SeeThrees

Looking to build a mild street aluminum big block and don't need to go

bigger than a 427 unless its really cost effective.

Most likely it will have EFI.

I appreciate insights from those who have gone this route.

Thanks,

Rick

StickShiftCorvette

I can't help you but have thought about this route if my very hot small block wears out or blows up.

I would want to make mine a hot enough to put about 400 rwhp to the ground. My small block puts down 320 while my '04 Viper has 414 on the pavement. By my test process a '69 350 300 HP has 165 HP.

I am interested in other's response to your question.

Gordonm

Build an aluminum headed 427 SB. It will weigh about the same and cost a lot less. You can easily get 500+ HP out of one. I would not waste the time or money on a mild 427 BB motor, aluminum or cast iron. The cost of a good aluminum BB just the block will set you back 3 to 4K.

My small 385 SB puts down 409 RWHP. Nothing to radical either.

norvalwilhelm

My canadian price for an aluminum bigblock block is about $6000. Add $3000-$4000 for heads, $3000 rotating assembly, $1500 for cam lifters and springs, $700 carb and $300 intake.
Gaskets $200 or so plus an oil pan, timing gears, valve covers, aluminum pump and you just about have it.
Your small block distributor and motor mounts will bolt right up.
While you are at it you may as well build a 540 since it costs the same

SeeThrees

I know what you're saying however...

I already have been the 427 small block route and want to do something

different.

Rich

GDaina

Buy the components, have a competent machine shop do the machine work, assembly, you can get the intake, cam, heads, carbs to fit your application, and save a few dollars in the process

427Hotrod

Norval's got it...I can see no reason to build anything smaller than a 540 if you're going to all the trouble to buy a high $$ block. 565's will scream to the moon and turn all the RPM you might want.

All the guts and heads are the same between big blocks on price really...except 427 might actually be higher because no one does them anymore. The only difference will be the price of the block.

Shafiroff sells aluminum crate deals...might give them a shout.


Alot depends on the valvetrain you want and what you really intend to do with it. If you're going EFI I assume you're not going after max HP...so will this be a hyd roller motor? If so.....you're spending a whole lot of money and not getting much back performance wise. For an EFI, hyd roller motor deal I'd build the biggest ***** I could figure out and would fit under the hood!

JIM

SeeThrees

You're right, it will be a hydraulic roller motor.

The car may do a little 1/4 mile or road course racing..haven't decided

which one yet.

While I'm looking at different head/block combos I can also look for a

'distress sale' motor someone has to get from under that has done by a

top notch builder.

427Hotrod

Hyd roller will limit you to the 6500 rpm range at best. There are folks out there climing more, but they use special lifters, shim them just like solids etc. Big block valvetrains are heavy...so you'll need to do all you can to lighten it if you want to rev it. 427's need to rev to make best power....shoot...ANYTHING needs to rev to make best power...but if you limit it to 6500 or less...that's why I'd think about a 540-555-565 etc deal. LOTS more power at lower RPM's. You'll never hurt one of them. Now road racing with all that extra power might require good footwork....but it will be fun.

There was an iron block and heads 540 for sale here on the Forum a few weeks ago. It looked like nice parts and was in the 700Hp range I think. You can always sell the heads and get aluminum ones. Check the for sale sections.

Right now I have one of the smallest motors in *my group*. They have all moved out to 548's, 598's and 638's. I'm going to have to nothc up my game!!


JIM

CorvetteDave01

I thought about going aluminum efi big block...until I saw the price of the blocks. I would have loved to have had another 4-6k for an aluminum big block with efi, but maybe some day. I did go with a 427 efi small block that I am still figuring out how to tune though. I wish I had gone for a bigger cube sb, like a tall deck setup, think you can go up to a 472 with a tall deck Dart block.

Other than for the nostalgia of a bigblock 427, I too wonder why you wouldn't go with more cubes with a big block. You can do pretty much the same thing with a sb 427 than you can with a bigblock 427, at least with a street setup, and your looking at 5-6k more going with the aluminum bigblock.

