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Login to post Forums » Grassroots Motorsports » Help me think of some large-cube, light-weight engines

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March 29, 2011 6:57 p.m. curtis73 Dork
I'm looking for an engine to build to around 650hp for a project.

Must be:
- streetable (which means large displacement or more advanced head design)
- on the lighter side of things. The current engine in it weighs about 675 lbs (iron V8) so anything lighter than that.
- not too exotic (meaning: affordable for the little guy)
- strong preference for naturally aspirated for packaging reasons.
My current list includes:
- LS1 and variants (not large displacement, but they're very light and have the head design to make it streetable)
- Caddy 500 (about the same weight as a SBC)
- Viper V10 (big cubes AND light weight, but I need to win the lottery first)
- new style Hemi 6.1L is vaguely on my radar, but the aftermarket sucks and the engines really aren't that special.
This is for an American muscle car, but nothing is out of bounds.
March 29, 2011 7:01 p.m. Javelin SuperDork

What about the older big blocks and whatnot that Edlebrock now makes modern alloy heads for? 455 Buick, 455 Olds, 455 Pontiac, and 460 Ford all come to mind. The Ford is probably your best bet.

How similar are the Dodge V10 truck motors and the Viper ones? Could you bolt a set of Viper heads to the (assuming) iron truck block?
March 29, 2011 7:12 p.m. curtis73 Dork

Javelin wrote:

What about the older big blocks and whatnot that Edlebrock now makes modern alloy heads for? 455 Buick, 455 Olds, 455 Pontiac, and 460 Ford all come to mind. The Ford is probably your best bet.

Good thoughts. These are all within a few pounds of what is currently in there. I haven't written them off, but dollar for dollar, you can usually get the same numbers out of lighter engines.

The 460 is one of my favorites, but the cam priority oiling can be an issue above about 500 hp.

How similar are the Dodge V10 truck motors and the Viper ones? Could you bolt a set of Viper heads to the (assuming) iron truck block?

You and I think alike From what I understand, the iron truck shortblock is basically the same as the Gen 1 Viper, but the pistons are different for lower compression. I'm currently researching how much more the iron block weighs and what can be done about performance parts that don't have the word "Hennessey" on them.

I'm also looking at costs to purchase parts individually and assemble vs. just sucking it up and buying a Viper V10
March 29, 2011 7:16 p.m. Ranger50 HalfDork

440/572 with the Indy Hemi head conversion?

460/557 with some Kaase '9 conversion heads?

650hp is kind of low for very streetable big block. You are pushing the limits if you want to stay small block, but still doable.

There is no aftermarket for the 5.7/6.1 hemi as the damn things don't need much help. Once you can cam the dang thing right, you just keep reusing stock parts.

No way in heck would I run a V10, just too dang long, plus the exhaust sound just isn't right, IE- it sounds like a wet fart.

Just one question, autotragic or MANual?
March 29, 2011 7:21 p.m. curtis73 Dork

Ranger50 wrote:

Just one question, autotragic or MANual?

Beefed up T56. Should be good to about 650 lb-ft but I think I'll be breaking things.
March 29, 2011 7:23 p.m. curtis73 Dork

Ranger50 wrote:

650hp is kind of low for very streetable big block. You are pushing the limits if you want to stay small block, but still doable.

I agree. My dream target is closer to 750, but saying 650 is more realistic. I'm also (don't laugh) thinking about fuel consumption since I KNOW I'll be driving this thing on the street every day.

I know I can get there easily with an LS and still turn in 20 mpg, but LS swaps are becoming the new SBC swap. I may end up with one though... there is a reason why they are a common swap.
March 29, 2011 7:42 p.m. Ranger50 HalfDork

curtis73 wrote:

I agree. My dream target is closer to 750, but saying 650 is more realistic. I'm also (don't laugh) thinking about fuel consumption since I KNOW I'll be driving this thing on the street every day.

I know I can get there easily with an LS and still turn in 20 mpg, but LS swaps are becoming the new SBC swap. I may end up with one though... there is a reason why they are a common swap.

With gas at the pump starting to get REALLY close to $4/gal, MPG's aren't nothing to not worry about. The double OD will help, but unless you want to "expensively" put EFI on a BB, you are still looking at 14-15mpg TOPS, IMO. I know of several GM twins running monster cams, 23x or 24x@.050 dur and .600"+ left, and still getting low-mid 20's. But even with the ready availability of LSx parts, they are a very pricey build if you want specific things.
March 29, 2011 9:20 p.m. AquaHusky Reader

GM P/N 88961499

If you can find one.
March 29, 2011 9:31 p.m. Will HalfDork

Ford FE 427 w/ Ford Racing aluminum block.

351W stroked to 427.
March 29, 2011 9:54 p.m. TR8owner Reader

Large cube/light weight is a bit of an oxymoron.

