That's a nice block, especially seeing the 4 bolt mains on there. Looks like it would be a nice foundation for a built engine.

 

The LS engines put in cars are aluminum. They hold up just fine in a street environment.

I believe Speedmaster has an aluminum 351w block cheaper than that, if you're up for swapping to the larger engine.
https://www.jegs.com/i/Speedmaster/746/PCE286.1049/10002/-1#

 

The info button says it weights 176lbs, that's got to be shipping weight? What's the bare block weight?
The 351W from speedway is 113 lbs.
Searching I'm finding that a bare iron block is 135-150?

 

The info button says it weights 176lbs, that's got to be shipping weight? What's the bare block weight?
The 351W from speedway is 113 lbs.
Searching I'm finding that a bare iron block is 135-150?

That might be shipping weight?
copied this:
Block Weight: 8.200” 100lbs w/ caps and sleeves

 

Oh. I did not see that. I thought aluminum blocks were usually about 50lbs lighter than iron. Must be a very beefy block. Well then.

I bet it'd be perfect for a D3 headed (or similar) 370. That's too much for me.

 

The rule of thumb is 100lbs of weight reduction is equal to freeing up 10hp. Even at a 50lb difference, I'm sure you could find a lot cheaper ways to free up 5hp than spending $5600 on an engine block.

 

My car is at 2740lbs. So getting down there. I'd like to see it at 2600.

You're also missing that if you reduce weight you have better braking, better handling and less stress on driveline parts.

Perhaps you are correct. But it's not much more than a Dart SHP, in the grand scheme, and I doubt I am ever going to build a stock block engine again.

But I am actually here to be talked out of it so keep the facts coming.

 

Will make less power than an aftermarket cast iron block. Worth the trade off though for a race car.

 

Will make less power than an aftermarket cast iron block.

Why is that?

 

Here is a post with an example of a Speedmaster aluminum block. You get what you pay for, I’d stay away. So I got a speedmaster (pro comp) 351 aluminium block

 

Here is a post with an example of a Speedmaster aluminum block. You get what you pay for, I’d stay away. So I got a speedmaster (pro comp) 351 aluminium block

No way I would buy that block.... I've had good luck with a lot of Chinese stuff over the years, but no way I'm bolting $12k+ of parts onto that block.

 

And here is what a quality block should look like. Now for the Bill Mitchell 9.5 Aluminum Block

 

Yeah. Going to have to pass on the Speedmaster. I'd buy, like brackets, and non-consiquesntial parts from them. Not heads, blocks, intakes or anything with moving parts or electronics.

I feel better about the BMP block after seeing it's actually 100lbs. Who doesn't want a $6000 part that your average meth zombie can just carry away?? What's the aluminum-to-Sudafed exchange rate these days anyway?

 

Drool!

 

Sorry, but I am just going to say it... I think losing 50lbs off the front of your car is now an imperative.

 

400hp to the wheels. But anyway... I do have adjustable suspension. I've seen these cars corner weighted many times. It's always about what you'd expect. I've seen people have really amazing results with the engine and driver moved back, battery in the trunk.

You're definitely not wrong though.

Considering lighter wheels. I really love my 16x8 steelies. But reality is I will probably end up with alloys at some point. I've been looking for 16x8 alloy wheels with 4.5 BS and weighing what I think will look good on the car. I was considering the black American Racing Outlaw IIs. It's a classic look. And I like the tire profile with the 16s as compared to 17s. They are still 20lbs. So half of what the steelies are, but by no means a super lightweight wheel.

 

I would have a 302 right now if it weren't for the fact that my 3.7L long block weighs in at 270lbs. It is offset by the fact the trans weighs 50lbs more than a T5 but that is acceptable when the goal is a perfect 50/50 weight balance and stock(v8)-weight car when all chassis stiffening and other weight-gain mods are done. Of course, the cost I paid(aside from the mods needed to fit the engine/trans) is that I lost about 8ft/lbs over a 289/302(though I gained 30HP over a HiPo) and powerband is moved up by about 2000RPM. In the end though...it was still cheaper than an aluminum block and had a larger affect on balance...at least if you look at it strictly from a materials cost. I can't count the number of one-off pieces I have made to make it all work anymore. To me its worth it though because the engine suits the goal of the build more than a SBF

 

I was looking at Ford aftermarket aluminum 351w blocks, but in the end I chose a Dart 4.125” 351w block because I knew it would take just about any power level I could throw at it and most likely be more durable, and I came to the realization that mine is a street car and I would never be setting lap records on the high banks at Daytona.

 

I also run a Dart 4.125" Block. You could buy a big bore dart block with a set of AFR heads for around the cost of that aluminum block lol. Speaking of heads - I run the AFR 220s on my 427W.... I had a 408 years ago with AFR 205s and its amazing how much harder this engine pulls through the top end than my 408 did.

 

I have TrickFlow 170s. They would need to be ported.

 

The heiress's 2016 Flex has a 3.5 with an aluminum block at 275HP. My 2021 F150 has an aluminum block 5.0 coyote making 410hp. And they have a sprayed in or something cylinder wall coating, they both do very well I'm not seeing the down side of an aluminum block? Besides, I just want one!

