I'm about to have my car payed this year and I was looking at going with a new motor setup for NA , I like the lsx blocks but don't want the extra weight of an iron block and thinks its overkill for NA. I was thinking of going with a forged 347 and a custom h/c setup from Cartek . I could reuse quite a bit from my 346 plus I like the idea of being the underdog . just not looking to put 14k in a motor setup , hell , this is just a hobby. What do guys think, open to other options.

 

I went forged after killing 4 ls1s blocks in 2 years time. Never sprayed it, but the options there if I ever descide to. Been running this setup over 2 years without any problems

 

only advantage is being able to run more camshaft and maybe a little more over the top heads to flow with the cam.

why not go with an LS2 or LS3 block and do a 402/418/427 type build?
they are aluminum blocks, and the cost of the block isnt that bad.

if youre going to have the block out, id want to get some more cubes in it for a pure N/A build.

you can do an LS2 402 very reasonably priced.

 

Move up instead of sticking with the 347.. you are leaving power on the table for no reason if you stay with the 347. If you were doing an FI build a 347 might be better but for NA scratch it. A stroked LS2 is definitely a good proven option.

If it were me, I would give Fraser a call at AES racing. They have been advertising a 390ci motor in the forced induction setup that I would get. You can also get it in an ls2 block (aluminum) and it'd be a 385ci. I believe that setup was about $4000 plus shipping and any added options for the shortblock and that is very good considering the attention to detail and wealth of knowledge AES has about motors.

You said something about being the underdog with the 347.. that's cool and all if you were out racing this for money every weekend etc but if your going to do it you might as well go big and be happy or go home and wish you had more.

 

Im running a stock crank, forged rod/ piston 346 now, the only reason is because of the budget. N/A with some good heads and higher compression the most you might get is 450hp. All said and done turning my bone stock car to what it is now (578hp) cost me about 7 grand and is 100% streetable, if you have more to spend than that I would do a LS3 build. When the time comes, that will most likely be my next powerplant.

 

IMO, that's all someone really needs. The stock crank is suppose to be good to 1k hp. With good rods/pistons you should be able to beat the **** out of it for a long time and not have to worry about it.

Hell some people push the stock pistons to 550-600rwhp with a good tune.

If you are staying 347 I see no need to a forged crank. You can put that money into something else like cylinder heads.

 

Obviously it depends a lot on what you want out of your car, but if you are looking for a N/A power I would recommend looking at something like the LS2 402 strokers. By the time you spend the money on the forged parts for the 347 you aren't too far away from building a full motor. These larger cubic inch strokers have a lot more potential because bore size allows for larger heads and the stroker package will pick up quite a bit of power down low over a stock stroke crank.

 

Yeah, looks like for a little more $ , i could have a 402 stroker.....May be the route i go with, thanks fellas,,,,Keep the comments comin

 

I'd go 408 iron! For literally a hundred or 2 more over the 347, you get all the extra cubes, the extra bore size which helps extract that head flow, etc! The only downside to it is a little extra weight on the front of your car, but that is also somewhat easily compensated for down the road with suspension upgrades!

 

Damn I didn't know it was that cheap. I will keep this in mind when I blow up my 346 this year on the bottle....which I am sure I will.

 

You can get decent money for a running LS1 that would easily offset the cost of going with an LS2/3 stroker. I went the forged 347 route when I blew my stock engine because I was trying to do it as cheap as possible. Six months down the road I was kicking myself for not waiting a bit longer and going with a 408 or 402. If you are looking at buying heads, cam, and engine components anyway then go with a stroker and buy the heads and cam to match. The added cubes will allow you to make much more power for almost the same money.

 

I'd sit down and figure out your budget before doing anything. I am in the same boat right now with my motor. One cylinder is scuffed and I'm debating on staying with a 347 with new rods/pistons or going up to a 383 or making the jump to a LS2-402 or 414. The cost of the shortblock only jumps maybe $800+/- from one extreme to the other (assuming you stay with an aluminum block). Iron blocks take the costs down, but I'd suspect you might give some of those savings back in suspension upgrade costs, don't know for sure?

