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Discussion Starter · #1 ·
Ok guys here is the thing. i have been wanting to build an all out street/track truck for some time now. I want to get a '90-93 454ss and build it or start from scratch with a small block. I know a guy selling a 4 bolt main LT1 block from a '95 corvette for $250. He says there is a main and a rod bearing spun in the engine and it needs to get rebuilt. i think this would be a good place to start for my build. I have seen folks on here make stupid hp numbers with their LT1s and I am very familiar with LT blocks and want to stick with them if I start from scratch with this truck build. My question is...how much power is a 4 bolt main LT1 block capable of producing NA...dont matter if its stroked or not? I dont want to do turbo or superchargers or nos, just a straight NA block. is it capable of being ported out to a 427 (4" crank and 4.125 bore)? what is the most hp that you guys have seen from a NA block? Im looking to get well into the 6-700 hp range if its possible and am willing to bore and stroke to the maximum allowed without destroying the block. also want to spin it to 7k rpm if possible.
 

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Discussion Starter · #6 ·
ok so...

ok so what is the best compromise of big horsepower and big reliability? i am not too much concerned about the price right now because im not trying to do this overnite if you get my drift. my goal is as close to 600hp as possible with as big a stroke as possible without sacrificing reliability of opti, valvetrain, rings, etc. i have seen many guys get 500+ hp from 383s and 396s and im thinking thats probably the best way of going instead of trying to get to a 427. i just like the idea of having a 427 small block like the one in the newest Z06 or the idea of having a 400 small block like they run in nascar. i know the blocks and everything are completely different but im looking to make huge power with something unique...mostly for "cooler talk" or bragging rights. suggestions of builds and parts that have worked...?
 

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Discussion Starter · #9 ·
go ltcc or dont go.
stroke wont effect opti, rpms will
how much rpm we talking about? is the msd opti good for over 7k? i couldve swore it was good until about 8-10k...at least thats what i have heard. also, no offense but i would rather not let this turn into a msd opti is crap type thing because im using one now and its awesome to me. ltcc is an option but i would like to stick with what i know. i have had no problems with any optis in the past.
 

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Discussion Starter · #10 ·
There is no replacement for cubic inches. Small blocks are boring anyway. When the LT1 in this Fleet dies it's getting a 500 with just a few select goodies. Far stronger motor that will eat an LT1 with major mods for breakfast. Plus THEN it'll be a Cadillac instead of a Chevy with aspirations. Sort of the same thing as a 454SS with a mouse motor... :D
so true...but im trying to weigh the pros and cons of both options. im wanting to decide between big block or stroked small block. i know i need a lot of rpms to make power in small blocks but there are way more options available that are way cheaper at this point when it comes to making power with a lt1 as opposed to making power with a 454ss pickup except for converting it over to carb or something. right now at this point with the mods i have done to my 96, i have spend a whole hell of a lot less buying parts on ebay and in these forums than what i would have spent otherwise plus the support for the lt engines is top notch which also makes me want to stick with it. im just listing all the pros of sticking with LTs at this point.
 

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Discussion Starter · #12 ·
A few answers:
Opti - Run a LTCC. They dont like compression or RPM. I am sure the really fast guys would agree. Hell my car only gets to around 6800 now and I have broke them. But Tad is right the computer freaks out above 7000.
Cubic Inch - The largest true LT1 I have seen and live is a 416. But to even go that big you have to worry about core shift. If it is not perfect, then no go.
HP - I think NA you will have a problem to have above 600 to the wheels and the engine living. I have seen a few that do, Mike Harris I am sure is over 500. To much stroke or to much RPM. Both can do some work on an engine, more so if you have both.
I would try for the 450-500 range then add the bottle.
But all this is about what??
Bragging rights or being able to dust anything on the street.
If is to dust cars, then I would add the bottle. Nitrous is great thing.
well...based on the info im getting right now, it looks to me like i might just stick with something between 380-396 ci and keep it below 7k rpm. and as far as what its all about...right now just bragging rights really. i mean lets be honest, about 80-85% of the cars on the street can be beat if your car is running 12s or better. the rare ones like srt8s and vettes and g8s and those exotics are the exception and even the cars i have seen on here will dust them off. its mostly just braggin rights for me...something to talk about. thats all.
 