 

This forum has taught me that practicality isn't the sole motivator. At the same time, it's also a place where we spend other people's money 99% of the time, so y'all should be stoked on this.

I want to build my car my way. And it may seem weird to people but to me it's art. Art is often weird. My vehicular projects are how I express myself creatively, and I think I have a pretty consistent style and sense to my art. If only I had more knowledge and skills.

 

The main downside is cost. A 9.2 or 9.5 deck aluminum block will save 80 to 100 lbs. if you have a solid cam, the cold lash will have to be much tighter. 100 lbs off the nose will make a difference in handling, but you have to decide bang for the buck. To me a downside is that foe aftermarket big bore blocks, you can get a 4.185 to 4.200 bore in iron, and maybe a 4.155 in aluminum.

 

I thought 100 lbs sounded too much but when looking up the specs of Darts various blocks, the weight savings are indeed between 80 and 100 lbs. That is however when comparing the Dart aluminum blocks with their heavy duty iron blocks. Stock Ford blocks are considerably lighter. For example, the Dart 302 based block weights 160 pounds, whereas a stock 289 block weights ~130 IIRC. 5.0 roller blocks are a little lighter.

 

Tom, you are mistaken. The centrifugal spun ductile iron sleeves in the aftermarket aluminum blocks are plenty stiff. And the factory blocks are sometimes now actually an aluminum bore, but sprayed with something like the NiKaSil stuff that the motorcycles have used for a long time. Their big engines have higher output per litre than the Coyotes. The idea that aluminum blocks might make less power is nonsense. You're remembering the Vega blocks from DECADES ago. LSG

 

Tom, you are mistaken. The centrifugal spun ductile iron sleeves in the aftermarket aluminum blocks are plenty stiff. And the factory blocks are sometimes now actually an aluminum bore, but sprayed with something like the NiKaSil stuff that the motorcycles have used for a long time. The big engines have higher output per litre than the Coyotes. The idea that aluminum blocks might make less power is nonsense. You're remembering the Vega blocks from DECADES ago. LSG

Owning 2 vehicles with aluminum bocks and the sprayed on cylinder wall "coating", wonder how the aftermarket will address that down the road now that the average vehicle life is near 12.5 years and sure to grow given the resistance to EV's.

 

There are solutions to reapply the coating too. But it's more involving and expensive than reboring and honing an iron block, that's for sure.

 

I don't know what your replacing but aluminum heads and intake are way lighter. A hollow front sway bar will drop weight. Competition Sway Bar 1965-66 Hollow 1-1/4''

 

At the power level you want id look at other weight changes. As others have mentioned lighter wheels and suspension, heads etc. Other options are loosing all the heavy metal in the front and go fiberglass hood. shelby apron, even fenders and headlight buckets etc. Also moving battery and radiator to the back does a lot for weight distribution. You can literally move everything minus the headlights of the nose of the car.

One thing that has recently caught my eye is the thin wave rotor brake systems, they claim average 20-25 lb reduction per wheel, and the rotors are far more durable vs conventional rotors. I used the wave rotors years ago when they first came out for sportbike applications. I had no idea they worked well in a race car appliction

 

There are virtually no downsides to an aluminum block, except the cost.

 

That is a rather large downside to be honest. $5000+ for 75lbs is a pretty big ask. I would love to grab an aluminum block for a SBF build, but the only way it will ever happen is if I find a used one with worn-out liners or something. I think the lack of a production Ford aluminum block is why most people go with an LS-series engine....at least as far as pushrod engines are concerned.

 

$8300.00 not bad

 

At this point, I think you're fool if you drop the coin on an aftermarket block and went with cast iron. Spend $3000 on a block that weighs MORE than stock? LOL.

 

Well...as foolish as it may seem, there are dozens of vintage racing clubs including the VMC that do still require cast iron blocks and heads.

 

I'm just josh'n ya, Patrick. There's a myriad of reasons to get something like a Dart SHP. Just like there's a similar number of reasons to build a 289 or 302 rather than a stroker. I get all that.

For me though, it's OEM (because it's cheap) or Aluminum (because it's strong and light). I am not tied down by any class rules. Makes my life a lot easier. Decisions become a strict cost/perceived benefit decision, rather than having a third party in the mix pulling some strings. If I was building an engine, it would be my last (that's what we all say!). I would have the mentality of "do it right the first time (that's what we all say!)."

And for me, spending the extra money-- given the money already spent (got some Morel high rev lifters for future use), the effort of doing an engine build/swap-- to drop the weight, is worth it. I'm a weight reduction junky too. Everyone has their thing. I do not respect these modern 5000lb slugs people call "sports/muscle cars" (that dudes trade in their Altima to take out a 30% $1000 a month hit on their Taco Bell Salary for!). And it reverberates through all my car projects.

Same reason one might pay $3000 for headers when JBA makes 1-3/4 stainless headers that fit pretty pretty pretty OK with a Z-bar or Automatic for $500.

I've just sold myself on aluminum. That's how this works, we're perpetually selling ourselves on something!