chomp

Well, I had originally planned on swapping a built up LT1 into my car, but to make a long story short, it didn't work out and I'm back to square one.

I've been considering keeping the TBI setup (for money and smog reasons-i live in Ca), but rebuilding it. I have ideas about making it a 383 or 350. I'd like to have a performance shop do it (I've talked to a guy about it.. I took my LT1 to his shop when I had it). I originally wanted to have 350-400HP to the wheels with some ported/polished heads and a custom grind cam with the lt1, but I've lowered my expectations now and I don't need the power anyway.

I'd like to have about 300-350 hp at the flywheel. I'm up for using new heads and intake, as long as it isn't too much of a change and is smog legal.


Since our motors (L03) are just SBC gen1's with a unique type of fuel injection, I figured it would be much easier to build this up than it would swap in an LT1.

Any suggestions? Is this realistic?

kyles88bird

chip buring and dataloggin are gonna be ur friends when ur done . get a set of decents heads and a nice roller cam.

chomp

Anyone out there have any suggestions?

I've never rebuilt a motor and I don't know what heads/cam/internals would work best with a TBI setup

ShiftyCapone

iTrader: (7)

What is your budget? For $3000 you can get close to a vortec 350 with a solid 300hp.

chomp

Yeah... $3000 is close to the most I'd like to spend... but would I be able to use the TBI setup w/vortec heads and still pass smog?


It seems more ideal to take the block I have, bore it (and maybe stroke it), use all new internals that are lightweight and buy some new heads... but then again I don't know what will work with the TBI as far as heads go...

crrllmich

GM sells a intake manafold for the TBI that is for vortec heads....your gonna need that.... emissions shouldn't be a problem...

I am building a 430 Fastburn 350CI engine on a TBI if you need help or wanna share ideas buzz me sometime.

BMmonteSS

vortecs are probably not going to work for you, just because they don't have egr provisions. I think there is a way to plump exhaust into a certain GM intake to remedy this problem. You need to look into that. Don't even bother with your current block, just go get a 350, it'll be cheaper to rebuild and you can work on it while you drive your car now. To pass emisions your going to need to become fluent in diy chip tuning. Start learning now on your 305, see if you can find a smog station that will let you do some experimenting with the tester, see how timing and fuel effects the different gasses. That way when you get your new motor done and it fails (it will) you'll know where to start working in order to get it to pass. Start doing some searches on what it takes to pass emisions. You need to very carefull on your cam selection, too much and you may not be able to get a clean idle that you'll need to pass smog.

I hope I don't sound too remedial, but making power in the republic of kalifornia is hard to do, you have to be smarter than man thats trying to bring you down.

crrllmich

I am pretty sure the GM Vortec Manifold has EGR.

http://store.summitracing.com/egnsea...8&autoview=sku

ShiftyCapone

iTrader: (7)

Correct but the heads don't. You have to tap into the exhaust and divert it into the intake that way. There are a few posts here on TGO that should come up with a search on how to do this. CHP's vortec 305 buildup also had a pretty good "how to" do the same thing.

crrllmich

Just lower the car so they can't get it onto the ramps

chomp

Yeah.... or find a someone who works at a station that is at least a little bit lineant with the testing. I actually just got my car smogged in May so I have 2 years to do this before I really need to worry about anything....


Anyhow, you think a vortec setup would be the best bang for the buck? What would be a good set of aluminum vortec heads to match that intake manifold?

And then as far as a block goes, should I just use any Gen I 5.7 block?

crrllmich

Fastburns are my favorite but thats gonna produce a little more power then 300HP lol. As for blocks.... yea any 350 blot two bolt or 4 bolt doesnt really matter at 300HP but if you plan on going for more later def. go for a 4 bolt main.

chomp

Fastburns... those are like LS1 heads right? How much are they and will they work with that Edelbrock manifold?

300HP isn't the limit I'm setting..... if I can get more for near the same money that's fine...

crrllmich

I am working on getting 450HP out of about 4000$ The fastburns will work with any vortec manifold. They are alot BIGGER then LS1 intakes... the intake and exaust runners are huge. If you compare them to any other small block vortec you just cant find better for the low price. And there alum. too.

