Well, the topic says it all. The latest development in my LT1 powered '72 is that I'm going to twin turbo it. Anyone know a series of parts from, say, Eagle or Lunati that can withstand 1000hp? When I did a couple of searches, the strongest rods and crank I could find were rated to 700hp. I know I found a site once that listed a set of Lunati rods that were good for 1000hp, but, I can't find it again and the site didn't mention the parts series (i.e Eagle ESP's or something like that). For the curious, my intended twin turbo recipe (highly simplified recipe, that is. I left out a lot of details, but I think I gave enough info) is as follows: Two Garrett T04 V1 P tubos running anywhere from 12 to 20psi. At 7000rpm with 20psi and a 90% efficient intercooler, the estimated output of the LT1 is 914bhp, flowing 84 lbs./min. The same twin turbo setup at 12psi puts out a little over 700hp. I figure I want to build the bottom end of the LT1 to withstand max boost for saftety's sake, even if I never run 20psi. So for the bottom end, I assumed I'd have to go forged everything, splayed billet 4-bolt main caps. The problem is that there are a number of different duty classes of 4340 components available, only I'm not sure the exact manufacturer and series to go with. At those power levels, I think we can all agree that I can't afford to make a mistake in choice of low end components. I surely wouldn't appreciate dropping $7K or so to turbo my LT1 only to have it grenade on me. What are your thoughts? Thanks.

[This message has been edited by Igot2'72's (edited 02-27-2002).]

[This message has been edited by Igot2'72's (edited 02-27-2002).]

hey 2'72's did you see the pro street camaro on phrtv,twin turbo,AWESOME,WICKED setup.
maybe if you goto www.phrtv.com (http://www.phrtv.com) they might have this vehicle.they said they were gonna check back on the guy.
shane

hey 2'72's did you see the pro street camaro on phrtv,twin turbo,AWESOME,WICKED setup.
maybe if you goto www.phrtv.com (http://www.phrtv.com) they might have this vehicle.they said they were gonna check back on the guy.
shane

hey 2'72's did you see the pro street camaro on phrtv,twin turbo,AWESOME,WICKED setup.
maybe if you goto www.phrtv.com (http://www.phrtv.com) they might have this vehicle.they said they were gonna check back on the guy.
shane

phrtv did a quad turbo (3rd gen) pro street small block,maybe you can goto there site and see if they got specs on that wicked mouse.
hope you accomplish that task,sounds like a mean wicked setup
shane
sorry bout the triple posts i thought they didnt go through so i did it over,but it wasnt a twin it was a quad turbo

[This message has been edited by sri3850341 (edited 02-27-2002).]

The TO4 V1 P will work , use a 0.96 housing A/R this should give you your "16 lb boost" mid goal at 7000 RPM. intercooled.

Now about your long block , If you realy are planning on 1000 HP with 18-20 lbs of boost get out the visa carb. You will not be using any chevy parts. Oh maybe a "rocket block" but nothing that came off the assembly line. Even with splayed caps in a production block it will be a crap shoot, You will need a O ringed block and for crank and rods get ahold of Crower or Carillo. Pistons are not going to be off the shelf items either.

It will also be very hard to control your air/ fuel ratio with out fuel injection. You will also be lucky to get an intercoller thats better than %75-80 efficient . In real terms these power levels are not back yard projects, its very easy to get burned ! This is not a combo to learn with.

My advice ? Drop it down a little 10-12 lbs of boost with a set of T3 60 0.82 A/R ( this will work with a single waste gate too)and 6500 RPM You will still need to be VERY carefull with your fuel distribution and A/F ratios and will need your above listed bottom end.Boost doesnt kill engines, detonition does ,that and RPM.

when i talked to scat they said there 5.7 H rods for a 383 were good to 1000hp and i didnt need them. not sure i beleive it though. ended up getting them anyway. better safe than sorry.

