hey guys, i have a question but its in the form of a story kind of. okay, i was thinking about buying a complete LS1 engine with the wiring harness and computer, kinda like one pulled from another fbody or something that somebody just wants to sell, but was a good block and good crankshaft, and i was going to mod the engine while saving and looking around for a 98-02 Trans Am roller car. and when finished modding the engine i was going to install the engine into the roller. okay a guy i know said that i shouldnt fool with the LS1 engines, which i over looked that part to begin with but he said that it was a bad idea for me to do the mods i wanted to do because i would have to run race gas because after 400hp you have to run race gas and i couldnt run pump gas. okay i thought that you could get different pistons to lower the compression in the engine and keep it between 10.5:1-11.5 and be able to run 93 octane pump gas. am i wrong? and here are the mods i want to do just incase anybody is wondering what i plan to do.

Callies Compstar Forged H-Beam rods
Diamond Racing LS1 Forged 347ci nitrous pistons
Stock LS1 crankshaft
ARP bolts on everything
Texas Speed 228r camshaft
AFR 225 heads
LS6 or FAST intake
Ported stock throttle body
Kooks longtube headers
TSP true dual setup
Underdrive pulleys
SLP air lid
125hp shot of nitrous
dynotuned at Thunder Racing

so what do you think? about how much hp am i looking at N/A and with the spray? and also would i have to run race gas or would i be alright running the 93 octane pump gas? please let me know.

 

okay here is how race gas or regular gas really works per say. Octane is the rating of the fuels resistance to combustion. 93 is harder to burn than 87 and so on. When you get up to about 10.5 to one compression or about 155 pounds of cylinder pressure you need more octane to keep the intake charge from combusting just from the pressure and not from the spark plug. This is predetonation and can cause very big problem. HP has nothing to do with what octane that you will need. This is why when you run bigger turbos or lots of nitrous it is reccomended that you at least run a race gas pump gas mix, or take lots of timing out of it. This guy you talk about is full of it and I hope you tell him that. As far as the LS series engine it is the most technologically advanced of the chevy sb engines so i would go with it.

 

buy a 99 or newer f-body, motor or not and buy a built motor from slp or who ever has a good hp to dollar ratio.no you will not need race gas .i see many LS1/LS2/LS3 etc motors running 11.5 static compression on pump gas with the right cam.

 

the elevation also has a lot to do with how much static compression you can run. The higher the elevation the more compression you can run on a n/a motor due to the air being thinner, there are charts that tell you what is safe to run with your combo

 

This guy is an a-hole.

I run 91 octane, H/C with 400+rwhp, 540rwhp on nitrous and no needs for race gas or mix. He doesnt have a clue what an LS1 is.

Almost the hole community on LS1tech runs on 91-93 with modded cars from 300 to 1000rwhp!!

As long as you pull timing on nitrous, get colder spark plugs, have enough fuel plus the safety accessories, no need for race gas. Unless you go with a 300shot for extra safety. Even then, most of the plp running 175-250 doesnt use race gas; you just need a nice tune.

Sounds like a nice setup my friend, but why not a stroker engine?

I would go with a nice 408ci SB from a sponsor if I were you. My LS1 is forged and I really regret not having a 408 for almost the same price(with an iron 6.0l stroked out to 408) as my stock ci SB...

 

the reason i wasnt going to go with a stroker engine is because i wanted to save a little money lol. plus i wanted to actually build the engine, or at least do everything except the bottom end and the machine work, ill let a shop do that. but how would i go about turning the 346 into a 383ci? would i just get a 383 crank and have the engine bored some or would that not work?

 

That guy is full of ****! Every LS car/truck that has atleast a 400 rwhp combo around here is on 93 octane with NO problems. Hell I even sprayed my car with 125 and 150 on pump gas in the old set-up.
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do any of you know about how much hp/tq my setup above would put down? or just a ballpark figure? and could you make one N/A #'s and one on the spray? thanks.

 

hp/tq numbers? n/a & on spray? look at the list at the top and tell me what ya think.

 

That friend of yours is a dumbass! Dont listen to him.

I think youd make 410-415RWHP and about 390RWTQ N/A
515RWHP and about 500RWTQ wit NOS
Just an estimation

 

alright thanks fastvet! i hope it really does make that much.

 

Youll hit at least 400rwhp with this combo.

About the stroker, you just need the stoker kit(eagle/or other crank for a 383ci stroker) and the rods/pistons. You cant really bore the stock LS1 that much. Of course a stock GM crank is cheaper, but a stroker will net you a big bunch of torque with your combo and room to grow for hp later. Of course youll need a bigger cam though.

look at this:https://ls1tech.com/forums/sponsor-s...gine-sale.html

so by going with a 347 insteqad of a 408, youll only save 800$, which is nothing when talking about building an new engine setup!!

