No replacement for displacement - really???

[hannes_slanec]

I am just about to build a Pro Touring Impala on a Jake´s Subrame.

I had a 540´short block that is sold now and now I have a second chance to start from new.

I want to build the car with a really strong but not to heavy engine.



I will go with an all aluminum BBC that is for sure but I dont have plan right now.
My first idea was to twin turbocharge the 540 but its bottom end was to weak.
Now that I start from the scratch again I could go with an 598, 632, 665 or even 707.
So an 707cid alu shortblock for around 7000 on racing junk.com (altough the seller is Dynoflo and I have heard nothing than bad about him, altough he seems to be a nice guy).

I did the homework and compared Dynovideo from NRE and another guy with 712BBC.
The plan was to see the difference between the big cube N/A suckers and the twin turbo BBC´s and I was surprised, here are the numbers:



Naturally aspirated big cube BBC´s


632 BBC N/A:

1076HP@6500rpm
893lb-ft@5900rpm
--------------------------

712BBC N/A
985HP@7000rpm
902lb-ft@7000rpm
----------------------------

Twin Turbo Charged BBC´s:


509BBC TT

996HP@6200rpm
911lb-ft@4700rpm
(10psi)

1209HP@6300rpm
1105lb-ft@4400rpm
(14psi)


-----------------------------

572BBC TT

1047HP@5700rpm
1083ft-lb@4500rpm
(10psi)


1295HP@5700rpm
1341lb-ft@4100rpm
(17psi)


If I compare that numbers I got a clear statement.
The stronger N/A compared with weaker TT on the lower boost:

HP
712cid N/A:985HP@7000rpm (had 654HP@4200)
509cid TT :996HP@6200rpm

Torque
712cid N/A:902lb-ft@7000rpm (had 818lb-ft@4200)
509cid TT :911lb-ft@4700rpm


I dont know if I interpret that numbers the right way but for me it looks like that even smaller boost leves make a BBC much better than the biggest N/A-motors.
Allowedly, the 632cid, in that very case, hade a better performance than the 712cid but this is a cam-story I think and I want to have a mellow camed and low boost (in the case that I go TTcharged) anyways.

Not only that they have higher HP and Torque-numbers, they also have it way earlier in the rpm-range (I thought that would be the strength of the N/A´s).

The only draw back on the TT-engines is the added weight in the front that makes a the weight transfer worse.

What would be the gross weight of two big turbos (I want the boost later, not from the bottom), the wastegates, blow off valve, turbo headers and an air/air intercooler?

If I do a mistake here please enlight me.

[rrunner68]

With all that engine and all that power you are adding a whole new level of complexity to the car. Cooling, driveline, traction, etc. Good luck.

[hannes_slanec]

And it is even a convertible ;)

That is why I go with further reinforced Jake´s Rod shop full perimeter subframe that consists of a 9" rear with 35spline axles, nodular center section, Corvette C6 IFS, Shockwaves, Bear Brakes.

I use a aluminum HiPo-Driveshaft and a reinforced 4l80e possibly with a GearVendors for a second overdrive.

Cooling should not be a problem with a good radiator. My radiator will be rear mounted.
In that way the heat blowen by the wind out of the radiator does not hear up the big block and turbo setup again and weight is off the nose of the car and added to the rear.

The long pipes that connects the radiator with the engine will have an additional cooling effect.

[1969CamaroRS]

If you are going to go with that much power, I'd make sure you get a good strong aftermarket block like Brodix, Dart or World, dont skimp on the internals either, especially if you are planning on adding boost.

Good point on the suspension, drivetrain and brakes needing to match the power you are going to produce with such a monster.

[hannes_slanec]

If you are going to go with that much power, I'd make sure you get a good strong aftermarket block like Brodix, Dart or World, dont skimp on the internals either, especially if you are planning on adding boost.

