B Block verse small block

[aussichev]

I asked a wile back if a big block could get resonable economy and the answer was no. I spoke to a local ford bronko importer that i have known for years ( he`s a good block.) and he has told me that he has a 400bb bronko that gets better economy than many of the 351`s. He and his and his partners think that it`s down to the fact that it`s working less hard than the 351. So can a BB do that? Could i make a BB compete withe a mild 350, after all a well sorted BB would give me all the go i would need.

Paul

[87 STEPPER]

Im not a big ford guy but iv'e never heard of a ford 400 BB and a bronco ain't that light of a truck if it's a f/s.

Here's the answer to your question.

BB= zero fuel economy chevy or ford or mopar plain and simple a bigger engine requires more fuel/air to operate it than a small block despite the weight of the truck.

Talk to a guy that own's a 90's 454SS and he will tell you fuel ecnomy sux.

And thats a modern computer managed fuel injection system designed to operate at peek efficiency.

Most people that install a BB usually dont use that car/truck as a daily driver so fuel economy isn't a big factor for them but power and torque is.

[aussichev]

Don`t you think it`s an irony that we are talking big blocks and you have just posted 454. Thanks for your reply Bruce but i want to dream, just sometimes. IT still does not explane the ford bb econ. compared to the 351`s .
Paul

[bigblock73]

If you go radical with whichever engine you decide consider this...

A 500 hp BBC will get about the same MPG as a 500 hp SBC...simply because that is alot of power to push thru a small block and not a really big deal for a big block. Either way, you are looking at 10MPG or so...tops.

Fuel injection will help each engine out a little, as will an OD transmission.

If you go "wild", BBC is the way to go...besides, 97% of 73-87 I see have small blocks in them...be different.

[87 STEPPER]

Wow i didn't even notice that.

That's pretty cool but now it will be 455 after this post.

[bigblock73]

Originally posted by 87 STEPPER
Wow i didn't even notice that.

That's pretty cool but now it will be 456 after this post.

actually, 455....you are a BOP guy now!

[Cole's 87]

Far as BBC & gas mileage you can get reasonable not great. My 77LWB BBC would get 13-15MPG very small rv cam and 600 Edelbrock of course I had a 3.08 gear

Now I have 390hp BBC in my 87SWB (9MPG) same tire height, 3.08 gear so HP does use fuel no matter how you look at it and at 9mph it sits in the driveway more than I like.

[87 STEPPER]

Damn you jeff i was hopping no one would see that!

BTW what's BOP? What ever it is im shure im one.

When i ordered my '87 i tried to get a BBC but they wouldnt do it i told the sales man i'll pay what ever it takes and he said there's no way it's going to happen

[Cole's 87]

Buick
Olds
Pontiac


Do what I did transplant you a BBC. Just get ready to buy alot of new back tires.

[bigblock73]

Cole is right, BOP means Buick Olds Pontiac...you had post 455.

[aussichev]

I was thihking of running what ever engine i decide on, on liquide petrolium gas. their is a small power drop, if it`s duel fuel but there is a bigger drop on running costs and the engine will last as long as a good diesle because there is no oil contamination. The price is 42c lpg a liter , crappy fuel is 97cents a liter , you use 20% more gas for the same amount of petrol. Do you U.S. guys use lpg??
Paul

[stepside454]

The Ford 400 isnt a big block anyway. it falls in family of Modifies, in the Cleveland family. Although many people seem to think Clevelands are big blocks...there not...same bore spacing as a windsor.

[gchemist]

Take the BB add the OD tranny and a gear vendors OD unit and you'll get better gas milage than a SB and still smoke the tires!!

[Kybol]

Yup my SS is not the greatest on gas, and it is pretty much stock.

[cgrossl]

Its hard to get a big block to get fuel mileage equal to that of a small block mainly because of the higher frictional losses that are present in a big block. It takes more power just to turn a big block over than a small block. This means that more of the energy that is produced during combustion is used up to turn the engine over, leaving less energy to produce power at the flywheel. Basically, big blocks are less efficient than small blocks, but they are capable of producing more power because of their larger displacement and better port configuration.

[aussichev]

Thankyou one and all , you have given me some thing to think about. B blocks nevcer came to oz that is untill the 454 was put into a Manaro coupe you will probably get it as the Pontiac GTO.