[[email protected]]

I'm starting to build my 31 durant coupe. I'm going to take my 327 from the 57 and put it in the coupe better power to weight ratio. Now the fun! I'm thinking big block for the 57. So here's where you guy's come in. My 327 put out 400hp I'd like more of course. I like the sound of big block tork sounds like it would be awsome in my car so I need build idea's! I don't have a ton of cash but I do like to upgrade along the way so I want some idea's on cobo's as well as the conversion to bbc. Hope to hear some good bench raceing here!

 

[56owner]

BIG BLOCK

You might not like me suggesting this but I'd look for a new LS3 ,six speed auto, and paddle shifter. plus the weight advantage. a few weeks ago a take out engine from new 2010 Camaro SS with 37 miles from a high performance shop was going for $5,000. You can't hardly build a 430 horsepower engine for that. or if you got the coins a supercharged 600+ horse for around 13 Big ones

 

[NHRAmike57]

There's no replacement for displacement..here's a $1200.00 ..496 CU , 10 to 1 compression pump gas stroker kit with crank/rods/pistons/rings and bearings. You add your 454 truck block core ..presto..there's a sturdy shortblock with a serious amount of torque for your trifive and you can upgrade heads and cams along the way

http://www.racingjunk.com/category/...05/BB-CHEVY-496-STROKER-KIT-10.2-PISTONS.html

 

[oceangoer]

New Engine

Did someone mention an LS with Six speed..

It is the way to go. You get the power and the mileage...

I love,, a great Combo !!

Michael

 

[[email protected]]

checked it out

I went to that racingjunk site and wow there are some good deals there. I would love to skip the cost of a build and get somthing ready to drop in and there are some good choices. I just moved to a new house so as soon as I'm caught up I'm gonna start hunting

 

[Chevynut]

I personally don't think you can beat a BBC for LOOKS as well as all-out torque. Some people don't like the looks of the "flat" top on the LS engine, but that can be fixed with sheetmetal manifolds or blowers. The tri5's have a big engine compartment and some engines just look to small, imo.

This is the look I like...Ramjet 502:

 

[jwmbishop]

I love the way a big block FEELS - nothing compares to feelin it in the soles of your feet as a bystander - or on the throttle as the driver! Volume of pipes has little to do with it (although when we ran the 383 straight header with turn downs it felt dang good)! A well built small block may buzz the boots - but a big block will move em!

 

[jwmbishop]

There's no replacement for displacement..here's a $1200.00 ..496 CU , 10 to 1 compression pump gas stroker kit with crank/rods/pistons/rings and bearings. You add your 454 truck block core ..presto..there's a sturdy shortblock with a serious amount of torque for your trifive and you can upgrade heads and cams along the way

http://www.racingjunk.com/category/...05/BB-CHEVY-496-STROKER-KIT-10.2-PISTONS.html

Plus a couple of mock ups and some grinding to work the oilpan rails to make it all fit - but that IS a good price.

 

[[email protected]]

MPG

Hey how bad is the gas mileage for the big block vs small block? I would like to know.

 

[56owner]

milage??

NOT EVEN IN THE SAME CITY BIG BLOCK 8-12. LS CLOSE TO 25 I'D GUESS ,WIEGH ABOUT THE SAME.

 

[jwmbishop]

Can't own a bb and be pump shy. 8-12 optimistically. 6-8 if you hate sitting in traffic!:sign0020:

 

[Chevynut]

Can't own a bb and be pump shy. 8-12 optimistically. 6-8 if you hate sitting in traffic!:sign0020:

I don't buy it. Maybe with an antiquated carb and 4-speed, but I think I'm going to get 17-20 mpg with my RJ502, 4:10 gears and Viper 6-speed on the highway at around 70 mph. I don't think that's unrealistic.

 

[56owner]

I don't buy it. Maybe with an antiquated carb and 4-speed, but I think I'm going to get 17-20 mpg with my RJ502, 4:10 gears and Viper 6-speed on the highway at around 70 mph. I don't think that's unrealistic.

