Build a ls1 347 or ls2 shortblock???
05-21-2006, 06:11 PM
#1
Build a ls1 347 or ls2 shortblock??? I am going to order a shortblock soon and I had planned on just having a 347 ls1 built but for $3-400 more I could have a ls2(stock cube) shortblock built. What if any gains would I see from the ls2. Is it worth the extra $$$ for the conversion? I will be on stock heads for atleast one year also. (243) Going to be N/A. Help me decide! Thanks!
05-21-2006, 06:41 PM
#2
New LS6 assembled block w/L7 pistons. They show up on e-bay from time to time. Usually left overs from new owners modifying the engine right when they purchase the car. I bought one blue printed for $1,995.00. Purchased the timing set & gaskets seperately. Is the LS2 worth the weight increase?
05-21-2006, 09:39 PM
#3
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Originally Posted by a98ws6
I am going to order a shortblock soon and I had planned on just having a 347 ls1 built but for $3-400 more I could have a ls2(stock cube) shortblock built. What if any gains would I see from the ls2. Is it worth the extra $$$ for the conversion? I will be on stock heads for atleast one year also. (243) Going to be N/A. Help me decide! Thanks!
05-21-2006, 09:50 PM
#4
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I agree, if your going to stay N/A the bigger cubes is a no brainer and better yet, if you can stroke it to 402 you will make huge power. I am running F/I with a D1SC so in a f/i appliation i would tell you a 346/7 that is blown or turbo charged will make more power than one will ever use on the street, but N/A you want the most cubes you can get and the bigger the better!!
Last edited by MTI 427 C5 Roadster; 05-22-2006 at 12:31 AM.
05-21-2006, 10:18 PM
#5
LS2 is only about 15lbs heavier (if I remember correctly)--and that's because it's a much stronger block. I'd go LS2 and maybe even look into a 402. Good 402 short-blocks run around 3800 or so. A forged 347 is going to be about $2800-3000, even if you have a core. You'd be better off selling the LS1 block to offset the price difference on the stroker crank with the 402 LS2.
on the 402. then you can throw on a set of 4in ET ls7s + ls7 intake and make insane power. 
very light wallet though Trending Topics
05-22-2006, 07:06 AM
#9
Ok but heres the thing. I could hold off a little while and go LS2 and MAYBE save a little more for a 402, but will the stock LS1 (243's) kill the power? This is going to be a 90% drag car but still streetable. Not a DD. Just wont have the $$$ to do a ls2-402 and heads. Also what are my options for a cheap intake if I go to a LS2 block? Was looking at a TREX cam for the 347, but I would figure that would change if I go more cubes??
Thanks for all the help guys!
Thanks for all the help guys!
05-22-2006, 07:27 AM
#10
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What's heppening to the heads listed in your sig?
As for power increase, yes there's no replacement for displacement. However there is an easy bit of Maths you can employ.
The LS2 is essentiall the same as the LS1 just more displacement, so it means each engine can acheive very similar specific outputs.
At 100bhp/litre state of tune a 346ci would be making 570bhp, while a 6.0 Ls2 in the same state of tune would be making 600bhp. However running these engines at this state of tune n/a is unlikely for most.
Taking you sig number of 430rwhp that means you're probably in the region of 500bhp flywheel. So your specific output would be about (500 / 5.7) 88bhp/litre. So a 6.0 lump running the same state of tune would give you somewhere around (88 x 6) 528bhp.
Personally I'd go for a 402ci aluminium block with forged internals. However if handling isn't your thing then a 408ci ccast iron block is slightly cheaper.
A 402ci running about the same state of tune should be seeing 580bhp, so a fairly decent hike over a 346ci unit. Also you can always up the anti and run the new engine in a more extreme state of tune.
As for power increase, yes there's no replacement for displacement. However there is an easy bit of Maths you can employ.
The LS2 is essentiall the same as the LS1 just more displacement, so it means each engine can acheive very similar specific outputs.
At 100bhp/litre state of tune a 346ci would be making 570bhp, while a 6.0 Ls2 in the same state of tune would be making 600bhp. However running these engines at this state of tune n/a is unlikely for most.
Taking you sig number of 430rwhp that means you're probably in the region of 500bhp flywheel. So your specific output would be about (500 / 5.7) 88bhp/litre. So a 6.0 lump running the same state of tune would give you somewhere around (88 x 6) 528bhp.
Personally I'd go for a 402ci aluminium block with forged internals. However if handling isn't your thing then a 408ci ccast iron block is slightly cheaper.
A 402ci running about the same state of tune should be seeing 580bhp, so a fairly decent hike over a 346ci unit. Also you can always up the anti and run the new engine in a more extreme state of tune.
05-22-2006, 07:47 AM
#11
The heads in my sig are long gone. I had to sell them cause the motor in my sig BLEW UP and I have to get some $$$ for this new engine so off they went. I would like to get heads next year but this year is just out of the question. If I do anything it will be an aluminum block. This is going to be in a somewhat light weight car also, with possibly a TH-350 and a 4500 stall.
