Barracuda Challenger Forum

Author Topic: 340: To Stroke or Not To Stroke  (Read 3479 times)

Offline dodge freak 2

  • Full Member
  • ***
  • Posts: 825
Re: 340: To Stroke or Not To Stroke
« Reply #15 on: September 18, 2012 - 05:43:49 PM »
In the old days you geared for torque and build for HP

The 340 works best wit 4.56 - 4.30 gears. The short stroke allows for all day running with 4.10 gears and 70- 75 mph. Sure it eat up the gas, only downside.

In the old days, cars got worst MPG on the freeway vs stop and go driving, then came 2.45 gears or OD.

Now today many believe torque is best to create from the engine and even 3,000 rpm on the freeways is too much 
« Last Edit: September 18, 2012 - 05:50:24 PM by dodge freak 2 »

Cuda-Challenger.com

Re: 340: To Stroke or Not To Stroke
« Reply #15 on: September 18, 2012 - 05:43:49 PM »



Offline dodge freak 2

  • Full Member
  • ***
  • Posts: 825
Re: 340: To Stroke or Not To Stroke
« Reply #16 on: September 18, 2012 - 05:49:07 PM »
The 4 inch stroke makes the piston skirts too short, the pistons rock more at TDC, there is higher fiction on the walls, the piston speed increases.

I'm glad my 340 is stock stroke, as for keeping up on the street, not a problem and if it had 4.30 gears vs 3.91's it be better yet.

Slap some W 2 heads and put in 4.30 gears and then see how it compares to a stroker engine.

High dollar BMW had a '550 hp" V10 engine, it has only a 3 inch stroke and 8,500 red line. If stroke is so great, how come BMW went with the 3 inch stroke crank ? Yeah yeah, emissions are better with a smaller bore, why its a V10 vs a V8 
« Last Edit: September 18, 2012 - 05:50:45 PM by dodge freak 2 »

Offline challengerx

  • Jr. Member
  • **
  • Posts: 366
Re: 340: To Stroke or Not To Stroke
« Reply #17 on: September 18, 2012 - 10:08:30 PM »
My first 340 years back was a 30 over 340 with x heads a hyd 509 mp cam, good intake, good pistons,headers, and 4.56 gears and it was a high revving beast that ran 12.80 in the quarter but was pretty tough to take any distance. The build was not to bad cost wise but with the gears it was brutal on gas and all those revs takes a toll after awhile. Current 340 is stroked to a 416 with scat forged crank,ross pistons, and .588 solid roller. You can't rev the stroker and my 3.91 are much better on the street and easier on the motor. Cost however was much more but I would not trade the stroker for anything.

Offline Road_Runner

  • Sr. Member
  • ****
  • Posts: 1675
  • Mopar Owner & Standard Bearer Since 1974
Re: 340: To Stroke or Not To Stroke
« Reply #18 on: September 18, 2012 - 10:12:21 PM »
I'm glad my 340 is stock stroke, as for keeping up on the street, not a problem and if it had 4.30 gears vs 3.91's it be better yet.

Slap some W 2 heads and put in 4.30 gears and then see how it compares to a stroker engine.

Does yours have W2 heads?  Aren't the ports totally different on these heads & if so what intakes are available today for these heads?  I was told the crank in my short block is forged so as long as it checked out I'd have that already for a stock stroke build.

Thanks, Jim
1970 383 Roadrunner
1973 318 Barracuda
2003 Harley FLSTC 100th Anniversary Heritage Softail
2013 Harley FLHTK 110th Anniversary Electra Glide Ultra Limited

Online Chryco Psycho

  • Global Moderator
  • C-C.com Guru
  • *****
  • Posts: 31776
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: 340: To Stroke or Not To Stroke
« Reply #19 on: September 19, 2012 - 12:22:08 AM »
W2 heads require different intake , headers rockers , valve covers & are expensive to set up but do make awesome power at the same time , most of the W2 intakes are race pieces as the heads are designed for that

Offline Road_Runner

  • Sr. Member
  • ****
  • Posts: 1675
  • Mopar Owner & Standard Bearer Since 1974
Re: 340: To Stroke or Not To Stroke
« Reply #20 on: September 19, 2012 - 09:06:09 AM »
W2 heads require different intake , headers rockers , valve covers & are expensive to set up but do make awesome power at the same time , most of the W2 intakes are race pieces as the heads are designed for that

I did a little research and TTI sells headers for these heads so that's good.  Not a ton of choices on intakes, looks like either a dual-plane M1 intake that says its RPM range is 0-6K, or hi-rise single planes from Mopar or Edelbrock with rpm ranges from 3500-8000 with nothing in between the two extremes.  Would it be a waste of time to add W2 heads and then put the dual plane on it?  I was wanting to keep a somewhat stock look including stock aircleaner that I might open up a little to breath more.  Decisions, decisions....