 

You can get a 408 for $3600 from texas speed with forged pistons. With those AFR heads and a nice cam, it should pump out to 500RWHP N/A!!

Good Luck Bro!

PS: and as far as that race gas thing goes, I believe the older iron blocks werent able to run High compression without race gas. The new aluminum blocks, that are street rods, are able to run one full point higher than the old iron block/street rods.

 

I noticed that you are also in LA, and plan on getting it tuned at Thunder. Take a ride over there (or at least call - 225-754-7223) and ask for a guy named Shane. They have my car in their shop right now (the red Trans Am racecar) - just finished a cam and stuff, and getting it tuned.

He'll tell you exactly what you need, what you don't need, and why both of those things are true. Plus, he'll make sure that everything works "together". I noticed that you have different parts listed. You may not need things like the forged rods if you are just doing heads/cam - rod bolts may be all you need. He can tell you all that stuff (don't trust me).

 

wait, i think you guys misunderstood me or i just didnt explain it good enough lol i am not actually going to build the engine from scratch. i am going to buy one already assembled, like a used LS1 that someone has pulled from their car, as long as it has the wiring harness & computer with it. then i am going to take it apart and have a local shop(very good shop, & good with LS engines) put all the new parts in. i am going to reuse the stock crankshaft and just add new forged pistons & forged rods. so all i am going to be buying is the pistons & rods not a crank also. thats why i said i was going with a stock crank to save money is because i wouldnt have to buy it at all, i would already have it lol. let me make it detailed now i guess lol, i saw a couple of complete LS1 engines with wiring harness & computer for $2000-$2500 and i was going to get one, and then just disassemble it and have the shop install the new rods and pistons, so i called today and the cost for the shop to do the work is $500-$600. so lets see:

engine-$2200(in bewteen 2-2500) complete with wiring harness & pcm
rods/pistons-$1400(callies forged hbeam rods, diamond 347 n20 pistons frged)
Shop cost-$500-600(balance engine,bore match pistons,install rods/pistons)

so thats $4200 for a forged 347ci and i can just put it all back together and have a stock forged 347ci engine, but im going to add performance parts which are on my list. but see if i buy a 402 or a 408 stroker engine, then i dont have anything but the shortblock or longblock assembly, i wouldnt have any of the pulleys or drive accessories or wiring harness or pcm, so i think for my 500-550rwhp goal i would be alright going with the 347ci engine, do you guys not agree with me?



and for you 00trans am, the reason i am putting in new rods and pistons is because i plan on spraying 125+hp nitrous.

 

Ahh - gotcha!

Still, call up Thunder. They have a few engines sitting around their shop that they are looking to move. I think they have an LS1 with forged internals that a customer never paid for. They showed it to me back in Feb or so, and I think it's still there.

 

alright cool, ill definately give them a call and check it out. thanks bro!

 

youre not counting the cost right bro...

Those SB are assembled and ready to put in a car. Just buy the accessories used!!


Anyway, I'm telling you from my personnal experience with my blown stock engine. It will cost you more in the end to get it reassembled by a shop instead of an already assembled SB. The only way it could cost less or equal is if you do the assembling yourself.

Time cost adds up quicker than you think and its ALWAYS ALWAYS pricier than its supposed to be.

 

okay, could you please show me how a 408 stroker shortblock ($4000) with absolutely nothing else with it(wiring harness,pcm,intake,cam,)is cheaper than me taking apart a 346 and replacing the bottom end with forged pistons & rods, and reusing the stock crank? i will buy the engine for $2000-$2500 then the parts would be $1400 and the shop would be $500 so the total for that would be $4400 at the most, could be less if i get the engine cheaper. and with the 346 i would already have all the pulleys and drive accessories and would have the wiring harness and pcm and probably already an
LS6 intake. and with the 408 i would only have the shortblock and nothing else. so me being inexperienced at most of this stuff i would need the wiring harness and computer already with the engine so i will know where to run all the wires when i get it back and ready to install into the car.

 

408 short block rods, crank, pistons rings and bearings $4000

COMPLETE ENGINE AND t56 with wiring harness, pcm,injectors, fuel rails, coils and all other necessary sensors it takes to build a LS1 $2500 thats including stock heads and all rockers that your going to need when you get those expensive AFR 225s. sell the stock heads money back in your pocket.
Want an auto instead of a t56 trade with somebody that wants a t56. or just sell the t56 and buy what you want. So how exactly is it only $800 bucks more for a 408 than a 347 if its done the way hes talking?