There are companies on eBay that sell 357 CI blocks for like 800$ Shipped I beleive. 4 Bolt mains too. Throw on a oil pan. Vortec Fastburn heads and a vortec intake manifold. Bore it to 2" and use the 454 tbi intake with the injector lifters upgrade fuel pump and injectors, and finaly a LT4 hotcam kit and you should be very close to your budjet and right were I am at.... tunning is gonna be very hard. Are you good at prom burning? Maybe if we end up building the same engine we could help each other out on that part lol.

Only problem is your gonna push over 400HP.... not sure if you want that much. If you want to tune it down you could use a lighter lift cam and maybe smaller heads like the summit vortec heads.

BMmonteSS

In my opinion if your going ot spend over a 1000$ on heads, you might as well go for AFR's. Best heads out there right now, just stupid expensive. Keep in mind that LS1 heads will blow any aftermarket gen 1 head off the map. There are some heads that have flow numbers that are in the same ball park, but don't make the same power.

You guys really need to do some in depth research on what is possible with TBI. The fastest guy is probably making around 400-425 flywheel HP. Your research should show that it's not how much HP but where you make that HP that determines the max HP TBI can support.

Cadillac

I wanna know what happened to the LT1?!?

I love that engine.

chomp

I bought an LT1 off ebay (95 Vette) and it was damaged in shipping, plus the internals were pretty much borked except for the crank.

After a couple weeks of contacting the guy who sold me the motor, he said he'd refund my money if I just sent the heads and intake back. I got to keep all the accesories and stuff so I think it came out pretty even ... plus I got the experience of taking apart an LT1 to bare block.



Anyhow, my plans for the LT1 were some Lloyd Elliot heads/cam and some other stuff that would get me about 450HP, but then I wanted to a forged rotating assembly and it just got to be too expensive. I wanted a complete LT1, but I was going to scrap the internals anyway which was a waste of money.


Plus, I'm still on my parents' insurance (I'm 20) and they don't like the idea of a 450HP motor, which is totally understandable. I figure with a 350TBI I can get something that will be fun (300-350HP) and way less expensive. I'm planning on $3000-4000 with this and with the LT1 it was more like $5000-7000

8Mike9

There's no EO# for running egr from the exhaust to the intake on Fbodies...here in Ca.

If you do this, you need to mimick the vette setup and get the car reclassified for emissions.

Kind of a PIA.

Cadillac

Oh yeah... the rebuild coach.

8Mike9

Just adding a voice of reason my friend.

I bet I see a post a week in the Cal. regional boards along the lines of "I need to put this back togther to pass smog"...or some such stuff.

Or "does anyone know who can do me a smog-favor"?.

But by all means if you don't mind tearing your engine apart every 2 years, or paying someone off..have at it

ls2twntur1200hp

I've got a an 88 formula with a 305 and I can easily out run an ls1 car. On the chassis dyno I came up with about 320 hp may be a little less or a little more and I did it cheap. I had the block bored to 60 over and four bolt main caps installed. I used the stock crank and rods exept i had to buy new ones. I had it balanced also. It has ported vortech heads I got out of the junkyard and rebuilt. the cam is custom grind from crane, email me for specs. I also raised the compression ratio to about 9.8 which is not to bad but it wont run on 87. I got a vortech tbi intake from sdpc and had it bored to 2 in. I bought a holley 502-6 throttle body and had the pod raised half an inch. For the exaust a edelbrock emission legal setup. Oh and dont forget pullys i have the water pump, crank and alt pullys and i still have the air pump and a/c. And for the air intake ive got a functional ram air hood from G&T fiberglass. Also i have a comlplete accel digital ignition and thats were a lot of the power came from. This setup is emmesion legal because i had it inspected.

