Why bother with a 7L big block when you can drop in a 7L small block and make insane power... N/A or turbo... whichever way you want... NA it can make 625 and turbos.. well.. look at lingenfelter TT.. anyways...

The only reason I see a big block is if you want to drop the 572 full aluminum that Moss did... and I think you could run the 9.55 on pump gas.. I think.. given a EFI system.. I mean.. 9.3L ought to give those 770HP on pump gas...

That is the only reason I see on a big block... PUmp gas insane power...

I always run with pump gas and I race everyone with pump gas... I dont like race gas.. if I am at the limit.. well im stuck there... and the bigger the engine the more power out of pump gas...

 

I did a search on him and read about that. That's a sweet setup he's got there, and he's really got my attention with it. I'm hoping he'll come out with a kit or at least a very detailed set of instructions.

 

I've got 2 reasons for wanting a big block, even though it doesn't look like it's going to happen at this point. #1. Insane power on pump gas, from idle. No lag or waiting for the powerband. #2. I can go bigger with the big block, and even a 427 small block seems to be VERY expensive once all the parts I would need get added in. The lower weight and added room in the engine bay do make it somewhat attractive, and now that I know that a roots type s/c can fit under there it's even more attractive. I would worry about cylinder wall thickness, though. Regardless, I don't think I can afford to build a 427 or 454 small block, which really leaves out the s/c. Oh, well. I'll probably do like rooster93v8 and maybe stroke it to 383 when the rings start to go. If I need more, there's always N2O. Not my favorite power adder, but what the heck. It's not like I'd need it very often. Just at the track.

 

Correct me if im wrong but 7L out of a big block or 7L out of a small block should yield exactly the same top power on pump gas...

Anyways.. check out.. www.cartek.net they have up to 436 on the lsx block.

 

Too many variables, but I 'd say you could get more power outta a big block.

 

I read once that the big block would actually make more power. This is assuming that all else is equal. The reason they gave was the ability to get better port placement with the big block. The example that I think they used was a 400sbc vs a 396 big block.

 

Yes you are correct... a lot bigger ports, you can have more combinations, a lot more bore than stroke and make an engine that revs a lot higher and thus makes more power, but.. what I was refering too is to MAX power on pump gas... It should be the same for both or so close that the cost offsets the advantage... I believe that max power its more dependant on size.... Although if you if use lower CR on the big block and since you get better port flow, well... I assume you could get a bit more power.. but all in all they are the same max power range.. I believe all of us here reach the max power on pump gas on the sb anyways...

 

OK, I didn't get you the first time. I guess part of it would depend on this. Assuming all else is equal(head design, cam specs, blah blah blah), do either stroke or bore affect an engines tendency to detonate? Also, the BB will have physically larger heads. Is it harder to cool them properly, or can the water jackets be made large enough to ensure that there are no hot spots when you get to such high numbers as we are talking about here? Remember, the BB has larger ports, so that is area that is denied for the use of water passages. Could this lead to detonation, meaning that the limit may be reached sooner with that head design? Maybe it's not a problem at all. I would think they have done all they can to correct any possible problems like that, but maybe it's something inherent in the design. Aluminum heads should help, I would think, but aluminum BB heads would still be at a disadvantage (maybe, if any of this makes a difference) compared to a SB aluminum head. What do you think? Remember, MAX power. Not just insane power.

 

Fear not about the BB. What makes the difference for at least cooling obviously your cooling system for one but if your building a BB from scratch and using the correct parts for the combination and not trying to get say 4.600 out of a stock 454 block then everythink will be ok. Using a Dart block these blocks have siemised bores and they can easly bore out to 4.600. I have a friend that runs a 632ci 17.1 compression,Big Chief motor in his car and with the electric water pump on along with one electric fan this engine also is filled 1/2 to 3/4 with devcon block filler and the engine stays at 150 to 180 deg. This motor runs cooler then a LT1.

