Firebirda7x

So I'm looking at an LS1 swap in the near future (a.k.a. before spring) and I wanted to know, should I buy one if it needs rebuilding, or is it the same price after a performance rebuild kit to buy one running off of ebay? I figured it would be cheaper to rebuild it but I don't know if there are LS1 specific rebuild kits or if I will just get shitty stock parts for a 350 and not the better internals the LS1 has. (I'm assuming it has better parts to make it's power over other 350s, unless it's just in the heads).

AmorgetRS

iTrader: (6)

Basically zero stock parts from a "350" as you put it will work in a LS1. They are a completely different engine. If you plan on building it up anyway buy that one needs a rebuild. If you are looking to swap a basically stock LS1 in buy one that is running.

Firebirda7x

Hmm I thought an LS1 is a 350, what won't work on it as far as the rotating assembly goes?

And I just went on ebay and did "LS1 Block" and found ridiculous prices, people selling blocks for $200 that have minor defects the factory rejected, and other bare blocks for $100 and $200. If you don't mind doing that search, how many of those are fake? They all say "5.3/5.7 LS1/LS6". It looks too good to be true to me.

And yes I will be rebuilding it even if I bought one from another vehicle, anyway. If those eBay prices are real I will probably go that route....

Edit: For example, this one.

hairysox33

iTrader: (4)

It IS a 5.7 Liter, The cubic inch count is 346 or something it I'm not mistaken.


I am also assuming nothing is a straight swap.

Firebirda7x

Yea but he said it's a completely different engine, so aside from it being a 6 bolt main, didn't know what is different. I'm still a student :/

AmorgetRS

iTrader: (6)

Everything is different. It's like a GM 302 vs a Ford 302. Same displacement, completely different motors.

Firebirda7x

So it's not based on the Chevy Small block architecture? Nothing is compatible?

AmorgetRS

iTrader: (6)

You are correct.

whatever84

Nothing. The LT-1 is similar to the first gen "small block Chevy" but not the LS-1.

Mark.

Firebirda7x

Hmm. So how do I build an LS1 with just the block? I couldn't really find LS1 specific rotating assemblies and rebuild kits on Summit Racing, just things for 350s.

whatever84

Google "Rotating assy for LS-1" You will find everything you need.

Mark.

JimKlim

if I'm not mistaken there is a lot of work you have to do with the drive shafts and what not if you switch to an LS1, a lot of pain but worth the blood

Air_Adam

Try searching by vehicle model.. use a 2000 Camaro or Trans Am as your base.

Firebirda7x

Yea, I've been hunting for a 6 speed manual from late model Firebirds to bolt it to, and I'll probably be getting a donor driveshaft and a stronger rear end. Lots of junkyards here that have everything but the motors.

Ah there we go A bit pricey with the cheapest being 2.6k and no rebuild kits just complete rotating assemblies, but they are all using forged parts, so... would it be cheaper to buy some stuff separately? I just want a running LS1 for now, and I'm going to have to buy all the engine accessories and **** too. Thought there would be a bigger assortment to choose from...

Air_Adam

3rdgen T5/700 driveshafts are interchangeable with 4thgen T56/4L60 driveshafts. Same length, same yoke, same size U-joint.

Pocket

iTrader: (24)

Read the swap sticky, alot of these questions are covered

For your first swap I seriously suggest not piecing it together and buy a complete 4th gen dropout. Starting with a bare block is a good way to overspend like crazy on the little parts. For example, I started with a complete 5.3 engine. It cost me $200 to begin with, I grabbed it because it was cheap. In the end it took $1600 in small parts just to get the engine ready to install and took about 9 months of wheeling/dealing. With complete ready to run dropouts being sold for $2300-2500 commonly it's stupid not to go that route from the start

Mkos1980

iTrader: (8)

You can swap roller lifters!

On a side note, I bought my 60K LQ4 complete with hanress and 411 ecm for 1200 bucks. Parted the intake ehads, harness and some other stuff, threw on 243 LS6/LS2 heads and intake and a cam for under 2K.

