421Ci LQ4 Build questions
03-04-2009, 06:47 AM
#1
421Ci LQ4 Build questions Who all here has done this combo?
Basically is a 6.0L Iron block .030 over with a 4.125 stroke. Im interested in mainly what people think about the 4.125 stoke? I was planning to use large ammounts of spray on the engine that I build.
So lets talk about 4.125 stoke is it worth it?
Basically is a 6.0L Iron block .030 over with a 4.125 stroke. Im interested in mainly what people think about the 4.125 stoke? I was planning to use large ammounts of spray on the engine that I build.
So lets talk about 4.125 stoke is it worth it?
03-04-2009, 08:07 AM
#3
So Am I stuck with a 408 only? I was thinking about 12:1 compression also Is that a issue? Also what is considered too much spray for the setup I listed
just difiniatively speaking here, There is also a 4.100 instead 4.125 crank. Does this make a difference for the better?
just difiniatively speaking here, There is also a 4.100 instead 4.125 crank. Does this make a difference for the better?
03-04-2009, 08:16 AM
#4
if you are considering a large amount of spray, i would go to a 404-408" motor. get as much compression height on the piston and lowest ringland available. a stronger piston is much more valuable than extra stroke. stroke doesnt make power in comparison to nitrous and rpm
03-04-2009, 12:14 PM
#5
Our lands on the 1.050 stuff isn't bad at .250 top, .152 2nd because of the GFX rings (versus .295, .165 on the 1.110ch parts). If it were mine, I would run 4.125 with up to a 300 shot, but I'm also quick to acknowledge my own errors when I've pushed my stuff to far and chalk it up to mother nature. You'll have to take into account your tuning ability and willingness to always run Big octane if you're really going to press it..
Trending Topics
03-05-2009, 07:29 AM
#9
We at Wiseco we have a line of 4.125 stroke pistons for various bores and compression ratios. The industry standard 1.5 (.060") and 1/16 (.062") rings leave a lot to be desired in terms of available land thickness. Our 1.2mm .047 GFX ring thickness gets us into a comfortable zone for a 250 or 300 shot. There are likely piston suppliers that can do you .043" ring stuff as well as customs. Skirt shape/taper is key with the iron block to avoid heavy skirt wear.
03-05-2009, 10:06 AM
#10
FormerVendor
Who all here has done this combo?
Basically is a 6.0L Iron block .030 over with a 4.125 stroke. Im interested in mainly what people think about the 4.125 stoke? I was planning to use large ammounts of spray on the engine that I build.
So lets talk about 4.125 stoke is it worth it?
Basically is a 6.0L Iron block .030 over with a 4.125 stroke. Im interested in mainly what people think about the 4.125 stoke? I was planning to use large ammounts of spray on the engine that I build.
So lets talk about 4.125 stoke is it worth it?
03-06-2009, 05:28 AM
#11
Im thinking 250 Shot Max.
Heads havent been purchsed but im thinking a nice set of afr 225s or Texas speed has a new fully aftermarket casting 237Cc that looks promising. Im going to select all the parts when i officially find the road im going to take. I just got the block.
Heads havent been purchsed but im thinking a nice set of afr 225s or Texas speed has a new fully aftermarket casting 237Cc that looks promising. Im going to select all the parts when i officially find the road im going to take. I just got the block.
03-08-2009, 12:25 PM
#12
bump I need some verdicts? I know itll hold spray, but How much? Heres The specs on the type of pistons Im looking into:
4.000,.030
4.125 stroke
1.050 1.5, 3mm
2618 Forged
FT+3cc
12.0 C/R with 66cc Heads
This is not a daily driver, and will be sprayed very occasionally
4.000,.030
4.125 stroke
1.050 1.5, 3mm
2618 Forged
FT+3cc
12.0 C/R with 66cc Heads
This is not a daily driver, and will be sprayed very occasionally
03-08-2009, 01:50 PM
#13
TECH Enthusiast
iTrader: (51)
Join Date: Jul 2008
Location: Billings, Mt
Posts: 616
Likes: 0
Received 0 Likes
on
0 Posts
well you never know how long it will last with large amounts of no2. it depends on more than what you have listed. what injectors, fuel pump, induction, and most of all who and how will you car be tuned. will it be speed denisty? are all of the sharp spots in the combustion chamer gonna be polished down? what heads?
03-08-2009, 02:11 PM
#15
TECH Apprentice
iTrader: (5)
Join Date: Dec 2007
Location: Southern Colorado Front Range
Posts: 347
Likes: 0
Received 0 Likes
on
0 Posts
I have a set of 4.125 JE pistons I purchased used. They were used in a 4.000 stroke, 427 cid application. There is a LOT of skirt scoring on them. To this point I have not used them until I can determine the cause of the skirt scoring issue. Briannutter may have hit on the key. The thin lands and the way the piston is situated may cause a lot of lolling around of the unit in the cylinder bore in operation. One Fast Z06 may have experienced the effect of this in blowby, ring sealing issues, and increased oil consumption.
03-08-2009, 07:19 PM
#17
TECH Enthusiast
iTrader: (51)
Join Date: Jul 2008
Location: Billings, Mt
Posts: 616
Likes: 0
Received 0 Likes
on
0 Posts
thats a 13 ci inch differance, i dont think that it will matter much in hp, but the intital tq would be lower. it would not be too hard to make 600 flywheel hp.
03-08-2009, 08:17 PM
#18
11 Second Club
iTrader: (4)
Join Date: Nov 2002
Location: SoCal
Posts: 897
Likes: 0
Received 0 Likes
on
0 Posts
I've got the 4.125" crank combo. Although I don't spray mine its held up fine for years. (built in '03) W/ the sheetmetal intake mine made 630rwhp with LS6 heads but made it at over 8k rpm.
03-09-2009, 12:15 AM
#19
TECH Apprentice
iTrader: (5)
Join Date: Dec 2007
Location: Southern Colorado Front Range
Posts: 347
Likes: 0
Received 0 Likes
on
0 Posts
Wow! 8k rpm! I didn't think a 4.125" stroker would rev that high, let alone make those numbers there. What else did you do to that engine to get it to perform at that rpm?