The same guy actually owns a chassis shop that builds drag cars to pro street cars. I have seen a few of these newer F-bodys come thru his shop for him to fit BB in the engine bays and honestly its not as bad as you would think. Depending on if you have your stock k-member or after market will help with oil pan selection to open up your choices more. I helped him do one F-body BB conversion with the stock K-member and it was a fabricators nightmare! We had to cut the oil pan,section the **** out of the K-member but besides that a little work required in the tunnel area and one other think I almost forgot and that is you will have a hell of a time getting exhaust under the car. There is a company that actually offers headers for this car and with BB engine.

If you want some advice I would say do the Big Block Chevy because cubic inch vs SB cubic inches you will spend a fortune building a SB vs a BB which will be cheaper and will make more power. Just be careful what deck height you go with because even though short deck if used more then likely you will have to cut the cowl depending on what you use for intake and carburation but cutting the cowl is no big deal.

I have owned quite a few BB Chevy setups but never one in a personal F-body. I drove a F-body that my buddy built and honestly the motor in that car was a puppy 427ci Big Block Chevy on pump gas and carbed. Running a Turbo 400 with 4.56 gears,nothing fancy for heads rectangle port GM cast iron and cam was a flat tappet solid 10.5 to1 compression. This car was as stock as they come besides subframe connectors and a few suspension bolt ons the first experience I can only say when I drove this was what a tun of fun! Even with a small cube BB Chevy like this owner had in the car it was more then enought.

When I drove the car on city streets you for sure can tell there is a BB in the front end that was about the only draw back but as for fun factor rating I would give it a 10 plus! This car would do block long burn outs and with Eagle GSC for tires you could be cruising at 45mph and nail the gas and instantly break the tires loose and keep spining for blocks. One thing for sure is you will love how the car will pull thats if you ever get the power to the ground which is allot of reason why many don't run a big block in these cars because they really turn out to be tire burnner cars plus some of the package problems to get it in the car but really it isn't as bad. Go with a Big Block Chevy.

As for Brady96Z,

That other guy's motor statement you made doesn't fly with me. That's your car that 540 is in. One bit of advice from someone that has had BB before and that is start saving your money because your never going to get that power to hook! 540 cubes! That will do! The saved money is for the backhalf your going to need for all that power. If your not careful you will get waxed by a strong running SB and thats only because he will be able to get the power to the ground and that 540ci well you will find out.

If you need any info as to what is needed or cut and so on give me a shout becuase like I said my buddy did a few of them and I helped him a two of them.

See Ya,
Jim

 

i still dont understaand why goto the trouble of shoehorning in a BBC, when you can build a 600+hp SBC for $6-7kish and it will fit easier, and weigh much less. (less weight = faster car).

unless youre just doing it to say "i have a big block in my 4th gen"

 

A little history for ya, the LT1 was my first small block in about 10 years, all I previously owned were big blocks. My car has stock style suspension, but there's not too much stock about it...

FYI, the 540 is a pump gas motor and only makes 750 flywheel horsepower.. My twin turbo LT1 made over 900 (est. by 1/8th mile times). I don't expect the big block to weigh too much more than my small block with all the twin turbo stuff, that crap was heavy! Also, the 540 is only temporary while my new turbo setup is being put together.

The big block is cake to put in if you have a manual rack and an aftermarket k-member.. I fabbed my own motor mounts and I found some headers that fit.. Not Lemons.

It's all good!
...Brady

 

It is all PERSONAL choices

I thought about it. But a BBC does not fit into the way I use the car. The BB will always make more power all things being equal....about 2% if I remember right.

I even looked at going with a LS1/6 motor.

In the end I decided to Stay with a LT1 for the ease and drivability. Well that and it is just flat cheaper right now(I am sure LS1 will be cheaper in the future). MOST every thing will bolt straight up and most of the mods will be in the engine compartment.

I can already do long huge burnouts(270+ Ft measured) from a roll. That is with a untouched short block and ported LT1 heads.

