I was reading the article in the new Chevy Hi-Po about big inch small blocks and I was wondering if anyone on here had built one. I was really intrigued by the article and would love to build one of those engines in the next few years, but I wanted to see if anyone had any experience with them and if they had problems finding parts and such.


*edit: for anyone who hasnt read the article, I'm talking about 440 range and up small blocks. I know in the article it says a number of places for cranks and stuff, but I searched around on the internet today and couldn't find any of the really big stuff thats in the article, like 4.250 stroke cranks for 4.250" pistons, so I'm assuming it would all have to be custom. thoughts/ideas?

 

You also need a custom block. Nothing like that will work in a production block.

By the time you're done building a big inch small block, I could build a BBC for a lot less money.

 

yea motown used there tall deck block for that motor...

there building a 4.25 bore 4 inch stroke small block...

4.25 bore
4" stroke...=454 cubes of bad@ss small block
also =very pricey

 

I read the article that you were refering too in CHP & it does not go much into specifics. I bought a book a few years ago & I believe it was called how to build big inch or long stroked small block chevy's or something like that, "I have it at work & when I go back in a couple of weeks I can get the true title of it for you if you'd like. It was comprised from past engine build up's from Hot Rod or Popular Hotrodding ? Magazine & went into quite a bit of detall on parts used, manufacturers & dyno results. It covered build-up"s of all sizes, pretty much everything 350.377.383.400.406.427 & 454 smallblocks.
BTW, you do not need a 4.250" stroke crank, as f-crazy posted a 4.00" stroke will make a 454 & I don't know if they make a 4.250" smallblock crank or not . It takes some block clearencing for a 4.00" crank to swing. even on an aftermarket block & as Stephen 87 IROC stated a production block isn't a option for that many CI's in a smallblock

Bruce (70GTO)

 

Out of curiosity what is the biggest you can get a production 400 block? You can use the 3.85 crank cant you?

Ben

 

In the book that I mentioned above, they built a 427 & used a production block by boring it to 4.125" & using a 4" stroke crank, but IMO the cylinder walls get pretty thin & they had to do a ton of grinding for everything to clear, plus a bunch of machine work. If I remember correctly they also had made a 454 using a factry block, however it wasn't just a run of the mill block. It was a particular casting # and they are not very plentyful.

 

Yeah I checked out World Products and their Little M block would work, not sure about cam clearance on that one though. not too worried about it right now, its still just a crazy idea.

Stephen, yeah I know you could build a big-block cheaper, but as soon as you pop your hood the cats out of the bag, everyone knows what you've got. With a big-inch small block, no ones the wiser, the only thing that might give it away would be the incredibly large for a small block headers. Some poor fool is going to want to race thinking you just have a 350 or maybe a 400, when in fact you're running a 454 or maybe even the 482.

70gto, if you could get that title, I'd appreciate it. I'd like to get as much info as I can now before I even get close to being ready to build such a monster.

I checked out Eagle cranks yesterday in Jegs and they listed a 4.00" stroke crank, but not a 4.25", so thats why I assumed anything larger than the 4" would probably be a custom grind.

Can anyone suggest pistons or a place that has 4.25" ones?

 

i said a 4 inch stroke and a 4.25 bore


there building a 4.25 bore 4 inch stroke small block...

4.25 bore
4" stroke...=454 cubes of bad@ss small block
also =very pricey

 

I read the article and it would be sweet. Too bad it would cost too much. If I had the money I'd do it though.

 

Hey f-crazy, I was agreeing with you man, not disputing you

 

Even www.jepistons.com who carry a huge assortment of race pistons, don't have anything for that combination of parts.

 

Well, according to that arcticle felpro just started making the head gasket for the 4.25" bore so there probably arent many people out there who have the pistons and such for them.

 

my bad gto i read it wrong....

yea i doubt there are many companies who make the pistons..but as this catches on im sure there will more compainies makeing them,...but this is a serious motor and expect to pay serious prices

 

TexasLT1- I'll be sure to get the tilte of the book to you, however I'm on vacation & won"t be going back to work until the 20th "unless by chance I stop in before then", but never theless I'll get it to you.
As far as a 4.250 crank, I'll be going to my engine builders shop in the next couple of days & I'll see if he's ever heard of a smallblock crank larger than 4".

Bruce

 

Stephen - yeah I assumed that it would probably take some custom parts. but by the time I'm ready to build one I'm sure the parts would be out. and if not, oh well, its a cool thought. besides, if all else fails, parts are already available to build a 443.

70GTO - thanks man, I'm not in any hurry for the title so whenever you get a chance is cool. besides, if I got it now I would only get distracted from all my school crap so its cool.


Another thought, the article states that the engine that World Products built, a 443, used their Motown 220 cc heads. Now, 220 cc heads are the largest I've seen for a small block. And I would think those would be fairly close to being maxed out on a 443, what kind of heads would you have to use if one were to build a 482 SBC?

 

ok, just forget my last statement, I stand corrected on my own research.... Dart Iron Eagle 230cc, 296 cfm at .600"

 

How much money do you have?

www.brodix.com has SBC heads that can flow over 400 cfm to feed those exotic large SBC engines.
www.canfieldheads.com has a couple but they're not so extreme.