You should take an inventory of what parts you currently have that are going to be reused and what kind of power/cubes they can realistically support in NA build. Don't guess on this, talk to a builder who knows. It might be come apparent that your current stuff won't really support 402+ cubes or maybe they will. My point being you could easily end up with a compromised situation or a be kicking your self for not going bigger if you don't plan it out.

Don't forget all the supporting mods for the swap and upgrades to take full advantage of the additional cubes. Why go for the cubes then handcuff yourself with woefully inadequate heads/cam/intake etc?

-LS2 covers/extension harnesses/sensors $300?
-Cylinder Head upgrade to support 402+ cubes? $2000+
-Intake/TB/Injector upgrade support 402+ cubes? $1800+
-Fuel system upgrade? $300+
-plus other unforseen supporting mods (how's that clutch and rear doing)?????

Camshaft/valvetrain/fasteners/gaskets etc. and tune are a wash as they would get upgraded no matter what.

So while the shortblock maybe a smallish step $$$ wise, the supporting cast of parts can be quite a good chunk of $$$$. If you are buying a new top end anyway, then definitely go for the cubes, but if you were planning to reuse a set of heads/intake etc then I'd figure what they can support and budget accordingly. Nothing would suck more than to get halfway into it and run out of cash and be stuck with a half built motor or a wicked short block and a compromised top end that is holding it back. Or even worse get it all built then realize that for another $500 you could have picked up 60 cubes and the power that goes with those 60 cubes.

It's a slippery slope and the cash can dissappear quick if you don't have a plan.

Good luck....

 

I surely appreciate the info man.....I currently a moser 9 , brand new Mcleod RTX being broke in, Fully built t56.....As far as everything else, i have an untouched Fast 90 that i can get ported to match whatever heads i decide to go with, Fuel system is upgraded to the Racetronix pump and 42 lb green top injectors already, i feel like im in pretty good shape with most everything, gonna go with an upgraded H/C setup (probably Cartek) and upgrade to larger headers.....Im thinking the 402 sounds good

 

You are going to love the 402 setup. No need to upgrade the injectors/tb/intake or even heads for that matter right now. I hate to say it but look at KC's car. 404 with 243s setup for a 3.9 bore and they are still flowing 325cfm. A 243 setup for a 4.0 bore isn't going to flow that much better but there would be an increase for sure. For your new cam choice it definitely needs to be custom ground. What are you thinking heads wise?

 

Definitely go for the cubes. I didn't realize you had all the other supporting mods in place.

 

i also thought about the same thing. No doubt i would go bigger cubes, but i have seen guys with 347 making big power! Im talking 700 hp range.. that is pretty impressive. My car will also be paid off next year, and i thought about the same thing.

 

Ya 700hp with boost or nitrous definitely not NA.. OP is wanting to stay NA.. sad story I know.. Sammy we need to talk you into gettin a d1sc or f1a lol.. boost is a wonderful thing

 

This.

 

Believe me, id thought about it more than once, just don't have the funds , id rather have a badass NA motor than a halfass boosted setup for around the same price

 

I am by far no expert engine builder here. Just a critical thinker. I believe TSP has balanced forged rotating assemblies for 347 for about $1800 last time i checked. Ready for install. You will probably hit 3/4 that amount pricing individual parts minus the crank and then having to assemble and balance setup with your stock crank with tens of thousands of miles on it.

Say you go forged with stock crank because you can't afford a complete build on bigger cubes. You later decide to n2o your car and end up snapping your crank. It is not unheard of. Sure they are stout from factory, but interchanging pistons and rods just transfers that energy to your crank. How much is it going to cost to rebuild your motor after that? Less than just getting a forged crank and forgetting about it? Just something to think about man. Not trying to persuade one way or another. Just helping you get all of your choices out there on the table.