69427

Build the big block. The torque and corner exit throttle response in those things is outstanding. I'm currently accumulating parts to build an aluminum 427 for my '69. I've had very good luck with the current AH/iron block combo I've been running for several years, and am planning on putting similar parts in this block. I'm sticking with a 427 as I like the shorter stroke, and I spend my time doing road course stuff, rather than short quarter mile stuff. The current engine is not terribly radical or street-unfriendly, but has plenty of grunt to keep up with the great majority of the faster cars down the straights on the course. My objective with this new engine is to keep up with the newer cars through the corners too. The domestic prices for the parts I'm using (Chevrolet sourced) are quite a bit less expensive than what Norval has had to deal with (international shipping/exchange rates, etc). I have no complaints about the current engine, other than the weight of the block. That complaint should be history by next spring.

ZL1powr

I would agree with Jim, Norval and CorvetteDave01...No need to build anything smaller than a 540.

I paid $4958 for my aluminum Brodix block. The Dart block was priced similarly.

I thought I would save some $ doing my own engine. Truth be known I could have bought a similar crate motor from Shafiroff for less $. The only difference would have been the head and intake porting, the cam and the satisfaction I got doing it myself.

VetteThunder1

This isn't EFI but its a good deal and comes with a 2 year warranty, its broken in and dyno'd

All aluminum 572

This beast puts out about 700HP and is the one I bought. They are also on sale too. Will run you about $16K + shipping. Prices have gone up a bit in the last year.

427Hotrod

I'm glad you had good luck with Mitchell. They build excellent parts...I have a Merlin block currently and some Merlin heads in the past. But there are tons of horror stories out there about build quality and lack of Customer Service. I mean BAD!

I recently heard of a Shafiroff 582" motor that had a rocker/pushrod failure. As bad as it sounds, the guy pulled the motor and took it back to Shafiroff (several hours). The good news is Scott got personally involved, they tore motor down while he waited and went through it to make sure all was good and assembled it all for him while he was there. At least they stood behind their product.

You might ought to study that BM warranty. It's got a few loopholes.


JIM

73, Dark Blue 454

"No need to build anything smaller than 540 cid?" You're kidding,..right?

After about 500 HP, most everything in the drivetrain between the harmonic to the rear lugs have to be upgraded. Building the HP is the easy part. Building a Vette that can take it is much more difficult.

KyleDallas

I think an Aluminum Block would be cool if you're committed that way...

I did notice the road racing mention so I thought I'd post my
engine weight link:

http://www.35pickup.com/mulligan/weight.txt

There's about 100lbs seperating the BBC and SBC..

I think with some work you could get a BBC into Iron SBC weight
without using an aluminum block...

1. Aluminum Heads
2. Aluminum Waterpump
3. Aluminum Manifold
4. Liteweight Starter
5. Liteweight Pulleys, Electric Plastic Fan, Liteweight Battery

I saved 15lbs on a battery swap... I found the original CCA's for
My old Dart's Heavy Group 24 Battery was only 350 CCA's...
So I installed a Honda type battery that was 15 lbs lighter and had 525 CCA's..

There are also several Sprint Car machinist who do Block Lightening
to both Small and BB Chevy's.... Block Lightening and the mods
above would put you under Iron Small Block weight.

Just thought I would post the Motor weights and suggestions in case
the weight issue was the critical factor vs. the Aluminum Block cool factor.

Good Luck regardless of which way you go.

427Hotrod

No, I'm not kidding at all. It doesn't cost much more to build serious power. Why not do it while you're at it?

Then you just start working down through the drivetrain. Or you can do it the other way around. Actually, Vette stuff holds up fairly well unless you put serious sticky tires on it and work it hard.

My car usually gets one new big thing each year. My engine combo has been pretty static for years now....just now getting it all to hook up and really use all the power at the dragstrip. But through all that other time..I still got to have LOTS of fun with it on street tires and from 40-50 mph rolling startss!!


JIM

roscobbc

I would have thought that a 'small block' 427 would always loose out ultimately against a big block 427 (or larger capacity) in the valve area. You will be limited by the bore diameter and spacing re. the use of bigger valves and inlet tracts.

bashcraft

Don't waste your time and money on a small block.

SeeThrees

As I mentioned I had one before, a 427 iron block with aluminum heads with a lot of stroke obviously.