roger-I apologize, I should've been more clear. It's a '72 Camaro, but motor is a '95 LT1 from a '95 Z28, not an original early 70's LT1. So it's already fuel injected, and I may go with an aftermarket setup from SDI if it turns out I can't use the factory EFI modded. I may even add 2 more fuel injectors, which will require the use of a controller for them. As for the intercooler, the guy that's going to build my intercooler says it'll be between 75 and 90% efficient. As for boost, I'll most likely be in the range you suggested, around 12psi, but I want the bottom end strong enough to handle max boost if I choose to use it. 12psi. will still produce around 700hp. And I intended to use a big single wastegate, so we are thinking similarly. Right now I'm focusing on the prepping the short block, and none of the turbo components I've selected are set in stone. Once my shortblock is built, I'll build the turbo system around its limitations. I checked out Crower, Carillo and Oliver rods. They are UNGODLY expensive at $1200+! Too much for my budget which overall will be between 6 and $7K. I'm thinking something from Lunati or maybe Eagle ESP's. LOL, that's why I asked you guys. So why don't you think the factory block will hold up? You don't think billet splayed 4 bolt caps are good enough? The engine will of course be balanced. And why are the O-rings necessary? Thanks guys.

[This message has been edited by Igot2'72's (edited 02-27-2002).]

At 1000 HP I dont think it would hold up but at 700 "Turboed" horses you stand a chance with a factory block. The trick is to make your power from the boost, not the rpm. You still should run ARP STUDS on everything. Felpro makes some head gaskets with o rings in them.

Most people think you have spin the crap out of a turbo motor to make power, this just isnt true. Its just the only thing the factory puts out thats turboed anymore is 4 bangers, you have to spin them no matter what.


For rods how about Manley H beams rated to 750 HP for $499
and a Pro Line 5140 crank rated to 800 HP for $399

Go to www.flatlanderracing.com (http://www.flatlanderracing.com) for prices and description of after markets parts at great prices.

For turbo selection and maps go here
http://www.turbofast.com.au/

I dont know to much about the fuel injection system with turbos, I do know most people that run them do go with the extra injectors like you stated,

The problems with a factory block aren't just gonna be in the main's at that kind of power level. The cylinder walls simply aren't thick enough to withstand that much cylinder pressure. Your looking at a $2,000 Little M or Motown block to start with.

Your gonna find real fast that your gonna need completely aftermarket engine management. The stock LT1 equipment isn't gonna do it.

As for crank/rods/pistons; Lunati Racer Series cranks will handle what you want, they start around $1,100. I think a set of Manley H-beam rods might do it, they run about $700. Ross can probably get you a set of pistons/pins that'll do the job. Expect to dish out another $650. ARP main studs, waveloc rod bolts are a must.

O-ringing either the block or heads needs to happen. Your headgaskets will thank you. I would also suggest using head studs, not just bolts. Bolts have a tendency to stretch and allow the head to lift in high boost applications.

That's all I can think of for now. I hope your $7,000 budget was just for the long block.

Good luck,
Joe

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79' Z28 4-spd- built 355, TRW 10:1 forged flat tops, WP SportsmanII heads, Crane Energizer 230/230 duration .480"/.480" lift, Edelbrock Victor Jr., Holley 750cfm, Dynomax headers, dual 3" flowmasters :) 3.73 Posi 10-bolt

Igot2'72's, I'm not going to comment on how to approach this project. But I will offer you this
http://www.flatlanderracing.com/

Has some of the better priceing on the more high ended brute strength stuff your gonna need!


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1967 Prostreet Camaro
BBC TH 400 w/4,500 stall 4:56 gears,narrowed and tubbed...
http://www.visionworks-usa.com/camaro
Momma's new toy
http://www.visionworks-usa.com/69camaro

Ok guys, from the top:

roger69-thanks for the suggestions for the rods and crank. I agree with you about what you said about getting power from the boost, not the rpm. Remember, I said the MAX I'd be spinning the motor to is 7000rpm, and more likely the motor will live at 6000 or 6500. I intended to use the ARP's, as well.

