Need advice Building a motor LQ4 or LQ9
09-02-2010, 12:07 PM
#1
Need advice Building a motor LQ4 or LQ9 I am wanting to build a budget friendly big stroker engine for an 4th gen f body, and I am new to the LS motors so I have lots of questions on what will and what won’t work. I bought the car as a fun toy and want to build a big naturally aspirated motor which I will tune and run on e85. It will primarily be a street car with occasion trips to the drag strip. I have been reading around and it seems as if most guys prefer the LQ9 truck engines. I want to build a stroker big bore, would ideally like to build a 427ci naturally aspirated motor to make as much power as possible. What I was thinking was get one of these truck engines as cheap as possible. I have a hook up for a crank, rods, and pistons from wiseco. Then I was thinking I would try and find LS3 intake and heads.
I know the LQ4 engines have a longer crank and flex plate causing issues, however if I am replacing the crank, rods, and pistons, heads and intake does it matter if I go with the cheaper LQ4 engine? Are the 6.0L engines the same blocks? Also on these blocks what is the largest bore and stroke you can safely go to? I believe I read that if you go with a 4” bore then it is okay to use the LS3 heads? Is this true and will the heads and intake bolt on with no issue?
As far as crank and rods I have a hook up and can get the K1 technology crank and rods threw wiseco, along with wiseco pistons. However K1 technologies only offer a forged crank. Are these good cranks? And what kind of power will they hold up to? I’m debating on going with those versus a billet crank. (My goal is a 600 rwhp street car naturally aspirated with high compression running on e85)
As far as performance mods, and fitting this engine into the car what do I need to be aware of? Do I need some type of adapter for the reducer wheel to get the right number of teeth, or is this specified when I order a new crank? What about throttle bodies? Do I get a throttle body setup for an ls1 car but is as large as the ls3 intake is ported too? I assume the headers for an ls1 will also work on the ls3 heads? Is the oil pan on lq4 or lq9 work in a f body? I have a hook up for injectors to get larger to supply the fuel needed for a big engine on e85. I believe the ls3’s take different type of injectors and fuel rails but that should come with the tock ls3 intake, correct? What about coils, will the stock ls1 coils bolt up to the ls3 heads? Also will accessories and stuff also hook up to the block and heads like it did on the original ls1 out of the car?
Mainly I am looking for tips and advice from people that have done something like this, as I don’t want to be half way through building an engine and realize it isn’t going to work. I’d like to know up front everything I will need to get, and or modify for it to work and work reliably. Also if you have any other suggestions for what i could use, i'm not set on using an lq4 or 9 was thinking it would be a cheap route to go, so if you have any other ideas lets here them.
I know the LQ4 engines have a longer crank and flex plate causing issues, however if I am replacing the crank, rods, and pistons, heads and intake does it matter if I go with the cheaper LQ4 engine? Are the 6.0L engines the same blocks? Also on these blocks what is the largest bore and stroke you can safely go to? I believe I read that if you go with a 4” bore then it is okay to use the LS3 heads? Is this true and will the heads and intake bolt on with no issue?
As far as crank and rods I have a hook up and can get the K1 technology crank and rods threw wiseco, along with wiseco pistons. However K1 technologies only offer a forged crank. Are these good cranks? And what kind of power will they hold up to? I’m debating on going with those versus a billet crank. (My goal is a 600 rwhp street car naturally aspirated with high compression running on e85)
As far as performance mods, and fitting this engine into the car what do I need to be aware of? Do I need some type of adapter for the reducer wheel to get the right number of teeth, or is this specified when I order a new crank? What about throttle bodies? Do I get a throttle body setup for an ls1 car but is as large as the ls3 intake is ported too? I assume the headers for an ls1 will also work on the ls3 heads? Is the oil pan on lq4 or lq9 work in a f body? I have a hook up for injectors to get larger to supply the fuel needed for a big engine on e85. I believe the ls3’s take different type of injectors and fuel rails but that should come with the tock ls3 intake, correct? What about coils, will the stock ls1 coils bolt up to the ls3 heads? Also will accessories and stuff also hook up to the block and heads like it did on the original ls1 out of the car?
Mainly I am looking for tips and advice from people that have done something like this, as I don’t want to be half way through building an engine and realize it isn’t going to work. I’d like to know up front everything I will need to get, and or modify for it to work and work reliably. Also if you have any other suggestions for what i could use, i'm not set on using an lq4 or 9 was thinking it would be a cheap route to go, so if you have any other ideas lets here them.
09-02-2010, 05:03 PM
#2
Get an LQ4 same block but cheaper.
.060 overbore is MAX. You choose the stroke. Remember the more stroke the farther the piston comes out of the hole at BDC and can cause sideloading and oil consumption issues I would do 4.125 stroke MAX..
That forged crank will hold more power than you will ever make n/a. K1 is a good crank and 4340 steel.
Assuming you already have a 4th gen LS1 PCM run a 24 tooth. If you don't have one read this thread and decide which PCM/reluctor combo you want. >>> https://ls1tech.com/forums/generatio...e-24x-58x.html
Yes LS1 headers will work. Get the biggest primary tubing you can. preferably 2"
Yes you will need LS3 rails and a bigger injector than LS3 OEM...
