I just read that there are issues with head lift on the LQx (IIRC) engines when the boost gets cranked. What is the best block/setup to go with for turbo? Looking for a SAFE and STRESS FREE 700whp.

Also would you use a block that has a helicoil in one of the head studs?


Thanks guys!




DM

 

Alot of people believe a helicoil is stronger then just taped hole
a stock lq9 block can holed that power level especially if you oring the heads

 

Harlan took a aluminum block to 1000HP, Fireball's LS2 took 1700HP+ before it let go (had it had filler it may not have). I'd go aluminum for the weight savings. My stock LS1 block out of a 98' has taken everything I've thrown at it thus far.

 

At 700 rwhp there are alot of things to worry about but a stock block and crank should not be counted amongst them.

 

Thanks for all the info guys!

Ok... I know it would be easier and less stressful to make 700whp with say a 408, but your saying that a stock LS1 would be OK with this kind of stress/power? I would still imagine that the best route would be the 408 since it would have the HP and TQ low down and off the boost, plus the lag time would be lower if none at all.

So as for the blocks and crank themselves, I take it that all LSx blocks are good, it just becomes a personal preference for N/A power (pre-boost). What about the head lift? Do all the LSx engine share the same bolt pattern and head design? Do they all experience head lift?



DM

 

408 would put more stress on your main caps/bearings than a 346/347 would due to the stroke. I haven't lifted the heads with 20psi of boost and standard size ARP studs.

 

Ahhh... Ok got ya.


Are you running a stroked 6.2?



DM

 

i would stay away from ls1 blocks,they are not nearly as strong as the others

 

It had hardblok in it...

 

I didn't think you could use that for a DD application?



DM

 

his wasn't a DD

 

if you run an oil cooler...hardblok can be used on the street...

 

I just spent 45+ mins searching for the avg price on clearing a block for a stroker kit. Does anyone have a ballpark estimate on working a LQ9 for a 408 or 416? And before anyone rants... I know all shops are different, hence the reason I said "ballpark"


DM

 

Wonder if anyone has tried it for the head flex issues? When I had my 3000GT VR4 there was a big issue on head flexing/lifting till Ray Pampena, a guru of the 3S scene, came up with a fix. I think it was on the likes of using something like hardblok, but I don't recall.


DM

 

One of the guys are selling a LS9 block with Ls9 steel crank and a Ls7 steel 4.0 stroke crank turned .010 .010 which comes with 8 Ls7 rods.

What would it take to make these work in my Bird? Would it be any more expensive that building a 408?


DM

 

Really it depends what they are selling the stuff for, without prices it would be hard to say. But a well built 408 can be had for around 5000-5500 dollars.

If your on a budget you can get a 370 which is a LQ4 with a stock crank but forged rods and pistons. You can get these for around 3800. A 370 with a 88mm turbo will be a nasty combo capable of making well over 800rwhp reliably.

 

They are asking $1,500 for the LS9 and $1,100for the LS7.


DM

 

I probably wouldn't pay that for a used block. I'm not sure what the difference is between the LS9 block and a LS3 block they may be the same but I'm not sure, but they're both 6.2's. If you can get them under a grand for the LS9 and the crank it could be worth it but you would still be at 376 cubes, and just about any GM LS crank is good to 1000hp so I dont know if the LS9 crank is worth extra money.

I wouldn't pay more than 600 or 700 for a used block being that you can get a LSx for 1900 and you can make a 440 with 6 bolt heads capable of 2500hp with that. Or you could get a new LS3 for about 1200 from scoggin dickey.

The LS7 rods arent going to be much good if you plan on running alot of boost either, but the block and crank are good.

Also what Gen bird do you have? A 4th gen the swap is pretty straight forward, but into a 3rd gen you'll probably need a K member and maybe a different tranny cross member depending on what you plan on using.

 

lq9 is a great choice

 

LS9 would be machined for piston oilers and have 12mm head bolts. The 12mm aftermarket studs could be problematic this early in the engines life if studs are wanted.

Kurt