Thanks Sir,

that is why I am starting with my engine from new.
I had a 540 short block bought off of eBay.
It had a 4340 Cat Crank, 4340 Cat H-Beam Rods and Probe domed Pistons and made 9,5:1 on open chamber 119ci heads.
The block had all the checks and machining after it and was sleeved plus it was a thick wall block.

I was planning to boost it and to make 1000HP on a low boost setup and still believe that it would have handled that power.

But now, how I stated, I can start from new.

I think I will go with the Brodix all aluminum BBC and would like to build the Eagle 4340 Rotating Assembly in as it is rated to 1500HP. More than I want to produce.

When I have bought it, everybody told me 9,5:1 is too much static compression and no one wanted to see that I am after a low boost setup, with maybe 10PSI, and that I will run LPG (Propane, 105-110 Octane) or CNG (rated to 130 Octane), so I wont see ping.
Now I can build from new and realize that the trend is going to raise the static compression to 9-9,5:1.

I would never like to drive a 7,5-8,5:1 comp as the car would run unefficient in the stop and go traffic off boost.

Since there seems to bee a rule of thumb for Turbo-Engines that says "a little bigger on the bore", and I do not want to buy a new engine with the same compression as well as the same displacement, I plan to stay with the 4.250-stroke crank and the biggest bore that seems to be 4.600 what yields 565cid.

I have a pair of Dart 320/2.300/1.880 alu heads but think about to sell them with the 540 short block and go with AFR 325 fully ported heads.

What are your toughts on that engine-project?

[DeltaT]

Doing some quick calculations, I figure you can expect to add ~60-75lbs. to the front end with 2 turbos, plumbing and a large A2A IC.

Jim

[hannes_slanec]

Doing some quick calculations, I figure you can expect to add ~60-75lbs. to the front end with 2 turbos, plumbing and a large A2A IC.

Jim

That would not be that much für my feeling.

Would that be bigger models as I want the boost later in the RPM-Range?

Thanks for your time

[64duece]

fwiw....you'll never get much of that power down in a useable configuration (aside from a full drag race chassis/suspension) which differs from a pro-touring setup.

Have you considered doing a large cube twin turbo LSx setup? The weight savings would certainly play better with handling, offer increased fittment options and still provide the ability to overkill your setup with hp/torque. We have a 570" BBC with twin 76gts in our 55 Chevy. 9lbs isn't usable on a 390/40/17 drag radial. If I did this over...I'd do the LSx in a heartbeat.

[hannes_slanec]

fwiw....you'll never get much of that power down in a useable configuration (aside from a full drag race chassis/suspension) which differs from a pro-touring setup.

Have you considered doing a large cube twin turbo LSx setup? The weight savings would certainly play better with handling, offer increased fittment options and still provide the ability to overkill your setup with hp/torque. We have a 570" BBC with twin 76gts in our 55 Chevy. 9lbs isn't usable on a 390/40/17 drag radial. If I did this over...I'd do the LSx in a heartbeat.

As far as I am informed, a all aluminum BBC is under the weight of an LSX.

My setup would have its highest power in the mid to upper range. No turbo boost from the bottom.

I want the thrill when I roll with 60-80MPH and I kick the pedal down to the metal.

I guess I know you, we was writing one another before. You advised me to look to get the boost early in the RMP-range and back in the days I figured it out as I am doing it no, no boost from the bottom.

Thanks for your opinion, are there some pics or videos of your great 55´?

[Procharmo]

fwiw....you'll never get much of that power down in a useable configuration (aside from a full drag race chassis/suspension) which differs from a pro-touring setup.

Have you considered doing a large cube twin turbo LSx setup? The weight savings would certainly play better with handling, offer increased fittment options and still provide the ability to overkill your setup with hp/torque. We have a 570" BBC with twin 76gts in our 55 Chevy. 9lbs isn't usable on a 390/40/17 drag radial. If I did this over...I'd do the LSx in a heartbeat.

You can get in the low 8's to high 7's with 3500lbs, 1500hp ish and leaf springs. Just how fast do you want it whilst still being able to handle...

