want my car to be streetable but still make plenty of power, i'd like to throw some nitrous on it with around a 150-200 shot, i'd hope to be able to make over 500whp all motor but maybe thats too far fetched?

i just picked up my lq9 and i've read you can bore these to 4.080 but then i heard .060 was pushing it. i'd like to do .060 if possible but will it be safe?

i then plan on getting a eagle 4.00 crank, i may just buy the rods and piston combo since alot of people say you save alot of money that way, but would all of that come balanced already? or would my machineshop have to balance it.

i'll then be going with the l92heads l76 intake combo.

not sure what timing chain is the best to use,rocker arms ect.

i am not sure what parts of my ls1 transfer over. i want to try and keep my ls1 assembled as much as possible so i can get some decent money to add to the spending funds

i've been searching high and low for a write up and stuff but no luck

i have no idea on what cam to pick as well

i'll be doing most of the work since i know how to do that, its just they dont teach you howto go fast when you goto school to be a mechanic.

i'm only 20 so spare the flameing, i've been looking all over for almost 2 weeks with no real luck

 

You can go with a 4.03 bore and a 4.0 stroke for a 408ci or a 4.03 bore and a 4.1 stroke for a 418ci. If you want to go more bore, you can get more cubes, but it's not a big deal and keeping the block .030 over is a better idea, IMO, in case something ever happened to it and you wanted to redo everything.

My 408 makes big power with a small cam. Here's what I would do:

LS2 Timing Chain Set or a Rollmaster Double Roller.
Stock Rockers (only other real upgrade would be a shaft rocker set)

Solid Roller or Hydraulic?

Something in the 25x/26x range with a 110 LSA and .625-.650 lift should put you in the ballpark of where you want to be with a +4 advanced cam.... or you can go with less duration and retard the cam to make it act like a bigger cam, but keep the street manners.

Check out the link in my sig if you need to look at a parts list or PM me, since I'm at work.

Mike

 

thanks mike for the reply

btw your vette is sick!

i'm kinda in a rush but i got a few more questions i'm sure

for lifters i saw guys on a different forum talking about using cts-v lifters cause their suppose to be better for higher rpms

but the l76 intake holds back the power in the higher rpms, i'd only like to shift in the 6500-6800rpm range

i know the cam will make the biggest impact with this setup

i think i'll stick with the .030 then cause it makes since, just thought if i could squeeze out a couple more cubes then why not.

don't want to go with anything over a 4" stroke because i read it puts alot of stress on the pistons or something i can't remember exactly.

can i use the l92 rockers like intake and exhaust? on a cutaway at the autoshow i seen that had roller tips stock so i'd think this would be better over say my ls1 rockers right?

also on deciding on pistons the l92 heads are 70cc's not sure what pistons to get to keep a good c/r for nitrous, would 10:1-10.5:1 be too much?

we have 94 octane here so i'm sure i'd have to run that right?

 

For lifters, I'd use the Morel lifters... hands down.

As far as RPM goes, most LS1 motors don't peak at high RPMs. Look at my setup. Horsepower peaks at 6000, but holds it to 7000, so you can shift anywhere from 6500-7000.

You want to keep the stroke down as well. Usually you want the stroke to be less than the bore for the best horsepower/torque combination. You're correct about a longer stroke putting more stress on the pistons/rings and decreasing the longevity of the motor.

I'm not really certain about the L92-style rockers, but they *shouldn't* be much different than the LS1 rockers. The LS1 is a 1.7:1 full roller.

As far as compression ratio goes, you want to keep it around 11.5:1 - 12:1 static compression ratio and 8.5-9.0 dynamic compression ratio for a 93 octane setup. There's no reason to lower the compression for nitrous like you would for a forced induction setup. The only thing about building a "nitrous motor" that you would really do differently is ring gap.

Usually when someone says they have a "nitrous motor", it's an excuse for someone who can't make power with an NA motor

Mike

 

^ FWIW: My guy building my 408 is using Comp Cams lifters for an engine that will push 930 someodd hp on boost..

For a timing chain he specified, rollermaster double roller w/ torrington bearings and nitrided gears.

I have no doubt in my mind that this engine can take the punch I'm willing to dish out.

 

exactly i want to be able to beat on it without haveing a doubt in the back of my mind wondering if theres a weak point.

i'm only going to add the nitrous if the n/a isn't enough and i'd only use it at the track

so i've read gears kind of go along in a cam selection too, i was thinking 4.11's ?

as for the t56 what should be done on the rebuild? am i going to need a stronger countershaft? switch to carbon fiber blocker rings?

rear end i plan on going with a ford 9in

its late i had a few more questions but too tired to remember

 

^ Call 6Speeds Inc and tell them what you have planned. They built my trans back when they were T56rebuilds, not too long ago.. THey do top notch rebuilds. Micronite main and countershafts, CF Micronited syncros, bronze shift pads... Ect... My trans is LOADED!

If it's a street car I'd say do the 3.73 gears. I was told that they are almost perfect for a 6 speed. 4.11's would be a little too steep for a street car, IMO.

I was told that 408 can take a beating, when beefed up like mine will be you can spray or boost the **** out of it. .. So I don't doubt the internals recommended by my builder.

 

4.10s will get you around 131 mph in the quarter mile with a 26" tire in 4th gear @ 7000 rpm. Go with less gear if you are going faster than that.

T56 will need steel shift forks, carbon fiber blockers, CF synchros, and pads. You need around $600 of hard parts to make it stay intact. Pretty simple rebuild.

Mike

 

my old setup made with a m6 about 537rwhp and 500rwtrq. It was a 408ci with lq9 stage 3 heads from ETP. 11.3:1c.r. Very streetable cam about 246/248 @.050 .613/.615 114lsa

Tune is the name of the game if you want it to be streetable. This cam had plenty on the street for mid range and pulled like a monster on top!!

 

and basically the only differences that need to be made to my wireing harness is lengthen the ks's cause they go on the sides of the block.

stock pcv isn't a issue?

 

You can use the LS6 pcv setup if you're concerned, but I'm using the stock one.

 

now is the cps in a diff area ?