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Discussion Starter · #15 ·
No No you have not.

there are just a hand full of 500RWHP NA LT1s
most are sticks that have 12 + CR and rev so high they have to run FAST managment



a real deal 12 second SS will dust stock srt8s vetts exotics
and will be a ton of fun and make super bike owners scratch there helmet with the visor up

what your talking about building;
a high rev stroker 500+ NA Lt1 is not something to just talk about....
it is a way of life
a way of life that has & will consume it's owner(s) ... that are on this forum
some of us will even regret it...
when were changing the forward input sprag the for the thrid time in 300 miles
lol...ok then what do you recommend? i mean im cool with it consuming my spare time...hell between my gsxr 1000 and this impala i have right now, i barely have enough time for another project but hey...i guess this is how god made me:D. seriously though, where would you start if u had to do it again? i mean im talking about buildine a regular cab shortbed truck that probably easily weighs about 500 lbs less than our impalas. im looking for 11s out of it and dont care about gas mileage or any of that crap...just want it o be somewhat reliable. your take?
 

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Discussion Starter · #23 ·
There are several of us running 11's or better N/A. Notables Pat Gish 11.20's, Mike Harris 10.50's, me Frank Staton 11.90's last week first time at the track with my new setup in 90 + degree weather. There are several more. And running from stock short blocks to 400+ cubes. I don't care what bottom end you may have but if you don't have a good top end to support it, it does not matter. Having a good set of heads and properly spec'd cam makes all the difference in the world. Pat Gish runs a rebuilt stock short block with AI heads and cam and with lightening of the car but still able to be driven back and forth to the track and runs 11.20's N/A. Mike Harris at 10.50's is still streetible. I don't care what you put into the bottom end its what you do with the top end that's going to make your power.
yeah i know about the top end being responsible for making all of the power, im just curious as to how much an lt1 block with 4 bolt mains is capable of with maximum stroke and best head options. i already have decided that if i do get this 4 bolt block that i want to go with an ai setup for my top end maybe even give their fully ported lt4 heads a try. tell me about this 385 block that you have if you dont mind. those numbers are super impressive. what exactly consists of a 385? i know what makes a 383 but not a 385.
 

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Discussion Starter · #24 ·
If you want big stroke, and you do for torque to move these heavy cars or a truck, then the 7000 RPM limit should not be a concern as you really should not need much more than that with a 4" stroke. So there is your torque and like Frank said, now it's all about the top end to make the HP.

If money is really no option then go 18 degree and you will have a better top end than any motor you have seen on here. I know, no one makes an 18 degree LT head, right? Well I always wanted to do a set of 18 degree heads so I would alter a set to bolt on to your LT block. If you can't find anyone that could do it then I can. It's just some welding and cutting to make a set. Match that with a custom 18 degree intake and you can get to 700HP with an Opti at only 7K RPM.

I see the Opti is getting bashed again. It's not a problem if you buy a GM, replace the cap and rotor with the MSD replacement and lock tight the screws. They will last a long time even at 7000 RPM's. I test my car about every other week at the track and it runs the tach to 7200 on every gear change. The Opti is over two years old currently and has hit 7200 RPM's 100 times with no issues. If thats not good enough then take one apart and there is nothing in their to fail other than the optical sensor. It's not a complicated part.

I would love to build this engine for you if you want to do something different. I think if you do the above you can make the 700HP goal with equal or greater torque numbers to match from a 409 CID LT motor.
well i should have been more specific about the money. its not an option at this point however, i dont want to get rediculous with it either. not trying to be 15k in the hole with engine because of custom one off parts and things of that nature.
 

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Discussion Starter · #25 ·
If you want to go big CI small block I would not go LTX. Either go Gen 1 small block, or go GenIII-IV (LS engines). Too much block prep, a PITA ignition. IMO, I don't think any of the big power makers here with LT1's would start with one if they were starting again from scratch. As an example, I just got a 383 LT1 block back from the machine shop, and had $1800 in machine work and main caps go into it. That was just buying and fitting splayed mains, line bore the mains, -0.015 the deck, TP bore and hone, and bake/blasting the block.

If you go Gen1, look into the Dart SHP block. Once you consider the $$ in beefing up the lower end of even a 4-bolt block, the price is cheaper than the machine work on a used block. IIRC, there is a 4.125 bore block available off the shelf. I have seen them in the $1500 range new, ready to assemble.

18 degree heads are a great option for big flow, but all the valvetrain and induction starts to get pricey, you are way out of the "typical" range for SBC performance parts. There are some that are making very good power with 23 degree heads, but you will be putting $$ into a good CNC'd casting to get there.

