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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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With no power adders the block is more than up to whatever you could try to make NA. I do think taking the bores to 4.125 is just too thin as you're going to want to really spin some RPM's to make great power in an NA motor.

I'm thinking 18 degree heads, sheet metal intake, 4 "stroke and a huge lift custom cam. 700HP from a SB of any kind is going to take some doing NA.

I would not worry about the block at all.
 

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With no power adders the block is more than up to whatever you could try to make NA. I do think taking the bores to 4.125 is just too thin as you're going to want to really spin some RPM's to make great power in an NA motor.

I'm thinking 18 degree heads, sheet metal intake, 4 "stroke and a huge lift custom cam. 700HP from a SB of any kind is going to take some doing NA.

I would not worry about the block at all.

agreed...making 700+hp N/A sounds expensive...lol making 530N/A was bank breaking
 

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I have made 5/6/7/800RW Boosted on the street w/ Ca 91 pump gas,.
so your pretty much golden to make what ever you want HP wise NA.

Your going yo run into brick wall on cylinder head flow well before you reach the limits of the block.

7000RPM is do able as well
but keep in mind the factory PCM is only good to 7100.
That leaves ALMOST no MARGIN for rev limit control.

Oil control starts to be an issue at extended 7K RPM.

At 7K you better have a good builder and parts.
the valve train has to be perfect or you wont even get to 7K
before it falls on its face

build and tune it right and your going to pay attention with the loud button to not over shoot in the burn out box and coming out of corners hot.

once the SBC gets snappy resonsive at 6K+ like that
you start to worry about ring land thickness, and wrist pin strength

hi RPM cruise
 

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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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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,
go ltcc or dont go.
stroke wont effect opti, rpms will
 

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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
 

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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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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.
 

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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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Get the hole shot and you would be surprised. Hell 6.0 GTo cant pull on my till above 100 range. Then weight takes over. It is amazing what the hole shot does. But street tires stuck.
 

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i have seen many guys get 500+ hp from 383s and 396s
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

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.
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
 

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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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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.
 

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Why did you specifically pick a 454SS pickup? Wouldn't it be cheaper to find a regular 2WD shortbed? If I was looking for a 454SS, the 454 would stay in the truck and build that up! It would be a lot cheaper to get 500+ hp out the big block.
 

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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.
 

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Jeff,
Maybe Tad and I just have bad luck then. I have been through (2) of them. Both were a misfire at high RPM, then one just died. Not sure why, but I have not seen them live like you say. Maybe I am doing something wrong with them. But I thought I saw you post something like you replace the cap and rotor pretty often.
 

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I'm guessing I meant I change the cap and rotor to the MSD because that fixed the rotor issue that the GM rotor has.

The only keys I have seen to them living at this point is a GM Opti to start with, not a Summit or other cheap brands, change the cap and rotor to the MSD and use blue lock tight on the screws.

The more I think about it the last one I lost was at the LT1 Shootout in KC three years ago. The rotor screw came loose in the burnout box and a huge backfire followed by a dead motor.

We both are just saying what we have seen on these and I have no explnation for why it works other than what I said above. When you look at the Opti if it doesn't come apart then all that is left is the optical sensor to go bad. There is just nothing to these things.
 
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