Thanks, Jim
1970 383 Roadrunner
1973 318 Barracuda
2003 Harley FLSTC 100th Anniversary Heritage Softail
2013 Harley FLHTK 110th Anniversary Electra Glide Ultra Limited

Offline V02Barracuda

  • Jr. Member
  • **
  • Posts: 55
Re: 340: To Stroke or Not To Stroke
« Reply #21 on: September 19, 2012 - 01:29:53 PM »
3 years ago I set out to build a 340 for the street.  I used a 3.58 stroke Scat crank, H-beams and .060 360 KB (off the shelf) pistons.  Had the block bored .020 for a nice clean-up, used Edelbrock aluminum heads and a .488/.510 lift 234/244 @ .050 cam.  Air-gap sits on top.  My 371ci engine provides plenty of torque and HP.   I have no regrets.

The only reason why I didn't go with a 4.00 inch crank was because I read that the pistons have a tendency of not staying square in the bore at BDC due to the extra stroke of the crank.  Maybe this isn't true, however, I felt it was in my best interest to use the 3.58 stroke crank for my application. 

Hope this helps you.

Offline Road_Runner

  • Sr. Member
  • ****
  • Posts: 1675
  • Mopar Owner & Standard Bearer Since 1974
Re: 340: To Stroke or Not To Stroke
« Reply #22 on: September 19, 2012 - 04:45:46 PM »
3 years ago I set out to build a 340 for the street.  I used a 3.58 stroke Scat crank, H-beams and .060 360 KB (off the shelf) pistons.  Had the block bored .020 for a nice clean-up, used Edelbrock aluminum heads and a .488/.510 lift 234/244 @ .050 cam.  Air-gap sits on top.  My 371ci engine provides plenty of torque and HP.   I have no regrets.

The only reason why I didn't go with a 4.00 inch crank was because I read that the pistons have a tendency of not staying square in the bore at BDC due to the extra stroke of the crank.  Maybe this isn't true, however, I felt it was in my best interest to use the 3.58 stroke crank for my application. 

Hope this helps you.

Reminding me there's a middle of the road option does help, thanks!  I read something about a 370 CI smaller stroker option a while back.  If you don't mind I'd like to ask a couple of questions: Where did you source your parts?  I think Muscle Motors sells this stroker kit if I remember right.  And do you think it still revs like a 340?  What I remember from the article I read (going to have to try to find it again) they said thanks to the lighter parts it actually revved better than a 'normal' 340.  Kind of the best of both worlds.

Thanks again, Jim
1970 383 Roadrunner
1973 318 Barracuda
2003 Harley FLSTC 100th Anniversary Heritage Softail
2013 Harley FLHTK 110th Anniversary Electra Glide Ultra Limited

Offline V02Barracuda

  • Jr. Member
  • **
  • Posts: 55
Re: 340: To Stroke or Not To Stroke
« Reply #23 on: September 20, 2012 - 01:05:53 PM »
Jim,

Eric from Muscle Motors helped me find the parts I wanted.  He set me up with everything I needed and they balanced it too.  The motor revs incredibly well.  The 360 pistons are a little lighter than the 340 pistons.  And the Scat crank is a few pounds lighter as well.  The crank is good up to 500 hp.  Let me know if you need anything else.

Mike

Offline Road_Runner

  • Sr. Member
  • ****
  • Posts: 1675
  • Mopar Owner & Standard Bearer Since 1974
Re: 340: To Stroke or Not To Stroke
« Reply #24 on: September 20, 2012 - 01:53:04 PM »
Jim,

Eric from Muscle Motors helped me find the parts I wanted.  He set me up with everything I needed and they balanced it too.  The motor revs incredibly well.  The 360 pistons are a little lighter than the 340 pistons.  And the Scat crank is a few pounds lighter as well.  The crank is good up to 500 hp.  Let me know if you need anything else.

Mike

Thanks Mike, I really like the idea of your build and think it just makes too much sense to do this at least vs. the stock stroke/components.  My son just picked up a CS/GT Mustang fastback 6 speed and its going to take a stout motor for the Barracuda to hang with that.  I'm not worried about super high performance, I just want to be in the neighborhood with the modern muscle cars.  I'll give Eric a call.

Later, Jim
1970 383 Roadrunner
1973 318 Barracuda
2003 Harley FLSTC 100th Anniversary Heritage Softail
2013 Harley FLHTK 110th Anniversary Electra Glide Ultra Limited

Offline EddieE

  • Jr. Member
  • **
  • Posts: 69
Re: 340: To Stroke or Not To Stroke
« Reply #25 on: September 20, 2012 - 10:21:24 PM »
I've got a 340 stroked to 416 by Ryan at Shady Dell.  He did all the engineering and parts selection with minimal input from me.  463 HP and 530 torque.  10 to 1 with a comp cam.  Power brakes and A/C so he designed it for usable vacuum, and he was right on with the final product.

My only regret is using the stock-size 10.5 flywheel and clutch, McCleod Street Pro.  When I hit the floor, even at 65 mph the clutch slips jsut a little from the torque (I can smell it).  I can still light the BFG TA 15" 265's tires at a 1500 RPM roll, but the clutch is about gone after 3,000 miles.

