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448 ci SB Chebby


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Ok first of all is 448 ci possible from a smallblock¿

2nd hows this deal sound¿

 

I was sitting over at my friend Tim's and we was talking about the datsun as always. He was asking me how the fabrication was coming along. and i said i still needed to find a good sbc, it just so happened that his wifes brother suddenly decided he was a ford man and was getting rid of everything chevy and offered the motor and whatever else chevy he has laying around the shop to Tim for $900,

 

The information i was given is:

5140 Steel crank

comp cam .572/610 lift

12.4:1

Iron eagle rotating assembly: 6 in rods

Heads: 2.05 1.68 bowtie 64cc; 220cc angle plug Port & Polish

triple valve spring

full roller rocker; guide plated

line bored/ deck shaved blue printed

Electric waterpump

Carb is a holley worked over to 930

Every cylinder has been sleeved

Motor has never been ran

 

Any idea on what kinda power something like that can make reliably?

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Depending on the cubic inch, I'd say it'll be about 600HP at the crank. Those heads don't flow that great, but are well matched to the cam, compression is about right, sounds like a little too much money, I'd bet that some of the forum guys would probably only give you about $500 for a set up like that, tops.. I'd offer about $550 just to top them, and of course, I'm just doing that from the goodness of my larcenous soul. Ha-ha! If you or your buddy don't buy that, then go beat your heads against the wall for 30 minutes or so and see if you can clear the cobwebs out.

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i was going to but i think it will be allright. another thing i forgot. the crank has been knife edged and balanced. i was told there was 13 hours that went into ballancing it.

 

also i would imagine it to be a custom crank to get 448 ci out of a 400 sb

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If you were going to drag race it constantly or road race it, I'd say yeah, change the crank, but for a street driven monster hero like you'd have with that in your z, it'll probably be ok IMHO.

 

I think the performer has to go though, the cam, heads, and cubic inch size are all calling for something that flows a little more like a victor Jr series, or team g or some other open plenum race type manifold. I think some of the rest of the guys will chime in on that one either with me or with a better idea. Several of them have some really in depth thoughts on parts relativity to one another and to overall use, TQ and HP. Pretty interesting stuff, kind of gives you an overall description of the engine's use, but I can't recall exactly who posted that info. It kind of matches all the parts and the engine falls into categories, like street, street/strip, race, etc.

 

Somebody ought to compile an archive or book that holds the best of the best information. You'd be amazed what all these guys know and readily share or have shared in the past, I know I'm amazed and pleased.

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Yeah, I agree with dr hunt, the performer has to go. Like he says get a victor jr, team g, or I would try the new worldproducts motown manifold for the sbc, looks pretty good to me. Check it out at this link:

http://www.worldcastings.com

It does sound like a great deal to me, I would buy it if you guys don't, if I knew where it was that is............lol.

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well thanks for the info fellas.

as soon as i get the motor {probably a week or so} i'll take some pics of it and figure out all the specifics ie. cam duration bore stroke blah blah and maybe someone will feel up to doing a desktop dyno for me.

 

ill throw in some pics of the tires too. 325-50-15 et street radials mounted on 12" weld pro stars

Well that is if im able to figure out how to post them. dont seem to hard.

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"Ok first of all is 448 ci possible from a smallblock¿" 4.155 bore with a 4.125 stroke will give you a 447.45 so yea its possible and has been done before. With a stock block your going to have a lot of grinding. With that much stroke you are better off to go to a aftermarket block with raised cam and spread pan rails. But for 900 bucks, what can you say. You can always sell off the parts and make a buck or two. Once you run it the price drops like a rock from new parts to once run parts. I would like to see something with that much stroke with some -12 Brodix heads.

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Allright the motors mine. I talked to the guy and he said I can pick it up monday, Pictures will follow

 

Thanks jap tin. I had always heard that 437 was the max on a sbc so when he told me 448 i was kinda skeptical if he had done his math right.

He told me to get that kinda cubes he had to have the crank lathed down and notches cut in the cylinder walls for rod clearance,

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  • 4 weeks later...

Too good to be true

 

Got it home and popped the heads off and found it had a chipped piston. I turned the motor over to get a look at the cylinder wall to see if there was any damage and found a 1" strip of the cylinder wall shoved out.

 

My guess is he didnt run high enough octane, detonated and busted the piston, then the chunk from the piston raised all kinds of hell.

 

http://www.picturetrail.com/gallery/view?username=theskrich&x=0&y=0

 

And yes I am getting my money back

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What kind of crank is that? Are you sure it's even a 4"+ stroke? It's hard to tell for sure in the pics, but that looks a lot like a cast crank to me.

 

Even though it's not what he said, there's still a lot of parts there. I would probably try to negotiate the price down and start a fresh build or part it out.

 

John

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Looking at the pictures and there is one good picture of the crank that shows casting marks and numbers. That is a cast crank, not a forged unit which means it's not a 448 but at most a 417 if it was offset ground. If it's cast, it's pretty much junk for much HP use over 400HP.

 

Too bad.

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