fasteddi

iTrader: (2)

Im not new to the site but I am new to V8s. Right now I have this in the car.

385 stroker. In the last thirdgen Fbird it was in the engine went 11.90-12.20s in the 1/4 mile at about 114mph.
Eagle Rotating assemble https://www.summitracing.com/parts/e...e040/overview/

Its not the best assebly but its what came with it and hopefully it does stand up to the 500 hp its rated for.

I have a casting number 3870010. Its just a 2 bolt main block.

Dart iron eagle platnum 200cc runner Heads.

Comp XE 268 (small cam i know it needs a bigger one for full potential of NA engine)

Comp Ultra Gold Al. 1.6 Roller tip rockers

Msd pro billet dizzy and msd coil

Msd 6al 2 programmable ignition box. With a 3 bar map currently set up with it.

Running $59 on a 7730 to datalog AFRs knock mph TPS RPM IAC and coolent temps via tunerpro.

The engine has all APR head bolts, main studs, exc. thoughout.

My question is what block do i need to start the foundation of making a 350, 355, 383, 385 capible to handle 800-1000 Hp?

Or what can this current block take if I installed the correct forged crank, Hbeam rods, and Pistons to take the power? And had the mains splayed?

The idea is that It will have twin S366 turbos on it. I currently have the stuff to do a single turbo. I have a borg warner s366 and plenty of turbosmart goodies to do the job. So instead of buying another bigger turbo, id get another of the same of what i already have. s366/ Also still havent desided on a blow though set up or if I would run some sort of EFI again.

For the last 6 years I ran decent HP though a 3.1 and 3.4L V6. Easily over 400 and almost 500hp on some passes when looking at weight and trap MPH. Now I never really cared how much the block was rated at because I knew it was a answer i didnt want to know. But if I end up spending 1700 bucks on a rotating assembly on this SBC this winter, I really want to make sure what holds it all in place doesnt come apart.

But my main question is how much can these blocks take. If the mains are splayed does that help hold it together longer? And when it comes to after market blocks which are best? Im staying away from gen 2 3 stuff. This is a gen 1 sbc idea. But for me to really start to get the whole project in line i have to start at the bottom, the block. Thanks for any tips on these sbc blocks.

Jorlain

iTrader: (4)

Honestly, for a SBC at that power level, I wouldn't trust any OEM block. If I were in your boat, I'd be looking at a Dart block. Frankly, the aftermarket blocks are so much superior to OEM blocks that I don't know that I'd even chance it.

That being said, you could possibly splay your caps on your 2-bolt and get away with that sort of power level. Maybe. It would hold 500, probably. I know we all hear the stories of 700HP on a SBC block, but... If I had that much money invested, I know I wouldn't want to risk throwing it all away.

GeneralDisorder

iTrader: (1)

Why not just go to an iron LS block? They are cheap and will hold 1500.

I'm sure an iron dart block with priority main oiling would probably do it also.

I think it's probably a little on the high side for a *reliable* stock SBC block. I'm sure people have done it but how long would it last?

GD

Orr89RocZ

iTrader: (20)

Dart SHP block will take 1000 all day long. Thats what i'd run.

Being a turbo car, you "might" get away with 800 hp on stock block with billet splayed main caps installed. Maybe half fill it. But buying the caps for 300-350$ and then having to line bore/hone block to fit caps, you'll have near 800-1000 into the old block. New shp is only 600-800 more at this point, depending where you get it

AlkyIROC

Unless you plan on going with an iron LS block, you're going to need some sort of aftermarket block. Dart would be #1 on my list also but that's mainly because I use a Dart Big M block in my race car. I considered other blocks before going to Dart. This is actually my second Dart block because I cracked the webbing in one of the mains after an engine failure. $3000 worth of scrap metal.

When I bought my second block, I optioned it out for steel main caps instead of the normal cast ones for the extra strength. Never had my engine on a dyno but calculated dyno HP based on how quick I run in the 1/4 mile adjusted for the weather puts my engine somewhere around 930 HP with no power adders. It's also pushing 588 CID and runs on injected alcohol.

An 800-1000HP SBC, unless you're running a whole lot of boost to get there, isn't going to be very streetable.

