Lets talk small block stroker cranks

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B3422w5

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As far as i am aware they come in the following flavors( generally available)
3.79
4.0
4.125
4.250

I used to be a big believer in the more inches the better. I know Ron Silva creatlvely came up with a 501 inch monster a few years back.
But in more recent times i think the 3.79 crank and if possible a big bore make the most effective combination, up to and including W8 heads.
The fact is most of these long arms create more inches than the majority of available heads can handle.
I have only run W5 heads thus far as the best i have used, and even they are marginal with a 4 inch crank.
They also start to get a diminishing return regards side loading, rod ratio and other things with the longer arms. You kinda get to the point do you want to drag race or sit on a tractor and plow a field.
Has anybody on here used 4.125/ 4.250 stuff, how did you like it? Race or street
Curious what the gurus on here( builders) think.
 
I'm not a guru but reading about BBC's with the 4.25" crank, it is recommended to use rectangular port heads to make the power. The ovals will give you more low end torque at the expense of top end power. A large inch short block could be built now, use you r current heads. If acceptable, leave as is or replace with a higher flow head later.Only my opinion,FYIW.
 
Mopar had quite a few stroker offerings back in the day. 3.454, 3.51, 3.58, 3.65, 3.79 and perhaps a few others.
I agree on the 3.79. Great drag racing combo with good heads. Going to try the 3.58 next myself for some street fun.
 
As you already noted, even a W-5 head struggles with a 4 inch stroke. I can make the argument that it isn't good enough (without massive work) to feed 345 inches at 8500.

We need to remember what these heads were designed for. The W-2 was designed for 330-340 inch engines, that were significantly induction limited. The W-5 head was an improvement on the W-2 and that's about all of that.

I've said before that a W-2 based engine, with today's cam and valve train with a reasonable RPM of say 7500 shift speed, with a well prepped head can only truly support 360, maybe 370 inches at that RPM. A single 4 hampers it even more, and required more total cam timing and will require more transmission gears with closer splits to keep the engine from falling too far below peak torque on gear changes.

With well prepped W-5 heads and the same configuration, my opinion is 385 inches or so is about all you can feed, relatively well.

That doesn't mean you can't use more inches. It will be down on specific power output, as in HP/CID and requires more cam timing, which obviously will start to peak the torque curve.

If you have enough gears, you can hobble the deal through.

That's my random thoughts on your question.

One last thought...if you use a 3.58 or even a 3.79 stroke crank I'd stick the longest rod in it I could. I'd rather use a 3.58 stroke and a 6.25 rod than be stuck with a 6.125 rod and a 3.79 stroke. When you become induction limited, rod ratio becomes more important.
 
B3422w5 said:
As far as i am aware they come in the following flavors( generally available)
3.79
4.0
4.125
4.250

I used to be a big believer in the more inches the better. I know Ron Silva creatlvely came up with a 501 inch monster a few years back.
But in more recent times i think the 3.79 crank and if possible a big bore make the most effective combination, up to and including W8 heads.
The fact is most of these long arms create more inches than the majority of available heads can handle.
I have only run W5 heads thus far as the best i have used, and even they are marginal with a 4 inch crank.
They also start to get a diminishing return regards side loading, rod ratio and other things with the longer arms. You kinda get to the point do you want to drag race or sit on a tractor and plow a field.
Has anybody on here used 4.125/ 4.250 stuff, how did you like it? Race or street
Curious what the gurus on here( builders) think.
Click to expand...
Rod Bloomer still has the 4.25 cranks?
What are you thinking of doing?
I have thought about it and was seriously considering running the 4.25 crank and just let the torque pull me through. But as mentioned below.....
yellow rose said:
As you already noted, even a W-5 head struggles with a 4 inch stroke. I can make the argument that it isn't good enough (without massive work) to feed 345 inches at 8500.

We need to remember what these heads were designed for. The W-2 was designed for 330-340 inch engines, that were significantly induction limited. The W-5 head was an improvement on the W-2 and that's about all of that.

I've said before that a W-2 based engine, with today's cam and valve train with a reasonable RPM of say 7500 shift speed, with a well prepped head can only truly support 360, maybe 370 inches at that RPM. A single 4 hampers it even more, and required more total cam timing and will require more transmission gears with closer splits to keep the engine from falling too far below peak torque on gear changes.

With well prepped W-5 heads and the same configuration, my opinion is 385 inches or so is about all you can feed, relatively well.

That doesn't mean you can't use more inches. It will be down on specific power output, as in HP/CID and requires more cam timing, which obviously will start to peak the torque curve.

If you have enough gears, you can hobble the deal through.

That's my random thoughts on your question.

One last thought...if you use a 3.58 or even a 3.79 stroke crank I'd stick the longest rod in it I could. I'd rather use a 3.58 stroke and a 6.25 rod than be stuck with a 6.125 rod and a 3.79 stroke. When you become induction limited, rod ratio becomes more important.
Click to expand...

Thank you thank you thank you!

You have taken the words right out of my mouth!
100%, I agree.
I also figure the head flow/port size/volume, etc....
can only support so much in certain applications and sizes before the limitations show up. Then compromise ones into play. Which leads me to think (or rethink) why go there? Well, I can see why but also question it and ponder the worth and the methods used to obtain more with less.