joesmith69-first, let me say that I plan on using 8:1 compression, not the LT1's stock 10:5:1 or anything higher. How does this factor with your opinion that the cylinders couldn't handle the pressure? As for the engine management, I may go with an aftermarket kit my turbo guy recommended from Simple Digital Systems, a company in Canada. Check out their site :www.sdsefi.com (http://www.sdsefi.com) The cost is similar to the stuff availble from Haltech, around 12 or $1300. As for your suggestions about the rods and crank, I believe my turbo guy recommended that same crank and he says he can get it for $900, so we're on the same page here. He also says I can get away with the Eagle ESP's with ARP bolts. I'll be looking into the O-ringing. You said the block OR the heads? Does it matter which one? Why or why not? And here's a silly question, but can you explain what exactly the O-rings do and why they're necessary. And most likely I'll have to have custom pistons done, any idea of what that would cost? LOL, at present calculation, I'm at $9000 in projected cost. Thanks all.

I'll answer the best I can for ya. I gained most of my turbo knowledge when I was into DSM's.

<BLOCKQUOTE>quote:</font><HR>first, let me say that I plan on using 8:1 compression, not the LT1's stock 10:5:1 or anything higher. How does this factor with your opinion that the cylinders couldn't handle the pressure? <HR></BLOCKQUOTE>

It doesn't change my opinion. I assumed you'd be running 8-8.5:1 compression.

<BLOCKQUOTE>quote:</font><HR>As for the engine management, I may go with an aftermarket kit my turbo guy recommended from Simple Digital Systems, a company in Canada. Check out their site :www.sdsefi.com The cost is similar to the stuff availble from Haltech, around 12 or $1300.<HR></BLOCKQUOTE>

Never heard of them. But it sounds like a nice plan.

<BLOCKQUOTE>quote:</font><HR>As for your suggestions about the rods and crank, I believe my turbo guy recommended that same crank and he says he can get it for $900, so we're on the same page here. He also says I can get away with the Eagle ESP's with ARP bolts. <HR></BLOCKQUOTE>

The ESP's are probably strong enough if you keep the rev's reasonable. That's a good price on the crank.

<BLOCKQUOTE>quote:</font><HR>You said the block OR the heads? Does it matter which one? Why or why not? And here's a silly question, but can you explain what exactly the O-rings do and why they're necessary. <HR></BLOCKQUOTE>

From my knowledge, o-ringing of the block or heads works equally well. It's typically cheaper to do the heads, not sure why. In an engine with o-ringed cylinders, the o-rings, rather than the head gaskets bear the load of the cylinder pressure. The o-rings are usually either iron or copper, and for obvious reasons are less likely to blow out then a head gasket that's sealing the cylinders. Picture this, you cut a groove in the cylinder block around the cylinder. Then have an o-ring installed around the CC on the head. The o-ring sticks down into the groove in the block. This is simply a much stronger design and almost blowout proof compared to a composite HG sealing the cylinder. In a high boost or nitrous application, it's generally conceded that you run o-rings, or deal with constantly failing head gaskets.

<BLOCKQUOTE>quote:</font><HR>And most likely I'll have to have custom pistons done, any idea of what that would cost? <HR></BLOCKQUOTE>

I wouldn't know the cost because I've never needed them. I agree that you do though. I would call up Ross and talk to a tech rep. He'll be able to answer your questions best.

Hope that helps.

-Joe



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79' Z28 4-spd- built 355, TRW 10:1 forged flat tops, WP SportsmanII heads, Crane Energizer 230/230 duration .480"/.480" lift, Edelbrock Victor Jr., Holley 750cfm, Dynomax headers, dual 3" flowmasters :) 3.73 Posi 10-bolt

Ok, I dont know anything about turbo stuff so I wont pretend to, but Id like to comment on a few things. First off, if your budget is 6-7k then there is almost no way to reach your 1000hp goal safely. I believe you could use an old 4 bolt main block for up to 700hp(be pushin it though), I agree with roger69. Look for a one of the 3970010 casting blocks, then look on the front of the block where the timing gears go and if theres a 010-020-509,you just found a beefy block. I scored one recently and they are rare but I hear they are the strongest that chevy made,they have high nickel. Scat H beams cant handle 1000hp unless you put different bolts,I have the scat H heams and I was told they are rated at 800hp out of the box,nice rods for the dollar. Flatlander racing is a great place to get performance stuff, real nice people too. Some good pistons you may consider are Wiseco, I bought mine from www.dirttrackthunder.com. (http://www.dirttrackthunder.com.) Free shipping and came with plasma-moly rings for $430. They have dished type but they cost more.Ive seen a few 800hp turbo camaros with Wiseco pistons,they are the best for the money.