Firebirda7x

I had read all of the stickies, but since I'm starting with just a block and an old tranny and rear end, I need to wait and do it right. The LT1 seems like a far cheaper option to start on, and I can get my manual swap in and get a better rear end so when the time comes for the LS1, I will be more prepared.

I think the LT1 will still have far more potential than the 305 Thing is, the 305 is knocking like mad, the rods are going to come out soon haha so I don't wanna rebuild it, it's time for a swap and that's how all this started. The 350 is in a 1996 Fleetwood Brougham.

Edit: Ok I didn't know it could also come with a L05. I can't get to the casting number, are the intakes different or is there a way to tell? I don't wanna buy it if it's an L05...

Pocket

iTrader: (24)

Lifters, valve springs, rod/main bearings and a handful of bolts interchange. Several parts work with machining, but thats out of the scope of std interchange

You cant go wrong with a budget LT1 swap. Out of the box 280hp from a $1-300 B-body LT1 is hard to beat, plus so much stuff from your SBC will directly work on it

Identifying LO3/5 vs L99/LT1 is pretty simple. One looks like a carb and the other doesnt. Also, The LTx platform wasnt used until 94 for B-bodys. To distinguish those, look at the pad behind the drivers cyl head above the bellhousing. It will either say LT1 5.7L or L99 4.3L. Skip the L99, you dont want to go there

Firebirda7x

The motor had this big plastic oval pan on top of the motor that covered the whole thing like a giant pancake carb, I thought it said TPI on it thought.

Speaking of TPI, is it really just fuel injection or is it something older? I keep reading people talking trash about it.

Flightoficarus

TPI = Tuned Port Injection, so yes, it is a type of fuel injection system. They're not necessarily bad, it's just that they're known to make monstrous torque at lower RPM's (some stock 350 TPI's supposedly beating LT-1's and LS1's off the line very briefly with a good driver), but they quickly run out of breath around 4000 RPMS or so I believe. This is due to the long runners, among other factors, and is why stock that they make like 230-245 HP, but 330-345 FT/LB's TQ.

Basically, they're beastly off the line, but will quickly lose grunt after that. With some modification, they can be beastly engines all around, but most people ditch the TPI system in favor of alternative fuel injection systems like Holley Steath Rams or Superrams, which offer a better balance of HP and TQ, and increases in both across the board.

350 TPI (aka, L98), or LT-1 are both budget friendly options, and of course, will offer WAY more potential than a 305.

kevinc

You are very mistaken, as pertains to the driveshaft.

Firebirda7x

Ok so pretty sure the 350 was an LT1. Now please don't get upset if this has been answered before but what is the major difference between TPI and modern fuel injection? I know TPI systems have long runners, why is this inherent in a TPI system but not modern cars? If i get an LT1 I don't want to deal with the TPI "low end torque and nothing after 4000" crap.

Pocket

iTrader: (24)

GEN II (LTx) and GEN III (LSx) were reworked versions of the generic SBC. It's a bad comparison to gauge a TPI control system vs one of the new age engines because it wasnt exactly an engineering marvel

Anyways, you wont run out of grunt with the LTx platform because the LT1 intake has 3" runners. Absolute shortest GM ever put on a production V8. This lets them spin up pretty good but sacrifices most of the bottom end torque

LSx on the otherhand has an intake design nearly identical to TPI. 19" runners for LS1/6 style intakes (vs 21" for TPIs), the difference is the runners were designed around a larger displacement engine since TPI was designed around the 305 and simply slapped on the 350 when customer demand was high enough. Better engineering from the start lets the engines breath up top and stock cam selection was based around mid-high range power, so like the LTx, these engines like to spin up

From a control point of view, the biggest upgrades are sequential injection and electronic transmission controls. TPIs were batch fire. You will like troubleshooting with an OBDII car, it pretty much spoonfeeds you the issue in detail

Firebirda7x

Sweet. The junkyard has a running LT1 for $400 so I'm going to scoop that **** up. What are electronic tranny controls? I was going to swap in a 5-speed and ditch the 700R, and get a new rear end to handle the new and future power.

kevinc

Slap a Stealth Ram on a TPI engine and that upper-range limitation disappears like cake at a birthday party. Gone. Fuggeddaboutit. Completely changes the TPI game.

