View Poll Results: Which would you choose and why 427ci or 440ci LS7?
427ci LS7
21
30.43%
440ci LS7
48
69.57%
Voters: 69. You may not vote on this poll
427ci vs 440ci LS7
02-29-2008, 05:17 AM
#1
Banned
Thread Starter
Join Date: Jun 2005
Posts: 778
Likes: 0
Received 0 Likes
on
0 Posts
427ci vs 440ci LS7 Being priced the same as long block by some vendors, I would like to get opinions about which do you prefer for all out, NA, FI or Nitrous use. Which will be more reliable?
02-29-2008, 06:26 AM
#2
10 Second Club
iTrader: (10)
Join Date: Feb 2004
Location: Manteca, CA
Posts: 1,212
Likes: 0
Received 0 Likes
on
0 Posts
I voted 440ci because I like the promise of more cubes, although for a FI build a 427 may be a bit better suited with the smaller 4.00 stroke.
440 gets my vote...
440 gets my vote...
02-29-2008, 06:39 AM
#3
Banned
Thread Starter
Join Date: Jun 2005
Posts: 778
Likes: 0
Received 0 Likes
on
0 Posts
I know that bigger cubes create greater backpressure problem for the turbo/s.
Edited to clarify.
Last edited by bluecamaroz28; 02-29-2008 at 08:24 AM.
02-29-2008, 08:09 AM
#5
Either engine will generate plenty of exhaust gas volume for your turbocharger.
The shorter stroke will make for a thicker upper ringland. It will also theoretically increase sideloads on the piston skirts, which will shorten engine life. However I doubt you would use either engine for 100K+ miles anyway.
The shorter stroke will make for a thicker upper ringland. It will also theoretically increase sideloads on the piston skirts, which will shorten engine life. However I doubt you would use either engine for 100K+ miles anyway.
02-29-2008, 08:47 AM
#6
NA the stroke is fine as long as the builder is not in the "learn" mode.
4.125 "squared" is well within the liners of a LS7 block and requires no boring or excessive clearancing. They make > 550 square rw hp/tq. We do those.
For FI I think I would go iron block.
4.125 "squared" is well within the liners of a LS7 block and requires no boring or excessive clearancing. They make > 550 square rw hp/tq. We do those.
For FI I think I would go iron block.
Last edited by See5; 02-29-2008 at 01:38 PM.
02-29-2008, 11:14 AM
#8
Then if stroke isn't the best for FI then why does everyone go big stroke
instead of just going big bore. I think a 387cid all bore will out do a 408 stroker
both running the same boost since the 387 with spin up faster. If the engine builder
knows what he's doing you can FI any motor. Dragsters are huge stroke and they are all
blown. But some of the best performing FI cars on this site are 347 forged motors like KP.
instead of just going big bore. I think a 387cid all bore will out do a 408 stroker
both running the same boost since the 387 with spin up faster. If the engine builder
knows what he's doing you can FI any motor. Dragsters are huge stroke and they are all
blown. But some of the best performing FI cars on this site are 347 forged motors like KP.
02-29-2008, 11:19 AM
#9
Then if stroke isn't the best for FI then why does everyone go big stroke
instead of just going big bore. I think a 387cid all bore will out do a 408 stroker
both running the same boost since the 387 with spin up faster. If the engine builder
knows what he's doing you can FI any motor. Dragsters are huge stroke and they are all
blown. But some of the best performing FI cars on this site are 347 forged motors like KP.
instead of just going big bore. I think a 387cid all bore will out do a 408 stroker
both running the same boost since the 387 with spin up faster. If the engine builder
knows what he's doing you can FI any motor. Dragsters are huge stroke and they are all
blown. But some of the best performing FI cars on this site are 347 forged motors like KP.
02-29-2008, 11:23 AM
#10
Then if stroke isn't the best for FI then why does everyone go big stroke
instead of just going big bore. I think a 387cid all bore will out do a 408 stroker
both running the same boost since the 387 with spin up faster. If the engine builder
knows what he's doing you can FI any motor. Dragsters are huge stroke and they are all
blown. But some of the best performing FI cars on this site are 347 forged motors like KP.
instead of just going big bore. I think a 387cid all bore will out do a 408 stroker
both running the same boost since the 387 with spin up faster. If the engine builder
knows what he's doing you can FI any motor. Dragsters are huge stroke and they are all
blown. But some of the best performing FI cars on this site are 347 forged motors like KP.
02-29-2008, 01:29 PM
#13
Launching!
Join Date: Oct 2007
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
LS7 block with 4.1" stroke, 438 cubes. Plenty of cylinder wall for piston stability with the high pin. Might as well get as many cubes as possible - this is what I'm building. There may be a small difference in the acceleration speed but it won't be much and valvetrain will probably be the rev limiting factor anyway.
If you're planning on some major spray or boost, either an LSX or Warhawk and pick the stroke and bore accordingly. One other thing to consider - rumor has it that there will be a raised cam/tall deck LSX block available that'll go to 500 cubes. I'd expect cylinder walls to be longer to handle all that stroke. Hell, yeah!!!!
If you're planning on some major spray or boost, either an LSX or Warhawk and pick the stroke and bore accordingly. One other thing to consider - rumor has it that there will be a raised cam/tall deck LSX block available that'll go to 500 cubes. I'd expect cylinder walls to be longer to handle all that stroke. Hell, yeah!!!!
Last edited by Busted Knuckles; 02-29-2008 at 04:19 PM.
02-29-2008, 05:19 PM
#14
10 Second Club
iTrader: (10)
Join Date: Feb 2004
Location: Manteca, CA
Posts: 1,212
Likes: 0
Received 0 Likes
on
0 Posts
Shoot we are using the Wiseco 4.187" custom forged nitrous pistons, Childs & Albert Fire Power rings (.043" .043" 3mm) with N2O... I have faith in our builder!
03-01-2008, 09:25 AM
#17
Registered User
Join Date: Feb 2008
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
There's no replacement for displacement like everyone says. I love that down low end grunt that a higher displacement engine gives you. When I get ready for a new engine, I'm going to be looking at the LSX 454 engine. I want some cooking down low torque and still want it to be my bi-weekly/daily driver!
03-01-2008, 06:47 PM
#18
370 motor Blanco,
True i like the 370. I ran the numbers on a engine building program and the 370 was a great motor and showed potential. someday i wanna try either a
387 all bore with 12lbs, or go crazy with 427 or 454 with low boost mostly cause those motor sizes are classic chevy size motors
Den
True i like the 370. I ran the numbers on a engine building program and the 370 was a great motor and showed potential. someday i wanna try either a
387 all bore with 12lbs, or go crazy with 427 or 454 with low boost mostly cause those motor sizes are classic chevy size motors
Den
03-04-2008, 09:04 AM
#20
11 Second Club
iTrader: (12)
Join Date: Sep 2006
Location: Utah
Posts: 647
Likes: 0
Received 0 Likes
on
0 Posts
personally I was looking at the 440 as well, I currently have a 427 and its almost too much hahaha but as soon as I can get a tall deck warhawk sourced I am going for a 472 or a humble "little" 500 cubic in small block that would be righteous!!!!!