I'm finishing up a twin turbo SBC 427 that should make between 1200-1300hp for my '82 Corvette street car.

As mentioned already, turbo setups do not have to be spun as high to make tremendous torque and power like a NA application does. Just because a part is only rated at 700hp by the manufacturer, does not mean it won't meet your needs and will fail at 701hp. The stretching load of RPM is what kills parts, not the compressive load created by boost. The Lunati racer or Sportsman Series offer alot of bang for the buck.

I went with a tall-deck Dart Iron Eagle block, which is the same as the GM Rocket block. Dart actually makes the Rocket block for GM. It features a 9.325" deck height, 400 mains, cam raised .391", pan rails spread .800", fully studded billet steel splayed mains, o-ringed, and BBC cam bearings.

I'm running custom JE pistons designed for my turbo application, full dish which will yield 8.5CR with my 70cc Dart 18* heads.

As for rods, I'm running a set of Crower Stroker Billets, 6.125", with ARP Custom Age 625+ cap screw bolts. The crank is a Crower Ultralight 4340 NT.

As for the turbo's I'm running two Precision PT-52's with their custom .85 A/R exhaust housings, two HKS Racing Wastegates, 2 Vortech Mondo BOV's, and a custom air/air intercooler based off of a 20" x 16" x 3.5" core. The intercooler is rated at 1500cfm @ 1.5 psi pressure drop. I'll probably run around 12-15 psi on the street, and around 20 psi at the track on race gas. All the hot side plumbing is .065" (16 gauge) 321 stainless steel. Cool side is .065" 6061 aluminum.

The engine management system consists of a FAST/SpeedPro sequential EFI box, wide-band O2, individual cylinder control, MSD Digital 7+ with HVC coil, 2 Aeromotive 1400hp Eliminator fuel pumps with billet fuel filters, 2 Aeromotive fuel pump controllers, 2 Aeromotive fuel pressure regulators, and 96# Siemens injectors.

Backing it up is a built 4L80E with a 3500rpm stall 9" convertor. The tranny is controlled by a FAST/TCI T-Com box, fullt laptop prgrammable for part throttle and WOT shifts, shift firmness and speeds, as well as torque convertor lockup.

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1982 Corvette
1200hp pump gas Twin Turbo SBC 427 (http://www.montygwilliams.com)
4L80E

OK guys, it looks like I'm gonna have to change the name of this post to either "need help in choosing rotating assembly strong enough for 600+hp" or "please come and shoot holes in my poorly planned, destined-to-grenade twin turbo LT1 plan". Seriously though, thanks for all the info. I think the first title revision is closer to accurate though. So let me ask a few more questions here. First, would a 400 block be strong enough if I wanted to stick with the same plan? Or would I simply have to go with a stouter aftermarket block? I'm just asking out of curiousity, 'cuz even if the 400 block would work, I'm not going to do it. I want to stick with the LT1, with the most mods being the upgraded bottom end. Truth be told, the plan I told you guys about is not what I originally had in mind. I originally wanted to use smaller turbos that were once factory equipment, like Garrett T3's with whatever the appropriate trim is, and I didn't want to get too radical with it. I figured 550-600hp would be plenty. More than enough really. I figured the upgrades I mentioned to the low end would be more than enough to handle 5 or 600hp, and I didn't want to run any higher than 10 or 12psi, max. I got greedy when I ran a few sims with the bigger T4 turbos that my turbo guy suggested I use, and saw the huge hp and torque numbers. Granted, I knew I'd have to have an intercooler, exhaust manifolds and downpipes made, wastegate(s) and I knew I'd have to have an aftermarket fuel management system, and expected the cost accordingly. In my defense (LOL), if I went through the turbo guy I've been talking to, I'd be able to get all of the turbo components (minus the computer system) for around $5K. With $900 for the crank, $600 for the rods, $5-700 for the pistons and say $350-500 for the maincaps, I'd be around $7700, so it's not TOO far over budget (for the milder, smaller turbo, lower boost setup that is!). So could I get away with the milder setup? With say, 8 maybe 10psi(max)? I mean, the average aftermarket centrifugal supercharger kit for LT1's runs 9psi and spins the motor to at least 6500. Of course, that's with ONE supercharger. Does the fact that I want to run 2 turbos put that much more stress on the motor if I'm not running that much boost? OK, open fire, guys!

