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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.
 

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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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If a person is looking as far as 18 heads with their resulting goofy geometry what about looking further at
http://www.cferacing.com/?pid=products&id=H24

The 18's are already going to have you into everything , intake, exhaust, lifters, valve train, anyway.

Just a thought,

Gerry, for a minute there, I thought you were going to out my secret motive.. talk him into an LSx.

It's funny, stay GenI/GenII based small block and get spendy going from 23 degree to 18, or even 15 as you linked to OR...

Jump into the GenIII gene pool and start with OEM 15 degree head castings with off-the-shelf valvetrain components OR..

Jump into the GenIV gene pool and start with OEM 12 degree head castings that support 300+cfm flow with off-the-shelf valvetrain components... STOCK.

Case in point. I just got my L92 (310-320 CFM is regularly measured) heads CNC ported. 350+ CFM from 0.590-0.610 lift.

Bottom end is already nicely structured with a deep skirt 6-bolt (4 big 2 small) main cap arrangement. OEM 7000 RPM capability on a 4" stroke. No block mods needed to accomodate that kind of stroke either. Taller deck than Gen1-II SBC, 6-ish" rods.
Coil per plug ignition capability out of the box. No need to spend $600 on an LTCC kit/peripherals).

The list goes on.

As for building a 700 HP big block... getting the top end to live at 7000 RPM gets pretty pricey as well.

Budget conscious, 700 HP, reliable, big block or old small block... these things usually don't got together. IF they do, pick 2 out of the 3.
 

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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.
 

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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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Get the pickup and buy 2 cheap Master Power turbos and feed the 454 with them.

Done.
 

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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.
A 385 is the simply a .040 over instead .030 over bore. Still a 3.75 stroke. My 385 is a 4 bolt slayed block with Moroso block filler to bottom of freeze plugs, Scat forged crank and 6" Scat Pro Comp forged rods, Mahle forged coated flat top pistons, AI ported 200cc stock casting aluminum heads, ported intake, and AI custom cam.
 

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I think thats a great point. Look at your 385 motor and what has been done. No short cuts and it's still 200HP short of 700HP.

You will have to go extreme on air flow numbers with the heads on any motor or you will need to run a cam, and valve springs, that will be huge numbers and that will not last if you want to drive it. Those large cam motors also run like crap under 3K or 4K so as long as it's just a race car then it's fine but thinking you can drive it is out. Keep your flow numbers up on your heads and intake and you can run less cam to get the goal which would make it more street friendly. As many CID as you can get is also the right way to get to this goal.

Like I said, 700HP would be no easy task. I still think it can be done in a motor that you could drive but it's going to be high dollar parts to get there. To do this with a big block wouldn't be that hard, to do it with a small block is going to be a trick motor.
 

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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.
 

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not trying to be 15k in the hole with engine because of custom one off parts and things of that nature.

I'm not sure I understand what you're saying... you dont want to spend 15k on a motor??

When building a 500 hp stroker from scratch you can hit the 15k$ mark EASY.

Best "bang for the buck" on N/A high hp street motors would be something like one of these: http://www.ultrastreet.net/

If you think you can build an equivalent engine for alot less, you're forgetting to count alot of stuff ;)
 

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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.
 

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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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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.
 

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I think thats a great point. Look at your 385 motor and what has been done. No short cuts and it's still 200HP short of 700HP.

You will have to go extreme on air flow numbers with the heads on any motor or you will need to run a cam, and valve springs, that will be huge numbers and that will not last if you want to drive it. Those large cam motors also run like crap under 3K or 4K so as long as it's just a race car then it's fine but thinking you can drive it is out. Keep your flow numbers up on your heads and intake and you can run less cam to get the goal which would make it more street friendly. As many CID as you can get is also the right way to get to this goal.

Like I said, 700HP would be no easy task. I still think it can be done in a motor that you could drive but it's going to be high dollar parts to get there. To do this with a big block wouldn't be that hard, to do it with a small block is going to be a trick motor.

I also have a 385 motor N/A that does make nearly 700 HP. I engage the same Ai 200 cc heads as Frank, but have obviously built mine a little different. It has excellent manners in around town driving with an exhaust system and x-pipe. The project is doable, however, not just anybody nor everybody will be able to do it in their backyard :)
 

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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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lol...ok then what do you recommend?.......
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
 
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