Change the front skinies for wider wheels, reset shock valving and then Protouring handling is available on leafs....You can regulate your power with boost controllers and your right foot...but it will be more balanced and have smoother power delivery with a boosted SBC than a boosted or N/A BBC IMHO.....

For only 950 - 1000hp you can do it with an SBC Procharged or turbo. If it's an ally SBC it'll be as light as can be......

Twin tubo 632's can put out as much as 2000 - 3000hp+ but will weigh a lot even with an ally block. Cast ally blocks have weaknesses when boosted, billet ally blocks are the way to go at over 1000 - 1500hp power levels.......

The same goes for SBC heads, billet needed over 1750hp but under that cast heads should live for a while.....

[64duece]

I'm not sure about an all aluminum BBC being lighter. Considering block weight aside...everything else is just plain bigger crank heads etc. You may want to double check that info.

If your building a short RPM engine (as I think you were considering back then) it doesn't lend well to have boost come in at 4500 if your only running 6k. Then I woul;d suggest having a setup designed for boost to come in at a more useable RPM.

There are a few ideas to throw around since we're on that topic. A quality boost controller along with a decent traction control system would help keep some of that power in check. I can tell you first hand at 60-80mph...we can black stripe the tires for 100ft....amusement ride worthy!

Here's a few shots before the drive-by-wire conversion (we're finishing up now)

[hannes_slanec]

I was looking at the LSX-Engines at Shaffirof and saw that they are almost twice as much than an all aluminum BBC.

12 000 for an all aluminum BBC
22 000 for an LSX

for what I saw, so what is the point for the LSX?

The BBC will run forever without maintenace. I can run a very low boost level and therefor a higher static compression what makes my milage better in the stop and go traffic.

I no a fan of 7,5 to 8:1 comp and than boosting 25 - 30 pounds of boost on it.

[64duece]

By no means am I saying a twin BBC being a "bad idea"....giving you some real world info. You won't be disapponted, if your building a car that autocrosses or similar, than the LSx would likely play better for a combination like that. If street fun is all your after....your not going to go wrong.

I agree, we never run much lower than 8.5:1...closer to 9:1 these days. We've just started to play with e85 abit more this year and really like how hat's going. We're also looking to improve our tune for milage this year...our best was 13.7mpg all highway last year (pumpgas). I'd like to see if we could improve on that some as we lost quite abit going to e85. I think the LSx would get near or over 20mpg (pumpgas).

[hannes_slanec]

@Deuce64

Sir, very interesting numbers.
Yes, it is for street fun only.

These days I see people run even higher than 9:1 StComp. As I am going to run that monster on LPG with its high octaine rating I will be able to go up a bit with the compression.

Are you using an overdrive tranny? I plan to go with an 4l80e and an Gear Vendors behind it. That way I got a double overdriven tranny.

Why would the LSX need only half of the gasoline? Because of the EFI? I plan an EFI for the BBC as well.

From what you said, maybe I should lower the start of the boost to 2500-3000rpm.

I have been on Shaffirofs site again. I made a mistake, the engine for 22 000 is a supercharged LSX.

What ever, all the bigger LSX engines at Shaffirof are cast iron. The 454 for example.
Would not thing that it is lighter than my all aluminum BBC plus it is still more expensive than the alu BBC:


http://www.ultrastreet.net/engines/454_lsx.asp

vs

http://www.ultrastreet.net/engines/5...treet_lite.asp

For what the difference is (4000usd) I can easily by a really very good aftermarket EFI like the Electromotive Tec3 that is already a very nice setup for a turbo engine its ability to run dual injection, crank trigger, single coil packs and so on.

Thats my opinion but I am open to yours



THX

[hannes_slanec]

@Deuce64

BTW, we really really need some videos from your crazy TT-Chevy. Outside and onboard!!!

Please please please.....

