but racer is right,aint none of these cranks fitting in a stock block with notch out the rail..sorry..
also look for a good casting,i got lucky and found a 511 casting,which is one of the better stock 40 blocks to build.some folk like to get a 2 bolt block cause theyre stronger down below and drill the 4 bolt mains ,which is good but costly ,just for the caps and then maching.if you find a 511 4 bolt block it will be good for most mild street engines.
also if your definetley lookng at a stroker with a stock block,look at the casting where the cam bore is,youll see a the bore and then its surrounded by a "boss" area,try to find a hole thats almost centered in that boss area.if its lower than the center line of the boss area move on.what happens there is when the block was made,that cam core shifted downwards and now your cam is a closer to the crank.in a stoke set up this isnt a problem,but when doing a stroker every inch counts and some blocks cant be used if this movent is off too much regardless of what you do.

 

racer,may i ask how what combo did you use to get 447 out of a stock block and was there any mods needed other than the orginal.

 

I am a believer that "bigger is better", but it won't do you much good to have big cubes if you don't have the heads, cam, valvetrain, etc. to support them. So, while this is a worthwhile topic to discuss, I don't want the newbies reading it to think that they have to worry about going to a lot of trouble/expense to eke out the last few cubic inches from their motor. Most people would get a lot more bang for the buck going with an "easy" combo like a 383, using readily available poarts, and putting the money into the rest of the components.

The World Products crate motor I posted the pic of uses a 4.25" bore and a 4.00" stroke for 454ci. The big bore is important for making hp as it unshrouds the valves relative to a longer stroke/smaller bore combo. A stock 350, if the core is carefully selected can be bored 60 over (for NA use) to 4.060". The upper limit on a 400 is 4.185". The Motown block that allows you to get these big bores costs ~$1,900. Not a huge amount in the contest buying the heads, valvetrain, etc. you need to support a big cube SB when compared to the costs of finding and rebuilding a 400 block. HP is not cheap.

I would use an aftermarket block for a big inch small block.

Rich

 

4.155 bore and 4.125 stroke on the 447 regular SBC. They make pans and gaskets with the notches too.

You have to cut the rods at the shoulder on 3.875 and more stroke but it;s not much at 3.875 and still not the much at 4.000 and I do these all the time.

Also done many 4.185 bore by 4.000 stroke deals in World and Dart blocks and in the Worlds all you do is cut .125 off the right part of the Eagle rods! I use full normal base circle cams in these too.

MANY circle track deals come with 1.000 high pistons and they work great. Wiseco has a deal coming that will revolutionize how short people are running pistons soon.

 

I agree Rich for the most part and the World blocks already are clearanced for a 4.000 stroke crank and normal steel rods. The Eagles swing through just fine but need to be trimmed up at the cam. Again you have to know what you are doing here are you will be screwed when the rods hit the cam.

Also keep in mind that damn near every engine master small block making 700 hp on pump gas did not use extremely big bores as some here would lead you to believe. Heads can absolutely flow big (enough) numbers on smaller than maximum bores to take the said CIDs to a streetable rpm almost everytime. If you're going unlimited hp, rpm and engine size then max out the bores as well.

Instead of people being obsessed with stroke I see more that are obsessed with overly large bores and yet they often do not make the power that they thought. They think that just because they have a big bore that everything will work out for them. It won't if you don't do everything right to actually use those bores.

 

racer,4 1.25 stroke on a stocker..wow..wish i knew that,also what kinda rod length that thing run?i had to get the notch oil pan for my 427....

 

Guys FWIW.... base circle is dependant on lobe lift too.

If you have .440" lift at the valve it's basically a small base circle lobe compared to a .325" lobe lift cam like a HotCam.

Eagle has stroker clearanced rods that can help all of this as well.... but the smaller the rod journal and better quality of the rod they can squeeze more stroke in the motors.

Bret

 

Right, and if you are doing .460-.480 lobes they can go no smaller really on the base circle as most cam grinders don't want a cam small than .875 even if its a steel cam core.

The reduced base circle deals are only going to pull the nose of the lobe back much if it's already a smaller lobe as Bret said.

I don't cut nearly as much off as Eagle does though on the rods as I just make it to where it doesn't enter the cam tunnel.

 

6 inch rods and in that case they were small journal chevrolet and a special carrillo stroker rod with the lower shoulders and it fit pretty tight!

 

Why buy a std. height cam tunnel block? I know it costs a little more to go with a raised cam but that's the way I've always looked at it. For a race block I wouldn't even consider anything I couldn't get a 55mm core in these days. They're the cat's meow IMO. For the street, at least you can step up to a BBC core and not have to worry about rod interference.

I've built three of these engines now and I wouldn't do it any other way. Yep, it costs a little more but I'd never lie to anyone and say that this stuff is cheap.

I do agree with Erik when he says to find someone experienced with this type of build. There are alot of issues that you will never have to deal with in a smaller engine.

-Mindgame

 

[/QUOTE]
also if your definetley lookng at a stroker with a stock block,look at the casting where the cam bore is,youll see a the bore and then its surrounded by a "boss" area,try to find a hole thats almost centered in that boss area.if its lower than the center line of the boss area move on.what happens there is when the block was made,that cam core shifted downwards and now your cam is a closer to the crank.in a stoke set up this isnt a problem,but when doing a stroker every inch counts and some blocks cant be used if this movent is off too much regardless of what you do.[/QUOTE]

No offense, but the cam location is referenced off the crank centerline. If the cam is closer to the crank then the block was machined out of tolerance.
If your machined holes are eccentric to the bosses then core shift occured or the block is just a poor casting. Lifter bores that are concentric to their bosses is usually a sign of a good block.

Dean

 

right stew,but my point was core shift is common,sometimes it doesnt effect the engine,but in a stroker case if your core shift lowered you cam closer to the crank then theres going to be that much less clearance between rods and lobes....

 

If it's that far out of tolerance (cam vs crank centerline) then you have bigger problems than rod to cam clearance.

-Mindgame

 

The big key is to find someone who can machine the block correctly for all of this.... BBC cam tunnels or even getting the stock size bearing tunnel in the right spot is a big deal!

Bret

 

Core shift does not effect cam location relative to the crank.

Dean