SwampWS6

iTrader: (7)

I was just trying to get a build together for later on down the line and would like your opinions and wisdom.

What is the largest CI you would go on a iron LS block and why?

I would like to have a low 8s car or minimum of 1500rwhp. I know ci/stroke plays a factor into a FI car. But I would rather ask guys with experience. The reason Im asking is I know that there are a lot of low 8 cars on iron blocks (not aftermarket) and just seeing what you guys think. I would like an ERL block eventually but dont wanna buy one unless its completely necessary.

I was thinking either a 416ci, 427ci and 434ci(I know the walls are getting thin). Mainly because they all retain a 4.00 stroke.

I may go LS sooner than I think. Just a little wishful thinking!

408GT

iTrader: (2)

There's a guy on here with a 403 that runs high 7's. It's tuned by Denmah check it out.

SwampWS6

iTrader: (7)

Thanks. Will do

cptinjak

I would not exceed ~370" in a single turbo stockish LS setup.

Jack

IronBlocked

360-388+ a good turbo will take you to the 8s if you keep the raceweight in the low 3100s

SwampWS6

iTrader: (7)

This wouldnt be a stock build by far. This would be an all out build. Forged everything/ Just was weighing my options on a iron block

cptinjak

I meant an OEM chevy iron block, stock configuration, etc.

Jack

SwampWS6

iTrader: (7)

Oh Ok, gotcha. How would you think a destroked 6L block fair in this situation? Since I have more wiggle room with boring on the iron block.

I think I over shot the CI with the 416ci+. Lol

ss1

iTrader: (32)

So you're talking about using a 6.0 iron block, not an LSX block, correct? Out of the cubic inch sizes you listed originally, the typical 416 uses an LS3 block with a 4.000" stroke. The 427 uses a 4.125" bore with a 4.000" stroke, which could be a sleeved LS1, LS2, LS3 block, or an LS7 block. Probably the largest you'd get out of a 6.0 iron block would be a 408, anything more would require a longer stroke or larger bore, neither being ideal. Now if you were thinking about an iron LSX block, that's another story.

SwampWS6

iTrader: (7)

Yea. Iron 6.0 block right now. Unless I need an aftermarket LSX block.

My next question is which is more important bore or stroke? I mean I understand a happy medium of having both.

Any thoughts on destroking a 6.0 block with a 3.268?

I dont wanna try to use an aluminum block unless its aftermarket. Which I am trying to hold off on unless completely necessary.

Thanks for the input guys. Keep em coming!

willizm

iTrader: (10)

My next motor is going to be around the 370-390ci area in an iron block.

SwampWS6

iTrader: (7)

I think Im leaning towards a 388ci. Shooting for 1500rwhp. I dont think I need much more than that.

Love that WSQ hood in white. I just bought one not too long ago.

JoeNova

1500whp is about 500 more than you need for low 8s, even at 3200 lbs.

SwampWS6

iTrader: (7)

Ok cool. Well I maybe could hit high 7s then.

gnx7

iTrader: (28)

beyond about 1200rwhp don't plan on a stock 6.0 iron block being able to keep the heads down reliably. You need 1/2" head studs/machining, aftermarket thick deck heads, doweled/pinned main caps to even propose realizing anything close to that.

At that point just get an LSX block.

Champagne dreams.... on a Boone's Strawberry Hill budget.... keep it around 1100rwhp or you'll be changing head gaskets as a weekly tune up. A goal of running 8's is a very achievable feat. Trying for 7's you better have a deep f*cking wallet as things break..... often.

The LS9 motor I have runs a stock $100 Ls1 crank (376ci) and makes more power than I can use 1100rwhp. That's about the limits of the block/heads reliably. Can it make more.... yes as the turbo is rated at 1650hp.... but it simply won't last. Decide how often you want to pull the motor apart.... weekly or annually.

SwampWS6

iTrader: (7)

Thanks a lot for the input. Well I guess I may have to get an aftermarket block and just start from there. I guess that will allow me to run a few more CI. So I guess the 416ci, 427ci and 434ci is more achievable.

cptinjak

Disregarding strength issues of OEM iron blocks vs LSX or other aftermarket blocks, I would still keep the displacement smaller in a single turbo setup. I would try to stay at or below 400" unless you're talking about twins. Keeping the displacement small will give you so much more room to grow on the turbine side and leave you lots more options when choosing a turbo.

Also, remember that turbo motors benefit greatly from a large stroke, but bigger bores yield very small gains compared to NA or nitrous combos. "No replacement for displacement" isn't always true in the turbo world. Just cram it in and give it a long lever to push on.


Jack

samdogmx

iTrader: (14)

^^^^ this

and for the bore stroke comment, I would not go bigger than 4" stroke, but with a bigger bore it opens up more cyl head options.

SCott5

iTrader: (40)

What would you do with a 91/94 single? I was going to be looking at a LSX block

I don't mean to piggy back on the OP thread but this question has been in my head for a while as I too am going to be looking to go bigger from my s475/347 setup

SwampWS6

iTrader: (7)

Thats a point I wanted hear about! So stroke is much more effective than bore on a Turbo motor. I guess too much bore and stroke will not yield any gains but whats on paper.

So Mr. Jack, would you say a standard bore on a 4.25 stroke would bee too much for a turbo app?