sidewayz28

iTrader: (24)

Well, basically i just want to understand what you can really do with a stock 346 ci LS1 block... EVENTUALLY i want to run a boosted motor..

I wanted to know what would be the most cost effective route to take...
You can buy a 370 iron shortblock for like $2800 which are obviously kick *** for boost, but i want to know if it would be worth it to build up the ls1 block.
In the LONG RUN what would be the best route to take?
A forged 346 will definitly handle its boost, but is a 370 THAT much better?

What exactly do you need to do to the internals to the 346 to handle ~800rwhp? Obviously rods/pistons are a must.. but can you bore out the 346, and do somethign with the stroke? (excuse my terms, im a rookie with rotating assemblies)..

From what i've read, it seems like the iron vs aluminum isnt as big of an issue w/ forged internals and what not.. both will hold its power. It seems like it might be cheaper to stick with your stock block & crank, and still be a kick *** motor for boost...

I was thinking of getting decent set of heads for around $1500, but i was thinking to my self.. thats already half way to a new short block (370) or a nice set of forged internals...

What do you do?

Thanks in advance!

Diesel_29

If you want boost, a 346/347 or a 370 will work great. Doesn't matter which one you choose, they'll both get the job done.

Secondly, I don't believe you can really bore a stock LS1 block without lots of machine work. You can hone it. The stock bore is 3.903", and you can hone it to 3.905". You can put a 4.00" crank with minimal machine work, you may have to notch the block, etc. A 4.00" crank alone with give you a 382, hone the block, and you have a 383 stroker. After that, you can re-sleeve your block and go 400+ CI. etc. etc. But, if you're on a budget, forget all that.

I always like to think about the long run. Don't spend money now on a 370, and then later on down the road you figured out you really wanted a 408...or a 427 N/A motor. Or, even one of these newer blocks...Dart, Warhawk, or the GMPP LSX block.

But, you can't go wrong with a Forged Iron 370 or 346 for high boost.

EDIT: Oh yeah...as far as the stock internals go, the stock crank has been proven for 900+HP. A bone stock LS1 bottom end can go to about 600+HP, wouldn't push a stock bottom end much past that. After that, a forged aluminum will hold up to around 1000+HP, then you might want to look into iron. Unless, of course...you wanted to buy a Dart Billet block.

sidewayz28

iTrader: (24)

dart billet block is sexy!
Thats what i was thinking though.. I just wanted to know if you'd save a little money reusing your stock block/crank... Right now im running a budget mild h/c/i set up with nitrous..
Eventually i wanted to throw in a large motor 400ci+ and run boost.. but that seems almost overkill for what i want. I dont need 1000rwhp, and the car will never be a 100% drag car. It would be a weekend warrior.
I think you corrected me, hone was the word i was looking for..

could you make a nasty low compression 346 that'll make some great N/A numbers, then when you add boost the world comes to an end?

Diesel_29

I would just go ahead and get a forged short-block...the money you're going to spend machining your stock block will add up. If I was you, I would buy a forged 346/347...and sell your current set-up.

As far as power is concerned...plenty of guys are making 600+ RWHP with boosted 346/347's. Current record is just over 800+ RWHP, and it runs on 93 octane with a meth injection I believe. As far as N/A power...it's not going to make 572 BBC kind of numbers obviously, but they will get you places. Also, be aware of the fact that all these high HP 346's don't have the the nice, flat torque curve that bigger cubed motors have.

And as I said before, no need to go iron unless you're on a serious budget or going for over 1000RWHP. No need for a donkey dick cam, or a donkey dick stall, either. Nothing pisses me off more than seeing a gutted car with a pin-on hood, a 4400 stall, and then it runs a 11.0 1/4 . No real point to that last rant except...you can make killer power and still be streetable. It's just in the right set-up.

sidewayz28

iTrader: (24)

LOL of course man!
I wouldnt be going d1sc or anything like that.. its either F1A or some kind of turbo system, APS is near the top of the list.. No question.

The main reason i posted this was i was just curious if it was cheaper to stay with your stock 346, stock crank, and just get forged rods and pistons but also be able to have a KILLER sb that will handle the power..

no replacement for displacement... but i think a well built 346/370 could handle its own

Thanks for all the input J. Howard

ss.slp.ls1

iTrader: (36)

Whenever I hear boost, I think of a LQ4/9 shortblock. Durable and affordable. And if money is not a huge concern, throw a 408 forged rotating assembly in that thing and create a beast.

sidewayz28

iTrader: (24)

LQ9 = 800$ block

i've definitly researched that area a little bit
lq9 + l92 heads nice budget combo... but i dont think those heads would be good for boost?

nice 97ss by the way!

ss.slp.ls1

iTrader: (36)

LQ4 would be slightly better for boost, the dished pistons yield a lower CR.
If you can get the alum heads (317's), have them P&P and strap on a blower.
Thanks for the compliment.

djsanchez2

iTrader: (14)

^^^^ Neither matters unless you are gonna use the stock bottom end. There is someone on here that is selling stock LQ4/LQ9 shortblocks for $450. So with that you will have a iron block, and crank to work with, just add forged pistons and rods and throw 800hp at it. I've been thinking about picking one up as a spare.

sidewayz28

iTrader: (24)

you wana PM me this guys name?? if you know it by chance?

i shuold have added LQ4 or LQ9 to the list

87silverbullet

iTrader: (11)

In the Multimedia section on here there is a video of a GTO with a stock lq4 motor with a z06 cam and 19 lbs of boost and it put down 825 rwhp but it was a while back.

white01ss

iTrader: (37)

After doing lots of research over the past couple weeks, I choose the iron block as the way to go. I wasn't really excited about adding the extra weight, but I'd really be pissed if my high dollar motor went kaput on me after a year. So the goal for me was to build a motor that can handle that chosen power level for years to come, or even some room to spare for the future.

Here's some rules of thumb from my research:

0 - 700 hp or under - alum is fine

700 - 1200 - Use an iron block like LQ9

800+ Use dowel pinned steel main caps

900+ Use a main cap girdle

1200+ Do an LSX block.


Now, these recommendations are for crank hp. So for a centri blower car you'd get 700 - 60 (spin blower) - 100 (drive train) = 540 rwhp. You get the idea.

lowbirdws6

iTrader: (62)

I'm with White01SS on this one. LQ9 block, stock crank rated to 1200 hp, balanced forged rotating assy, 243's P & P or 317's, 15psi of turbo boost and we'll see what numbers that produces. I'm about a month away!!!

cjg454ss

iTrader: (27)

i had my iron 370 o-ringed, cost 300 bucks. since then its been running great. no water pushing that i can see