You will need LS3 coil brackets but I am 99% sure the rest is plug-n-play..
F-body oil pan needed to clear the K-member.
Yes on accessories and brackets. The block is tapped for only two alternator bracket bolts so you can tap the 3rd or will be fine on just 2.
And lastly don't be disappointed if you don't see 600rwhp.........
.060 overbore is MAX. You choose the stroke. Remember the more stroke the farther the piston comes out of the hole at BDC and can cause sideloading and oil consumption issues I would do 4.125 stroke MAX..
That forged crank will hold more power than you will ever make n/a. K1 is a good crank and 4340 steel.
Assuming you already have a 4th gen LS1 PCM run a 24 tooth. If you don't have one read this thread and decide which PCM/reluctor combo you want. >>> https://ls1tech.com/forums/generatio...e-24x-58x.html
Yes LS1 headers will work. Get the biggest primary tubing you can. preferably 2"
Yes you will need LS3 rails and a bigger injector than LS3 OEM...
You will need LS3 coil brackets but I am 99% sure the rest is plug-n-play..
F-body oil pan needed to clear the K-member.
Yes on accessories and brackets. The block is tapped for only two alternator bracket bolts so you can tap the 3rd or will be fine on just 2.
And lastly don't be disappointed if you don't see 600rwhp.........
09-02-2010, 07:38 PM
#3
Thanks for the help on this stuff. Yeah I'm not too worried what the actual power output will be. i own my own dyno so i know how guys sling numbers around the internet. I am mostly looking to build a very fast street car to have fun in, and one that lopes like a mother as i never get tired of a v8 lopy idle.
with the 4.125" stroke crank and 4.060 over bore i am right at my goal of 427 ci. However i will likely inspect the block and bore it only as much as i need to clean it up, in case i need to go further in the future.
should i go with billet rods or are forged rods also ok to run naturally aspirated? If i ever did decide to supercharge it (as i have been know to custom build supercharge and turbo setups for fun) what would a forged crank be able to handle power wise?
Also on a 4.125" stroke is oil consumption an issue, or once you go bigger? reason i ask is i have been reading around and it seems as if some say it is okay and some say they burn oil. some say 4" stroke is max you need, but then a few guys say a larger stroke is okay when setup properly. Well how are they setting it up properly???? In past experiences with building big motors the design of piston and type of rings made a huge difference in whether a motor burnt oil or whether it sealed and ran good, and simply swapping piston brands solved the problem.
now that i'm on the topic of pistons, what do they use to accommodate the longer stroke crank? are they simply offsetting the piston pin for the added stroke? aka using a special stroker piston? Also on a longer stroke crank like this are they using stock length rods? I never read what everyone was using on these strokers cranks to make them fit.
I have the stock ls1 so i will have the oil pan and stuff off of it to reuse. My last question would be is my flywheel and clutch going to fit on this lq4 motor and crank? i would assume so but want to make sure. But it sounds like all the same sensor wire harness etc.. that is currently on my ls1 will work when running this new block with ls3 heads?
btw, anyone know of a great source for a cheap lq4 motor and ls3 heads and intake?
with the 4.125" stroke crank and 4.060 over bore i am right at my goal of 427 ci. However i will likely inspect the block and bore it only as much as i need to clean it up, in case i need to go further in the future.
should i go with billet rods or are forged rods also ok to run naturally aspirated? If i ever did decide to supercharge it (as i have been know to custom build supercharge and turbo setups for fun) what would a forged crank be able to handle power wise?
Also on a 4.125" stroke is oil consumption an issue, or once you go bigger? reason i ask is i have been reading around and it seems as if some say it is okay and some say they burn oil. some say 4" stroke is max you need, but then a few guys say a larger stroke is okay when setup properly. Well how are they setting it up properly???? In past experiences with building big motors the design of piston and type of rings made a huge difference in whether a motor burnt oil or whether it sealed and ran good, and simply swapping piston brands solved the problem.
now that i'm on the topic of pistons, what do they use to accommodate the longer stroke crank? are they simply offsetting the piston pin for the added stroke? aka using a special stroker piston? Also on a longer stroke crank like this are they using stock length rods? I never read what everyone was using on these strokers cranks to make them fit.
I have the stock ls1 so i will have the oil pan and stuff off of it to reuse. My last question would be is my flywheel and clutch going to fit on this lq4 motor and crank? i would assume so but want to make sure. But it sounds like all the same sensor wire harness etc.. that is currently on my ls1 will work when running this new block with ls3 heads?
btw, anyone know of a great source for a cheap lq4 motor and ls3 heads and intake?
09-02-2010, 07:42 PM
#4
Is there another budget friendly way to build a big ci motor with high flowing heads? Seems like most like these iron blocks and the newer style heads, thus why i thought i would use lq4 and ls3 head combo.
btw, what is the weight difference between aluminum block and iron block?
btw, what is the weight difference between aluminum block and iron block?