Tibo

iTrader: (15)

It's not hard to find to find articles and threads online about LS engines with iron blocks making 700+ horsepower. I've even read one on hotrod that made over 1000 hp on a freshened up stock assembly and made dozens of passes over 1000hp. From what I understand though they switch to race gas or E85 somewhere around 700hp

Why are you wanting to ditch your 6? A car that can do an 11.7 quarter mile will beat almost anything on the street. You will be losing some handling ability and probably gas mileage. Unless your'e driving to/from a car show/drag strip your car is king of the road. Look at Alky's car's numbers for what 800-1000hp will get you- 9.0 seconds is hella fast. Are you wanting to make a drag only car now?

fasteddi

iTrader: (2)

I am ditching the V6 because I made way too much horsepower anymore for any of the blocks or crank. I broke a crank and wiped out a forged piston LOL tired of throwing money into that car trying to keep it together. It's time to move forward right now I have this 385 in the car and it runs really good so that I can bracket racing hopefully tomorrow.

the V6 was really cool and it was fast but I really don't drive it on the street very often anymore. I have a trailer, rv, truck so I trailer it to the racetrack. Although I still have the interior on my car it has a rollcage and everything else so it's not very streatable or at least very comfortable LOL

cardo0

If you trailer it to the strip and drag race only then just pour the block and fill it up - no coolant, filler only. That will stabilize the bores and strengthen the cylinders and deck. But the main caps need to be splayed and with good steel. This leaves the main webs the week spot along with the lifter valley where cracking and separation isn't improved w/o welding in more metal. Welding and some machining gonna be expensive.
But then again turbo boost doesn't come on like a shot of NOx or supercharging so just filling the block my get you by. Its kind of a $1000 question that you have to try it to answer it.

Good luck.

Orr89RocZ

iTrader: (20)

Theres no reason that car cant be streetable. A cage may make it mild discomfort getting in and out but not unstreetable.

Dart shp block with good forged crank and rods like callies h beams, you'll beable to drive around on pump gas and run 800 hp easy. 9 sec car

fasteddi

iTrader: (2)

if my turbo 6 was streetable and made 450hp or more, then a 800hp turbo v8 would be. And I'm sure much more reliable too. The cage isn't too bad really. I sure feel a lot safer with it.

I really like the dart block route. This build would take time but the goal is simply a 9 second car period. I don't wana take any chances with the block. Or I'll end up with the problem I had with the v6. Lots of forged items down the drain because of one part that just couldn't handle the power.

thanks for the helps and tips on what block would be best and handle the power.

Went racing yesterday it was a grudge racing up. I wasent pickey. I just wanted ti go down the track. So it was no et. Have no clue on the time. But it felt like a 12.30 give or take. I really miss the top end turbo power. This v8 is slow up top but way faster out of the hole.

fasteddi

iTrader: (2)

Not going ls. Sticking with a sbc. Gen 1. I don't think I'll have any problem making 800 900 hp with 10psi 12psi of boost if done right. I'm new to a v8 but not boost and I believe i can easily take a 400hp v8 and turn it into double pretty easily and tune it as well. I might be a little hard headed for sticking with an older V8 and not going to the new stuff like everybody else but then again I stuck with the good old V6 for six years of racing and did about anything I could to make it faster

hopefully I don't have to eat my words later but regardless the build will be exciting and fun. The hope is this winter I'll be building up the engine.

Orr89RocZ

iTrader: (20)

Basically what i did for my first turbo v8, mild heads cam pump gas car that went 9's on 14 psi at 141 mph lol

Reused same shortblock and darn near pushed it to 7 sec zone. I over stressed it at this level. 1000 ish hp was fine. 1400 was not. Block main caps were moving some. It survived but was not enjoying it. Dart lil m would be required there

fasteddi

iTrader: (2)

not bad at all. I have these dart iron 200cc 80cc heads they are ok but would like some aluminum ones a lot better.

what sort of turbo sizing did you have to not have a spool up issue?

I worrie of over sizing like I did on the v6 but I had to because up top any t3 turbo was way too restrictive. So I wonder if 2 366s Borg warner would be too much for a build like this, Or if one 80-88mm would be better.

Orr89RocZ

iTrader: (20)

Twin 60 and 70 mm snails with p trim t4 housings. 65/74 turbine. .68 ar is too quick on boost and hard to control. I spooled instantly and made 690 whp and over 1000 trq. Moved to .96 ar and much smoother. Delayed spool a bit and was great. Spool is matching to converter specs. Gotta have stall speed close to boost threshold rpm.

Last setup used 68mm turbonetics turbines in .81 t4 housings. 72mm small cover compressors. Fantastic street setup. 15 psi was about 720 whp thru the th400. Pump gas friendly to 1000 whp

A t6 s480-s485 with the 96mm turbine would be ideal for 800 whp ish power on 380-400 inches in a street car. It would spool fast
Twin s366 with the t4 .91 housings also would work pretty good. Alittle tighter housing even better

fasteddi

iTrader: (2)

The one s366 i have is a .91 open t4 hot side housing. The turbo is in perfect shape. I thought it would be easier just to buy one more of them. Just wasent sure if it would be too much for it but sounds like it would work well. I probly will aim at that route. Thanks.

the th350 I have is supposedly rated at 800hp by the manufacture and has a t brake. I had it built last summer. Spent a lot on the trans and a pic 5k converter but probly willl have to switch over to a th400 and build it up a bit more.


my last few turbo set ups were 8.5:1 and 9.6:1. I liked the 9.6:1 alot better. Is that about the area of compression you had on your set ups?

