Blasphemy..

 

What part of that is blasphemy?

 

Its a joke. You seem to be one of the few people that understand what Boost can actually do for you when setup correctly.

 

Ah lol gotcha. Yes people seem to be stuck in the "no replacement for displacement" mentality which is definitely not the case when it comes boost

 

Question for you guys. If I intend on going with a dragon slayer crank on an lq4 with some good callies billet rods and wisco pistons wouldn't it be worth going with a 4" stroke and not bore it out? I get that weakening the cylinder walls is no good, but what about stroke?

 

The more stroke you add, the more it side loads the cyl walls.... again, not a good thing when block strength is in question. Most successful OEM turbo engines are are square or oversquare because of this.

 

I always told my frends to do a 370. It is cheaper, and I doubt there will come a point in the future when you say, "Ahh ****, I only made XXXhp, man I really wish I would have gone with that bigger cube setup." When you can usually turn it up a whole 1 more psi, and make the power.

 

I'm gonna give you "little motor guys" a scenario here

Lets say you have a drag race which if you win you get to live, if you lose you die. The car is given to you and will hook any amount of power you can throw at it. You are not limited to turbo size...........as a matter of fact you not limited to anything and the car will be set up to handle anything you put in it. The only thing you have to choose is a motor smaller than 360 inches or a motor over 400 inches. Everything else goes.

The guy you have to race has to use the displacement engine you don't pick. His combo is not limited either other than that. So if you pick smaller than 360 inches, he gets over 400 inches. If you pick over 400 inches, he has to run with less than 360 inches.

Which do you choose?

 

....remember, you can run any turbo or turbos you want.

 

Factory block stuff, I would stay at factory bore & stroke.

LSNext or billet block, I would go 440-460".


Ask 10 different people and get 10 different answers.
Make your decision off of what you want and proven combos in that realm. If you want to nail down killer track numbers or are looking to say you have "xxxxrwhp" and want to Starbucks pimp is what you need to decide.

 

Kurt Urban's user name isnt "427" by accident!

 

Don't bore it if you're going for boost, 403>408 in terms of durability and no power loss
403>366 Because you can still rev to 6500-7k, lights turbos better

 

and... both using the same (as close as possible sonic tested) stock 6.0 block and... the life or death race is after 100 passes?

to your point - cubes make horses... and 15psi on top will bout double it.

40 on top will make it fun as hell until it blows
budget and reliability major factors

 

Mid 7 car with a stock --bottom end--, whodathunk

 

Stock crank, stock block, good rods/pistons is all you need for 1000rwhp. Beyond that keeping the heads sealed will be the challenge in the long term.

Over time the stock crank will show signs of wear above 1000rwhp as some people have shown cracks in the journals. You really don't hear of stock cranks failing at this level.

Bigger bore allows larger valves and more potential airflow. Longer stroke means more torque down low and less a ability to rev within reason. There are plenty of race motors with 4" strokes revving above 8000rpm... But they are solid roller. My motor runs a stock stroke and can rev to 7800rpm when needed. Mainly I shift at 7000rpm. Used Morel link bar lifters.

All boils down to budget and goals. For 95% of the people out there a 4 bolt style block will suffice because you can easily run 8s with one. Going beyond that is when the cost easily triples if not more to safely and reliably make the big power numbers.

 

And judging from what the op wants id say 370 is his way to go. Like ive said before you don't need cubes to make power with a turbo build. Also a question for the OP why twins?

 

guys, if you are looking for engines, or thinking about building them, shoot me an email! we can set you up with long or short blocks, with good parts, and a WARRANTY, shipped to your door.. the same price it would cost you to buy the parts, have the machine work done and assemble yourself..with no warranty.

370/408/416/427/big 6 bolt stuff you name it.

shoot me an email. its worth talking some numbers with me.

Casey@huronspeed.com

 

This is the type of information i'm looking for. So lets say in my scenario I want to keep my 317 4bolt heads and want to go dragonslayer with good rods/pistons. Where is my limiting factor considering drivetrain and fueling are up to the task? If I go 408 I can push less boost to make great power at the risk of the side load on the cylinder walls, but with a 370 my cylinder walls will hold up better and I can push more boost to make the difference up at the risk of lifting the heads. I may eventually go with an ls3 topend swap, but want to avoid 6bolt due to the added up front costs. Thoughts?

 

Block is the limiting factor IMO. With a factory block at those levels I’d bore it .005 (or whatever your forged piston expansion requirement is) and run a 4” piston. Even .030 bore is sketchy. The pic I posted above was a 370, 1000+whp 3000lb race weight.

 

So if I have a perfectly good stock crank it almost doesn't make sense going forged crank if i'm going to be block limited anyway, right? I'll spend money, I just want to do so effectively of course. If I knew I could push the lq4 block to say 1200whp then I'd go with a dragonslayer, but if the block itself is limited to around 1000whp then the stock crank would be within the same thresholds.