Yes, it is possible but why when there’s other ways and material to be used. OK! Money limitations are an issue. Throwing away good parts is senseless to a degree. An example could be perfectly good high flowing W5’s on top of a 440 did small block and all out racing effort..... There is a better head for this, but cost could be an issue.

Limitations!
 
yellow rose said:
We need to remember what these heads were designed for. The W-2 was designed for 330-340 inch engines, that were significantly induction limited. The W-5 head was an improvement on the W-2 and that's about all of that.
Click to expand...
Best single 4 being the INDY and the tunnel ram dual quads. Unless you know of a manufacturer of a IR set up....

I've said before that a W-2 based engine, with today's cam and valve train with a reasonable RPM of say 7500 shift speed, with a well prepped head can only truly support 360, maybe 370 inches at that RPM.

With well prepped W-5 heads and the same configuration, my opinion is 385 inches or so is about all you can feed, relatively well.
Click to expand...
That’s how I see it at a max. I pondered the worth of the new Victor head on these displacements.
These displacements & heads still make a good package, street or strip. But only so quick they can run.
One last thought...if you use a 3.58 or even a 3.79 stroke crank I'd stick the longest rod in it I could. I'd rather use a 3.58 stroke and a 6.25 rod than be stuck with a 6.125 rod and a 3.79 stroke. When you become induction limited, rod ratio becomes more important.
Click to expand...
Yup!
 
I didnt think you guys ran the stroker cranks that fast. Thought it was more of a torque thing. I rev limit my MP cast 4.00 stroker to 6200 RPM. I dont want any faster piston speed than that.
 
rumblefish360 said:
Rod Bloomer still has the 4.25 cranks?
What are you thinking of doing?
I have thought about it and was seriously considering running the 4.25 crank and just let the torque pull me through. But as mentioned below.....


Thank you thank you thank you!

You have taken the words right out of my mouth!
100%, I agree.
I also figure the head flow/port size/volume, etc....
can only support so much in certain applications and sizes before the limitations show up. Then compromise ones into play. Which leads me to think (or rethink) why go there? Well, I can see why but also question it and ponder the worth and the methods used to obtain more with less.

Yes, it is possible but why when there’s other ways and material to be used. OK! Money limitations are an issue. Throwing away good parts is senseless to a degree. An example could be perfectly good high flowing W5’s on top of a 440 did small block and all out racing effort..... There is a better head for this, but cost could be an issue.

Limitations!
Click to expand...


The only cranks Rod currently has in inventory are 360 main 4.125 and 4.250.
I have an assembled 4 inch 418 i plan to use with trick flows. To big for those heads but i have limited goals( lower 10’s)
 
pishta said:
I didnt think you guys ran the stroker cranks that fast. Thought it was more of a torque thing. I rev limit my MP cast 4.00 stroker to 6200 RPM. I dont want any faster piston speed than that.
Click to expand...

I ran a 4 inch i had 7500 every pass, no issues
 
Pretty sure a 4.00 stroke will easily get you where you want to go. My 408 went 9.70’s with Edelbrock heads at 2860 pounds with a powerglide in my duster and 10.08 in the summer heat at 3200 pounds in my sons Duster with a 727 transmission. His current stock crank 360 has gone 6.54 which should be 10.20’-10.30’s.
 
pittsburghracer said:
Pretty sure a 4.00 stroke will easily get you where you want to go. My 408 went 9.70’s with Edelbrock heads at 2860 pounds with a powerglide in my duster and 10.08 in the summer heat at 3200 pounds in my sons Duster with a 727 transmission. His current stock crank 360 has gone 6.54 which should be 10.20’-10.30’s.
Click to expand...


I forget what heads are on your kids engine?
 
yellow rose said:
I forget what heads are on your kids engine?
Click to expand...


He has my old set of Edelbrock heads that I ported with 2.08 intakes. They were an old set of open chamber 340 style heads that a guy on Moparts hurt and sold them to me for 450.00
I have Indy 360-1’s on my engine now
 
B3422w5 said:
The only cranks Rod currently has in inventory are 360 main 4.125 and 4.250.
I have an assembled 4 inch 418 i plan to use with trick flows. To big for those heads but i have limited goals( lower 10’s)
Click to expand...
Thanks on the Bloomer info.

I think you’ll be in good shape.
The way I see it, the engine could use more head but at the same time, it can make do with what your plan is. Pittsburgh racer has an excellent example though he is very light weight, the other end of the equation..... power to weight....

I forget what the trick flows flow but 300 cfm area is enough to make enough power to do your ET number. Of course, how you get it done is one of many ways the cat is skinned. I wouldn’t be worried about it. You did well with the W5’s. How well did there numbers do vs the Trick flows?
 
38059074622_866a8248eb.jpg
Untitled by John Cadamore, on Flickr
 
yellow rose said:
As you already noted, even a W-5 head struggles with a 4 inch stroke. I can make the argument that it isn't good enough (without massive work) to feed 345 inches at 8500.