Orr89RocZ

iTrader: (20)

I was 9:1. Wish it was more but it was safe and a good tuning window

AlkyIROC

Not in the same class but a turbo V6 can still make a lot of power. Somewhere in Oregon, Washington area many years ago, there was a Buick GN competing in Super Stock with a V6. It was keeping up with all the hemi cars. Problem he was having is he was putting so much boost into the engine to make that kind of power, he kept stretching head studs.

Same goes for those 800HP 4 cylinder import engines. Yes you can do it but I could build a couple of big blocks for less than what one of those engines are worth and their life expectancy isn't very high.

five7kid

iTrader: (14)

Dart, or the Chevy Bow Tie Racing block.

It's your money, but an iron LS block will hold as much power as those more expensive options.

fasteddi

iTrader: (2)

I understand the ls blocks can handle some juice too, but if i have to spend 1600 on a forged rotating assembly, then 2000 on a block and the time im done i have 4-5 grand into a 1000hp rated motor. Its compartible for me to do a ls swap then built that all up in the guts to handle 1000hp as well. By the time im done im out the same 4 grand and had to do alot more work to make it fit into my car compared to now where its literly pull it out, and toss in another engine that bolts up exactly the same.

Just my thoughts..... Id feel safter with a aftermarket block gen 1 sbc compared to a 4.8 5.3 ls one anyday when going for 1000hp. But then again. I still need to learn more about the ls world. Its just hard for me to understand a stock block making it to 1000hp with no major improvments on the mains, oiling, exc.

But then again it always comes to mind that if im going to spend that much, which i plan to do something like that this winter, why limit myself to a 350 main and not go with 454 mains?

But then again... a forged ls short block can be had for only 3800 bucks... https://www.summitracing.com/parts/hpe-sp40/overview/

AlkyIROC

That's cheap. My engine has a factory alternator and starter on it. Everything else about the engine is aftermarket. Stock components just can't take the abuse. A replacement value for my engine would be somewhere around $20,000 for parts and all machine shop work. The heads alone are worth about $5000 with all the port work that's been done to them.

You can build an inexpensive high HP engine but never expect it to last for very long. Once you break it, you're spending all that money again. Spend it all at once in the beginning for something that can take the abuse.

fasteddi

iTrader: (2)

20k. What engine and set up are you running? I believe it. I sat down and ran some numbers and I listed almost 8k in parts just to build a respectable 350 main engine. Considering I'd reuse some parts off the sbc I have now. Adds up fast.


Some good points. After the whole turbo v6 build over the last 6 years I finally learned that you can polish Crap. I'd rather over build items now then anything. The more i read it does seem the ls blocks are better just require some work to swap it in correctly. I've seen some threads where a stock LS layied down 700 rwhp and even 800. Stock internals and block just with slot of boost. This is amazing to me. Is that a fluke? Its hard for me to understand that stock rods and pistons could handle that much although no matter my build it's getting new forged internals all the way around.

Theses comments have given me a lot to think about and I like the feed back. Thanks.

Orr89RocZ

iTrader: (20)

It is real, that a later model gen iv lsx 4.8-6.0 can hold big power on stock internals, with proper tuning.

Thats what makes them so nice to have. Relatively cheap yet once with fresh bearings and gapped rings for boost, they work extremely well to near 1000. Stock cranks are strong. Rods are strong enough lol. A forged piston h beam rod stock crank deal is even better and hard to beat.

Its all up to you. Yes its probably alittle more money to go sbc with price of a block. But you also get 5 bolts per cylinder to seal heads. Alittle less finicky than ls 4 bolt but guys are getting big numbers out of ls 4 bolt head stuff now. Aftermarket Sbc has better oiling.

five7kid

iTrader: (14)

That's the bottom line. When you get into those HP numbers, it becomes less and less important which platform you choose.

"Tell me how much money you have and I'll tell you how fast you can go." Platform choice not required.

Tibo

iTrader: (15)

Everyone's definition of "stock" seems to be different. I'm just a keyboard warrior when it comes to turboing LS's but I've read articles where stock meant rebuilt with new stock replacement parts and ARP this and aftermarket bearings that and they report high numbers. Then I watch YouTube videos where guys just pull a truck engine and drop it in and the engine blows around 600 rwhp. How big of a role tuning played, you never know.

