drivelikeIstoleit

i dont know about the rest of you, but alot of guys work can be very inspirational on the site and can lead to a snowball effect. awhile back Pat G made a detailed thread in which a stock cube (346) LS1 laid down 509rwhp. While i cant find that link to place it in this thread right now , heads, cam, etc were covered with thorough explanations to the use in the combo. After reading the thread a few times i figured why couldnt this same platform be adaptable to the LT1 platform?

instead of 346ci though i will be looking at 383 or 388ci, as an LS1 already has a hp advantage over LT1s to begin with. Pat G stressed head flow was key, and his Mamo'fied heads flowed the following numbers:

AFR 205s with 57cc
I .158 .220 .264 .285 .296 .300
E .122 .178 .217 .232 n/a .241

matching that flow isnt hard, as ive found three options close within the same flow range, which are:

AI 215cc CNC'd TFS
I .146 .206 .253 .285 .294 .300 .304
E .110 .148 .177 .196 .200 .205 .210

TEA 220cc LT4 TFS - on a 4.030 bore
I .144 .212 .263 .295 .306 .307 .310
E .119 .182 .224 .247 .253 .257 .260

AFR 210cc LT4s Comp. Version - on a 4.060 bore
I .147 .206 .257 .290 .301 .308 .311
E .120 .166 .214 .225 .229 .235 .237


As far as intakes, Pat G used a Mamo'fied FAST 90/90 set up. in his thread he had said those composite intakes lost flow after 280cfm, which helped determine the head choice. currently my choice will be a ported LT1/4 manifold, unless i decide to do single plane and 4 barrel tb. fuel system will be easy, nasty performance setup, theyre only a state away. the cam that was used in the 346 specs were 238/242 .605/.610 112LSA +3 with comp XE-R lobes. i dont see why a company wouldnt or couldnt make a similar grind for an LT1. i had made an earlier post abot 1-7/8" LTs as those were used in the flow testing of the AFRs. header choice is currently up in the air, as the motor will be 10:1 with a forged AI assembly and will get boosted eventually. D1sc or pte-76gts, descisions descisions. but yeah, thats what my mind is currently concocting, what do you guys think?

the_merv

iTrader: (88)

It's an idea..it'll make some power. Your Cam will be a little different than that particular one..the LS Cams have a little bit of a different profile, but like you said if you get one of a similar design for the LT1 it will go together.

Good luck.

Racin96ss

iTrader: (3)

Sorry but this isn't going to happen. There are too many combo out there that are close enough...if you need to hit a number then swap in a LS3 and go for it.

drivelikeIstoleit

how couldnt it happen? if i wanted an ls3 id just buy a car that had one and be done with it, but our economy sucks. I can afford an LT1 so thats what im going to work with.

Speed Density

iTrader: (38)

The parts arent just a linear swap from LT to LS. Sure, you'll make some good usuable power but I would be hardpressed to see taht 500rwhp.

drivelikeIstoleit

ok, im not talking linear swap. its not that hard to find LT1 heads that flow similar to what he used, i showed 3 diff heads that flow almost the same. I know an LS1 cam wont work in an LT1 motor, doesnt mean you cant get a custom LT1 grind based of an LS1 cam. i guess i was thinking up in the stars..... AI has a car that makes 530rwhp with the AI heads i listed, their cam, and a pro-ram fwiw.

the_merv

iTrader: (88)

One of the big things is the Cam profiles..LS Cams are totally different..main reason is to match the Heads. Better Heads can run a bigger Cam and make more power..the LT1 doesn't have that capability. Yea those LT1 Heads flow the same..but the LS Head can flow it quicker and more efficiently, 15* vs. 23*..that is why the LS does what it does.

I'm not trying to dog on your idea..go for it..I'm just comparing your numbers to what they actually do and how they do it.

**** I have L92 Heads..them in stock form just about out-flow the LS1 AFR Heads.. kinda funny when you think about it..

Edit.. mine flow 328/215, that's on a 4.030 Bore, .621/.612 Lift. Alot less on the Exhaust side than that LT4 Head, but they will make more power with less cubic inches, main reason is cause of the nature of the Heads & Cam to match them.

Puck

iTrader: (17)

You can easily make 500rwhp through an M6 if you do your homework.

You will need more then 10:1 CR though, and probably a larger cam. It is not just the flow numbers that make LS1 heads rock - many 23* heads flow the same or more then a lot of LSX stuff. They have a more efficient head that just plain makes more power then what we have on our side, even with the same flow numbers.

Also, I would step up to a single plane with heads that flow that much. A big cam with heads that flow over 300cfm will want a lot of rpms, and you will gain power over ~6500 with a single plane over an LTX style intake.

Don't let anyway steer you away from your goal. Give it a try, I and many others would love to see your results. Even if you don't make 500 the first try you can then tweak and change it until you do .

Good luck and keep us posted

the_merv

iTrader: (88)

Exactly what I was saying with the 15* vs. 23* part..they are just more efficient so there is the advantage.

drivelikeIstoleit

yeah his end CR was 11.92:1 for 509rwhp. i chose 10.1:1 for boost later on.

FASTFATBOY

iTrader: (23)

Aint happenin, cant have both.

drivelikeIstoleit

shoulda just kept my mouth shut, thanks for the replies guys, make people not want an LT1 reaaal quick

Puck

iTrader: (17)

You can't make a 500rwhp build then just slap on a blower later.

What a blown car and what an all motor car want are two very different things. At the very least you will need to change your pistons, cam, tune, and injectors.

Both your goals are obtainable - just not at the same time .

SS RRR

iTrader: (2)

Absolutely agree. Now get on-line, punk!

94Z28rag

iTrader: (10)

Instead of pouting, take these replies for what they are: un-biased opinions from people with some pretty serious LT1s...and rationally re-think your goals.

the_merv

iTrader: (88)

It's not that..we are just telling you the capabilities of that engine and how it will perform to the standard you are trying to put it too..nothing against the LT1, it's just not going to achieve that goal as easily as you think it will..

buzz12586

iTrader: (17)

Like others have said if you are shooting for 500rwhp N/A you will need more than 10:1 compression. Also why shoot for a dyno number? Dynos can be manipulated to say whatever you want them to say. Shoot for an ET at the track. Try to go 9.99 with an N/A LT1.

JasonShort

iTrader: (242)

You are the one that needs to do more homework on this before jumping all over those who are speaking the TRUTH to you. This topic is nothing new. No one is trying to be discouraging here, but rather realistic. 500rwhp for a LT1 is alot more difficult than 500rwhp from a LSx motor. Comparing PatrickG's old combo to any LT1 setup is apples to oranges. You will also learn quickly (if you are willing to listen) that flow number are not the final verdict on how much power a motor will make. Just because a head will flow a numerically higher number doesn't mean that it will make more power.

I've owned a 500rwhp LT1 and built a few other similar engines that made 480+rwhp. It's not cheap, it's not going to happen with 10:1 compression, and you are most likely going to need to go with a solid roller to get it.

So, do yourself a favor and listen to people on here. We all have LT1's because we have an affinity for them. Otherwise, there wouldn't be a LT1 section here.

Jason

Puck

iTrader: (17)

You also never mentioned a budget. Don't even start the build without being willing to spend over $10G's, and thats shopping smart...

94Z28rag

iTrader: (10)

Very true.