We need to remember what these heads were designed for. The W-2 was designed for 330-340 inch engines, that were significantly induction limited. The W-5 head was an improvement on the W-2 and that's about all of that.

I've said before that a W-2 based engine, with today's cam and valve train with a reasonable RPM of say 7500 shift speed, with a well prepped head can only truly support 360, maybe 370 inches at that RPM. A single 4 hampers it even more, and required more total cam timing and will require more transmission gears with closer splits to keep the engine from falling too far below peak torque on gear changes.

With well prepped W-5 heads and the same configuration, my opinion is 385 inches or so is about all you can feed, relatively well.

That doesn't mean you can't use more inches. It will be down on specific power output, as in HP/CID and requires more cam timing, which obviously will start to peak the torque curve.

If you have enough gears, you can hobble the deal through.

That's my random thoughts on your question.

One last thought...if you use a 3.58 or even a 3.79 stroke crank I'd stick the longest rod in it I could. I'd rather use a 3.58 stroke and a 6.25 rod than be stuck with a 6.125 rod and a 3.79 stroke. When you become induction limited, rod ratio becomes more important.
Click to expand...
Yank harder on the intake charge ,absolutely. The problem is : everyone buys into flow numbers ,.. forgetting deck height, T.D.C piston dwell during combustion cycles, and cam timing ,especially intake valve closing points...
 
rumblefish360 said:
Thanks on the Bloomer info.

I think you’ll be in good shape.
The way I see it, the engine could use more head but at the same time, it can make do with what your plan is. Pittsburgh racer has an excellent example though he is very light weight, the other end of the equation..... power to weight....

I forget what the trick flows flow but 300 cfm area is enough to make enough power to do your ET number. Of course, how you get it done is one of many ways the cat is skinned. I wouldn’t be worried about it. You did well with the W5’s. How well did there numbers do vs the Trick flows?
Click to expand...

W5 is a bigger head with more cross section than this new TF head is ever gonna have.
My W5’s were the first set Ryan ever ported. They ultimately went right at 140@ 3220 on super stock springs, so he learned well from Brett.
The trick flow deal with the 418 isnt gonna be a max effort deal. Honestly, i am getting old(62) am awaiting hip replacement surgery this fall, and have zero interest anymore i jumping through the hoops to run 9’s.
Cam wont be big enough to take full advantage of even the flow numbers trick flow claims. Probably something around 640 gross lift before lash/ deflection. Might not even run a roller even though the shortblock is tubed and set up to do so.
I have Harland Sharp rocker gear and that stuff wont clear more than a 1.50 OD spring. Looking around, i couldnt find anybody that made such a roller spring( 1.50 or smaller) Then at Norwalk Vic Bloomer told me such a spring exists that is 1.46 OD. If so, maybe i will go roller, have to get that part number from Vic.
Car wont get any lighter than what it is( 3280 ish with my 320) so of i can run 10.20-30’s i will be plenty happy. Probably need bigger header tubes than the dinky ones i have, and a nice Victor.
Its a zero deck flattop shortblock, so it should have plenty of squeeze to thump pretty good.
Those TF heads are only 60cc
 
pittsburghracer said:
View attachment 1715207213Untitled by John Cadamore, on Flickr
Click to expand...
Thank ya John....
B3422w5 said:
W5 is a bigger head with more cross section than this new TF head is ever gonna have.
My W5’s were the first set Ryan ever ported. They ultimately went right at 140@ 3220 on super stock springs, so he learned well from Brett.
The trick flow deal with the 418 isnt gonna be a max effort deal. Honestly, i am getting old(62) am awaiting hip replacement surgery this fall, and have zero interest anymore i jumping through the hoops to run 9’s.
Cam wont be big enough to take full advantage of even the flow numbers trick flow claims. Probably something around 640 gross lift before lash/ deflection. Might not even run a roller even though the shortblock is tubed and set up to do so.
I have Harland Sharp rocker gear and that stuff wont clear more than a 1.50 OD spring. Looking around, i couldnt find anybody that made such a roller spring( 1.50 or smaller) Then at Norwalk Vic Bloomer told me such a spring exists that is 1.46 OD. If so, maybe i will go roller, have to get that part number from Vic.
Car wont get any lighter than what it is( 3280 ish with my 320) so of i can run 10.20-30’s i will be plenty happy. Probably need bigger header tubes than the dinky ones i have, and a nice Victor.
Its a zero deck flattop shortblock, so it should have plenty of squeeze to thump pretty good.
Those TF heads are only 60cc
Click to expand...
Ah-ha! I see. Well, I think it’s there.
 
I have one virgin blue plug W5 Head that I grabbed just because the price was right. I would like to find a match just to play around some
 
pittsburghracer said:
That would be great. The head I have has been powder coated but I’m thinking that could be blasted off
Click to expand...

The guy who has my old car has that max effort set that Ryan did for me eons ago. They started leaking water, so guy bought a virgin set and had Modern Cnc them.
Anyhow i guess Dwayne “ fixed “ them to where he said they can be used, but my( and his now) engine builder said no.
So they are laying around on a shelf in Jersey. They made great steam.
 
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