aftermarket block...$2000
4340 steel crank (Lunati or Crower) $1200-1800
Oliver billet rods $1200
Blower pistons $600-800

Don't even think about skimping and trying to use a factory block or cheap offshore crank/rods/pistons. I don't believe Eagles claims of 700-1000HP on their H beams rods in sbc...I would not use them on a 500-600 N/A sbc. If you skimp on internal parts, your gonna have a big surprise eventually when a rod fails or the crank does.

Oh yea, stainless turbo headers (custom fabbed) can start at $3000 a set and go up from there.

I'd say $7k will cover the shortblock. A strong blower engine will easily cost $15k. You can't expect to have an engine make 1000hp with factory heads either...your gonna be looking at a real good pair of 23 degree heads miminum, or in reality a pair of 18 degrees would be better.

Local racer here ran a Duttweiler sbc twin turbo in a late model Outlaw Street car that made upwards of 1700 hp and ran 6.80's (engine was in excess of $25-30k, but was much cheaper than the 813 ci Sonny Leonard engine ($50-70k if I remember) he had the previous year... and was much, much less maintence as well). The car could idle just like any daily driver until he turn the boost up and let it eat http://www.camaros.net/forum/biggrin.gif

I think a factory block with splayed billet mains is safe to around 700hp or so.

I think with a 600hp goal in mind, what we've been talking about still pretty much holds true with the exception of the block.

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79' Z28 4-spd- built 355, TRW 10:1 forged flat tops, WP SportsmanII heads, Crane Energizer 230/230 duration .480"/.480" lift, Edelbrock Victor Jr., Holley 750cfm, Dynomax headers, dual 3" flowmasters :) 3.73 Posi 10-bolt

So you think the built factory shortlblock can handle 700hp max. That's fine, 'cuz I don't expect to go much higher than 600hp with the milder turbo setup. One thing I'm not clear on is what you said here:

I think with a 600hp goal in mind, what we've been talking about still pretty much holds true with the exception of the block.

[/B][/QUOTE]

You say that what we've talked about still holds true. Specifically, does that mean you still think the cylinders couldn't take the pressure, even with the lowered boost? I mean around 8psi, max 10psi. I used the Vortech supercharger kits as an example becuase they run comparable boost (9psi), and I asked whether running two turbos puts significantly more stress on the motor. What do you say? Or is it more a matter of boost level and rpms? Thanks.

With 'exception' to the block. In my first post, I was trying to push the aftermarket blocks. Since your HP goal considerably dropped, I think a factory block will do. Just try and keep it too a minimum(.030") overbore.

I meant the rotating assembly should still be built like we already mentioned.

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79' Z28 4-spd- built 355, TRW 10:1 forged flat tops, WP SportsmanII heads, Crane Energizer 230/230 duration .480"/.480" lift, Edelbrock Victor Jr., Holley 750cfm, Dynomax headers, dual 3" flowmasters :) 3.73 Posi 10-bolt

Cool, well that's sort of encouraging. As for the bore, I'm leaving it the standard 4.00", no overbore. Thanks all, I'll post new info as it progresses.