inspector12

Pretty sure I've been giving you my HONEST opinion lol! Everyone has to do what they want or there would be nothing but the same setups on every car lol! Limited Budget doesn't tell me much although either motor will be close in price if you chose to use aftermarket cranks. You could save money and use a stock crank and I have done that as well. But there is lots of torsional vibrations on SC setups so that one is on you if you want to do that, but it will save you a grand right there. I didn't have any issues with mine and I know others have had good luck as well, but some might say your cutting corners. I personally like the bigger CI as the extra TQ makes it quicker when not going WOT and the car feels faster in a lot of instances. I have a few 4" Lunati cranks so for me its a no brainer.

Rkreigh

I want to try something on my next build, a small bore 4.8 iron block with a 4.0 crank and ttix with the larger .82 housings

but based on this comment, maybe it's better to go with the short stroke to hold down the low end torq and make it up on a higher rpm top end pull

either way I want the cubes to be right around 370 - 383 and I'm curious if you all think this is too big an engine size for the small ttix turbos. I have a 58/62 I believe and don't want to upgrade turbos unless I can fit it in the budget.

I'm going to stay with the good arp stock size studs and I'm using a AFR 225 head which I believe has pretty thick deck

also, will the stock bore size ls6 3.89 AFR 225 head work fine on the small bore 4.8 block? or do I need to do a bit of massaging on the head chambers to close them up?

I'm thinking of boring the 4.8 block only to 3.8 or leave it stock to keep a very thick block for better hg sealing

my goal is around 900 at the tire so 1050 on motor

I also have 127 fic injectors and a haltech to stir into this mix so I can take advantage of the tuning and boost by speed

the last part of the build is the ECS direct port alchy

that looks like a nice way to go "dual fuel" on a budget and use the alchy to cool it at high boost

for sure it will be an alchy dependent tune, but with the many safegaurds with the haltech it won't be as risky

comments, thoughts? 1k or bust

I

inspector12

Those turbos will be fine. It looks like you already have a plan together for the most part. I would do what you want, I'd probaly just have used a stock stroke crank and made it a 326 or 346, but it will work the way you want as well. I wouldn't over engineer somethings that have been done over and over again VS doing something that hasn't for the sake of doing it. But some ppl bleieve in longer stroke motors being better for various reasons. But I like the KISS method. Just like the direct injection alky system. I haven't seen a MAJOR advantage over the nozzels. But like I said ppl have to do what they want and not what I or anyone else tells them they should do. I'd keep the CR @ 9.5-10 and tune accordingly. the difference in Bore size your talking about isn't enough to worry about. I wouldn't worry about shrinking a head for that little amount, but the bigger bore could be worth a little power and its why I'd do a 346 more than likely. GL!

Rkreigh

thanks for the tips. I got a good deal on the crank and rods and actually would have preferred a stock stroke

will the 4.8 block bore to the LS6 size without being too weak?

some have cautioned to leave is a small bore size even though the bigger bore size will make more power, I think I'll be fine in that department!

might just do stronger rods, pistons, and stay with the short stroke as I think the factory crank especially with the shorter stroke is probably plenty strong and I can always sell a new crank!

inspector12

Yeah 3.89" bore is plenty strong for anything really.

Rkreigh

the 346 size has worked out very well, and the crank from my exisiting engine may be ok

I think I'll save the lunati crank for a 383 build on the alum block

ace32x

probably going to see what the ls9 4 bolt will take this winter, going to do some heads a larger cam and some other goodies and see if she will take 1200 and be reliable