Why aren't super-strokers making a lot more power than the all bore motors?
12-15-2003, 04:04 PM
#21
TECH Senior Member
Sure, with a high stalling converter you can at least narrow down the RPM range you use...but not everyone has an auto tranny or cares to run a huge stall. Even with carefully chosen converters and gearing, a 500 RWHP 434 is going to outrun a 500 RWHP 388...all else being equal. You'll need more gearing (spinning things up quicker robs more power) and more converter (to come even close to keeping the power output the same at all times as the 434 which can easily make power over a wider range) with the 388.
DG, that's not at all suprising. Generally speaking, with a larger cam you'll bring the peak TQ rpm up and often you'll lower the peak TQ number. My 224/220 cam made 396 ft/lbs even with a 116 LSA. I don't see many 230+ cams making much more than that (even with their 110-112 LSAs) nor would I expect to.
DG, that's not at all suprising. Generally speaking, with a larger cam you'll bring the peak TQ rpm up and often you'll lower the peak TQ number. My 224/220 cam made 396 ft/lbs even with a 116 LSA. I don't see many 230+ cams making much more than that (even with their 110-112 LSAs) nor would I expect to.
12-15-2003, 07:17 PM
#24
Launching!
Join Date: Mar 2003
Location: Oceanside CA
Posts: 250
Likes: 0
Received 0 Likes
on
0 Posts
Here is an interesting write-up that covers the subject pretty well (although a bit dated).
http://www.g-speed.com/pbh/bore-vs-stroke.html
http://www.g-speed.com/pbh/bore-vs-stroke.html
12-15-2003, 10:41 PM
#27
Originally Posted by Linear Velocity
I'll take a little less peak torque and some power under the curve for $4k less and more reliability anyday 
12-16-2003, 01:23 AM
#28
TECH Fanatic
iTrader: (1)
Join Date: Nov 2002
Location: Venice, Ca
Posts: 1,829
Likes: 0
Received 0 Likes
on
0 Posts
Dyno numbers don't mean much without track times. Case in point. Look at reckless's car. Flat power curves not much over 400, and that car is flyin at the track. People are too interested in peak numbers, but area under the curve is what makes a fast car. That and weight reduction.
12-16-2003, 11:24 AM
#29
TECH Resident
iTrader: (1)
Join Date: Nov 2001
Location: Huntington Beach, Ca
Posts: 813
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 11 Bravo
4k difference? Not even close to that with my setup. And, no way that much more with the Eagle cranks. How is a 388 more reliable?
12-16-2003, 11:27 AM
#30
Moderator
Join Date: Apr 2002
Location: Murrieta
Posts: 814
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Linear Velocity
I was refering to a 434 setup vs a 388. A 434 is a 4.155 bore x 4.0 stroke. And yes when you add the cost of getting that 4.155 bore plus pistons, head gaskets, etc, plus $2k currently for a crank yes it adds up. There have been lots of reliability issues with a 4.155 bore, I just don't think we've perfected the process for going that big, also with a longer stroke people have had oil consumption problems as well. Basically to me, the more cubes the more potential problems you can have with it, that's why I like my 388 making 511rwhp vs having a 434 making 511 rwhp
12-16-2003, 12:26 PM
#32
TECH Senior Member
P Mack, these "small block heads" would be the envy of many big block owners. LS1, and especially LS6 heads, are awesome. 
It's the intake manifolds, not the heads, that have been limiting the larger CI engines.
600+ RWHP will become commonplace for 400ci+ Gen III engines in the not too distant future.
It's the intake manifolds, not the heads, that have been limiting the larger CI engines.600+ RWHP will become commonplace for 400ci+ Gen III engines in the not too distant future.
12-16-2003, 03:20 PM
#35
9 Second Club
Join Date: Nov 2001
Location: Bay Area, CA
Posts: 1,445
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Colonel
P Mack, these "small block heads" would be the envy of many big block owners. LS1, and especially LS6 heads, are awesome. It's the intake manifolds, not the heads, that have been limiting the larger CI engines.
600+ RWHP will become commonplace for 400ci+ Gen III engines in the not too distant future.
It's the intake manifolds, not the heads, that have been limiting the larger CI engines.600+ RWHP will become commonplace for 400ci+ Gen III engines in the not too distant future.
12-16-2003, 06:42 PM
#36
I've noticed that alot of Stroker owners run way to small of a Cam too.A popular Cam is around a 240/240.People are running close to that in 346's.The right Cam (250+)and intake will give over 600hp.
The benifit of a stroker is all the torque and hp across the rev range and still have it sound stock.An excellent daily driver with big power.
The benifit of a stroker is all the torque and hp across the rev range and still have it sound stock.An excellent daily driver with big power.
12-16-2003, 07:37 PM
#37
Originally Posted by Slowhawk
I've noticed that alot of Stroker owners run way to small of a Cam too.A popular Cam is around a 240/240.People are running close to that in 346's.The right Cam (250+)and intake will give over 600hp.
The benifit of a stroker is all the torque and hp across the rev range and still have it sound stock.An excellent daily driver with big power.
The benifit of a stroker is all the torque and hp across the rev range and still have it sound stock.An excellent daily driver with big power.
12-16-2003, 10:04 PM
#38
TECH Fanatic
iTrader: (1)
Join Date: Nov 2002
Location: Venice, Ca
Posts: 1,829
Likes: 0
Received 0 Likes
on
0 Posts
All you guys spouting about big cams don't own a big cube motor. Try building your own before telling people which cam to buy. My 242 cam makes plenty of power, and it would idle like crap with a 250 cam. It wouldn't make a difference on the ls6 intake anyhow, because like the colonel already stated that is the limiting factor. There is no difference in reliabilty between a 427 and a 388. It really depends on how the block is built that determines how it holds up (ie bearing clearance, ring gap, rod geometry, vavle train geometry)
12-16-2003, 10:51 PM
#40
Originally Posted by strokedls1
All you guys spouting about big cams don't own a big cube motor. Try building your own before telling people which cam to buy. My 242 cam makes plenty of power, and it would idle like crap with a 250 cam. It wouldn't make a difference on the ls6 intake anyhow, because like the colonel already stated that is the limiting factor. There is no difference in reliabilty between a 427 and a 388. It really depends on how the block is built that determines how it holds up (ie bearing clearance, ring gap, rod geometry, vavle train geometry)
They are talking total power,not idle.There are sheet metal intakes out there that work good with Strokers.
I'm personally going with a small cam in my Stroker because I'm not looking for all out power and crappy idle.