Think it through and use a high-dollar 11" clutch set if possible.  My little 416 makes more than original hemi HP and torque, and it handles better without the front-heavy posture (don't get me wrong, I'll take your hemi if you're jealous  :ylsuper:).  Just plan for the HP and torque and save yourself the dollars it costs to overwhelm anything that is an "upgrade from OEM spec".

Online Chryco Psycho

  • Global Moderator
  • C-C.com Guru
  • *****
  • Posts: 31776
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: 340: To Stroke or Not To Stroke
« Reply #26 on: September 21, 2012 - 05:42:48 PM »
I have seen Cascar engines restricted to a 2 bbl intake make over 500 hp using modern W2 casting

Offline Road_Runner

  • Sr. Member
  • ****
  • Posts: 1675
  • Mopar Owner & Standard Bearer Since 1974
Re: 340: To Stroke or Not To Stroke
« Reply #27 on: September 21, 2012 - 09:14:59 PM »
I've got a 340 stroked to 416 by Ryan at Shady Dell.  He did all the engineering and parts selection with minimal input from me.  463 HP and 530 torque.  10 to 1 with a comp cam.  Power brakes and A/C so he designed it for usable vacuum, and he was right on with the final product.

My only regret is using the stock-size 10.5 flywheel and clutch, McCleod Street Pro.  When I hit the floor, even at 65 mph the clutch slips jsut a little from the torque (I can smell it).  I can still light the BFG TA 15" 265's tires at a 1500 RPM roll, but the clutch is about gone after 3,000 miles.

Think it through and use a high-dollar 11" clutch set if possible.  My little 416 makes more than original hemi HP and torque, and it handles better without the front-heavy posture (don't get me wrong, I'll take your hemi if you're jealous  :ylsuper:).  Just plan for the HP and torque and save yourself the dollars it costs to overwhelm anything that is an "upgrade from OEM spec".

That's good advice on the the clutch, thanks.  Right now the car has a 904 which will likely need to beefed up or possibly replaced if my engine makes what yours does.  A 4/5 speed is an attractive upgrade, but a little harder to undo so I'm still considering that one.

thanks again, jim
1970 383 Roadrunner
1973 318 Barracuda
2003 Harley FLSTC 100th Anniversary Heritage Softail
2013 Harley FLHTK 110th Anniversary Electra Glide Ultra Limited

Offline Road_Runner

  • Sr. Member
  • ****
  • Posts: 1675
  • Mopar Owner & Standard Bearer Since 1974
Re: 340: To Stroke or Not To Stroke
« Reply #28 on: September 21, 2012 - 09:22:15 PM »
I have seen Cascar engines restricted to a 2 bbl intake make over 500 hp using modern W2 casting

So I take it you believe the dual plane M1 W2 intake rated at 6000 rpm max along with the W2 heads would still be a killer combo.  Awesome.  I really like the idea of building this engine with the W2 heads, M1 W2 dual plane, TTI headers, 3.58 stroker kit, and a Lunati cam of some description.  Figure I'll be running a 3.91 or 4.10 rear with O/D, what cam specs would you recommend for this build?  Again, decent street behavior & driveability and compatibility with the power brakes is a must.  I've got the Roadrunner for a max HP effort!

Thanks, Jim
1970 383 Roadrunner
1973 318 Barracuda
2003 Harley FLSTC 100th Anniversary Heritage Softail
2013 Harley FLHTK 110th Anniversary Electra Glide Ultra Limited

Offline 73restomod

  • Jr. Member
  • **
  • Posts: 322
Re: 340: To Stroke or Not To Stroke
« Reply #29 on: September 22, 2012 - 01:04:24 AM »
There tends to be a misconception that a short stroke motor makes less torque or at a higher rpm than that of a long stroke one. A short stroke stays a TDC longer than a long stroke motor, timing events are less critical, lastly the area of the piston increases the force on the crank throw, increasing torque. The other benefit is less valve shrouding, so more flow into the cylinder. Other benefits are piston stability which decreases friction in the bore, the rods endure far less side loading, because the piston speed is lower at any given RPM the acceleration and deceleration seen at the piston and rod, at BDC and TDC, the shock loading is lower and more progressive. Years ago Hot Rod built two identical BB Chevy's. A long stroke 540 (using World Merlin Blocks) and a short stroke. The heads, cam, intake, etc. were swapped from block to block. The short stroke motor beat the long stroke in average torque, peak torque, average HP, and peak HP hands down. The real reason to build a stroker is cost. Its just so much cheaper to by a stroker kit than it is a new block, and still have to buy the rotating assembly to run a big bore. I believe I still have that tech issue stored downstairs, I'll see if I can find it and scan in the results. Might even be in hotrod's online tech.

Sent from my DROID RAZR using Tapatalk 2
« Last Edit: September 22, 2012 - 01:10:05 AM by 73restomod »

Cuda-Challenger.com

Re: 340: To Stroke or Not To Stroke
« Reply #29 on: September 22, 2012 - 01:04:24 AM »