[64duece]

I see what your looking into there....a few notes for you. You can't compare those engines (apples to apples) on a price standpoint. The BBC is built with budget friendly parts that help keep the costs reasonable for what it is (e.g Eagle, Patriot etc) while the LSx engine has premium parts (GM, Callies etc) and includes some fuel and induction and complete with EFI.

I wouldn't consider using that BBC without making some changes to allow it to live better on a boost application (rods/bolts, rings, custom cam, possibly exhaust valves). You may want to reach out and duiscuss your plans and see what they thnk. Add these cost "changes/upgrades" along with and EFI system and you'll see the price likely exceed the LSx.

As for the LSx vs BBC fuel economy....the LSx is just smaller and more efficient. It's gonna win hands down on those merits alone (EFI vs EFI). We run a 4L80E behind our our engine....would never go without OD again! The ability to program shift points/line pressure and converter lockup have a huge impact on the drivability and manners of our cars.

[hannes_slanec]

I also would not go without an 4l80e but can do that with different EFI-Systems that support the newer, computer controlled trannies.

As for the LSX, how do I adjust it? Back in the days I wanted to buy a LT1 but droppend that plan after I had the impression that I would need that LS1-edit programm which was extraordinary expensive.

The BBC with an aftermarket-EFI is easy to adjust by a Laptop, may be that this is now easy with the LSX engines as well but dont know...

As for the cheap stuff, the Eagle 4340 parts are rated to 1500HP and I have been told that people ran them well over 1600HP without a problem.

[JustinB]

It would be worth your time to put a call or email into JR@JR Competition Motors in San Diego 760-745-4540. He is putting a together a 540 BBC for me as we speak. He really know his stuff when it comes down to big cube big blocks. He would really help get you going in a good direction.

[383hq]

Thanks Sir,

When I have bought it, everybody told me 9,5:1 is too much static compression and no one wanted to see that I am after a low boost setup, with maybe 10PSI, and that I will run LPG (Propane, 105-110 Octane) or CNG (rated to 130 Octane), so I wont see ping.
Now I can build from new and realize that the trend is going to raise the static compression to 9-9,5:1.

What are your toughts on that engine-project?

Here in australia LPG (Propane) is readily available. You need to foucs on DCR not SCR.
I have supercharged my LPG (ex daily driver) sbc motor due to environment and cost benefits. you will really struggle to see those numbers on LPG.
I run a twin converter GRA throttle body setup with twin LPG tanks and twin lines in a WB ute. The system maxes out at around 590 engine hp. Note that packaging gets complicated at this point.
To go bigger (I have seen 3&4 convertors used -ugly engine bays). The restriction becomes the fuel from the tanks (twin lines etc over 360kw).
I believe the guys with unlimited budgets really struggled to get the gaseous fuel into the combustin chamber from 800hp on.Drag racers here with great budgets, experience and reputations all seem to switch to petrol (gas) at this point. -Unlimited budgets here in Australia have seen no better then 800-900hp on LPG.
I cannot speak on the new liquid injection that occurs with LPG, this technology has occured in the last few years, but I am unwilling to spend another $5K to replace what I have for a few more rwkw. The benefit is in the increased timing available from the natural intercooling effect of the liquid converting to gas . I have learnt there comes a point where the engine overpowers everything else chassis brakes, tyres....

As far as driveability goes comparing force feed SBC to BBC back to back, I prefer the force feed sbc - increased torque cannot be described through dyno numbers.

[gearbanger]

If I ws starting from scratch with a Chevy, I would not even consider another engine than an LS based combo. That being said, I would build a large cube engine regardless, because I think it is smart to start with the most cubes you can. It will require less boost to reach your target and the engine will have more torque while not in boost. I am not that knowledgable about boost, but from what I do know, I wouldn't do a long stroke engine with much boost because of increased dwell at TDC causing potential for detonation. For a street car that will sit in traffic and heat soak, you need to always keep detonation resistance in mind. So, if you go BBC, I'd probably stick with the 502 or something like that to keep the bore>stroke and the stroke not so huge.