BMmonteSS

You also have to consider that you could be putting down around 350 to 360 at the wheels if you had just built a 350, and had no more money it it than you do now. Who did your tuning? I find it kinda hard to believe you actually passed a sniffer with all that you have done without some serious chip work. I also find it hard to believe that your making around 400 FWHP with a 305. If you actually are, then you probably have one of the fastest 305's on the board.

ls2twntur1200hp

That's crank horsepower. I only had 252hp at the rear wheels. I got an accel gen 7 engine management system off ebay. Turbo city in Orange, CA tuned the system and thats also where i got my dyno figures. Since then i've destroyed my 700r4 and i'm trying to retrofit a t56 in it. Your right about the sniffer though. The first time i took it i failed. So i bought a high performace coverter and mixed a 25/75 mixture of 93 and etanol. Then i was ony a couple of digits over so he passed but remeber i dont live in CA so i don't know if i would of got the sticker. I think with the dfi system i could turn the fuel down enough to pass but i dont want to mess somthing up changing those digits. Your also rite that i could of built a 350 and made more power but i wanted to out run an ls1 with a tbi 305. I accaplished my goal but i'm minus a tranny and my rear end is about to go out. I only spent about $2700 on the whole thing and that includes the t56. The car isnt legal now but before the tranny went out i drove it to texarkana and back and got about 22 mpg.

BMmonteSS

The devil is in the details. That explains alot, thanks. You wouldn't even dream of passing smog in cali with the DFI setup (EGR, canister purge). You overall price is pretty low as well considering a custom cam is over 300 and the DFI is well over a grand. I also don't quite see how your outrunning LS1's with only 256 rwhp. They put down over 300, granted they weigh a little more, but they should still be a bit quicker.

I don't mean this as flame, just want people to realize that there is ALOT more to making power and passing smog than just slapping the right parts together.

senatorcbp

LS1 makes 320 at flywheel but not at rear wheel. So hes telling the truth. besides you can easily beat a stock LS1 with a 305 by simply adding gears and 1000 bucks worth of engine mods. Headers, camshaft, intake (somethines a 75hp shot of nitrous). I know I had two friends that did it. But then the others guys with the LS1 went out and spent 1000 bucks and they started winning again.

BMmonteSS

No LS1's put down over 300 AT THE WHEELS. They run bottom to mid 13's, and there are very few smog legal 305's that have done that, and none that have done that without a well planned out combo and lots of tuning. Of course a power adder like NOS changes everything.

flaming-ford

iTrader: (7)

well in my opinion if i were you man i'd build up the 305. You can get the 300-350 pretty easily out of that motor. I'd convert it from tbi to carb'd add the world torquer heads, a fairly mild aftermarket cam, buy the stroker kit to stroke it out to a 335, performer manifold, 600/650 double pumper carb or something close to it and you'd have about 350hp at least. With a more radical roller cam and some roller rockers you could probably see 400hp.

You already have the 305 why not use it. These guys are just being pesimists, no one likes the 305. It's almost the same engine as a 350 except a smaller bore (hence the reason everyone drops a 350 in).

BMmonteSS

Big difference between pesimist and realist.

When you have to pass smog that puts certain restraints on what you can do. You have to stick with a pretty mild cam, low compression, and you can't even dream of slapping a carb on it. The way the smog test are run, they look for certain chemicals in so many parts per million. Which means their looking for the % of CO or NOx in your tail pipe, not the over all volume of gases coming out. So thats why bigger cubes are desired for making power and staying smog legal.

When you get past 1hp per cubic inch, you start to really encrouch into the drivability of the motor. How much fun is a 300 hp 305 that gets 15 mpg? With a well tuned (DIY chip tuned) setup you can have your cake and eat it too. You can get mid to low 20 mpg, and put down over 300 to the wheels. Thats as good as it's gonna get and stay within the reins of the smog police, drivability, and a budget. This is why the LS1's are so amazing, their head design allows you to make tons of power on very little fuel very efficiently, which in my opinion makes it the ultimate street engine.

Ronny

iTrader: (1)

recently in an article regarding fuelcrisis it was mentioned that 10% ethanol ius about the max allowable due to pollution issues without a reformulation. i believe 20% ethanol helps CO but it adversely affects N02. so making you own concoction may not be of much benefit to pass sniffer....