact that everyone was moving to and promoting stroker engines for every build.

You build a 572 right there is no small block stroker that would touch it.
Take your time at Walmart, make sure you get you a good one.

 

[Rat Bastid]

The old IHRA “ mountain motor” pro stocks were quicker and faster than the NHRA pro stock cars. Correct me if i am wrong, but i think basically the only difference was the cubes

But not by enough to say the big inch engine was better because it was far less efficient and gave up too much rpm.

 

[Rat Bastid]

You build a 572 right there is no small block stroker that would touch it.
Take your time at Walmart, make sure you get you a good one.

Depends on weight, gear and rpm. You can’t give up rpm at the track and think you’ve done something. There is a reason even the “super” class racers are turning their 632 and bigger stuff 8k plus.

 

[273]

The old IHRA “ mountain motor” pro stocks were quicker and faster than the NHRA pro stock cars. Correct me if i am wrong, but i think basically the only difference was the cubes

Cause 840 cid at 8200 rpm can move way more air than 500 Cid at 10500 rpm
Cid x rpm / 3456 = cfm
840 = 1993 cfm vs 500 = 1519 cfm

Rpm becomes a liming factor at some point and then you need to increase displacement even if it's compromised.

Eg. For the street most don't want to go higher than 5500-6000 rpm peak hp so displacement is the only with the appropriate top end. So if happy with 275-325 hp a 273 could do it but if you want 700 plus hp your gonna need 500 plus Cid or turn a 273 14000 plus rpms

 

[B3422w5]

But not by enough to say the big inch engine was better because it was far less efficient and gave up too much rpm.

right. But people in this thread are trying to say a stock stroke motor with a given head is just as fast as a stroker with the same head.
That isn't true. Have personally proven it, many times

 

[B3422w5]

But not by enough to say the big inch engine was better because it was far less efficient and gave up too much rpm.

What’s “enough”… there was a good 10 mph difference, that is a bunch.
Mountain motor has been 228 in the 6 teens
NHRA 215..
6.45

 

[273]

right. But people in this thread are trying to say a stock stroke motor with a given head is just as fast as a stroker with the same head.
That isn't true. Have personally proven it, many times

The example you gave had work to the heads more Cr different intake same gears and stall each one of those time could add up to make a difference.

It's hard to do apples to apples comparison cause a 360 vs 408 all parts have to be tailored to each of them, port of the heads cam timing gears stall intake exhaust etc...

If a 408 is making more power than a similar built 360 than that means the 408 has a higher VE% so the parts being used is more in lined with what a 408 needs vs a 360.

 

[33IMP]

If your building a stroker, better heads and more camshaft should be part of the equation. That's just common sense. Just putting more stroke in, without enough peripherals to feed it, is a waste of time and money. I wouldn't expect to see a huge improvement. Same applies to a 90% effort race motor, that is already using major power producing parts, comp ratios, heads and cams.
Which do you think will run better, an oval port 396....or a big port 496?

 

[rumblefish360]

This is kind of my point ^^. Like PBR posted, people don't "ask questions", just beller "408". To me, if a guy is building a "bracket-drag only A-body", I absolutely do NOT see the need for a "408" and end up running 11's. 70aarcuda has how many lower 10 second cars stock stroke ? PBR mid 9's stock stroke ? I seen a 3200 lbs demon go 10.9's on a stock stroke/cast head/cast iron intake and TQ. 5500 stall and 4.56 gears in a 2900 lbs drag car, whose looking at bottom end torque under 3k rpm's? Now a truck, van, or street car with a 2400 stall and 3.23 gears, then I see a huge benefit in a stroker.

Is all application dependent ain’t it?

Top end makes power eg. Heads cam bore intake carb cr etc. displacement dictates where that powerband will be eg. idle -5000 or 3000 - 7500 etc.

I don’t believe this is correct. Unless you read the “Displacement dictates power” words along with the earlier written words before “etc.”

It’s the whole package.

A lot keep on saying displacement makes torque and hp, never say how that can be accomplished, we all know displacement is the main way to make torque but more displacement trades rpm for torque with a given top end.

It depends on how the displacement is made.

How does displacement make hp ??

More air and fuel to burn.

An old engine, stroked or not, makes torque. The lobed that torque is made in the rpm range the more power it can make for hp. The stroked engine should make more torque than he non stroked engine in the upper rpm range to make more HP. If all things are equal or optimized for the given displacement.

 

[B3422w5]

The example you gave had work to the heads more Cr different intake same gears and stall each one of those time could add up to make a difference.



It's hard to do apples to apples comparison cause a 360 vs 408 all parts have to be tailored to each of them, port of the heads cam timing gears stall intake exhaust etc...

If a 408 is making more power than a similar built 360 than that means the 408 has a higher VE% so the parts being used is more in lined with what a 408 needs vs a 360.

the extra compression helps, no doubt
All the heads got was 2.05 intakes and fresh valve job, as I said, maybe 20 horse.
The excellerator is so small not sure it is any better than the airgap it .replaced.
Heads only flow to 550, have good low lift numbers, peak at 272@550
They are too small for the stroker, were not for the 360.
Of note, car picked up nearly 7 mph to the 1/8, only 4.5 in the 1/4.
Ran 6.78 in 1/8, 10.77 in 1/4, shows head is too small... but, still picked up 1/2 second in 1/4,picked up .44 in 1/8th.
1/4 numbers are like 10.60 ish car if you convert numbers.
Also reusing 1 5/8 headers.
Guess what I am saying is, 418 isn’t nearly as optimized as 360 was, still lots faster, especially in the 1/8... from 7.19 Best to 6.78. That’s a bunch

 

[273]

What’s “enough”… there was a good 10 mph difference, that is a bunch.
Mountain motor has been 228 in the 6 teens
NHRA 215..
6.45

Cause the mountain motor can move around 30% more air, the 500 would have to spin 30% higher to achieve the same potential eg. 14000 rpm lol but I imagine the mountain motor has a bigger bore which is the ultimate limiting factor for power.

 

[pittsburghracer]

Ok here’s my example. Like I said both engines were in the same 1970 Duster (3200 pounds) 727 with 5600 stall. Same heads but a ported Victor340 on the 360 and a ported Super Victor on the 408. The 360 had a .620 lift Reed roller cam (that’s all we could fit for valve to piston clearance). The 408 had a .660 lift roller cam. Now this 408 was pulled out of my duster as I felt it was due for its 4th rebuild but my son needed it so I let him use it. He only ran it 1/4 mile one weekend in semi bad summer air at Keystone (1100-1200 feet altitude) and it ran a 10.12. The best 1/8 mile was 6.38 thru the exhaust. He never ran the 360 the full 1/4 and it ran 6.54 four or five times. Here’s a conversion chart for 1/4 mile. This 360 not only pulled the wheels, it carried the wheels.