i think the real question is, is it worth it?

Mark Montalvo, who used to post here regularly has built two different versions of a 421ci LT1. One was a 4.090" bore x 4.00" stroke, and the other was a 4.030 X 4.125" stroke. Neither was an inexpensive engine, but it can be done.

a 90 overbore? i wouldnt feel comfortable running that really. IMO, .060 is the max i would go on a smallblock.

4.125 stroke? how the hell, block must have been filled right? even with the 4.00 stroke?

 

Yeah you could run 118mph, but with alot bigger cam . Unless you convert to 18 or 15 degree etc. heads, even if you get bigger 23 * AFRs ported, unless you go quite a bit bigger on the cc off the heads , you will still need alot bigger cam than an ls1 to make the same power even with ported heads of the same cc. Even with bigger AFR's ported unless you go quite a bit bigger, they are still 23* heads vs 15*. And even still 23* vs 15* . The 15's will flow better and make more power for a given cc from low to medium to probably even high lifts. Thats whats good about an lt1 though. You can run converted 18 ,15,14, * etc heads. Although it co$$$t.

The person above said the car runs a 224 cam in the 118 mph LS1. Even with bigger ported AFR's you would need something around the size of a 306 cam( 23x in, 244 ex I think) or at least something well into the 23x range to make the same power, Unless you ran 15*18* etc heads, or HUGE 23* heads alot bigger than an ls1.

By the way if 13.6 is the quickest ls1 stock you have seen. There are many quicker that.




As far as the block issue, I agree with Injuneer, I don't know if the ls1 block is weaker than lt1, the lower end main set up is well designed for strength. I think the main problems they are having , is like he said the heads staying down, not block problems. I think there were sleeve problems, but I think some shops have that taken care or now.
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The ls1's can go bigger because of block deminsions, deck height, etc. You can only run so much stroke and or rod in a given block. Also only so much bore. We don't have sleeves, and the stock block wall thickness is only so thick, although some go to the "limits" . Like some of the guys said , there are lt1's in the 420's.

 

Hey I am going to try and be politically correct. By big power I mean over 600hp naturally aspirated.Which seems to take a big stroker LS1 to get the job done. You spend the coin to put a big arm in an LS1 it leaves you a good amount of money to build a smaller CID and quite possibly cheaper SBC that will make the same power or maybe even a little more if the motor is very well done. The Ls1 is a nice motor and it makes an excellent street engine and its even a good race engine but when you get into making IMHO serious power the cost out weighs the benefits. A good SBC with all the toys making over 600hp NA ie aftermarket block, great heads, solid roller cam etc... will set a person back somewhere between 10-15k depending on the quality of parts. I am seeing prices higher then that for 600hp big inch LS1's with equal build ie C5R block and heads, big sleves etc...
IMHO the better deal is the Lt1/SBC because it basically has no end with where you want to go with it. Parts are limitless. LS1's have allot of parts but at the end of the day they are fewer and more expensive then conventional parts. And please. Don't tell me a regular SBC engine with good parts can't perform with an LS1. That would just be crazy.

 

Someone mentioned that the LS1 block isn't as strong as the LT1 block. I dunno if the LS1 block is what you would call "weak," but under most circumstances, iron is a much stronger metal than aluminum. I personally wouldn't trust an aluminum block- i.e. LS1. I'm an "old-school" fan. If it isn't an iron block/aluminum head combo, I don't want it.

Aside from that, I've just heard of too many people botching shifts with their hand-built-by-god LS1s and really doing some damage to them. Hmmmm.

I think both, the LT1 and the LS1 have their weak points, but in the end, I'll settle for the optispark problems, because I know the motor is going to last more than 139,000 miles.

I will NEVER even considering anything but the LT1 for my car....unless it's a 502ci.

 

aluminum blocks have had thousands of hp run thru them.some people prefer them due to being lighter.if you miss a shift on any motor damage is possible not just on ls1s.


ls1 tech. is still in its early stages and theyre making awesome power.of course parts are going to be more expensive but you get what you pay for.

 

put your money on an lt1 every time over an ls1?youll be broke pretty quickly.what you run ls1s have run better NA on stock internals.please tell me again how youve never seen that so it must be BS.

 

A member of my car club with a 2000 WS6, the only mods that I know of are air lid and K&N filter, just put down 303, 305, and 307 RWHP in back to back pulls. I have a .PDF of the dyno sheet if you want to see it.

Another member of my car club with a 2000 Camaro SS with these mods (from his sig):
Mods: Direct-Flo lid w/K+N, SLP 160* thermo, MSD wires, NGK TR-6's, cut-out, free mods, Pro 5.0, Harlan Shift Light, RAM 6130/402 combo, Mcleod Adj. MC w/drill mod, GM "145" Slave, ES Poly TA and Tranny mounts, G2 LCA's, BMR STB.