Going LT1 just for that issue does not make sense. Reverse cooling and Opti-Spark are real downers.

An upgraded L98 and better intake as mentioned above are much more attractive than an LT1, IMHO.

kevinc

Gen II, sure...but your opinion on the Gen III being a rework of the SBC is non-factual. If you're going to make that assertion, why not include the Gen IV?

In fact, TPI hit the showroom on both 305 and 350 engines in 1985. Same year. May or may not have been designed to feed a 305 but the rest of your statement is false.

Firebirda7x

Well I am mainly wanting the aluminum heads and 275-ish HP stock from the LT1. Is the L98 a standard 350 that I can use the much cheaper and more plentiful rebuild kits and aftermarket on?

kevinc

L98 is the TPI 350, regular Gen-1 SBC.

I'd pick up a 350 from a '97 truck or SUV, you get factory roller cam provisions, 1-piece rear main seal, and usually 4-bolt main caps as a bonus.

Swap the heads for better aluminum ones, pop in a decent cam (GM LT4 HOT was my favorite) and put a Stealth Ram on it. Off you go.

Firebirda7x

At that point, what advantage would an LT1 have? Cuz the L98 should be much cheaper to rebuild too.

Ouch, I just looked at the prices for Stealth Ram kits. I could afford an LS1 complete swap for that price!

kevinc

In reality, the LT1 would not have any meaningful advantage.


If you already have a TPI setup, you only need the intake and fuel rail. You re-use your TB, injectors, sensors, and ECM. Cost me around $500 back in 2002 or whenever, and I recovered much of that when I sold my TPI intake.

Firebirda7x

Oh. I just went to Summit and typed it in and found kits for $3 grand. My injectors all need replacing though. So is it just a redesigned plenum or something then? I thought I need shorter runners and a reprogrammed ECU and wiring to handle the new firing?

kevinc

The runners are shorter and straighter.

Some tuning to optimize the fueling and ignition is a good thing.

InjectorsPlus

iTrader: (1)

Lots of good information here.

LSX engines are cheap now. How about a blend of new/used.

Buy a used one that has been run to death, disassemble it and take the block to a machine shop and have it checked out and rebuild that. You'll have all the little bits and pieces so you don't get nickle and dimed to death, but you'll have a "new"" engine.

InjectorsPlus

iTrader: (1)

It's more than a redesigned plenum, it's a different system altogether.

Yes, the injectors on the LSX are different. If you go LS1 we make a special set because of deficiencies in the LS1 intakes.

You would be better off with an LSX ECU.

kevinc

Interesting post!

I'm still running the factory 28# Delphi injectors on my LS1 and my Long Term Fuel Trims aren't as close bank-to-bank as they used to be...injectors are starting to pick up variation in flow rate.

What tweaks do you perform on LS1 injectors?

InjectorsPlus

iTrader: (1)

Here's the thing, I do a lot of stuff to injectors and I don't put them on my site. I do all the R&D and once the competition finds out they copy it.

I'll PM you on that.

Firebirda7x

Talked to my instructor tonight, he said a Stealth Ram kit is not going to be cheaper than $3grand cuz I will need all of it and new injectors and stuff so guess I'm not going that route. Whatever, I guess I should just build up a L98....

five7kid

iTrader: (14)

http://www.summitracing.com/parts/WND-7540/

Your stock injectors will work. I believe people are using a stock TB as well. Might need a different fuel rail (not sure - I'm only a TPI parrot). But you don't need this:

http://www.summitracing.com/parts/HLY-91403211/

AmorgetRS

iTrader: (6)

Find a better instructor...

Firebirda7x

Oh ****. Nice. So...maybe I could convert my 305 to a higher revving motor haha. How come every 305 buildup is mechanically strained or seemingly weak when compared to 350s? Is the .7 liters of displacement really that big?

AmorgetRS

iTrader: (6)

It's the bore size. 350 has a 4" bore, 305 has a 3.736.

Good read on why the 305 isn't that great:

http://www.carcraft.com/techarticles...ore/index.html

Firebirda7x

So smaller bore = lower volumetric efficiency.