For the money you will have in either, you may want to consider an upgraded GenIV LS7. Forged pistons and rods (factory Ti rods have a limited life over ~575 HP), and a moderate cam will get you into the mid-600's with little drama.
i been thinking about going lsx for some time but if i decide to do that, im gonna look for a used 454 block from out of one of the newer 3500 series trucks. i have seen a few so far with engine, xmsn, wire harnes, etc for some decent prices but i dont have a vehicle to put it in right now. im mostly just trying to make up my mind if i want to do something with a lt1 block or stick with a big block. im leaning more towards the big block at this point due to the fact that i can already get a good base to start with (454ss pickup) and it would probably be a bit cheaper to build a lot of power from it and it would also probably do a little better on the street due to the massive amounts of torque that they make. we'll see. im still taking in everything everyone is saying right now and you guys are helping me out a great deal with my options.
 

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Discussion Starter · #28 ·
To make 700 with any of the options above is going to take some money going NA unless you use a power adder of some kind. I don't disagree the LT is not the cheap option and it really is just a reverse cool SB chevy at the end of the day.

It just what you want to do. You can get there with any of these motors if you're willing to spend the money to do it. There is a huge differnce in what it cost to make 500 hp NA vs. 700 hp NA.
yeah thats the biggest problem im having now...trying to figure out how much i want to spend or what gives me the best bang for the buck.
 

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Discussion Starter · #35 ·
Eshaw I was wondering where do u come up with ur horsepower numbers? Are u trying to run a certain number? Have u ever dealt with a n/a motor makin that power? Why do u want to spin it to 7k if its not neccessary? It seems *** a 500hp motor is a pretty decent number and a small adder would be a lot more feasible. Not trying to kill a dream but reliable is more important than fast and unreliable.
yeah its just a number i came up with as a goal to shoot for. nothing in particular, just always wanted to build a motor that made 700 hp...not necessarily at the wheels but definitely at the crank. based on what i am seeing and from discussing this with you guys and a few ford guys at work they are all telling me that it will be WAAY easier to get to that point with a big block than a small block. as far as spinning to 7k, yeah it aint necessary, just something i thought would be cool also. you know how it is when you do things like this...you just set a goal and go for it. just trying to get the project started right now. more in the planning phase of it all at this point.
 

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Discussion Starter · #36 ·
There is no way you can bore a stock block to 4.125". Even a 4.060" bore requires sonic testing. $15k may not be enough to have a 409+ ci deep stroker to rev to > 7000 rpms reliably.

For 600+ hp a big cube LSx engine is a much better value.
i didnt think it was possible either but still had to ask.
 

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Discussion Starter · #39 ·
you want a street/track truck, right? Personally, I would start with a 4WD or AWD model and turbocharge whatever engine you decide to go with. Then you will be able to hook in almost any road/track condition. Sure, it will increase weight and reduce drivetrain efficiency, but most races are won the first few feet from the starting line.

But to answer your original question, I have personally seen a turbocharged LT1 put nearly 1000horsepower to the rear wheels with the stock block, and that was spinning the tires on the dyno back in 2003~4.
well yeah thats a great idea to but now i think im pretty much sold on going with the 454ss and building that up. i've got about 3 or 4 that im looking into right now and will be making a decision soon. i originally wanted to play around with a big block and i think im gonna stick to my original plan. im looking at top end options at this point and seeing what it will cost. the 454ss already comes with a big block and a turbo 400 tranny so its a good basic setup already. i will keep you guys posted as to what i go with.
 

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Discussion Starter · #44 ·
Well.....so far......and in my opinion, Jeff, Tad and others have given you some real good info.

As for me......I'm a couple weeks away from completing an engine build that should've been completed a long, long time ago.

Decked 398ci LTx Block (4.040" bore & 3.875" stroke)
12.3:1 Compression Ratio with .043" Quench
Ported AFR 210 racing heads
1.7 ratio Comp Cams shaft mounted rockers
Solid roller cam; 242* intake duration, 110 LSA, .667" Intake Lift
Super Ram Intake w/Monoblade TB & 60LB injectors
No Freakin' Opti.........LTCC ;)
Stock PCM Tuned by PCMforLess......
I may go to a F.A.S.T. system later after I see what the HP curve looks like.
I plan to rev to about 6800 RPMs.

Engine builder believes 575+ HP/600+ Tq at the crank is likely.

Once complete......engine & chassis dyno figures will be posted.

My only concern is the effect the Super Ram will have on my HP curve. I'm hoping that the rest of the combination can 'break through' the HP & rev limitations of the intake. But hell, that's why we do these things......to see what happens :) .

KW
yes i agree you guys have given me some awesome info and to be honest, this response right here is what i was looking for when i originally asked the question of the hp potential of a small block. now this creates another option because your block is going to be making the exact amount of power that im looking for...at least in the ballpark. im guessing you have about 10-15k in this build.
 
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