He's put down 322 RWHP and has run a 12.66 I believe. But I do not have the timeslip or the dyno sheet.

 

I have an XE 230/236 cam on stock ported heads that flow 255cfm@.550 lift intake 185cfm@.550 exhaust on a 383 LT1.

Car makes 478hp and 490 lb ft of torque at the motor. I could have easily gone with a bigger cam and more aggressive port job but I wanted something very streetable and well mannered.

I'll post the video of the run tomorrow.

 

What is the fastest car on boards? ls1 or lt1
This discussion all has come down to a manner of opinion you got what you got run it dont try to explain why you do.

 

I rest my case. Streetable, and as fast as all hell.

Yeah, I'm so scared of LS1s. The majority of the LS1s (with their big-mouth owners) are running high 12s if they're lucky. Most of them have nothing more than an air lid and a Flowmaster exhaust. I'm shaking in my Nikes. There's always somebody faster. And I've seen pretty wicked LT1s. And as far as how well LS1s run on stock internals, I could give a damn. Tell me who buys an Fbody to leave stock. And if you think I've never had my *** handed to me by an LS1, I can name more than one occasion off the top of my head. But I'd bet your LS1's NEVER been beaten by a "low technology" LT1, now has it?

I've seen plenty fast cars of both breeds, LT1s and LS1s. And considering your car must be the "ultimate," according to your signature, I'll just assume you're one of those sour LS1 owners that has had your *** handed to you on more than numerous occasions by LT1s. Oh wait, that's impossible. Your motor was hand-crafted and built by god. Maybe I should ask for the blueprints so I can have as great a car as yours.

You're right, LS1s are great, and LT1s suck. I think I'll go drive my LT1 off a cliff right now.

Oh yes, and one other thing. LT1s have also ran better with stock internals than mine does. Your point is what? And if you think the LT4 HC is some wild setup, you're sorely mistaken. Indeed it will enhance performance, as well as the fun-factor, but in no way does it turn the car into a hotrod. If I wanted a hotrod, I would have built one.

 

Dan, I understand where you are coming from. I got sick of the common, "oh, you've got an LT1, why race?" mentality of the majority of LS1 owners around here. However, they are fast out of the box, and it took me a set of longtubes and exhaust to pull on most of 'em around here. However, it is simply foolish to deny the potential of the motor. Basically Chevrolet implemented a ton of racing techniques and designs in the LS1. The LS1 head is about the closest thing you'll see to a race head in a production car. It is better on emissions, better on fuel economy, better on power, etc. Also, with the better vavle angle, you need less cam to make more power with equal head flow. Thats why there are so many 400 rwhp cam only LS1s. Sure, it can be done in an LT1, but you aren't gonna want to drive it on the street, and you'll have to rev pretty high to get it. Lack of an optispark is a big plus. Also, I'm not positive, but I believe the LS1 ecu is not hindered by the 7000 rpm limit the LT1s have. I think that is one of the worst things about these cars. I'd love to put a solid roller cam in my car and turn 7500 rpms. Then again, all rpms do is ruin people's motors. I guess its better to have a bigger motor and shift earlier.

 

Can't argue the Ls1 not being a better motor. I look at it like this, they took a good thing lt1 and made it better ls1.
Wonder what the next gen motor will be called? Lr1? R1 sounds better to me.

 

i love dans constant talking out his *** about ls1s.i never said lt1s suck.youre the one denying what ls1s are capable of and badmouth them constantly for no reason.yes,most run 12s.go to an all EFI fbody day and see what cars are running the strongest.youd never admit it anyway.despite GMs major redesign of the SBC ls1s suck because dan said they do.he must be right.all the mags lied about running 12s stock and dynoing over 300rwhp.




also i said stock internals NA running 11s.how many lt1s can do that?that doesnt include nitrous and RRs arent a bolton either.i dont claim to be fast or the fastest and never will.but when GM comes out with something better i wont cry and badmouth it about ill be happy it was GM and not a competitor.

 

Hey did anyone read that article about the 454 LS1 in CHP. cost 25,000 for 558HP. Granted that was a small cam, but you can build a Gen1 383 to make that kind of horsepower for about 6500 or a blown alcohol 572 that makes 2500HP for about 20,000. Anyway not trying to dis LS1's I think they will probably be a very viable force in the small block world once the aftermarket can bring us some parts a little cheaper.

 

IMO, LS1s are overpriced, and LS1 parts are overpriced. Someone said that he wouldn't have any other motor other than an LT1 unless it was 502ci. I personally would not go with anything else but an LT1. LS1s sound like ****. I'd hate to start an F-Body war here, but LS1 owners always think theyre the **** and are usually conceited. Don't get me wrong, LS1s are sweet bolt-on engines, but if I was going to go any further, I would say **** it and go with an LT1 (speaking as if I was an LS1 owner).