I love the 3.5 Buick/Olds/Rover V8 because its all aluminium and around 300 lbs, half the weight of typical 5.0 iron V8 and much less than the big blocks. Rover eventually extended them 4.2/4.6.

You won't get the same power than you will out of a big block, but you did mention weight didn't you?
March 29, 2011 9:59 p.m. KATYB New Reader

3.5 twin turbo ford v6. hey you said lightweight and powerful. its all there for you.
March 29, 2011 10:06 p.m. patgizz SuperDork

KATYB wrote:

3.5 twin turbo ford v6. hey you said lightweight and powerful. its all there for you.

no, he said 650 hp

which puts the ecoboost in the wimpy category.

i vote big caddy or 6.2 ls based.
March 29, 2011 10:16 p.m. Maroon92 SuperDork

I vote for the 460. Cam and heads away from 450 horse. I've done it!

For light weight, the LS family is hard to beat. The LS7 is a 427ci small block. Best of both worlds.
March 29, 2011 10:34 p.m. curtis73 Dork

Ok, so a possibility ended up falling in my lap today.

The long story is there is a guy about 3 hours away who is an old machinist who worked out of his garage. He's retired and selling all of his stuff. So MY machinist was buying it all up and mentioned that this guy has a 73 Cad 500 sitting in the corner. It was built for a guy's truck in 1995, 30-over, mild cam, port polish (but not fully ported). The customer got a divorce, never paid, yadda yadda.

The price he's asking is ridiculously cheap for what it is, but with Caddys you don't have much option... you either stretch the limits of stock components (cast pistons, weak rods, modest heads) or dive into the expensive side by turning the crank for BBC rods, custom pistons, and very expensive aftermarket heads.

Then there is the fact that its a flat cam and rollers for Caddys are berkeleying expensive.

Oh, dilemmas.
March 29, 2011 10:38 p.m. KATYB New Reader

ecoboost will do 650 im sure of it. wouldnt be surprised to see 650 whp. heck people have been making 450 whp off of the old 3.0 with a stock bottom end. thats at 10.1 compression so boost limited to around 14 to 16 psi with pump gas.
March 30, 2011 7:05 a.m. tuna55 Dork

The aftermarket, if Hot Rod and Car Craft are any indication, for Caddy 500s is improving daily. Get the valvetrain in order, spin it all of the way "up" to 5500 or so, use cheapo chevy parts machined for the caddy crank (and offset grind it while you're there), and a modern piston package (with a modern piston ring package - just bore the caddy to what you need and order the pistons for whatever small end you end up using) and that will get you into the 600 ft lbs region. It won't get you 650 HP, but it will be cheap. Then get some turbos and run a tiny bit of boost.

I like the idea of cheaper weirdo engines too, remember that all of these engines used to be obscure at one point, even the SBC. The flathead guys never thought it would work. Think more Garlits and less Foose. Just because engine parts aren't available in a catalog doesn't mean you can't make it happen - it's just metal. There are a myriad of rods out there, same for pistons. Cranks and blocks are harder. Depending on how much time you want to spend, super stock guys are hogging out their heads and then backfilling them with brass to keep the runner volume the same, enough time and some sort of objective measurement system and you can make some pretty darn good heads too.
March 30, 2011 7:26 a.m. John Brown SuperDork

Single Holset on a 6.0L LQ4 with an aftermarket cam. There is a dyno video of one making @ 525hp and 575ft/lb RWHP in a Chevy Silverado with an automatic.

That'll do it.
March 30, 2011 7:40 a.m. RossD Dork

factory engine with factory boost = 624 hp SAE (with warranty?). Cost $6999 + $8099 = $15098
March 30, 2011 7:45 a.m. aussiesmg SuperDork

And out of left field...........

RB25DET with a bigger turbo.

http://www.youtube.com/watch?v=wNPZ7Sd4EiM
March 30, 2011 7:47 a.m. DoctorBlade HalfDork

There's the L92, which is an all aluminum truck engine. It's a 6.2l engine. I'm not sure if the Escalade's 7.0l is AL or not.
March 30, 2011 7:53 a.m. BoneYard_Racing Reader

The early viper engine used 5.9 magnum rods and pistons might be an easy way to hot up the truck V10

460 ford is the cheapest big block Ive found

Best of both worlds would be a 6.2 truck LS
March 30, 2011 7:53 a.m. aussiesmg SuperDork

Off the shelf if you have deep pockets

http://www.jegs.com/i/GM%20Performance/809/19211708/10002/-1?CT=999
March 30, 2011 8:04 a.m. pinchvalve SuperDork

Cummins Diesel?
March 30, 2011 8:09 a.m. tuna55 Dork

aussiesmg wrote:

Off the shelf if you have deep pockets

http://www.jegs.com/i/GM%20Performance/809/19211708/10002/-1?CT=999

Also a full 100 hp down from his target.
March 30, 2011 8:12 a.m. John Brown SuperDork

http://www.proformanceunlimited.com/specs/540_625.html

Done and done.

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