Orr89RocZ

iTrader: (20)

Yeah i have a problem with the ls community and their lingo

Apparently stock bottom end just means stock crank rods and pistons. Doesnt mean stock. Bearings and rings or rod bolts even. Refreshed gm engine.

Taking a junkyard engine is hit or miss. Condition varies. One well maintained is far likely to hold power than one that was abused and had 10k mile oil change intervals. Compression test and leakdown tests should be done to decide if you wanna use it or not

Stock ring gaps are typically tight for sealing. Best na power. Boosted deals need alot more due to increased pressure and heat

GeneralDisorder

iTrader: (1)

Ding, ding, ding!! We have a winner!

It's all about the tuning. No engine will survive a turbocharger and a bad tuner. You can pound the rod bearings out in mere moments on a dyno with a tool at the keyboard.

I've watched it happen live

GD

Ja85z28

Personally, I wouldn't spray more than a 200 shot on any production sbc......without fi, wide band O2, and excellent tune.....I have seen way too sbc window the blocks running c16. The sbc production blocks are soft

fasteddi

iTrader: (2)

Good point. Im relizing that more and more. At least with the choice here I can build it up as much as I want. Compared to my days with the V6 where I was always gambling each time i raced it on a crank rated at 1/2 of the power i was pushing at best and so forth.

Ive got alot to think about till winter when I plan to start this build. Of course i want the less exspencive build but also one where i dont have to completly redue the car again to make it all come together. Although I did swap in a carbed V8 in about 10 hrs total from a blown up Turbo 6 to a running V8. SO a ls cant be that bad....

fasteddi

iTrader: (2)

I dont plan to shot any n20 when i build up this 1000hp goal of a turbo set up.

On my current engine i do have a nice set up because my last engine (turbo V6) I had a elaberate set up so i could spool up my turbo at the line and launch only. So if i do shoot it itll be though a elderbrock plate bar system. But even if i do it will be 75 or 100hp no more then that.

BTW I always use a Wideband and Kr sensor for tuning even now with the carb. Of course I check the plugs but I also use those tools to further tune it. From years of riding on the edge with that Turbo 6 I got pretty good at tuning EFI with n20 and boost. Because if not im sure my engines wouldnt have made it as long as they did. The one, best motor I ever built. 3.1/3100 that went the 11.59@119mph..... lasted 3 seasons with well over 300 passes and alot of beatings on the street since it was still a street car and a car i had to drive to and from the track each time. I would love to have that engine back again. The 3.1 in my mind was either a freak engine or just a better one then the 3.4 versions. I had nothing but issues with the 3.4/3400 even though it made some wicket HP. Im sure 450-500 daily. and 11.20s at 120+mph on 15psi of boost, it just was a basket case and a constant repair one after another.

Ja85z28

Granted nitrous creates violent hp as compared to forced induction, but the resultant impact of both is cylinder pressure. A production sbc block is not going to last subjected to cylinders pressires anywhere close to those necessary to produce 800-1000 hp. I have owned, built, and successfully drag raced a 800+ rwhp 1st generation f-body. It's a scary SOB on a 9" slick.

Good luck

Orr89RocZ

iTrader: (20)

If you want more than 1000 hp down the road might want to look at dart little m with billet caps. The shp moves around by 1400 hp. Caps walk. I wouldnt do more than 1000 whp thru it which is near 1200 crank. As with anything tune is important. Little m is 2800 bucks tho, 1000 ish more than shp

The shp pro has billet caps and probably would hold 1400-1500 hp. But it also has bbc cam tunnel and i think larger lifters. So those parts would be custom and more money.

mrestrictrplate

iTrader: (2)

What intake was on the car when you bought it and which one are you using for your build?

fasteddi

iTrader: (2)

the current motor has a rpmperformer dual-plane intake that is not what I would be using on the new one I haven't decided on that yet

fasteddi

iTrader: (2)

I have some dart iron eagle platnum 23* 200cc heads. Are they worth a damm for boosted applications?

Orr89RocZ

iTrader: (20)

They can work but being iron you want to be abit more careful with the tune. They hold more heat than alum. Could be more detonation prone. Keep compression down towards 9:1 for sure imo. Give you a nice wide tuning window. They could be ported some and be more than enough for your goals

fasteddi

iTrader: (2)

Yea I ran into that with v6s. Loved the aluminum heads as I could add in more timing. I will definitely keep that in mind. If I could reuse these heads that would save a lot of money where I could put it elsewhere.

they could definitely use some blending of the bowls and porting.

Orr89RocZ

iTrader: (20)

Could have chambers softened alittle