Help with LQ9 Top end build for BMW M3 Swap
#11
Ive been debating and researching as well... Ive been told by "smart/educated" folks that keep saying 243s without a doubt...
I personally may go with some AI 243s... should be close to 500hp
#12
Moderator
iTrader: (20)
https://ls1tech.com/forums/dynamomet...k-results.html
The LS3 heads are awesome, but as mentioned they are better with the larger bore. People are making GREAT power with the 'old' cathedral port heads. I think pat G nailed what you are looking for in that build... and thats through an unlocked auto.
If I was doing heads again I'd either buy new AFR, or go with a very reputable porter like Advanced Induction or Flowtech induction.
The LS3 heads are awesome, but as mentioned they are better with the larger bore. People are making GREAT power with the 'old' cathedral port heads. I think pat G nailed what you are looking for in that build... and thats through an unlocked auto.
If I was doing heads again I'd either buy new AFR, or go with a very reputable porter like Advanced Induction or Flowtech induction.
#13
not sure about the hokus pokus..
but GM puts the ls3 heads on 4" bore from out the factory... I get tired of this talk. They rate the engines at more power too. I went with the L92 heads, and going to mill them .020 with the .040 gaskets. The cam I have will be it, Im not looking to go radical with this setup, but IMO it should walk with plenty cathedral setups, if not out perform them. I actually am building my setup to be able to outrun the bigger bore motors 6.2s!
remember the old tbi vs vortec head debate, no the old heads are better.... yea they make more tq velocity. yes. but vortec was the way to go. On a 4" bore, for the bang for the buck, and the options, L92 might be a cheaper route for equal to more power with less effort.
My cam is pretty big too, its not tame I would say, but if I want to go bigger, like say if I had a M3... I would run the Ls3 heads, milled, about .030-.040... I would then have compression up to about 11.6:1 + and I would then measure and FLY cut the pistons to avoid PTV problems... Put some ARP rod bolts in it. And spin that **** to 8-9000 rpm. with the right valve train..
^^^probably the answer you looking for ^^^^
but GM puts the ls3 heads on 4" bore from out the factory... I get tired of this talk. They rate the engines at more power too. I went with the L92 heads, and going to mill them .020 with the .040 gaskets. The cam I have will be it, Im not looking to go radical with this setup, but IMO it should walk with plenty cathedral setups, if not out perform them. I actually am building my setup to be able to outrun the bigger bore motors 6.2s!
remember the old tbi vs vortec head debate, no the old heads are better.... yea they make more tq velocity. yes. but vortec was the way to go. On a 4" bore, for the bang for the buck, and the options, L92 might be a cheaper route for equal to more power with less effort.
My cam is pretty big too, its not tame I would say, but if I want to go bigger, like say if I had a M3... I would run the Ls3 heads, milled, about .030-.040... I would then have compression up to about 11.6:1 + and I would then measure and FLY cut the pistons to avoid PTV problems... Put some ARP rod bolts in it. And spin that **** to 8-9000 rpm. with the right valve train..
^^^probably the answer you looking for ^^^^
Last edited by sleeperlqx; 11-24-2013 at 06:26 AM.
#15
TECH Junkie
iTrader: (18)
Hello all. I have just bought a 2006 LQ9 with 78k. I'm going to be swapping this into my 1998 BMW M3 and need help specing out a top end. I'm looking to have some where between 450-500whp thru a LS2 T56 6spd. This car is going to be an all around toy.. it will be put thru Drifting, Drag racing, & street beating.. I could car less of the manors on the street as long as it does not stall out i don't care how aggressive it is.
Here is a list of what I'm thinking of going with please leave your feed back.
Heads/Springs/valve's Package: From Texas Speed - PRC LS3 and L92 CNC Ported Heads
- PRC LS3/L92 CNC Ported
- PRC .650" Dual Spring Kit
- Valve Options
-- 2.165"/1.59" Standard GM Valves
-- 2.165"/1.59" Stainless Steel valves
-- 2.165"/1.59" GM hollow stem intake valves
-- 2.165"/1.59" Stainless Steel hollow stem intake valves
Intake / Throttle body:
- Fast 102 LSXR LS3 Intake
- PTM 102mm Cable Driven Throttle Body
I need help with the above head package and what Cam/Rockers/pushrods to go with. I'm also trying to stay away from having to cut Valve reliefs into the pistons.. as i don't have the tools to cut them or measure the Piston to Valve Clearance.
I have been reading on here to Mill L92 heads .015 and run .040 head gasket's.. but i don't know what that translates into as far as Combustion chamber CC's
Thank you all for any advice / guidance that is given.
Here is a list of what I'm thinking of going with please leave your feed back.
Heads/Springs/valve's Package: From Texas Speed - PRC LS3 and L92 CNC Ported Heads
- PRC LS3/L92 CNC Ported
- PRC .650" Dual Spring Kit
- Valve Options
-- 2.165"/1.59" Standard GM Valves
-- 2.165"/1.59" Stainless Steel valves
-- 2.165"/1.59" GM hollow stem intake valves
-- 2.165"/1.59" Stainless Steel hollow stem intake valves
Intake / Throttle body:
- Fast 102 LSXR LS3 Intake
- PTM 102mm Cable Driven Throttle Body
I need help with the above head package and what Cam/Rockers/pushrods to go with. I'm also trying to stay away from having to cut Valve reliefs into the pistons.. as i don't have the tools to cut them or measure the Piston to Valve Clearance.
I have been reading on here to Mill L92 heads .015 and run .040 head gasket's.. but i don't know what that translates into as far as Combustion chamber CC's
Thank you all for any advice / guidance that is given.
if interested i have my FAST intake fuel rails and direct port system ready to sale just need injectors, i do have 50 # in jectors for it but wont fit with the direct port system. hit me up if interested. even have the altered alt bracket and bolts needed all you need is the water pump spacers and F body water pump
#17
TECH Junkie
iTrader: (18)
then i met a not so well known head porter in Baytown, but knows his **** about porting, we spent weeks porting and bench testing the heads until we got what we wanted, then the heads were setup with the best of best of parts from custom PAC springs to ferrea valves
so to answer your question YES they were! look up Pat Foreman he had his hands on them also
#18
comment of the day right there..
Im going to have fun too I cant wait... Me and you both have had Skeet give us the right advice. But more towards daily drivers with reliability.
Hey Skeet I got Brian Tooley Springs, I hope they keep up with my cam, as their .660 on the lift.
#19
TECH Junkie
iTrader: (18)
comment of the day right there..
Im going to have fun too I cant wait... Me and you both have had Skeet give us the right advice. But more towards daily drivers with reliability.
Hey Skeet I got Brian Tooley Springs, I hope they keep up with my cam, as their .660 on the lift.
Im going to have fun too I cant wait... Me and you both have had Skeet give us the right advice. But more towards daily drivers with reliability.
Hey Skeet I got Brian Tooley Springs, I hope they keep up with my cam, as their .660 on the lift.
daily driver lol take it for what its worth if i wouldnt have floated one of the valves in my lq9 setup i was just about to put the AC back in it and call it done with just a roll bar inside the cab, but when i floated a valve i went straight to a 410 which then disaster struck and ended up with a 408, damn i miss the lq9 stock shortblock and most of all the 410, i feel it was more powerful than the 408
#20
Also IIRC GM makes the square bore heads for smaller displacements smaller than a 4" bore now.