 

I'll just say that when the time comes I won't be too worried about how much it costs. I would like to keep it reasonable and not spend extreme amounts on it, but its not going to be on a tight budget either. I'm going to the Air Force Academy next year and we get a substantial signing bonus our Junior year when we contract, I plan on investing about half of it and putting the other half towards my car. If I do decide to build this engine then I plan on doing it right and not cutting any corners, if that means spending a little bit more then thats fine.

Thanks for those addresses Stephen, I'll check them out in a little while and see what they've got.

 

If you plan to use a giant inch small block like that, good for you. I hope you only plan to street race it for maybe a year or so and make as much money as you can and then sell it

With a inch monster like that you need a head that flows over 300cfm and 400cfm would be better

Minimum would be 18* heads but some brodix 15* would be better.

 

Why do you say that? I realize the more I check into it that its definitely not going to be a daily driver, unless I plan on spending the amount the engine is worth on gas. But why only for a year? durability? reliability?

 

400 cfm heads should produce about 825 hp. I don't have any flow numbers but the heads on my BBC were rated at having 269cc intake runners. They've been ported so they have a bit more now but flow nowhere near 400 cfm.

 

Definitely seems to me that the heads would become the limiting factor on a big cube small block. BB heads are just huge compared to SB heads, can you really get enough flow out of them? Sorry for my kinda newbieish question, just trying to learn what I can. What about those 16 valve heads (don't remember who makes them), I heard those had off the chart flow numbers. Oh yeah, small blocks with big cubes are cool!

 

As stated earlier in the topic, there are heads that flow plenty for those motors, but you are going to have to spend a chunk of money to get them.

Ben

 

Toyota Guy - nevermind

Stephen - The article says that World Products just used a set of their 220cc Motown Heads, didn't say anything about porting or anything, and that engine produced 607 hp. So basically for a street/strip engine any of the exotic heads would be pure overkill? I didn't even want to look at the prices of SBC heads that flow in the 400 range. But if the Motowns only flow in the 300 range, why would you need something that much larger?

 

TexasLT1

OK, I've got the information for you

The book is; "How to build Big Inch Chevy Small Blocks". It is Volume 9 of the "Hot Rod Technical Library" "The Best of Hot Rod Magazine"

The book is published by,
Cartec
11605 Kost Dam Road
North Branch, MN 55056
Phone 651-583-3471/800-551-4754
(Sorry, no mention of a web site)

There is quite a bit of good research & reading in this book. Hope this helps.


If you can't find a copy of it, get with me & I'll send you mine

Thae Care, Bruce (70GTO)

 

the only heads that outflow those heads are either the canted small block chevy heads and/or SB2 heads

both need insane compression to run well too

 

my bad, I didn't look up any numbers before I opened my mouth.

70GTO, thanks for the book info. I'll check into it and see if I can find it.

 

There are parts available right now to build a 461 CI small block:

Use a Dart Iron Eagle block
Lunati assembly part #EA68
4.155 bore & 4.25 stroke crank=461 CI
Or use a 4.185 bore and 4.125 crank for 454 CI

http://www.dartheads.com/bliron.htm

http://www.holley.com/HiOctn/ProdLin...SBProRace.html

Part #: EA68
Pro Series crankshaft with all pin holes drilled, 4.125" - 4.250" stroke. Minimum 6.000" Lunati billet connecting rods, Lunati flat top or dome pistons, bearings and rings.

Figure about 2g for the block, 3500 for the rotating assembly, etc

With the stock 400 block, I have a 434 CI-4.155 bore & 4" crank

Good luck

 

bbunting, thanks alot for the info. I'll check into it later on and get some definite prices. And try and figure out a fuel system for the beast. I would like to keep it fuel injected but not too sure how well that would work. Like I've said before, right now this is just a crazy idea I'm checking into to see if I could pull it off in a couple of years. How streetable is the 434 you run? Or was it even meant to be streetable? That is my main concern is streetability. While the car would absolutely see track time, I plan on building more for street use. Therefore I would want to build something that wouldn't need to be torn down ever so often and rebuilt.

Thanks,
Tristan

 

The 434 is a high compression NOS motor built for drag racing. To see how it runs, click on the brothers car link in my sig. As far as streetability goes, that is all in the cam/compression you choose.

 

Well, I've got a serious jones for a 421 now. I've geen doing some looking, and It seems like you can get shortblocks in the $3K-$4K range and assembled longblocks for $5K-$6K. I want Fuel Injection, too.

I think a '421 SD' Trans Am would be a baddass machine, don't you ?

I've also been toying around a long-rod 389 with a 'Tr-Power' EFI setup breathing through three TPI/LT1 throttle bodies.

Maybe I'm just nuts.

 

wow, sounds pretty badass. good luck if you do any of them.


I just saw the video of your brothers car. WOW!

 

Probably. Has anyone done this with multiple throttle bodies like you say? What kind of comptuter would you have to run?

Ben

 

I beleive Monty is running a Small block 427 pushing nearly 1300 Horsepower and it all fits under a stock hood.

taking a big-small block and cramming it full of intercooled boost is a good way to make tons of power, and still get decent fuel economy it seems.

 

large engines can be built up from converted diesel blocks.
'68-72 blocks had the thickest main webs

source: Hotrod ENGINES winter 2002

And the olds rocket block can work
in those 'large engine' build ups