The Ramjet and double overdrive 6 speed weren't mentioned as part of the equation when starting questioned. Does your ecm allow for dropping a couple degrees of igniton lead after peak torque in high gear?

oh yeah and 1 gallon for each quater mile.

 

[warner]

blg block

youll love the feel of the big block plus it looks kick ass!

 

[trifive]

The differance between big block VS Small Block

Small blocks try to spin the tires.

Big Blocks try not to spin the tires.

Otis

 

[HIGH ROLLER]

Antiquated carb and 4-speed:happy0030: Thats me, 730 antiquated cfm 4.88 gears 14 mpg small blocks spin the tires my BBC LIFTS the front tires:sign0020:

 

[KDs56210]

GOD BLESS ANTIQUATED! My poor GI budget wouldnt allow for them thar computed-ECM'd-RJ'd fan dingo-lectrified nonsense..lolarty0031:Your just gonna love the power and sound! Good luck and keep everyone posted!

 

[jwmbishop]

If I remember correctly the viper 6 has fifth and sixth as overdrives - that's a HUGE help and the computer control is better. But don't hold your breath hoping for 17 with your foot down in the under gears. I don't think I was being BS'ed when an owner with the gear vendor od mated to a NV4500 5 speed (2.26 final in double over with 3.90 rear) said he gets 15 at best avg - all around (just cruising at 70 in 2 x od, his readout on the dash says 19 but it drops to 14 just to go decently up 5 mph - and each 5 mph lowers instant eco by about half an mpg). 5000 lb weight (49 chev sedan).

When he plants his foot in it from a stop - the "instant eco" display from his onboard drops to 6 and slowly comes up to 10.

But the questions begs - if you can afford the efi rj502 and viper 6 - what concern is fuel economy? lol

 

[Chevynut]

If I remember correctly the viper 6 has fifth and sixth as overdrives - that's a HUGE help and the computer control is better. But don't hold your breath hoping for 17 with your foot down in the under gears. I don't think I was being BS'ed when an owner with the gear vendor od mated to a NV4500 5 speed (2.26 final in double over with 3.90 rear) said he gets 15 at best avg - all around (just cruising at 70 in 2 x od, his readout on the dash says 19 but it drops to 14 just to go decently up 5 mph - and each 5 mph lowers instant eco by about half an mpg). 5000 lb weight (49 chev sedan).

When he plants his foot in it from a stop - the "instant eco" display from his onboard drops to 6 and slowly comes up to 10.

But the questions begs - if you can afford the efi rj502 and viper 6 - what concern is fuel economy? lol

Yeah, the Viper 6-speed has a 0.5 overdrive 6th gear (0.75 in 5th) so a 4.10 rear gear would be like a 4-speed with a 2.05 rear gear. arty0031:

That's a heavy 49 Chevy! I expect my Nomad to be under 3600 pounds.....hopefully . That will help.

I'm not "concerned" about fuel economy, it's just kind of a challenge to see what I can get with it. I'm using a Holley Commander 950 ECU so I can program it to do what I want within the constraints of the software. I'm not sure what all is possible, but I have added a knock sensor, and a wideband O2 sensor upgrade for tuning.

I know my right foot will largely control MPG , and I tend to play around some around town. But if I want to travel longer distances, it's nice to know my mileage is going to be reasonable, not 8-10 mpg. I built a 23+ gallon fuel tank that I now think may be slightly overkill.....:sign0020:

I had a 55 Chevy with a carbed Corvette 427 and Muncie with a 4:11 rear and I actually measured around 17 mpg on a long trip to Kansas in the early 70's. I don't remember my speed, but that was before the mandatory 55 MPH federal speed limit. I think it was 70 MPH. However, I don't believe I ever corrected for the speedo error with the 4:10 gears. I think I was still getting at least 14.

 

[Chevynut]

Let me ask you guys this....would you expect to see a MPG difference between a 427 BBC and a 427 SBC? If so, why?

My thought is that no matter what engine you're running, it takes the same HP to propel the car down the highway at some given speed. So it all comes down to the efficiency of the engine. Is that wrong?