So far I have spent $5,000 on building the new motor. A 6.2L LT1 with 18* heads and a hogans intake. Gases will be put out through custom stepped headers going into my present 4in Exhaust. I am figuring I will wrap the motor up for just under $10K. We are looking for 700hp N/A and stack a 300hp Shot on top of it. I plan on commuting with it on a daily basis(60 miles stop and go a day)

Now it will not be as Cool as saying I have a Big Block. But I will still be able to auto-X with it and get close to the 20+MPG I am getting now

Like I said it is a tamato/tamato thing. All things being equal a BBC WILL make more power....But is it really worth it?

That is what you need to ask your self.

Good luck all!

 

$6-7kish for a 600 plus horsepower SB Chevy? Where the hell can you find parts that cheap for a SB especially a LT motor to arrive at those power figures? Your figures for money would get those power numbers if building a BB but I would have to disagree with you if your saying you can build a SB chevy for $6000 and make 600+ hp. There is know way! But building a BB with that amount of money would get ya a 600hp motor or even a 750hp motor and all for $6,000.00.

That why putting a BB in the car is appealing. Cost is considerably less and power is way more vs SB making that much power. A SB making say 650hp you woulld have BIG MONEY wrapped up in it especially if your looking NA.

BB is probably starting to make more and sense now.

 

So whats your point?

Don't get me wrong I don't mean to be blunt but I don't see what your saying to me? Makes no difference if you had a BB in your lawn mower I to have owned and few BB powered cars in my time and by you telling me that has been the engine for the most part you have been acustom to I would have though you would see eye to eye with me about the torq and hp a BB has not to mention trying to get it to the ground. I'll be the first to say I loved a BB in some of my cars and the fun I had in it but **** I lost a lot of races becuase of the power the motor made was just to much.

I don't know what your combinations where but the BB Chevy's I owned IMOP I felt didn't make insane power and ,maybe 725hp if that but the torq a large cube motor puts out will never allow a small tire f-body to hook IMOP. You figure your small block was making 900+ hp and maybe it was but that type of power is easy to come by with turbo setups. The single biggest probleme associated with turbo setups is getting the power to the ground. A big inch BB in some small way has the same problem becuase of the torq it makes and usually will over come the tires unless of corse the car has large tires on it.

I'm guessing by the comment you made sounds to me as if your logically seeing the BB only make 750hp vs 900hp you shouldn't have tracktion problems with the BB? Hey I'm not trying to insult you but I just think your in for a surprise with that 540ci motor.

I'm all for the BB idea in the F-body but unless your looking to win the longest burn out contest your going to have to have way more tire then what that car offers in order to hook. This was the biggest reason I had my whole chassis done, I wanted to go to big power and go fast not talk about what it should have run and what it probably is making for power. It sucks after awhile never getting the power the engine has to the ground its like why have a motor that makes big power if you can't use it? I purchased one of the old 447ci TT BBC Reiger motors that will find its way into my car the following summer but without having anything less then a Lenco or Liberty with a slipper style clutch behind it there is no sense to even runnning it now. I use a Rossler stage 4 Turbo 400 with 2.10 first gear and my 440ci motor in my F-body running a turbo 400 that is know to eat hp still was a complete mess with even using slicks that where cramed in the wheel wells.

I wish ya the best and hope your car puts up the time you want but honestly BB + stock suspension or stock wheel well restricked tire sizes = Tire spinning low ET car.

Good Luck in the build
Jim

 

I think I see eye to eye with ya... obviously we're both accustomed to the wicked big block torque but I think my chassis will handle it, and you might not completely agree. It's really irrelevant until I put it on the track... Which is this weekend. We've been scrambling to get this thing together in time for the Thunder Shootout. We got it fired up tonight and it sounds pretty decent.

here are some pics from this evening after we fired it up:

http://turbocharged.net/bigblock/som...r/dsc00603.jpg
http://turbocharged.net/bigblock/som...r/dsc00604.jpg
http://turbocharged.net/bigblock/som...r/dsc00605.jpg
http://turbocharged.net/bigblock/som...r/dsc00606.jpg

It runs great and sounds awesome as is, but tomorrow the Big Shot plate goes on it and we head to the dyno..

We may have converter issues as I'm still running my turbo converter, but that's the way it goes..

cheers!
...Brady